SSM框架中实现将json串显示到前台页面中

首先在Controller中的方法中定义如下如所示：

JSONObject json = new JSONObject();
	json.put("vcode", Vcode);
	json.put("username", "username");
	json.put("password", "password");
	HtmlUtil.writerJson(response, json);

当然，这里引用了JSONObject，需要一个jar包， 下载地址

然后就是公共类HtmlUtil

package com.jh5bframework.common.utils;

import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.http.HttpServletResponse;
import org.json.JSONException;
import com.jh5bframework.common.json.JSONUtil;

public class HtmlUtil {
	
	/**
	 * 功能：输出json格式
	 * @param response
	 * @param jsonStr
	 * @throws Exception
	 */
	public static void writerJson(HttpServletResponse response,String jsonStr) {
			writer(response,jsonStr);
	}
	
	public static void writerJson(HttpServletResponse response,Object object){
			try {
				response.setContentType("application/json");
				writer(response,JSONUtil.toJSONString(object));
				
			} catch (JSONException e) {
				e.printStackTrace();
			}
	}
	
	/**
	 * 功能：输出HTML代码
	 * @param response
	 * @param htmlStr
	 * @throws Exception
	 */
	public static void writerHtml(HttpServletResponse response,String htmlStr) {
		writer(response,htmlStr);
	}
	
	private static void writer(HttpServletResponse response,String str){
		try {
			StringBuffer result = new StringBuffer();
			//设置页面不缓存
			response.setHeader("Pragma", "No-cache");
			response.setHeader("Cache-Control", "no-cache");
			response.setContentType("text/html; charset=utf-8");
			PrintWriter out= null;
			out = response.getWriter();
			out.print(str);
			out.flush();
			out.close();
		} catch (IOException e) {
			e.printStackTrace();
		}
	} 
}

然后是JSONUtil公共类：

package com.jh5bframework.common.json;

import java.lang.reflect.Array;
import java.lang.reflect.Method;
import java.util.Collection;
import java.util.Iterator;
import java.util.Map;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import org.json.JSONString;

/** 
 * JSON工具类，反射的方式转换整个对象
 * @author 
 *
 */
public class JSONUtil{

    private static JSONUtil instance = null;
    
    public JSONUtil(){
    	
    }
    
    /** 
     * 代理类时做的检查.返回应该检查的对象.
     * @param bean
     * @return
     */
    protected Object proxyCheck(Object bean){
        return bean;
    }

    static public String toJSONString(Object obj) throws JSONException{
        return toJSONString(obj, false);
    }
    
    static public String toJSONString(Object obj, boolean useClassConvert) throws JSONException{
        if(instance == null)
            instance = new JSONUtil();
        return instance.getJSONObject(obj, useClassConvert).toString();
    }

    @SuppressWarnings("unchecked")
	private String getJSONArray(Object arrayObj, boolean useClassConvert) throws JSONException{
        
        if(arrayObj == null)
            return "null";
        
        arrayObj = proxyCheck(arrayObj);
        
        JSONArray jSONArray = new JSONArray();
        if(arrayObj instanceof Collection){
            Iterator iterator = ((Collection)arrayObj).iterator();
            while(iterator.hasNext()){
                Object rowObj = iterator.next();
                if(rowObj == null)
                    jSONArray.put(new JSONStringObject(null));
                else if(rowObj.getClass().isArray() || rowObj instanceof Collection)
                    jSONArray.put(getJSONArray(rowObj, useClassConvert));
                else
                    jSONArray.put(getJSONObject(rowObj, useClassConvert));
            }
        }
        if(arrayObj.getClass().isArray()){
            int arrayLength = Array.getLength(arrayObj);
            for(int i = 0; i < arrayLength; i ++){
                Object rowObj = Array.get(arrayObj, i);
                if(rowObj == null)
                    jSONArray.put(new JSONStringObject(null));
                else if(rowObj.getClass().isArray() || rowObj instanceof Collection)
                    jSONArray.put(getJSONArray(rowObj, useClassConvert));
                else
                    jSONArray.put(getJSONObject(rowObj, useClassConvert));
            }
        }
        return jSONArray.toString();
    }

    @SuppressWarnings("unchecked")
	JSONStringObject getJSONObject(Object value, boolean useClassConvert) throws JSONException{

        //处理原始类型

        if (value == null){
            return new JSONStringObject("null");
        }
        value = proxyCheck(value);
        if (value instanceof JSONString){
            Object o;
            try{
                o = ((JSONString)value).toJSONString();
            } catch (Exception e){
                throw new JSONException(e);
            }
            throw new JSONException("Bad value from toJSONString: " + o);
        }
        if (value instanceof Number){
            return new JSONStringObject(JSONObject.numberToString((Number) value));
        }
        if (value instanceof Boolean || value instanceof JSONObject ||
                value instanceof JSONArray){
            return new JSONStringObject(value.toString());
        }
        if (value instanceof String)
            return new JSONStringObject(JSONObject.quote(value.toString()));
        if (value instanceof Map){
            
            JSONObject jSONObject = new JSONObject();

            Iterator iterator = ((Map)value).keySet().iterator();
            while(iterator.hasNext()){
                String key = iterator.next().toString();
                Object valueObj = ((Map)value).get(key);
                jSONObject.put(key, getJSONObject(valueObj, useClassConvert));
            }
            return new JSONStringObject(jSONObject.toString());
        }

        //class

        if(value instanceof Class)
            return new JSONStringObject(JSONObject.quote(((Class)value).getSimpleName()));
        
        //数组

        if (value instanceof Collection || value.getClass().isArray()){
            return new JSONStringObject(getJSONArray(proxyCheck(value), useClassConvert));
        }

        return reflectObject(value, useClassConvert);
    }//value.equals(null)


    @SuppressWarnings("unchecked")
	private JSONStringObject reflectObject(Object bean, boolean useClassConvert){
        JSONObject jSONObject = new JSONObject();

        Class klass = bean.getClass();
        Method[] methods = klass.getMethods();
        for (int i = 0; i < methods.length; i += 1){
            try{
                Method method = methods[i];
                String name = method.getName();
                String key = "";
                if (name.startsWith("get")){
                    key = name.substring(3);
                } else if (name.startsWith("is")){
                    key = name.substring(2);
                }
                if (key.length() > 0 &&
                        Character.isUpperCase(key.charAt(0)) &&
                        method.getParameterTypes().length == 0){
                    if (key.length() == 1){
                        key = key.toLowerCase();
                    } else if (!Character.isUpperCase(key.charAt(1))){
                        key = key.substring(0, 1).toLowerCase() +
                            key.substring(1);
                    }
                    Object elementObj = method.invoke(bean, null);
                    if(!useClassConvert && elementObj instanceof Class)
                        continue;

                    jSONObject.put(key, getJSONObject(elementObj, useClassConvert));
                }
            } catch (Exception e){
                /**//* forget about it */
            }
        }
        return new JSONStringObject(jSONObject.toString());
    }
}

最后是JSONStringObject公共类：

package com.jh5bframework.common.json;

import org.json.JSONString;

public class JSONStringObject implements JSONString{

    private String jsonString = null;
    
    public JSONStringObject(String jsonString){
        this.jsonString = jsonString;
    }

    @Override
    public String toString(){
        return jsonString;
    }

    public String toJSONString(){
        return jsonString;
    }
}