Package java.beans

Source Code of java.beans.GenericBeanInfo

/*
* @(#)Introspector.java  1.145 09/04/29
*
* Copyright 1996-2009 Sun Microsystems, Inc. All rights reserved.
* SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*/

package java.beans;

import java.lang.ref.Reference;
import java.lang.ref.SoftReference;

import java.lang.reflect.Method;
import java.lang.reflect.Modifier;

import java.security.AccessController;
import java.security.PrivilegedAction;

import java.util.Collections;
import java.util.Map;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.EventListener;
import java.util.List;
import java.util.WeakHashMap;
import java.util.TreeMap;
import sun.awt.AppContext;
import sun.reflect.misc.ReflectUtil;

/**
* The Introspector class provides a standard way for tools to learn about
* the properties, events, and methods supported by a target Java Bean.
* <p>
* For each of those three kinds of information, the Introspector will
* separately analyze the bean's class and superclasses looking for
* either explicit or implicit information and use that information to
* build a BeanInfo object that comprehensively describes the target bean.
* <p>
* For each class "Foo", explicit information may be available if there exists
* a corresponding "FooBeanInfo" class that provides a non-null value when
* queried for the information.   We first look for the BeanInfo class by
* taking the full package-qualified name of the target bean class and
* appending "BeanInfo" to form a new class name.  If this fails, then
* we take the final classname component of this name, and look for that
* class in each of the packages specified in the BeanInfo package search
* path.
* <p>
* Thus for a class such as "sun.xyz.OurButton" we would first look for a
* BeanInfo class called "sun.xyz.OurButtonBeanInfo" and if that failed we'd
* look in each package in the BeanInfo search path for an OurButtonBeanInfo
* class.  With the default search path, this would mean looking for
* "sun.beans.infos.OurButtonBeanInfo".
* <p>
* If a class provides explicit BeanInfo about itself then we add that to
* the BeanInfo information we obtained from analyzing any derived classes,
* but we regard the explicit information as being definitive for the current
* class and its base classes, and do not proceed any further up the superclass
* chain.
* <p>
* If we don't find explicit BeanInfo on a class, we use low-level
* reflection to study the methods of the class and apply standard design
* patterns to identify property accessors, event sources, or public
* methods.  We then proceed to analyze the class's superclass and add
* in the information from it (and possibly on up the superclass chain).
*
* <p>
* Because the Introspector caches BeanInfo classes for better performance,
* take care if you use it in an application that uses
* multiple class loaders.
* In general, when you destroy a <code>ClassLoader</code>
* that has been used to introspect classes,
* you should use the
* {@link #flushCaches <code>Introspector.flushCaches</code>}
* or
* {@link #flushFromCaches <code>Introspector.flushFromCaches</code>} method
* to flush all of the introspected classes out of the cache.
*
* <P>
* For more information about introspection and design patterns, please
* consult the
*  <a href="http://java.sun.com/products/javabeans/docs/index.html">JavaBeans specification</a>.
*/

public class Introspector {

    // Flags that can be used to control getBeanInfo:
    public final static int USE_ALL_BEANINFO           = 1;
    public final static int IGNORE_IMMEDIATE_BEANINFO  = 2;
    public final static int IGNORE_ALL_BEANINFO        = 3;

    // Static Caches to speed up introspection.
    private static Map declaredMethodCache =
  Collections.synchronizedMap(new WeakHashMap());

    private static final Object BEANINFO_CACHE = new Object();

    private Class beanClass;
    private BeanInfo explicitBeanInfo;
    private BeanInfo superBeanInfo;
    private BeanInfo additionalBeanInfo[];

    private boolean propertyChangeSource = false;
    private static Class eventListenerType = EventListener.class;

    // These should be removed.
    private String defaultEventName;
    private String defaultPropertyName;
    private int defaultEventIndex = -1;
    private int defaultPropertyIndex = -1;

    // Methods maps from Method objects to MethodDescriptors
    private Map methods;

    // properties maps from String names to PropertyDescriptors
    private Map properties;

    // events maps from String names to EventSetDescriptors
    private Map events;

    private final static String DEFAULT_INFO_PATH = "sun.beans.infos";

    private static String[] searchPath = { DEFAULT_INFO_PATH };

    private final static EventSetDescriptor[] EMPTY_EVENTSETDESCRIPTORS = new EventSetDescriptor[0];

    private static final String ADD_PREFIX = "add";
    private static final String REMOVE_PREFIX = "remove";
    private static final String GET_PREFIX = "get";
    private static final String SET_PREFIX = "set";
    private static final String IS_PREFIX = "is";
    private static final String BEANINFO_SUFFIX = "BeanInfo";

    //======================================================================
    //         Public methods
    //======================================================================

    /**
     * Introspect on a Java Bean and learn about all its properties, exposed
     * methods, and events.
     * <p>
     * If the BeanInfo class for a Java Bean has been previously Introspected
     * then the BeanInfo class is retrieved from the BeanInfo cache.
     *
     * @param beanClass  The bean class to be analyzed.
     * @return  A BeanInfo object describing the target bean.
     * @exception IntrospectionException if an exception occurs during
     *              introspection.
     * @see #flushCaches
     * @see #flushFromCaches
     */
    public static BeanInfo getBeanInfo(Class<?> beanClass)
  throws IntrospectionException
    {
  if (!ReflectUtil.isPackageAccessible(beanClass)) {
      return (new Introspector(beanClass, null, USE_ALL_BEANINFO)).getBeanInfo();
  }
        Map<Class<?>, BeanInfo> map;
        synchronized (BEANINFO_CACHE) {
            map = (Map<Class<?>, BeanInfo>) AppContext.getAppContext().get(BEANINFO_CACHE);
            if (map == null) {
                map = Collections.synchronizedMap(new WeakHashMap<Class<?>, BeanInfo>());
                AppContext.getAppContext().put(BEANINFO_CACHE, map);
            }
        }
        BeanInfo bi = map.get(beanClass);
  if (bi == null) {
      bi = (new Introspector(beanClass, null, USE_ALL_BEANINFO)).getBeanInfo();
      map.put(beanClass, bi);
  }
  return bi;
    }

