Java遍历Json中的key和value问题

 
    public String appendSignData(JSONObject obj){
 
        StringBuffer sb = new StringBuffer();
        //fastjson解析方法
        for (Map.Entry<String, Object> entry : obj.entrySet()) {
            System.out.println("key值="+entry.getKey());
            sb.append(entry.getValue());
        }
 
 
        return sb.toString();
    }

import java.util.Iterator;
 
 
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
 
 
public class testGetKeys {
 
	
	 public static String getKeys(JSONObject test) throws JSONException{
		   
		 String result = null;
		 testJsonCompare t = new testJsonCompare();
		 Iterator keys = test.keys();
		 while(keys.hasNext()){
			 
			 try{
				 
			 String key = keys.next().toString();
			 String value = test.optString(key);
			 
			 int i = t.testIsArrayORObject(value);
			 
			 if(result == null || result.equals("")){
				 if(i == 0){
				
					 result = key + ",";
					 System.out.println("i=0 | key="+key+"| result="+result);
					 
					 
				 }else if( i == 1){
					
					 result = key + ",";
					 System.out.println("i=1 | key="+key+"| result="+result);
					 result = getKeys(new JSONObject(value))+",";
				 }else if( i == 2){
					 
					 result = key + ",";
					 System.out.println("i=2 | key="+key+"| result="+result);
					 JSONArray arrays = new JSONArray(value);
					 for(int k =0;k<arrays.length();k++){
						 JSONObject array = new JSONObject(arrays.get(k));
						 result = getKeys(array) + ",";
					 }
				 }
				 
			 }else{
				  if(i == 0){
				
				 result = result + key + ",";
				 System.out.println("i=0 | key="+key+"| result="+result);
				 
				 
			 }else if( i == 1){
				
				 result = result + key + ",";
				 System.out.println("i=1 | key="+key+"| result="+result);
				 result = result + getKeys(new JSONObject(value));
			 }else if( i == 2){
				 result = result + key + ",";
				 System.out.println("i=2 | key="+key+"| result="+result);
				 JSONArray arrays = new JSONArray(value);
				 for(int k =0;k<arrays.length();k++){
					 JSONObject array = new JSONObject(arrays.get(k));
					 result = result + getKeys(array) + ",";
				 }
			 }
			 }
			
			 
		 }catch(JSONException e){
			 e.printStackTrace();
		 }
			 }
		
		 
		 return result;
	 }
	 
	 public static void main(String args[]) throws org.json.JSONException{
		 
		 JSONObject test = new JSONObject();
		 JSONObject test1 = new JSONObject();
		 
		 try{
			  test1.put("A", "1");
			  test1.put("B", "2");
			  
			  test.put("a", "1");
			  test.put("c", test1);
			  test.put("b", "2");
		  
			  System.out.println(test.toString());
			  
		 }catch(JSONException e){
			 e.printStackTrace();
		 }
		 
		 String s = getKeys(test);
		 System.out.println(s);
		
		 
	 }
}

	public int testIsArrayORObject(String sJSON){
		/*
		 * return 0:既不是array也不是object
		 * return 1：是object
		 * return 2 ：是Array
		 */
		try {
			JSONArray array = new JSONArray(sJSON);
			return 2;
		} catch (JSONException e) {// 抛错 说明JSON字符不是数组或根本就不是JSON
			try {
				JSONObject object = new JSONObject(sJSON);
				return 1;
			} catch (JSONException e2) {// 抛错 说明JSON字符根本就不是JSON
				System.out.println("非法的JSON字符串");
				return 0;
			}
		}
 
	}