webwork加入result-types为json的返回类型(支持自动组装JSONObject的JSONResult，支持encoding编码)

import java.io.OutputStream;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import javax.servlet.http.HttpServletResponse;
import java.lang.reflect.Field;

import com.opensymphony.webwork.ServletActionContext;
import com.opensymphony.xwork.ActionContext;
import com.opensymphony.xwork.ActionInvocation;
import com.opensymphony.xwork.Result;
import org.json.JSONObject;

/**
 * 支持自动组装JSONObject的JSONResult，支持encoding编码。
 * 
 * @author WUZHENZHONG
 * @data 2012-07-02
 */
public class JSONResult implements Result {

	/**
	 * 
	 */
	private static final long serialVersionUID = 9010804483391553391L;
	private static final Log log = LogFactory.getLog(JSONResult.class);
	// action中的json对象的名词
	private String jsonObjectProperty = "jsonObject";
	private String contentType = "application/json";
	private String encoding = "utf-8";

	@Override
	public void execute(ActionInvocation invocation) throws Exception {

		if (log.isDebugEnabled()) {
			log.debug("executing JSONResult");
		}
		// 通过xwork的invocation从webwork的action中获得JSONObject对象
		JSONObject jsonObject = getJSONObject(invocation);
		if (jsonObject != null) {
			String json = jsonObject.toString();
			HttpServletResponse response = getServletResponse(invocation);
			response.setContentType(getContentType());
			// encoding
			byte[] bs = json.getBytes(this.encoding);
			response.setContentLength(bs.length);
			OutputStream os = response.getOutputStream();
			os.write(bs);
			os.flush();

			if (log.isDebugEnabled()) {
				log.debug("written [" + json + "] to HttpServletResponse outputstream");
			}
		}

	}

	protected JSONObject getJSONObject(ActionInvocation invocation) throws Exception {
		ActionContext actionContext = invocation.getInvocationContext();
		// 从xwork配置中获得JSON对象名词
		Object obj = actionContext.getValueStack().findValue(jsonObjectProperty);

		if (obj == null) {
			log.error("property ["
						+ jsonObjectProperty
						+ "] returns null, please check xwork.xml file");
			return null;
		}
		// 如果Action中的对象是JSONObject，那么就不需要反射动态转换为JSONObject
		// 如果Action中的对象就是POJO，那么这里自动组装JSONObject
		if (!JSONObject.class.isInstance(obj)) {
			log.debug("build json object by reflection.");
			JSONObject jsonObj = new JSONObject();
			for (Field field : obj.getClass().getDeclaredFields()) {
				String getter = "get"
								+ Character.toUpperCase(field.getName().charAt(0))
								+ field.getName().substring(1);
				jsonObj.append(field.getName(), obj	.getClass()
													.getDeclaredMethod(getter)
													.invoke(obj));
			}
			return jsonObj;
		}

		return (JSONObject) obj;
	}

	protected HttpServletResponse getServletResponse(ActionInvocation invocation) {
		return (HttpServletResponse) invocation	.getInvocationContext()
												.getContextMap()
												.get(ServletActionContext.HTTP_RESPONSE);
	}

	public void setEncoding(String encoding) {
		this.encoding = encoding;
	}

	public String getEncoding() {
		return encoding;
	}

	public void setJsonObjectProperty(String jsonObjectProperty) {
		this.jsonObjectProperty = jsonObjectProperty;
	}

	public String getJsonObjectProperty() {
		return jsonObjectProperty;
	}

	public void setContentType(String contentType) {
		this.contentType = contentType;
	}

	public String getContentType() {
		return contentType;
	}

}

 配置文件：

   

<xwork>
   <package name="system-default" extends="webwork-default">
	<result-types>
      		<result-type name="json" class="com.guagua.chat.search.JSONResult" />
    	</result-types>
                <action name="search" class="com.guagua.chat.search.SearchAction">
               	     <result name="cjcategory" type="json">
	          <param name="jsonObjectProperty">cjroomcategory</param>
	     </result>
                 </action>
    </package>
</xwork>

 类例子：

   

import java.io.IOException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.log4j.Logger;

import com.guagua.base.AuthFactory;
import com.guagua.base.AuthToken;
import com.guagua.base.UnauthorizedException;
import com.guagua.vas.constants.CacheConstants;
import com.guagua.vas.redis.RedIsService;
import com.opensymphony.webwork.ServletActionContext;

public class SearchAction {

	private static Logger logger = Logger.getLogger(SearchAction.class.getName());

	public CjRoomCategoryVo cjroomcategory = new CjRoomCategoryVo();
	
	
	/**
	 * 获取房间分类接口
	 * @return JSON
	 * @throws Exception
	 */
	@SuppressWarnings("unchecked")
	public String getcjcategory()  throws Exception {
		Map<String,String> catemap = RedIsService.getJedisByKey(CacheConstants.CJ_ROOM_CATEGORY);
		String returnstr = "";
		if(catemap==null || catemap.size()<=0){
			catemap.put("cj_room_category_101_0", "{'category_id':101,'name':'桂林','parent_id':0}");
			catemap.put("cj_room_category_1011_101", "{'category_id':1011,'name':'桂林s','parent_id':101}");
			catemap.put("cj_room_category_1012_101", "{'category_id':1012,'name':'桂林sf','parent_id':101}");
			catemap.put("cj_room_category_102_0", "{'category_id':102,'name':'桂林1','parent_id':0}");
			catemap.put("cj_room_category_1013_102", "{'category_id':1013,'name':'桂林sf','parent_id':102}");
		}
		List arrayList = new ArrayList(catemap.entrySet());
		Collections.sort(arrayList, new TariffMapComparator());   
		for(Iterator it = arrayList.iterator();it.hasNext();){
			Map.Entry<String,String> entry = (Map.Entry<String,String>)it.next();
			if(entry.getKey().endsWith("_0")){
				String tempstr = "'category':"+entry.getValue();
				String[] tp = entry.getKey().split("_");
				StringBuffer subtempstr = new StringBuffer("");
				for(Iterator subit = arrayList.iterator();subit.hasNext();){
					Map.Entry<String,String> subentry = (Map.Entry<String,String>)subit.next();
					if(subentry.getKey().endsWith("_"+tp[3])){
						subtempstr.append(subentry.getValue()+",");
					}
				}
			    String tempsubstr = subtempstr.toString();
			    if(tempsubstr.length()>0){
			    	tempsubstr = tempsubstr.substring(0, tempsubstr.length()-1);
			    }
			    tempsubstr = "'subcategory':["+tempsubstr+"]";
			    String tempcountstr = "{"+tempstr+","+tempsubstr+"}";
			    returnstr = returnstr + tempcountstr+",";
			}
		}
		returnstr = "["+returnstr.substring(0, returnstr.length()-1)+"]";
		cjroomcategory.setJsonstr(returnstr);
		return "cjcategory";
	}

	public CjRoomCategoryVo getCjroomcategory() {
		return cjroomcategory;
	}

	public void setCjroomcategory(CjRoomCategoryVo cjroomcategory) {
		this.cjroomcategory = cjroomcategory;
	}
	
	/**
	 * 分类排序
	 * @author WUZHENZHONG
	 *
	 */
	@SuppressWarnings({"unused", "unchecked"})
	private class TariffMapComparator implements Comparator{   
		  
        public int compare(Object o1, Object o2) {   
            Map.Entry<String,String> obj1 = (Map.Entry<String,String>)o1;   
            Map.Entry<String,String> obj2 = (Map.Entry<String,String>)o2;            
            return obj1.getKey().toString().compareTo(obj2.getKey().toString());   
       }   
    }     
	
}