    /**
     * Introspect on a Java bean and learn about all its properties, exposed
     * methods, and events, subject to some control flags.
     * <p>
     * If the BeanInfo class for a Java Bean has been previously Introspected
     * based on the same arguments then the BeanInfo class is retrieved
     * from the BeanInfo cache.
     *
     * @param beanClass  The bean class to be analyzed.
     * @param flags  Flags to control the introspection.
     *     If flags == USE_ALL_BEANINFO then we use all of the BeanInfo
     *     classes we can discover.
     *     If flags == IGNORE_IMMEDIATE_BEANINFO then we ignore any
     *           BeanInfo associated with the specified beanClass.
     *     If flags == IGNORE_ALL_BEANINFO then we ignore all BeanInfo
     *           associated with the specified beanClass or any of its
     *     parent classes.
     * @return  A BeanInfo object describing the target bean.
     * @exception IntrospectionException if an exception occurs during
     *              introspection.
     */
    public static BeanInfo getBeanInfo(Class<?> beanClass, int flags)
            throws IntrospectionException {
  return getBeanInfo(beanClass, null, flags);
    }

    /**
     * Introspect on a Java bean and learn all about its properties, exposed
     * methods, below a given "stop" point.
     * <p>
     * If the BeanInfo class for a Java Bean has been previously Introspected
     * based on the same arguments, then the BeanInfo class is retrieved
     * from the BeanInfo cache.
     *
     * @param beanClass The bean class to be analyzed.
     * @param stopClass The baseclass at which to stop the analysis.  Any
     *    methods/properties/events in the stopClass or in its baseclasses
     *    will be ignored in the analysis.
     * @exception IntrospectionException if an exception occurs during
     *              introspection.
     */
    public static BeanInfo getBeanInfo(Class<?> beanClass, Class<?> stopClass)
            throws IntrospectionException {
  return getBeanInfo(beanClass, stopClass, USE_ALL_BEANINFO);
    }

    /**
     * Only called from the public getBeanInfo methods. This method caches
     * the Introspected BeanInfo based on the arguments.
     */
    private static BeanInfo getBeanInfo(Class beanClass, Class stopClass,
          int flags) throws IntrospectionException {
  BeanInfo bi; 
  if (stopClass == null && flags == USE_ALL_BEANINFO) {
      // Same parameters to take advantage of caching.
      bi = getBeanInfo(beanClass);
  } else {
      bi = (new Introspector(beanClass, stopClass, flags)).getBeanInfo();
  }
  return bi;

  // Old behaviour: Make an independent copy of the BeanInfo.
  //return new GenericBeanInfo(bi);
    }


    /**
     * Utility method to take a string and convert it to normal Java variable
     * name capitalization.  This normally means converting the first
     * character from upper case to lower case, but in the (unusual) special
     * case when there is more than one character and both the first and
     * second characters are upper case, we leave it alone.
     * <p>
     * Thus "FooBah" becomes "fooBah" and "X" becomes "x", but "URL" stays
     * as "URL".
     *
     * @param  name The string to be decapitalized.
     * @return  The decapitalized version of the string.
     */
    public static String decapitalize(String name) {
  if (name == null || name.length() == 0) {
      return name;
  }
  if (name.length() > 1 && Character.isUpperCase(name.charAt(1)) &&
      Character.isUpperCase(name.charAt(0))){
      return name;
  }
  char chars[] = name.toCharArray();
  chars[0] = Character.toLowerCase(chars[0]);
  return new String(chars);
    }

    /**
     * Gets the list of package names that will be used for
     *    finding BeanInfo classes.
     *
     * @return  The array of package names that will be searched in
     *    order to find BeanInfo classes. The default value
     *          for this array is implementation-dependent; e.g.
     *          Sun implementation initially sets to {"sun.beans.infos"}.
     */

    public static synchronized String[] getBeanInfoSearchPath() {
  // Return a copy of the searchPath.
  String result[] = new String[searchPath.length];
  for (int i = 0; i < searchPath.length; i++) {
      result[i] = searchPath[i];
  }
  return result;
    }

    /**
     * Change the list of package names that will be used for
     *    finding BeanInfo classes.  The behaviour of
     *          this method is undefined if parameter path
     *          is null.
     *
     * <p>First, if there is a security manager, its <code>checkPropertiesAccess</code>
     * method is called. This could result in a SecurityException.
     *
     * @param path  Array of package names.
     * @exception  SecurityException  if a security manager exists and its 
     *             <code>checkPropertiesAccess</code> method doesn't allow setting
     *              of system properties.
     * @see SecurityManager#checkPropertiesAccess
     */

    public static synchronized void setBeanInfoSearchPath(String path[]) {
  SecurityManager sm = System.getSecurityManager();
  if (sm != null) {
      sm.checkPropertiesAccess();
  }
  searchPath = path;
    }


    /**
     * Flush all of the Introspector's internal caches.  This method is
     * not normally required.  It is normally only needed by advanced
     * tools that update existing "Class" objects in-place and need
     * to make the Introspector re-analyze existing Class objects.
     */

    public static void flushCaches() {
        Map map = (Map) AppContext.getAppContext().get(BEANINFO_CACHE);
        if (map != null) {
            map.clear();
        }
  declaredMethodCache.clear();
    }

    /**
     * Flush the Introspector's internal cached information for a given class.
     * This method is not normally required.  It is normally only needed
     * by advanced tools that update existing "Class" objects in-place
     * and need to make the Introspector re-analyze an existing Class object.
     *
     * Note that only the direct state associated with the target Class
     * object is flushed.  We do not flush state for other Class objects
     * with the same name, nor do we flush state for any related Class
     * objects (such as subclasses), even though their state may include
     * information indirectly obtained from the target Class object.
     *
     * @param clz  Class object to be flushed.
     * @throws NullPointerException If the Class object is null.
     */
    public static void flushFromCaches(Class<?> clz) {
  if (clz == null) {
      throw new NullPointerException();
  }
        Map map = (Map) AppContext.getAppContext().get(BEANINFO_CACHE);
        if (map != null) {
            map.remove(clz);
        }
  declaredMethodCache.remove(clz);
    }

    //======================================================================
    //       Private implementation methods
    //======================================================================

    private Introspector(Class beanClass, Class stopClass, int flags)
              throws IntrospectionException {
  this.beanClass = beanClass;

