package com.googlecode.jsonplugin;
import com.googlecode.jsonplugin.annotations.JSON;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import java.beans.BeanInfo;
import java.beans.IntrospectionException;
import java.beans.Introspector;
import java.beans.PropertyDescriptor;
import java.lang.reflect.Array;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Date;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.Set;
import java.math.BigDecimal;
import java.math.BigInteger;
/**
* Isolate the process of populating JSON objects from the Interceptor class itself.
*/
public class JSONPopulator {
private static final Log log = LogFactory.getLog(JSONPopulator.class);
private String dateFormat = JSONUtil.RFC3339_FORMAT;
public JSONPopulator() {
}
public JSONPopulator(String dateFormat) {
this.dateFormat = dateFormat;
}
public String getDateFormat() {
return dateFormat;
}
public void setDateFormat(String dateFormat) {
this.dateFormat = dateFormat;
}
@SuppressWarnings("unchecked")
public void populateObject(Object object, final Map elements)
throws IllegalAccessException, InvocationTargetException, NoSuchMethodException,
IntrospectionException, IllegalArgumentException, JSONException,
InstantiationException {
Class clazz = object.getClass();
BeanInfo info = Introspector.getBeanInfo(clazz);
PropertyDescriptor[] props = info.getPropertyDescriptors();
//iterate over class fields
for (int i = 0; i < props.length; ++i) {
PropertyDescriptor prop = props[i];
String name = prop.getName();
if (elements.containsKey(name)) {
Object value = elements.get(name);
Method method = prop.getWriteMethod();
if (method != null) {
JSON json = method.getAnnotation(JSON.class);
if ((json != null) && !json.deserialize()) {
continue;
}
//use only public setters
if (Modifier.isPublic(method.getModifiers())) {
Class[] paramTypes = method.getParameterTypes();
Type[] genericTypes = method.getGenericParameterTypes();
if (paramTypes.length == 1) {
Object convertedValue = this.convert(paramTypes[0], genericTypes[0], value, method);
method.invoke(object, new Object[]{convertedValue});
}
}
}
}
}
}
@SuppressWarnings("unchecked")
public Object convert(Class clazz, Type type, Object value, Method method)
throws IllegalArgumentException, JSONException, IllegalAccessException,
InvocationTargetException, InstantiationException, NoSuchMethodException,
IntrospectionException {
if (value == null) {
//if it is a java primitive then get a default value, otherwise leave it as null
return clazz.isPrimitive() ? convertPrimitive(clazz, value, method) : null;
}
else if (isJSONPrimitive(clazz))
return convertPrimitive(clazz, value, method);
else if (Collection.class.isAssignableFrom(clazz))
return convertToCollection(clazz, type, value, method);
else if (Map.class.isAssignableFrom(clazz))
return convertToMap(clazz, type, value, method);
else if (clazz.isArray())
return convertToArray(clazz, type, value, method);
else if (value instanceof Map) {
// nested bean
Object convertedValue = clazz.newInstance();
this.populateObject(convertedValue, (Map) value);
return convertedValue;
} else if (BigDecimal.class.equals(clazz)) {
return new BigDecimal(value != null ? value.toString() : "0");
} else if (BigInteger.class.equals(clazz)) {
return new BigInteger(value != null ? value.toString() : "0");
}
else
throw new JSONException("Incompatible types for property " + method.getName());
}
private static boolean isJSONPrimitive(Class clazz) {
return clazz.isPrimitive() || clazz.equals(String.class) ||
clazz.equals(Date.class) || clazz.equals(Boolean.class) ||
clazz.equals(Byte.class) || clazz.equals(Character.class) ||
clazz.equals(Double.class) || clazz.equals(Float.class) ||
clazz.equals(Integer.class) || clazz.equals(Long.class) ||
clazz.equals(Short.class) || clazz.equals(Locale.class) ||
clazz.isEnum();
}
@SuppressWarnings("unchecked")
private Object convertToArray(Class clazz, Type type, Object value, Method accessor)
throws JSONException, IllegalArgumentException, IllegalAccessException,
InvocationTargetException, InstantiationException, NoSuchMethodException,
IntrospectionException {
if (value == null)
return null;
else if (value instanceof List) {
Class arrayType = clazz.getComponentType();
List values = (List) value;
Object newArray = Array.newInstance(arrayType, values.size());
//create an object for each element
for (int j = 0; j < values.size(); j++) {
