/*
* $Id: DebuggingInterceptor.java 452707 2006-10-04 03:15:14Z mrdon $
*
* Copyright 2006 The Apache Software Foundation.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.struts2.interceptor.debugging;
import java.beans.BeanInfo;
import java.beans.Introspector;
import java.beans.PropertyDescriptor;
import java.io.IOException;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.lang.reflect.Array;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import javax.servlet.http.HttpServletResponse;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.struts2.ServletActionContext;
import org.apache.struts2.views.freemarker.FreemarkerResult;
import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionInvocation;
import com.opensymphony.xwork2.interceptor.Interceptor;
import com.opensymphony.xwork2.interceptor.PreResultListener;
import com.opensymphony.xwork2.util.ValueStack;
/**
* Provides several different debugging screens to provide insight into the
* data behind the page. The value of the 'debug' request parameter determines
* the screen:
* <ul>
* <li> <code>xml</code> - Dumps the parameters, context, session, and value
* stack as an XML document.</li>
* <li> <code>console</code> - Shows a popup 'OGNL Console' that allows the
* user to test OGNL expressions against the value stack. The XML data from
* the 'xml' mode is inserted at the top of the page.</li>
* <li> <code>command</code> - Tests an OGNL expression and returns the
* string result. Only used by the OGNL console.</li>
* </ul>
* <p/>
* <p/>
* This interceptor only is activated when devMode is enabled in
* struts.properties. The 'debug' parameter is removed from the parameter list
* before the action is executed. All operations occur before the natural
* Result has a chance to execute. </p>
*/
public class DebuggingInterceptor implements Interceptor {
private static final long serialVersionUID = -3097324155953078783L;
private final static Log log = LogFactory.getLog(DebuggingInterceptor.class);
private String[] ignorePrefixes = new String[]{"org.apache.struts.",
"com.opensymphony.xwork2.", "xwork."};
private String[] _ignoreKeys = new String[]{"application", "session",
"parameters", "request"};
private HashSet<String> ignoreKeys = new HashSet<String>(Arrays.asList(_ignoreKeys));
private final static String XML_MODE = "xml";
private final static String CONSOLE_MODE = "console";
private final static String COMMAND_MODE = "command";
private final static String SESSION_KEY = "org.apache.struts2.interceptor.debugging.VALUE_STACK";
private final static String DEBUG_PARAM = "debug";
private final static String EXPRESSION_PARAM = "expression";
private boolean enableXmlWithConsole = false;
/**
* Unused.
*/
public void init() {
}
/**
* Unused.
*/
public void destroy() {
}
/*
* (non-Javadoc)
*
* @see com.opensymphony.xwork2.interceptor.Interceptor#invoke(com.opensymphony.xwork2.ActionInvocation)
*/
public String intercept(ActionInvocation inv) throws Exception {
Boolean devMode = (Boolean) ActionContext.getContext().get(
ActionContext.DEV_MODE);
boolean cont = true;
if (devMode) {
final ActionContext ctx = ActionContext.getContext();
String type = getParameter(DEBUG_PARAM);
ctx.getParameters().remove(DEBUG_PARAM);
if (XML_MODE.equals(type)) {
inv.addPreResultListener(
new PreResultListener() {
public void beforeResult(ActionInvocation inv, String result) {
printContext();
}
});
} else if (CONSOLE_MODE.equals(type)) {
inv.addPreResultListener(
new PreResultListener() {
public void beforeResult(ActionInvocation inv, String actionResult) {
String xml = "";
if (enableXmlWithConsole) {
StringWriter writer = new StringWriter();
printContext(new PrettyPrintWriter(writer));
xml = writer.toString();
xml = xml.replaceAll("&", "&");
xml = xml.replaceAll(">", ">");
xml = xml.replaceAll("<", "<");
}
ActionContext.getContext().put("debugXML", xml);
FreemarkerResult result = new FreemarkerResult();
result.setContentType("text/html");
result.setLocation("/org/apache/struts2/interceptor/debugging/console.ftl");
result.setParse(false);
try {
result.execute(inv);
} catch (Exception ex) {
log.error("Unable to create debugging console", ex);
}
}
});
} else if (COMMAND_MODE.equals(type)) {
ValueStack stack = (ValueStack) ctx.getSession().get(SESSION_KEY);
String cmd = getParameter(EXPRESSION_PARAM);
HttpServletResponse res = ServletActionContext.getResponse();
res.setContentType("text/plain");
try {
PrintWriter writer =
ServletActionContext.getResponse().getWriter();
writer.print(stack.findValue(cmd));
writer.close();
} catch (IOException ex) {
ex.printStackTrace();
}
cont = false;
}
}
if (cont) {
try {
return inv.invoke();
} finally {
if (devMode) {
final ActionContext ctx = ActionContext.getContext();
ctx.getSession().put(SESSION_KEY, ctx.get(ActionContext.VALUE_STACK));
}
}
} else {
return null;
}
}
/**
* Gets a single string from the request parameters
*
* @param key The key
* @return The parameter value
*/
private String getParameter(String key) {
String[] arr = (String[]) ActionContext.getContext().getParameters().get(key);
if (arr != null && arr.length > 0) {
return arr[0];
}
return null;
}
/**
* Prints the current context to the response in XML format.