  // Check stopClass is a superClass of startClass.
  if (stopClass != null) {
      boolean isSuper = false;
      for (Class c = beanClass.getSuperclass(); c != null; c = c.getSuperclass()) {
          if (c == stopClass) {
        isSuper = true;
          }
      }
      if (!isSuper) {
          throw new IntrospectionException(stopClass.getName() + " not superclass of " +
          beanClass.getName());
      }
  }

        if (flags == USE_ALL_BEANINFO) {
      explicitBeanInfo = findExplicitBeanInfo(beanClass);
        }

  Class superClass = beanClass.getSuperclass();
  if (superClass != stopClass) {
      int newFlags = flags;
      if (newFlags == IGNORE_IMMEDIATE_BEANINFO) {
    newFlags = USE_ALL_BEANINFO;
      }
      superBeanInfo = getBeanInfo(superClass, stopClass, newFlags);
  }
  if (explicitBeanInfo != null) {
      additionalBeanInfo = explicitBeanInfo.getAdditionalBeanInfo();
  }
  if (additionalBeanInfo == null) {
      additionalBeanInfo = new BeanInfo[0];
  }
    }

    /**
     * Constructs a GenericBeanInfo class from the state of the Introspector
     */
    private BeanInfo getBeanInfo() throws IntrospectionException {

  // the evaluation order here is import, as we evaluate the
  // event sets and locate PropertyChangeListeners before we
  // look for properties.
  BeanDescriptor bd = getTargetBeanDescriptor();
  MethodDescriptor mds[] = getTargetMethodInfo();
  EventSetDescriptor esds[] = getTargetEventInfo();
  PropertyDescriptor pds[] = getTargetPropertyInfo();

  int defaultEvent = getTargetDefaultEventIndex();
  int defaultProperty = getTargetDefaultPropertyIndex();

        return new GenericBeanInfo(bd, esds, defaultEvent, pds,
      defaultProperty, mds, explicitBeanInfo);
 
    }

    /**
     * Looks for an explicit BeanInfo class that corresponds to the Class.
     * First it looks in the existing package that the Class is defined in,
     * then it checks to see if the class is its own BeanInfo. Finally,
     * the BeanInfo search path is prepended to the class and searched.
     *
     * @return Instance of an explicit BeanInfo class or null if one isn't found.
     */
    private static synchronized BeanInfo findExplicitBeanInfo(Class beanClass) {
  String name = beanClass.getName() + BEANINFO_SUFFIX;
        try {
      return (java.beans.BeanInfo)instantiate(beanClass, name);
  } catch (Exception ex) {
      // Just drop through

        }
  // Now try checking if the bean is its own BeanInfo.
        try {
      if (isSubclass(beanClass, java.beans.BeanInfo.class)) {
          return (java.beans.BeanInfo)beanClass.newInstance();
      }
  } catch (Exception ex) {
      // Just drop through
        }
  // Now try looking for <searchPath>.fooBeanInfo
   name = name.substring(name.lastIndexOf('.')+1);

  for (int i = 0; i < searchPath.length; i++) {
      // This optimization will only use the BeanInfo search path if is has changed
      // from the original or trying to get the ComponentBeanInfo.
      if (!DEFAULT_INFO_PATH.equals(searchPath[i]) ||
    DEFAULT_INFO_PATH.equals(searchPath[i]) && "ComponentBeanInfo".equals(name)) {
    try {
        String fullName = searchPath[i] + "." + name;
        java.beans.BeanInfo bi = (java.beans.BeanInfo)instantiate(beanClass, fullName);

        // Make sure that the returned BeanInfo matches the class.
        if (bi.getBeanDescriptor() != null) {
      if (bi.getBeanDescriptor().getBeanClass() == beanClass) {
          return bi;
      }
        } else if (bi.getPropertyDescriptors() != null) {
      PropertyDescriptor[] pds = bi.getPropertyDescriptors();
      for (int j = 0; j < pds.length; j++) {
          Method method = pds[j].getReadMethod();
          if (method == null) {
        method = pds[j].getWriteMethod();
          }
          if (method != null && method.getDeclaringClass() == beanClass) {
        return bi;
          }
      }
        } else if (bi.getMethodDescriptors() != null) {
      MethodDescriptor[] mds = bi.getMethodDescriptors();
      for (int j = 0; j < mds.length; j++) {
          Method method = mds[j].getMethod();
          if (method != null && method.getDeclaringClass() == beanClass) {
        return bi;
          }
      }
        }
    } catch (Exception ex) {
        // Silently ignore any errors.
    }
      }
  }
  return null;
    }

    /**
     * @return An array of PropertyDescriptors describing the editable
     * properties supported by the target bean.
     */

    private PropertyDescriptor[] getTargetPropertyInfo() {

  // Check if the bean has its own BeanInfo that will provide
  // explicit information.
        PropertyDescriptor[] explicitProperties = null;
  if (explicitBeanInfo != null) {
      explicitProperties = explicitBeanInfo.getPropertyDescriptors();
      int ix = explicitBeanInfo.getDefaultPropertyIndex();
      if (ix >= 0 && ix < explicitProperties.length) {
    defaultPropertyName = explicitProperties[ix].getName();
      }
        }

  if (explicitProperties == null && superBeanInfo != null) {
      // We have no explicit BeanInfo properties.  Check with our parent.
      PropertyDescriptor supers[] = superBeanInfo.getPropertyDescriptors();
      for (int i = 0 ; i < supers.length; i++) {
    addPropertyDescriptor(supers[i]);
      }
      int ix = superBeanInfo.getDefaultPropertyIndex();
      if (ix >= 0 && ix < supers.length) {
    defaultPropertyName = supers[ix].getName();
      }
  }

  for (int i = 0; i < additionalBeanInfo.length; i++) {
      PropertyDescriptor additional[] = additionalBeanInfo[i].getPropertyDescriptors();
      if (additional != null) {
          for (int j = 0 ; j < additional.length; j++) {
        addPropertyDescriptor(additional[j]);
          }
      }
  }

  if (explicitProperties != null) {
      // Add the explicit BeanInfo data to our results.
      for (int i = 0 ; i < explicitProperties.length; i++) {
    addPropertyDescriptor(explicitProperties[i]);
      }

  } else {

      // Apply some reflection to the current class.