Object listValue = values.get(j);
if (arrayType.equals(Object.class)) {
//Object[]
Array.set(newArray, j, listValue);
} else if (isJSONPrimitive(arrayType)) {
//primitive array
Array.set(newArray, j, this.convertPrimitive(arrayType, listValue,
accessor));
} else if (listValue instanceof Map) {
//array of other class
Object newObject = null;
if (Map.class.isAssignableFrom(arrayType)) {
newObject = convertToMap(arrayType, type, listValue, accessor);
} else if (List.class.isAssignableFrom(arrayType)) {
newObject = convertToCollection(arrayType, type, listValue, accessor);
} else {
newObject = arrayType.newInstance();
this.populateObject(newObject, (Map) listValue);
}
Array.set(newArray, j, newObject);
} else
throw new JSONException("Incompatible types for property " +
accessor.getName());
}
return newArray;
} else
throw new JSONException("Incompatible types for property " +
accessor.getName());
}
@SuppressWarnings("unchecked")
private Object convertToCollection(Class clazz, Type type, Object value, Method accessor)
throws JSONException, IllegalArgumentException, IllegalAccessException,
InvocationTargetException, InstantiationException, NoSuchMethodException,
IntrospectionException {
if (value == null)
return null;
else if (value instanceof List) {
Class itemClass = Object.class;
Type itemType = null;
if (type != null && type instanceof ParameterizedType) {
ParameterizedType ptype = (ParameterizedType) type;
itemType = ptype.getActualTypeArguments()[0];
if (itemType.getClass().equals(Class.class)) {
itemClass = (Class) itemType;
} else {
itemClass = (Class) ((ParameterizedType) itemType).getRawType();
}
}
List values = (List) value;
Collection newCollection = null;
try {
newCollection = (Collection) clazz.newInstance();
} catch (InstantiationException ex) {
// fallback if clazz represents an interface or abstract class
if (Set.class.isAssignableFrom(clazz)) {
newCollection = new HashSet();
} else {
newCollection = new ArrayList();
}
}
//create an object for each element
for (int j = 0; j < values.size(); j++) {
Object listValue = values.get(j);
if (itemClass.equals(Object.class)) {
//Object[]
newCollection.add(listValue);
} else if (isJSONPrimitive(itemClass)) {
//primitive array
newCollection.add(this.convertPrimitive(itemClass, listValue,
accessor));
} else if (Map.class.isAssignableFrom(itemClass)) {
Object newObject = convertToMap(itemClass, itemType, listValue, accessor);
newCollection.add(newObject);
} else if (List.class.isAssignableFrom(itemClass)) {
Object newObject = convertToCollection(itemClass, itemType, listValue, accessor);
newCollection.add(newObject);
} else if (listValue instanceof Map) {
//array of beans
Object newObject = itemClass.newInstance();
this.populateObject(newObject, (Map) listValue);
newCollection.add(newObject);
} else
throw new JSONException("Incompatible types for property " +
accessor.getName());
}
return newCollection;
} else
throw new JSONException("Incompatible types for property " +
accessor.getName());
}
@SuppressWarnings("unchecked")
private Object convertToMap(Class clazz, Type type, Object value, Method accessor)
throws JSONException, IllegalArgumentException, IllegalAccessException,
InvocationTargetException, InstantiationException, NoSuchMethodException,
IntrospectionException {
if (value == null)
return null;
else if (value instanceof Map) {
Class itemClass = Object.class;
Type itemType = null;
if (type != null && type instanceof ParameterizedType) {
ParameterizedType ptype = (ParameterizedType) type;
itemType = ptype.getActualTypeArguments()[1];
if (itemType.getClass().equals(Class.class)) {
itemClass = (Class) itemType;
} else {
itemClass = (Class) ((ParameterizedType) itemType).getRawType();
}
}
Map values = (Map) value;
Map newMap = null;
try {
newMap = (Map) clazz.newInstance();
} catch (InstantiationException ex) {
// fallback if clazz represents an interface or abstract class
newMap = new HashMap();
}
//create an object for each element
Iterator iter = values.entrySet().iterator();
while (iter.hasNext()) {
Map.Entry entry = (Map.Entry) iter.next();
String key = (String) entry.getKey();
Object v = entry.getValue();
if (itemClass.equals(Object.class)) {
//String, Object
newMap.put(key, v);
} else if (isJSONPrimitive(itemClass)) {
//primitive map
newMap.put(key, this.convertPrimitive(itemClass, v,
accessor));
} else if (Map.class.isAssignableFrom(itemClass)) {
