defaultactioninvocation.java

在Struts2中的jar包xwork的源代码.版本为2.0.7

/*
 * Copyright (c) 2002-2006 by OpenSymphony
 * All rights reserved.
 */
package com.opensymphony.xwork2;

import com.opensymphony.xwork2.config.ConfigurationException;
import com.opensymphony.xwork2.config.entities.ActionConfig;
import com.opensymphony.xwork2.config.entities.InterceptorMapping;
import com.opensymphony.xwork2.config.entities.ResultConfig;
import com.opensymphony.xwork2.interceptor.PreResultListener;
import com.opensymphony.xwork2.util.ValueStack;
import com.opensymphony.xwork2.util.ValueStackFactory;
import com.opensymphony.xwork2.util.profiling.UtilTimerStack;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Map;


/**
 * The Default ActionInvocation implementation
 *
 * @author Rainer Hermanns
 * @author tmjee
 * 
 * @version $Date: 2007-03-31 18:32:47 +0200 (Sa, 31 Mrz 2007) $ $Id: DefaultActionInvocation.java 1414 2007-03-31 16:32:47Z rainerh $
 * 
 * @see com.opensymphony.xwork2.DefaultActionProxy
 */
public class DefaultActionInvocation implements ActionInvocation {
    
	private static final long serialVersionUID = -585293628862447329L;

    //static {
    //    if (ObjectFactory.getContinuationPackage() != null) {
    //        continuationHandler = new ContinuationHandler();
    //    }
    //}
    private static final Log LOG = LogFactory.getLog(DefaultActionInvocation.class);

    protected Object action;
    protected ActionProxy proxy;
    protected List preResultListeners;
    protected Map extraContext;
    protected ActionContext invocationContext;
    protected Iterator interceptors;
    protected ValueStack stack;
    protected Result result;
    protected String resultCode;
    protected boolean executed = false;
    protected boolean pushAction = true;
    protected ObjectFactory objectFactory;
    protected ActionEventListener actionEventListener;

    protected UnknownHandler unknownHandler;

    protected DefaultActionInvocation(ObjectFactory objectFactory, UnknownHandler handler, ActionProxy proxy, Map extraContext) throws Exception {
        this(objectFactory, handler, proxy, extraContext, true, null);
    }

    protected DefaultActionInvocation(final ObjectFactory objectFactory, final UnknownHandler handler, final ActionProxy proxy, final Map extraContext, final boolean pushAction) throws Exception {
        this(objectFactory, handler, proxy, extraContext, pushAction, null);
    }

    protected DefaultActionInvocation(final ObjectFactory objectFactory, final UnknownHandler handler, final ActionProxy proxy, final Map extraContext, final boolean pushAction, final ActionEventListener actionEventListener) throws Exception {
    	UtilTimerStack.profile("create DefaultActionInvocation: ", 
    			new UtilTimerStack.ProfilingBlock<Object>() {
					public Object doProfiling() throws Exception {
						DefaultActionInvocation.this.proxy = proxy;
                        DefaultActionInvocation.this.objectFactory = objectFactory;
				        DefaultActionInvocation.this.extraContext = extraContext;
				        DefaultActionInvocation.this.pushAction = pushAction;
                        DefaultActionInvocation.this.unknownHandler = handler;
                        DefaultActionInvocation.this.actionEventListener = actionEventListener;
                        init();
						return null;
					}
    			});
    }
    
    public void setActionEventListener(ActionEventListener listener) {
        this.actionEventListener = listener;
    }

    public Object getAction() {
        return action;
    }

    public boolean isExecuted() {
        return executed;
    }

    public ActionContext getInvocationContext() {
        return invocationContext;
    }

    public ActionProxy getProxy() {
        return proxy;
    }

    /**
     * If the DefaultActionInvocation has been executed before and the Result is an instance of ActionChainResult, this method
     * will walk down the chain of ActionChainResults until it finds a non-chain result, which will be returned. If the
     * DefaultActionInvocation's result has not been executed before, the Result instance will be created and populated with
     * the result params.
     *
     * @return a Result instance
     * @throws Exception
     */
    public Result getResult() throws Exception {
        Result returnResult = result;

        // If we've chained to other Actions, we need to find the last result
        while (returnResult instanceof ActionChainResult) {
            ActionProxy aProxy = ((ActionChainResult) returnResult).getProxy();

            if (aProxy != null) {
                Result proxyResult = aProxy.getInvocation().getResult();

                if ((proxyResult != null) && (aProxy.getExecuteResult())) {
                    returnResult = proxyResult;
                } else {
                    break;
                }
            } else {
                break;
            }
        }

        return returnResult;
    }

    public String getResultCode() {
        return resultCode;
    }

    public void setResultCode(String resultCode) {
        if (isExecuted())
            throw new IllegalStateException("Result has already been executed.");

        this.resultCode = resultCode;
    }


    public ValueStack getStack() {
        return stack;
    }

    /**
     * Register a com.opensymphony.xwork2.interceptor.PreResultListener to be notified after the Action is executed and before the
     * Result is executed. The ActionInvocation implementation must guarantee that listeners will be called in the order
     * in which they are registered. Listener registration and execution does not need to be thread-safe.
     *
     * @param listener
     */
    public void addPreResultListener(PreResultListener listener) {
        if (preResultListeners == null) {
            preResultListeners = new ArrayList(1);
        }

        preResultListeners.add(listener);
    }

    public Result createResult() throws Exception {

    	if (result != null) {
    		return result;
    	}
        ActionConfig config = proxy.getConfig();
        Map results = config.getResults();

        ResultConfig resultConfig = null;

        synchronized (config) {
            try {
                resultConfig = (ResultConfig) results.get(resultCode);
            } catch (NullPointerException e) {
            }
            if (resultConfig == null) {
                // If no result is found for the given resultCode, try to get a wildcard '*' match.
                resultConfig = (ResultConfig) results.get("*");
            }
        }

        if (resultConfig != null) {
            try {
                Result result = objectFactory.buildResult(resultConfig, invocationContext.getContextMap());
                return result;
            } catch (Exception e) {
                LOG.error("There was an exception while instantiating the result of type " + resultConfig.getClassName(), e);
                throw new XWorkException(e, resultConfig);
            }
        } else if (resultCode != null && !Action.NONE.equals(resultCode) && unknownHandler != null) {
            return unknownHandler.handleUnknownResult(invocationContext, proxy.getActionName(), proxy.getConfig(), resultCode);
        }
        return null;
    }

    /**
     * @throws ConfigurationException If no result can be found with the returned code
     */
    public String invoke() throws Exception {
    	String profileKey = "invoke: ";
    	try {
    		UtilTimerStack.push(profileKey);
    		
    		if (executed) {
    			throw new IllegalStateException("Action has already executed");
    		}