      // First get an array of all the public methods at this level
      Method methodList[] = getPublicDeclaredMethods(beanClass);

      // Now analyze each method.
      for (int i = 0; i < methodList.length; i++) {
          Method method = methodList[i];
    if (method == null) {
        continue;
    }
          // skip static methods.
    int mods = method.getModifiers();
    if (Modifier.isStatic(mods)) {
        continue;
    }
          String name = method.getName();
          Class argTypes[] = method.getParameterTypes();
          Class resultType = method.getReturnType();
    int argCount = argTypes.length;
    PropertyDescriptor pd = null;

    if (name.length() <= 3 && !name.startsWith(IS_PREFIX)) {
        // Optimization. Don't bother with invalid propertyNames.
        continue;
    }

    try {

              if (argCount == 0) {
            if (name.startsWith(GET_PREFIX)) {
                // Simple getter
                      pd = new PropertyDescriptor(decapitalize(name.substring(3)),
            method, null);
                  } else if (resultType == boolean.class && name.startsWith(IS_PREFIX)) {
                // Boolean getter
                      pd = new PropertyDescriptor(decapitalize(name.substring(2)),
            method, null);
            }
              } else if (argCount == 1) {
            if (argTypes[0] == int.class && name.startsWith(GET_PREFIX)) {
                pd = new IndexedPropertyDescriptor(
            decapitalize(name.substring(3)),
            null, null,
            method,  null);
            } else if (resultType == void.class && name.startsWith(SET_PREFIX)) {
                // Simple setter
                      pd = new PropertyDescriptor(decapitalize(name.substring(3)),
            null, method);
                if (throwsException(method, PropertyVetoException.class)) {
              pd.setConstrained(true);
          }     
            }
              } else if (argCount == 2) {
          if (argTypes[0] == int.class && name.startsWith(SET_PREFIX)) {
                      pd = new IndexedPropertyDescriptor(
            decapitalize(name.substring(3)),
            null, null,
            null, method);
                if (throwsException(method, PropertyVetoException.class)) {
              pd.setConstrained(true);     
          }
      }
        }
    } catch (IntrospectionException ex) {
        // This happens if a PropertyDescriptor or IndexedPropertyDescriptor
              // constructor fins that the method violates details of the deisgn
        // pattern, e.g. by having an empty name, or a getter returning
        // void , or whatever.
        pd = null;
    }

    if (pd != null) {
        // If this class or one of its base classes is a PropertyChange
        // source, then we assume that any properties we discover are "bound".
        if (propertyChangeSource) {
      pd.setBound(true);
        }
        addPropertyDescriptor(pd);
    }
      }
  }
  processPropertyDescriptors();

  // Allocate and populate the result array.
  PropertyDescriptor result[] = new PropertyDescriptor[properties.size()];
  result = (PropertyDescriptor[])properties.values().toArray(result);

  // Set the default index.
  if (defaultPropertyName != null) {
      for (int i = 0; i < result.length; i++) {
    if (defaultPropertyName.equals(result[i].getName())) {
        defaultPropertyIndex = i;
    }
      }
  }

  return result;
    }

    private HashMap pdStore = new HashMap();

    /**
     * Adds the property descriptor to the list store.
     */
    private void addPropertyDescriptor(PropertyDescriptor pd) {
  String propName = pd.getName();
  List list = (List)pdStore.get(propName);
  if (list == null) {
      list = new ArrayList();
      pdStore.put(propName, list);
  }
  list.add(pd);
    }

    /**
     * Populates the property descriptor table by merging the
     * lists of Property descriptors.
     */
    private void processPropertyDescriptors() {
  if (properties == null) {
      properties = new TreeMap();
  }

  List list;

  PropertyDescriptor pd, gpd, spd;
  IndexedPropertyDescriptor ipd, igpd, ispd;

  Iterator it = pdStore.values().iterator();
  while (it.hasNext()) {
      pd = null; gpd = null; spd = null;
      ipd = null; igpd = null; ispd = null;

      list = (List)it.next();

      // First pass. Find the latest getter method. Merge properties
      // of previous getter methods.
      for (int i = 0; i < list.size(); i++) {
    pd = (PropertyDescriptor)list.get(i);
    if (pd instanceof IndexedPropertyDescriptor) {
        ipd = (IndexedPropertyDescriptor)pd;
        if (ipd.getIndexedReadMethod() != null) {
      if (igpd != null) {
          igpd = new IndexedPropertyDescriptor(igpd, ipd);
      } else {
          igpd = ipd;
      }
        }
    } else {
        if (pd.getReadMethod() != null) {
      if (gpd != null) {
          // Don't replace the existing read
          // method if it starts with "is"
          Method method = gpd.getReadMethod();
          if (!method.getName().startsWith(IS_PREFIX)) {
        gpd = new PropertyDescriptor(gpd, pd);
          }
      } else {
          gpd = pd;
      }
        }
    }
      }

      // Second pass. Find the latest setter method which
      // has the same type as the getter method.
      for (int i = 0; i < list.size(); i++) {
    pd = (PropertyDescriptor)list.get(i);
    if (pd instanceof IndexedPropertyDescriptor) {
        ipd = (IndexedPropertyDescriptor)pd;
        if (ipd.getIndexedWriteMethod() != null) {
      if (igpd != null) {
          if (igpd.getIndexedPropertyType()
        == ipd.getIndexedPropertyType()) {
        if (ispd != null) {
            ispd = new IndexedPropertyDescriptor(ispd, ipd);
        } else {
            ispd = ipd;
        }
          }
      } else {
          if (ispd != null) {
        ispd = new IndexedPropertyDescriptor(ispd, ipd);
          } else {
        ispd = ipd;
          }
      }
        }
    } else {
        if (pd.getWriteMethod() != null) {
      if (gpd != null) {
          if (gpd.getPropertyType() == pd.getPropertyType()) {
        if (spd != null) {
            spd = new PropertyDescriptor(spd, pd);
        } else {
            spd = pd;
        }
          }
      } else {
          if (spd != null) {
        spd = new PropertyDescriptor(spd, pd);
          } else {
        spd = pd;
          }
      }
        }
    }
      }

