json构造和解析

创建json:

//construct json and output it 
public String jsonTest() throws JSONException{
 JSONObject json=new JSONObject();
 JSONArray jsonMembers = new JSONArray();
 JSONObject member1 = new JSONObject();
 member1.put("loginname", "zhangfan");
 member1.put("password", "userpass");
 member1.put("email","[e-mail]");
 member1.put("sign_date", "2007-06-12");
 jsonMembers.put(member1);

 JSONObject member2 = new JSONObject();
 member2.put("loginname", "zf");
 member2.put("password", "userpass");
 member2.put("email","[e-mail]");
 member2.put("sign_date", "2008-07-16");
 jsonMembers.put(member2);
 json.put("users", jsonMembers);

 return json.toString();
}

解析json:

//construct json from String and resolve it.
public String jsonTest2() throws JSONException{
 String jsonString="{\"users\":[{\"loginname\":\"zhangfan\",\"password\":\"userpass\",\"email\":\"[e-mail]\"},{\"loginname\":\"zf\",\"password\":\"userpass\",\"email\":\"[e-mail]\"}]}";
 JSONObject json= new JSONObject(jsonString);
 JSONArray jsonArray=json.getJSONArray("users");
 String loginNames="loginname list:";
 for(int i=0;i<jsonArray.length();i++){
  JSONObject user=(JSONObject) jsonArray.get(i);
  String userName=(String) user.get("loginname");
  if(i==jsonArray.length()-1){
   loginNames+=userName;
  }else{
   loginNames+=userName+",";
  }
 }
 return loginNames;
}