*/
protected void printContext() {
HttpServletResponse res = ServletActionContext.getResponse();
res.setContentType("text/xml");
try {
PrettyPrintWriter writer = new PrettyPrintWriter(
ServletActionContext.getResponse().getWriter());
printContext(writer);
writer.close();
} catch (IOException ex) {
ex.printStackTrace();
}
}
/**
* Prints the current request to the existing writer.
*
* @param writer The XML writer
*/
protected void printContext(PrettyPrintWriter writer) {
ActionContext ctx = ActionContext.getContext();
writer.startNode(DEBUG_PARAM);
serializeIt(ctx.getParameters(), "parameters", writer,
new ArrayList<Object>());
writer.startNode("context");
String key;
Map ctxMap = ctx.getContextMap();
for (Object o : ctxMap.keySet()) {
key = o.toString();
boolean print = !ignoreKeys.contains(key);
for (String ignorePrefixe : ignorePrefixes) {
if (key.startsWith(ignorePrefixe)) {
print = false;
break;
}
}
if (print) {
serializeIt(ctxMap.get(key), key, writer, new ArrayList<Object>());
}
}
writer.endNode();
serializeIt(ctx.getSession(), "request", writer, new ArrayList<Object>());
serializeIt(ctx.getSession(), "session", writer, new ArrayList<Object>());
ValueStack stack = (ValueStack) ctx.get(ActionContext.VALUE_STACK);
serializeIt(stack.getRoot(), "valueStack", writer, new ArrayList<Object>());
writer.endNode();
}
/**
* Recursive function to serialize objects to XML. Currently it will
* serialize Collections, maps, Arrays, and JavaBeans. It maintains a stack
* of objects serialized already in the current functioncall. This is used
* to avoid looping (stack overflow) of circular linked objects. Struts and
* XWork objects are ignored.
*
* @param bean The object you want serialized.
* @param name The name of the object, used for element <name/>
* @param writer The XML writer
* @param stack List of objects we're serializing since the first calling
* of this function (to prevent looping on circular references).
*/
protected void serializeIt(Object bean, String name,
PrettyPrintWriter writer, List<Object> stack) {
writer.flush();
// Check stack for this object
if ((bean != null) && (stack.contains(bean))) {
if (log.isInfoEnabled()) {
log.info("Circular reference detected, not serializing object: "
+ name);
}
return;
} else if (bean != null) {
// Push object onto stack.
// Don't push null objects ( handled below)
stack.add(bean);
}
if (bean == null) {
return;
}
String clsName = bean.getClass().getName();
writer.startNode(name);
// It depends on the object and it's value what todo next:
if (bean instanceof Collection) {
Collection col = (Collection) bean;
// Iterate through components, and call ourselves to process
// elements
for (Object aCol : col) {
serializeIt(aCol, "value", writer, stack);
}
} else if (bean instanceof Map) {
Map map = (Map) bean;
// Loop through keys and call ourselves
for (Object key : map.keySet()) {
Object Objvalue = map.get(key);
serializeIt(Objvalue, key.toString(), writer, stack);
}
} else if (bean.getClass().isArray()) {
// It's an array, loop through it and keep calling ourselves
for (int i = 0; i < Array.getLength(bean); i++) {
serializeIt(Array.get(bean, i), "arrayitem", writer, stack);
}
} else {
if (clsName.startsWith("java.lang")) {
writer.setValue(bean.toString());
} else {
// Not java.lang, so we can call ourselves with this object's
// values
try {
BeanInfo info = Introspector.getBeanInfo(bean.getClass());
PropertyDescriptor[] props = info.getPropertyDescriptors();
for (PropertyDescriptor prop : props) {
String n = prop.getName();
Method m = prop.getReadMethod();
// Call ourselves with the result of the method
// invocation
if (m != null) {
serializeIt(m.invoke(bean), n, writer, stack);
}
}
} catch (Exception e) {
log.error(e, e);
}
}
}
writer.endNode();
// Remove object from stack
stack.remove(bean);
}
/**
* @param enableXmlWithConsole the enableXmlWithConsole to set
*/
public void setEnableXmlWithConsole(boolean enableXmlWithConsole) {
this.enableXmlWithConsole = enableXmlWithConsole;
}
}