      // At this stage we should have either PDs or IPDs for the
      // representative getters and setters. The order at which the
      // property descriptors are determined represent the
      // precedence of the property ordering.
      pd = null; ipd = null;

      if (igpd != null && ispd != null) {
    // Complete indexed properties set
    // Merge any classic property descriptors
    if (gpd != null) {
        PropertyDescriptor tpd = mergePropertyDescriptor(igpd, gpd);
        if (tpd instanceof IndexedPropertyDescriptor) {
      igpd = (IndexedPropertyDescriptor)tpd;
        }
    }
    if (spd != null) {
        PropertyDescriptor tpd = mergePropertyDescriptor(ispd, spd);
        if (tpd instanceof IndexedPropertyDescriptor) {
      ispd = (IndexedPropertyDescriptor)tpd;
        }
    }
    if (igpd == ispd) {
        pd = igpd;
    } else {
        pd = mergePropertyDescriptor(igpd, ispd);
    }
      } else if (gpd != null && spd != null) {
    // Complete simple properties set
    if (gpd == spd) {
        pd = gpd;
    } else {
        pd = mergePropertyDescriptor(gpd, spd);
    }
      } else if (ispd != null) {
    // indexed setter
    pd = ispd;
    // Merge any classic property descriptors
    if (spd != null) {
        pd = mergePropertyDescriptor(ispd, spd);
    }
    if (gpd != null) {
        pd = mergePropertyDescriptor(ispd, gpd);
    }
      } else if (igpd != null) {
    // indexed getter
    pd = igpd;
    // Merge any classic property descriptors
    if (gpd != null) {
        pd = mergePropertyDescriptor(igpd, gpd);
    }
    if (spd != null) {
        pd = mergePropertyDescriptor(igpd, spd);
    }
      } else if (spd != null) {
    // simple setter
    pd = spd;
      } else if (gpd != null) {
    // simple getter
    pd = gpd;
      }

      // Very special case to ensure that an IndexedPropertyDescriptor
      // doesn't contain less information than the enclosed
      // PropertyDescriptor. If it does, then recreate as a
      // PropertyDescriptor. See 4168833
      if (pd instanceof IndexedPropertyDescriptor) {
    ipd = (IndexedPropertyDescriptor)pd;
    if (ipd.getIndexedReadMethod() == null && ipd.getIndexedWriteMethod() == null) {
        pd = new PropertyDescriptor(ipd);
    }
      }

            // Find the first property descriptor
            // which does not have getter and setter methods.
            // See regression bug 4984912.
            if ( (pd == null) && (list.size() > 0) ) {
                pd = (PropertyDescriptor) list.get(0);
            }

      if (pd != null) {
    properties.put(pd.getName(), pd);
      }
  }
    }
   
    /**
     * Adds the property descriptor to the indexedproperty descriptor only if the
     * types are the same.
     *
     * The most specific property descriptor will take precedence.
     */
    private PropertyDescriptor mergePropertyDescriptor(IndexedPropertyDescriptor ipd,
                   PropertyDescriptor pd) {
  PropertyDescriptor result = null;

  Class propType = pd.getPropertyType();
  Class ipropType = ipd.getIndexedPropertyType();

  if (propType.isArray() && propType.getComponentType() == ipropType) {
      if (pd.getClass0().isAssignableFrom(ipd.getClass0())) {
    result = new IndexedPropertyDescriptor(pd, ipd);
      } else {
    result = new IndexedPropertyDescriptor(ipd, pd);
      }
  } else {
      // Cannot merge the pd because of type mismatch
      // Return the most specific pd
      if (pd.getClass0().isAssignableFrom(ipd.getClass0())) {
    result = ipd;
      } else {
    result = pd;
    // Try to add methods which may have been lost in the type change
    // See 4168833
    Method write = result.getWriteMethod();
    Method read = result.getReadMethod();
               
    if (read == null && write != null) {
        read = findMethod(result.getClass0(),
              "get" + result.capitalize(result.getName()), 0);
        if (read != null) {
      try {
          result.setReadMethod(read);
      } catch (IntrospectionException ex) {
          // no consequences for failure.
      }
        }
    }
    if (write == null && read != null) {
        write = findMethod(result.getClass0(),
               "set" + result.capitalize(result.getName()), 1,
               new Class[] { read.getReturnType() });
        if (write != null) {
      try {
          result.setWriteMethod(write);
      } catch (IntrospectionException ex) {
          // no consequences for failure.
      }
        }
    }
      }
  }
  return result;
    }

    // Handle regular pd merge
    private PropertyDescriptor mergePropertyDescriptor(PropertyDescriptor pd1,
                   PropertyDescriptor pd2) {
  if (pd1.getClass0().isAssignableFrom(pd2.getClass0())) {
      return new PropertyDescriptor(pd1, pd2);
  } else {
      return new PropertyDescriptor(pd2, pd1);
  }
    }

    // Handle regular ipd merge
    private PropertyDescriptor mergePropertyDescriptor(IndexedPropertyDescriptor ipd1,
                   IndexedPropertyDescriptor ipd2) {
  if (ipd1.getClass0().isAssignableFrom(ipd2.getClass0())) {
      return new IndexedPropertyDescriptor(ipd1, ipd2);
  } else {
      return new IndexedPropertyDescriptor(ipd2, ipd1);
  }
    }

    /**
     * @return An array of EventSetDescriptors describing the kinds of
     * events fired by the target bean.
     */
    private EventSetDescriptor[] getTargetEventInfo() throws IntrospectionException {
  if (events == null) {
      events = new HashMap();
  }

  // Check if the bean has its own BeanInfo that will provide
  // explicit information.
        EventSetDescriptor[] explicitEvents = null;
  if (explicitBeanInfo != null) {
      explicitEvents = explicitBeanInfo.getEventSetDescriptors();
      int ix = explicitBeanInfo.getDefaultEventIndex();
      if (ix >= 0 && ix < explicitEvents.length) {
    defaultEventName = explicitEvents[ix].getName();
      }
  }

  if (explicitEvents == null && superBeanInfo != null) {
      // We have no explicit BeanInfo events.  Check with our parent.
      EventSetDescriptor supers[] = superBeanInfo.getEventSetDescriptors();
      for (int i = 0 ; i < supers.length; i++) {
    addEvent(supers[i]);
      }
      int ix = superBeanInfo.getDefaultEventIndex();
      if (ix >= 0 && ix < supers.length) {
    defaultEventName = supers[ix].getName();
      }
  }

  for (int i = 0; i < additionalBeanInfo.length; i++) {
      EventSetDescriptor additional[] = additionalBeanInfo[i].getEventSetDescriptors();
      if (additional != null) {
          for (int j = 0 ; j < additional.length; j++) {
        addEvent(additional[j]);
          }
      }
  }

  if (explicitEvents != null) {
      // Add the explicit explicitBeanInfo data to our results.
      for (int i = 0 ; i < explicitEvents.length; i++) {
    addEvent(explicitEvents[i]);
      }

  } else {

      // Apply some reflection to the current class.