Object newObject = convertToMap(itemClass, itemType, v, accessor);
newMap.put(key, newObject);
} else if (List.class.isAssignableFrom(itemClass)) {
Object newObject = convertToCollection(itemClass, itemType, v, accessor);
newMap.put(key, newObject);
} else if (v instanceof Map) {
//map of beans
Object newObject = itemClass.newInstance();
this.populateObject(newObject, (Map) v);
newMap.put(key, newObject);
} else
throw new JSONException("Incompatible types for property " +
accessor.getName());
}
return newMap;
} else
throw new JSONException("Incompatible types for property " +
accessor.getName());
}
/**
* Converts numbers to the desired class, if possible
*
* @throws JSONException
*/
@SuppressWarnings("unchecked")
private Object convertPrimitive(Class clazz, Object value, Method method)
throws JSONException {
if (value == null) {
if (Short.TYPE.equals(clazz) || Short.class.equals(clazz))
return (short) 0;
else if (Byte.TYPE.equals(clazz) || Byte.class.equals(clazz))
return (byte) 0;
else if (Integer.TYPE.equals(clazz) || Integer.class.equals(clazz))
return 0;
else if (Long.TYPE.equals(clazz) || Long.class.equals(clazz))
return 0L;
else if (Float.TYPE.equals(clazz) || Float.class.equals(clazz))
return 0f;
else if (Double.TYPE.equals(clazz) || Double.class.equals(clazz))
return 0d;
else if (Boolean.TYPE.equals(clazz) || Boolean.class.equals(clazz))
return Boolean.FALSE;
else
return null;
} else if (value instanceof Number) {
Number number = (Number) value;
if (Short.TYPE.equals(clazz))
return number.shortValue();
else if (Short.class.equals(clazz))
return new Short(number.shortValue());
else if (Byte.TYPE.equals(clazz))
return number.byteValue();
else if (Byte.class.equals(clazz))
return new Byte(number.byteValue());
else if (Integer.TYPE.equals(clazz))
return number.intValue();
else if (Integer.class.equals(clazz))
return new Integer(number.intValue());
else if (Long.TYPE.equals(clazz))
return number.longValue();
else if (Long.class.equals(clazz))
return new Long(number.longValue());
else if (Float.TYPE.equals(clazz))
return number.floatValue();
else if (Float.class.equals(clazz))
return new Float(number.floatValue());
else if (Double.TYPE.equals(clazz))
return number.doubleValue();
else if (Double.class.equals(clazz))
return new Double(number.doubleValue());
else if (String.class.equals(clazz))
return value.toString();
} else if (clazz.equals(Date.class)) {
try {
JSON json = method.getAnnotation(JSON.class);
DateFormat formatter = new SimpleDateFormat(
(json != null) && (json.format().length() > 0) ?
json.format() : this.dateFormat);
return formatter.parse((String) value);
} catch (ParseException e) {
log.error(e.getMessage(), e);
throw new JSONException("Unable to parse date from: " + value);
}
} else if (clazz.isEnum()) {
String sValue = (String) value;
return Enum.valueOf(clazz, sValue);
} else if (value instanceof String) {
String sValue = (String) value;
if (Boolean.TYPE.equals(clazz))
return Boolean.parseBoolean(sValue);
else if (Boolean.class.equals(clazz))
return Boolean.valueOf(sValue);
else if (Short.TYPE.equals(clazz))
return Short.parseShort(sValue);
else if (Short.class.equals(clazz))
return Short.valueOf(sValue);
else if (Byte.TYPE.equals(clazz))
return Byte.parseByte(sValue);
else if (Byte.class.equals(clazz))
return Byte.valueOf(sValue);
else if (Integer.TYPE.equals(clazz))
return Integer.parseInt(sValue);
else if (Integer.class.equals(clazz))
return Integer.valueOf(sValue);
else if (Long.TYPE.equals(clazz))
return Long.parseLong(sValue);
else if (Long.class.equals(clazz))
return Long.valueOf(sValue);
else if (Float.TYPE.equals(clazz))
return Float.parseFloat(sValue);
else if (Float.class.equals(clazz))
return Float.valueOf(sValue);
else if (Double.TYPE.equals(clazz))
return Double.parseDouble(sValue);
else if (Double.class.equals(clazz))
return Double.valueOf(sValue);
else if (Character.TYPE.equals(clazz) || Character.class.equals(clazz)) {
char charValue = 0;
if (sValue.length() > 0) {
charValue = sValue.charAt(0);
}
if (Character.TYPE.equals(clazz))
return charValue;
else
return new Character(charValue);
} else if (clazz.equals(Locale.class)) {
String[] components = sValue.split("_", 2);
if (components.length == 2) {
return new Locale(components[0], components[1]);
} else {
return new Locale(sValue);
}
} else if (Enum.class.isAssignableFrom(clazz)) {
return Enum.valueOf(clazz, sValue);
}
}
return value;
}
}