jsonresultdetail.java

因为许多人出去吃饭都一个人付帐

package cn.com.sdcncsi.lunch.balance.result;

import java.io.PrintWriter;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.struts2.ServletActionContext;

import cn.com.sdcncsi.lunch.balance.domain.AccountBook;
import cn.com.sdcncsi.lunch.balance.domain.AccountDetail;
import cn.com.sdcncsi.lunch.balance.domain.AccountType;
import cn.com.sdcncsi.lunch.domain.User;
import cn.com.sdcncsi.lunch.result.JSONResult;

import com.opensymphony.xwork2.ActionInvocation;
import com.opensymphony.xwork2.util.ValueStack;
import com.thoughtworks.xstream.XStream;
import com.thoughtworks.xstream.io.json.JettisonMappedXmlDriver;

/*
 * The JSONResult is a custom result to serlialize an object to the JSON format.  This
 * result type can be used to provide Ajax clients with JSON repsonses.
 * 
 * This result is basically just to show two things.  First, the fundamentals of making
 * a custom result.  And second, how Ajax applications can be easily integrated with the 
 * framework.  
 * 
 * This result takes a single parameter, classAlias, which will be the JSON object name
 * under which the domain model object will be serialized.  As far as what gets serialized,
 * the JSON result will look for a property on the ValueStack called jsonModel.  This 
 * value could arrive on the ValueStack via a variety of methods.     
 */

public class JSONResultDetail extends JSONResult {

	private static Log logger = LogFactory.getLog(JSONResultDetail.class.getName());
	
	String classAlias;

	public void execute(ActionInvocation invocation) throws Exception {
		
	    ServletActionContext.getResponse().setContentType("text/plain; charset=UTF-8");
		PrintWriter responseStream = ServletActionContext.getResponse().getWriter();
		
		/* Retreive Objects to Serialize to JSON from ValueStack*/
		ValueStack valueStack = invocation.getStack();
		Object jsonModel = valueStack.findValue("jsonModel");
		
		XStream xstream = new XStream(new JettisonMappedXmlDriver());
		
		/*If there's no parameter passed in, just write the objects under a default name. */
		if ( classAlias == null ){
			classAlias = "object";
		}
		logger.debug("classAlias:"+classAlias);
	    xstream.alias(classAlias, jsonModel.getClass() );
	    logger.debug("jsonModel:"+jsonModel.getClass());
	    xstream.alias("detail", new AccountDetail().getClass() );
	    xstream.alias("book", new AccountBook().getClass() );
	    xstream.alias("user", new User().getClass() );
	    xstream.alias("type", new AccountType().getClass() );
	    
	    /* Write to the response stream */
	    String jsonxml = xstream.toXML( jsonModel );
	    responseStream.println(jsonxml);		
	    logger.debug("jsonxml="+jsonxml);
	    //logger.debug("HiJSONUtil="+);

	}

}