      // Get an array of all the public beans methods at this level
      Method methodList[] = getPublicDeclaredMethods(beanClass);

      // Find all suitable "add", "remove" and "get" Listener methods
      // The name of the listener type is the key for these hashtables
      // i.e, ActionListener
      Map adds = null;
      Map removes = null;
      Map gets = null;

      for (int i = 0; i < methodList.length; i++) {
          Method method = methodList[i];
    if (method == null) {
        continue;
    }
          // skip static methods.
    int mods = method.getModifiers();
    if (Modifier.isStatic(mods)) {
        continue;
    }
          String name = method.getName();
    // Optimization avoid getParameterTypes
    if (!name.startsWith(ADD_PREFIX) && !name.startsWith(REMOVE_PREFIX)
        && !name.startsWith(GET_PREFIX)) {
        continue;
    }

          Class argTypes[] = method.getParameterTypes();
          Class resultType = method.getReturnType();

          if (name.startsWith(ADD_PREFIX) && argTypes.length == 1 &&
        resultType == Void.TYPE &&
        Introspector.isSubclass(argTypes[0], eventListenerType)) {
        String listenerName = name.substring(3);
        if (listenerName.length() > 0 &&
      argTypes[0].getName().endsWith(listenerName)) {
      if (adds == null) {
          adds = new HashMap();
      }
      adds.put(listenerName, method);
        }
    }
    else if (name.startsWith(REMOVE_PREFIX) && argTypes.length == 1 &&
       resultType == Void.TYPE &&
       Introspector.isSubclass(argTypes[0], eventListenerType)) {
        String listenerName = name.substring(6);
        if (listenerName.length() > 0 &&
      argTypes[0].getName().endsWith(listenerName)) {
      if (removes == null) {
          removes = new HashMap();
      }
      removes.put(listenerName, method);
        }
          }
    else if (name.startsWith(GET_PREFIX) && argTypes.length == 0 &&
       resultType.isArray() &&
       Introspector.isSubclass(resultType.getComponentType(),
             eventListenerType)) {
        String listenerName  = name.substring(3, name.length() - 1);
        if (listenerName.length() > 0 &&
      resultType.getComponentType().getName().endsWith(listenerName)) {
      if (gets == null) {
          gets = new HashMap();
      }
      gets.put(listenerName, method);
        }
    }
      }

      if (adds != null && removes != null) {
    // Now look for matching addFooListener+removeFooListener pairs.
    // Bonus if there is a matching getFooListeners method as well.
    Iterator keys = adds.keySet().iterator();
    while (keys.hasNext()) {
        String listenerName = (String) keys.next();
        // Skip any "add" which doesn't have a matching "remove" or
        // a listener name that doesn't end with Listener
        if (removes.get(listenerName) == null || !listenerName.endsWith("Listener")) {
      continue;
        }
        String eventName = decapitalize(listenerName.substring(0, listenerName.length()-8));
        Method addMethod = (Method)adds.get(listenerName);
        Method removeMethod = (Method)removes.get(listenerName);
        Method getMethod = null;
        if (gets != null) {
      getMethod = (Method)gets.get(listenerName);
        }
        Class argType = addMethod.getParameterTypes()[0];
       
        // generate a list of Method objects for each of the target methods:
        Method allMethods[] = getPublicDeclaredMethods(argType);
        List validMethods = new ArrayList(allMethods.length);
        for (int i = 0; i < allMethods.length; i++) {
      if (allMethods[i] == null) {
          continue;
      }
       
      if (isEventHandler(allMethods[i])) {
          validMethods.add(allMethods[i]);
      }
        }
        Method[] methods = (Method[])validMethods.toArray(new Method[validMethods.size()]);

        EventSetDescriptor esd = new EventSetDescriptor(eventName, argType,
                    methods, addMethod,
                    removeMethod,
                    getMethod);

        // If the adder method throws the TooManyListenersException then it
        // is a Unicast event source.
        if (throwsException(addMethod,
          java.util.TooManyListenersException.class)) {
      esd.setUnicast(true);
        }
        addEvent(esd);
    }
      } // if (adds != null ...
  }
  EventSetDescriptor[] result;
  if (events.size() == 0) {
      result = EMPTY_EVENTSETDESCRIPTORS;
  } else {
      // Allocate and populate the result array.
      result = new EventSetDescriptor[events.size()];
      result = (EventSetDescriptor[])events.values().toArray(result);

      // Set the default index.
      if (defaultEventName != null) {
    for (int i = 0; i < result.length; i++) {
        if (defaultEventName.equals(result[i].getName())) {
      defaultEventIndex = i;
        }
    }
      }
  }
  return result;
    }

    private void addEvent(EventSetDescriptor esd) {
  String key = esd.getName();
  if (esd.getName().equals("propertyChange")) {
      propertyChangeSource = true;
  }
  EventSetDescriptor old = (EventSetDescriptor)events.get(key);
  if (old == null) {
      events.put(key, esd);
      return;
  }
  EventSetDescriptor composite = new EventSetDescriptor(old, esd);
  events.put(key, composite);
    }

    /**
     * @return An array of MethodDescriptors describing the private
     * methods supported by the target bean.
     */
    private MethodDescriptor[] getTargetMethodInfo() {
  if (methods == null) {
      methods = new HashMap(100);
  }

  // Check if the bean has its own BeanInfo that will provide
  // explicit information.
        MethodDescriptor[] explicitMethods = null;
  if (explicitBeanInfo != null) {
      explicitMethods = explicitBeanInfo.getMethodDescriptors();
  }

  if (explicitMethods == null && superBeanInfo != null) {
      // We have no explicit BeanInfo methods.  Check with our parent.
      MethodDescriptor supers[] = superBeanInfo.getMethodDescriptors();
      for (int i = 0 ; i < supers.length; i++) {
    addMethod(supers[i]);
      }
  }

  for (int i = 0; i < additionalBeanInfo.length; i++) {
      MethodDescriptor additional[] = additionalBeanInfo[i].getMethodDescriptors();
      if (additional != null) {
          for (int j = 0 ; j < additional.length; j++) {
        addMethod(additional[j]);
          }
      }
  }

  if (explicitMethods != null) {
      // Add the explicit explicitBeanInfo data to our results.
      for (int i = 0 ; i < explicitMethods.length; i++) {
    addMethod(explicitMethods[i]);
      }

  } else {

      // Apply some reflection to the current class.

      // First get an array of all the beans methods at this level
      Method methodList[] = getPublicDeclaredMethods(beanClass);

      // Now analyze each method.
      for (int i = 0; i < methodList.length; i++) {
          Method method = methodList[i];
    if (method == null) {
        continue;
    }
    MethodDescriptor md = new MethodDescriptor(method);
    addMethod(md);
      }
  }

  // Allocate and populate the result array.
  MethodDescriptor result[] = new MethodDescriptor[methods.size()];
  result = (MethodDescriptor[])methods.values().toArray(result);

  return result;
    }

    private void addMethod(MethodDescriptor md) {
  // We have to be careful here to distinguish method by both name
  // and argument lists.
  // This method gets called a *lot, so we try to be efficient.
  String name = md.getName();

  MethodDescriptor old = (MethodDescriptor)methods.get(name);
  if (old == null) {
      // This is the common case.
      methods.put(name, md);
      return;
 

  // We have a collision on method names.  This is rare.

  // Check if old and md have the same type.
  String[] p1 = md.getParamNames();
  String[] p2 = old.getParamNames();

  boolean match = false;
  if (p1.length == p2.length) {
      match = true;
      for (int i = 0; i < p1.length; i++) {
    if (p1[i] != p2[i]) {
        match = false;
        break;
    }
      }
  }
  if (match) {
      MethodDescriptor composite = new MethodDescriptor(old, md);
      methods.put(name, composite);
      return;
  }

  // We have a collision on method names with different type signatures.
  // This is very rare.

  String longKey = makeQualifiedMethodName(name, p1);
  old = (MethodDescriptor)methods.get(longKey);
  if (old == null) {
      methods.put(longKey, md);
      return;
 
  MethodDescriptor composite = new MethodDescriptor(old, md);
  methods.put(longKey, composite);
    }

    /**
     * Creates a key for a method in a method cache.
     */
    private static String makeQualifiedMethodName(String name, String[] params) {
  StringBuffer sb = new StringBuffer(name);
  sb.append('=');
  for (int i = 0; i < params.length; i++) {
      sb.append(':');
      sb.append(params[i]);
  }
  return sb.toString();
    }

    private int getTargetDefaultEventIndex() {
  return defaultEventIndex;
    }

    private int getTargetDefaultPropertyIndex() {
  return defaultPropertyIndex;
    }

    private BeanDescriptor getTargetBeanDescriptor() {
  // Use explicit info, if available,
  if (explicitBeanInfo != null) {
      BeanDescriptor bd = explicitBeanInfo.getBeanDescriptor();
      if (bd != null) {
    return (bd);
      }
  }
  // OK, fabricate a default BeanDescriptor.
  return (new BeanDescriptor(beanClass));
    }

    private boolean isEventHandler(Method m) {
  // We assume that a method is an event handler if it has a single
        // argument, whose type inherit from java.util.Event.
  Class argTypes[] = m.getParameterTypes();
  if (argTypes.length != 1) {
      return false;
  }
  if (isSubclass(argTypes[0], java.util.EventObject.class)) {
      return true;
  }
  return false;
    }

    /*
     * Internal method to return *public* methods within a class.
     */
    private static synchronized Method[] getPublicDeclaredMethods(Class clz) {
  // Looking up Class.getDeclaredMethods is relatively expensive,
  // so we cache the results.
  Method[] result = null;
  if (!ReflectUtil.isPackageAccessible(clz)) {
      return new Method[0];
  }
  final Class fclz = clz;
  Reference ref = (Reference)declaredMethodCache.get(fclz);
  if (ref != null) {
      result = (Method[])ref.get();
      if (result != null) {
    return result;
      }
  }

  // We have to raise privilege for getDeclaredMethods
  result = (Method[]) AccessController.doPrivileged(new PrivilegedAction() {
    public Object run() {
        return fclz.getDeclaredMethods();
    }
      });


  // Null out any non-public methods.
  for (int i = 0; i < result.length; i++) {
      Method method = result[i];
      int mods = method.getModifiers();
      if (!Modifier.isPublic(mods)) {
     result[i] = null;
      }
        }   
  // Add it to the cache.
  declaredMethodCache.put(fclz, new SoftReference(result));
  return result;
    }

    //======================================================================
    // Package private support methods.
    //======================================================================

    /**
     * Internal support for finding a target methodName with a given
     * parameter list on a given class.
     */
    private static Method internalFindMethod(Class start, String methodName,
                                                 int argCount, Class args[]) {
        // For overriden methods we need to find the most derived version.
        // So we start with the given class and walk up the superclass chain.

  Method method = null;

        for (Class cl = start; cl != null; cl = cl.getSuperclass()) {
            Method methods[] = getPublicDeclaredMethods(cl);
            for (int i = 0; i < methods.length; i++) {
                method = methods[i];
                if (method == null) {
                    continue;
                }

                // make sure method signature matches.
                Class params[] = method.getParameterTypes();
                if (method.getName().equals(methodName) &&
                    params.length == argCount) {
        if (args != null) {
      boolean different = false;
      if (argCount > 0) {
          for (int j = 0; j < argCount; j++) {
        if (params[j] != args[j]) {
            different = true;
            continue;
        }
          }
          if (different) {
        continue;
          }
      }
        }
                    return method;
                }
            }
        }
  method = null;

        // Now check any inherited interfaces.  This is necessary both when
        // the argument class is itself an interface, and when the argument
        // class is an abstract class.
        Class ifcs[] = start.getInterfaces();
        for (int i = 0 ; i < ifcs.length; i++) {
      // Note: The original implementation had both methods calling
      // the 3 arg method. This is preserved but perhaps it should
      // pass the args array instead of null.
            method = internalFindMethod(ifcs[i], methodName, argCount, null);
      if (method != null) {
    break;
      }
        }
        return method;
    }

    /**
     * Find a target methodName on a given class.
     */
    static Method findMethod(Class cls, String methodName, int argCount) {
  return findMethod(cls, methodName, argCount, null);
    }

    /**
     * Find a target methodName with specific parameter list on a given class.
     * <p>
     * Used in the contructors of the EventSetDescriptor,
     * PropertyDescriptor and the IndexedPropertyDescriptor.
     * <p>
     * @param cls The Class object on which to retrieve the method.
     * @param methodName Name of the method.
     * @param argCount Number of arguments for the desired method.
     * @param args Array of argument types for the method.
     * @return the method or null if not found
     */
    static Method findMethod(Class cls, String methodName, int argCount,
                             Class args[]) {
        if (methodName == null) {
            return null;
        }
        return internalFindMethod(cls, methodName, argCount, args);
    }

    /**
     * Return true if class a is either equivalent to class b, or
     * if class a is a subclass of class b, i.e. if a either "extends"
     * or "implements" b.
     * Note tht either or both "Class" objects may represent interfaces.
     */
    static  boolean isSubclass(Class a, Class b) {
  // We rely on the fact that for any given java class or
        // primtitive type there is a unqiue Class object, so
  // we can use object equivalence in the comparisons.
  if (a == b) {
      return true;
  }
  if (a == null || b == null) {
      return false;
  }
  for (Class x = a; x != null; x = x.getSuperclass()) {
      if (x == b) { 
    return true;
      }
      if (b.isInterface()) {
    Class interfaces[] = x.getInterfaces();
    for (int i = 0; i < interfaces.length; i++) {
        if (isSubclass(interfaces[i], b)) {
      return true;
        }
    }
      }
  }
  return false;
    }

    /**
     * Return true iff the given method throws the given exception.
     */
    private boolean throwsException(Method method, Class exception) {
  Class exs[] = method.getExceptionTypes();
  for (int i = 0; i < exs.length; i++) {
      if (exs[i] == exception) {
    return true;
      }
  }
  return false;
    }


    /**
     * Try to create an instance of a named class.
     * First try the classloader of "sibling", then try the system
     * classloader then the class loader of the current Thread.
     */
    static Object instantiate(Class sibling, String className)
     throws InstantiationException, IllegalAccessException,
            ClassNotFoundException {
  // First check with sibling's classloader (if any).
  ClassLoader cl = sibling.getClassLoader();
  if (cl != null) {
      try {
          Class cls = cl.loadClass(className);
    return cls.newInstance();
      } catch (Exception ex) {
          // Just drop through and try the system classloader.
      }
        }

  // Now try the system classloader.
  try {
      cl = ClassLoader.getSystemClassLoader();
      if (cl != null) {
          Class cls = cl.loadClass(className);
    return cls.newInstance();
      }
        } catch (Exception ex) {
      // We're not allowed to access the system class loader or
      // the class creation failed.
      // Drop through.
  }

  // Use the classloader from the current Thread.
  cl = Thread.currentThread().getContextClassLoader();
  Class cls = cl.loadClass(className);
  return cls.newInstance();
    }

} // end class Introspector

//===========================================================================

/**
* Package private implementation support class for Introspector's
* internal use.
* <p>
* Mostly this is used as a placeholder for the descriptors.
*/

class GenericBeanInfo extends SimpleBeanInfo {

    private BeanDescriptor beanDescriptor;
    private EventSetDescriptor[] events;
    private int defaultEvent;
    private PropertyDescriptor[] properties;
    private int defaultProperty;
    private MethodDescriptor[] methods;
    private BeanInfo targetBeanInfo;

    public GenericBeanInfo(BeanDescriptor beanDescriptor,
    EventSetDescriptor[] events, int defaultEvent,
    PropertyDescriptor[] properties, int defaultProperty,
    MethodDescriptor[] methods, BeanInfo targetBeanInfo) {
  this.beanDescriptor = beanDescriptor;
  this.events = events;
  this.defaultEvent = defaultEvent;
  this.properties = properties;
  this.defaultProperty = defaultProperty;
  this.methods = methods;
  this.targetBeanInfo = targetBeanInfo;
    }

    /**
     * Package-private dup constructor
     * This must isolate the new object from any changes to the old object.
     */
    GenericBeanInfo(GenericBeanInfo old) {

  beanDescriptor = new BeanDescriptor(old.beanDescriptor);
  if (old.events != null) {
      int len = old.events.length;
      events = new EventSetDescriptor[len];
      for (int i = 0; i < len; i++) {
    events[i] = new EventSetDescriptor(old.events[i]);
      }
  }
  defaultEvent = old.defaultEvent;
  if (old.properties != null) {
      int len = old.properties.length;
      properties = new PropertyDescriptor[len];
      for (int i = 0; i < len; i++) {
    PropertyDescriptor oldp = old.properties[i];
    if (oldp instanceof IndexedPropertyDescriptor) {
        properties[i] = new IndexedPropertyDescriptor(
          (IndexedPropertyDescriptor) oldp);
    } else {
        properties[i] = new PropertyDescriptor(oldp);
    }
      }
  }
  defaultProperty = old.defaultProperty;
  if (old.methods != null) {
      int len = old.methods.length;
      methods = new MethodDescriptor[len];
      for (int i = 0; i < len; i++) {
    methods[i] = new MethodDescriptor(old.methods[i]);
      }
  }
  targetBeanInfo = old.targetBeanInfo;
    }

    public PropertyDescriptor[] getPropertyDescriptors() {
  return properties;
    }

    public int getDefaultPropertyIndex() {
  return defaultProperty;
    }

    public EventSetDescriptor[] getEventSetDescriptors() {
  return events;
    }

    public int getDefaultEventIndex() {
  return defaultEvent;
    }

    public MethodDescriptor[] getMethodDescriptors() {
  return methods;
    }

    public BeanDescriptor getBeanDescriptor() {
  return beanDescriptor;
    }

    public java.awt.Image getIcon(int iconKind) {
  if (targetBeanInfo != null) {
      return targetBeanInfo.getIcon(iconKind);
  }
  return super.getIcon(iconKind);
    }
}
TOP

Related Classes of java.beans.GenericBeanInfo

TOP
Copyright © 2018 www.massapi.com. All rights reserved.
All source code are property of their respective owners. Java is a trademark of Sun Microsystems, Inc and owned by ORACLE Inc. Contact coftware#gmail.com.