首页手记看懂这篇文章，让你简单懂得解析Json字符串

看懂这篇文章，让你简单懂得解析Json字符串

标签：

Android

本篇文章全部以示例为主，方便大家简单易懂！
{
    "condition": "ooppp",
    "data": [
        {
            "date": "2013-08-29 12:32:31",
            "message": "xxxxxxxxxx",
            "utime": "2013-08-29 12:32:31"
        },
        {
            "date": "2013-08-29 12:32:31",
            "message": "xxxxxxxxxx",
            "utime": "2013-08-29 12:32:31"
        },
        {
            "date": "2013-08-29 12:32:31",
            "message": "xxxxxxxxxx",
            "utime": "2013-08-29 12:32:31"
        },
        {
            "date": "2013-08-29 12:32:31",
            "message": "xxxxxxxxxx",
            "utime": "2013-08-29 12:32:31"
        }
    ],
    "ischeck": "1",
    "state": "0",
    "status": "200",
    "xxu": "61995"
}

把上面的解析出来：

str表示服务器返回来的字符串(上)

try {
   JSONObject jo = new JSONObject(str);
   System.out.println(jo.toString());
   JSONArray ja = new JSONArray(jo.getString("data"));
   System.out.println(ja.toString());
   for (int i = 0; i < 4; i++) {
    JSONObject temp = (JSONObject) ja.get(i);
    System.out.println(temp.getString("date")+" "+temp.getString("message")+" "+temp.getString("utime"));
   }
} catch (JSONException e) {
   // TODO 自动生成的 catch 块
   e.printStackTrace();
}

代码构建json字符串：一般以字符串的形式传给服务器
package sn.len.json;

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

import android.app.Activity;
import android.os.Bundle;
import android.util.Log;

public class JSONActivity extends Activity {
    private String jsondata;
    @Override
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        try
        {
            //调用构建JSON字符串方法
            buildJson();
        }
        catch (JSONException e)
        {
            e.printStackTrace();
        }
    }
    //构建JSON字符串
    public void buildJson() throws JSONException
    {
        JSONArray json=new JSONArray();
        JSONObject jsonObj=new JSONObject();
        for(int i=0;i<2;i++)
        {
            jsonObj.put("id", "001");
            jsonObj.put("age", "20");
            jsonObj.put("name", "snoanw");
            //把每个数据当作一对象添加到数组里
            json.put(jsonObj);
        }
        jsondata=json.toString();
        Log.i("JSON", jsondata);
        //调用解析JSON方法
        parserJson(jsondata);
    }
    // 解析JSON字符串
    public void parserJson(String jsondata) throws JSONException
    {
        //构建JSON数组对象
        JSONArray json1=new JSONArray(jsondata);
        for(int i=0;i<json1.length();i++)
        {
            JSONObject jsonObj2=json1.optJSONObject(i);
            String id=jsonObj2.getString("id");
            String age=jsonObj2.getString("age");
            String name=jsonObj2.getString("name");
            Log.i("JSONDATA", id+age+name);
        }
    }
}

构建成的样子：
[{"id":"001","name":"snonaw","age":"20"},{"id":"002","name":"chace","age":"23"}]

服务器返回的字符串：
{
    "userbean": {
        "Showname": "u75afu72c2u7684u7334u5b50",
        "State": 1,
        "Uid": "100196"
    }
}

代码解析：builder.toString()代表请求服务器时，服务器返回的字符串

JSONObject jsonObject = new JSONObject(builder.toString()).getJSONObject("userbean");

                String Uid;
                String Showname;
                String Avtar;
                String State;

                Uid = jsonObject.getString("Uid");
                Showname = jsonObject.getString("Showname");
                Avtar = jsonObject.getString("Avtar");
                State = jsonObject.getString("State");

服务器返回的字符串：
{
    "calendar": {
        "calendarlist": [
            {
                "allDay": false,
                "calendar_id": "1705",
                "category_name": "u9ed8u8ba4u5206u7c7b",
                "endshowtime": "1288931400",
                "showtime": "1288927800",
                "title": "(u4eb2u5b50)ddssd"
            },
            {
                "allDay": false,
                "calendar_id": "1706",
                "category_name": "u9ed8u8ba4u5206u7c7b",
                "endshowtime": "1288936800",
                "showtime": "1288933200",
                "title": "(u65c5u884c)"
            }
        ]
    }
}

代码解析服务器返回的字符串：builder.toString()同样代表服务器返回的字符串

SONObject jsonObject = new JSONObject(builder.toString()) .getJSONObject("calendar");
        JSONArray jsonArray = jsonObject.getJSONArray("calendarlist");
                    for(int i=0;i<jsonArray.length();i++){

                        JSONObject jsonObject2 = (JSONObject)jsonArray.opt(i);
                        CalendarInfo calendarInfo = new CalendarInfo();
                        calendarInfo.setCalendar_id(jsonObject2.getString("calendar_id"));
                        calendarInfo.setTitle(jsonObject2.getString("title"));
                        calendarInfo.setCategory_name(jsonObject2.getString("category_name"));
                        calendarInfo.setShowtime(jsonObject2.getString("showtime"));
                        calendarInfo.setEndtime(jsonObject2.getString("endshowtime"));
                        calendarInfo.setAllDay(jsonObject2.getBoolean("allDay"));
                        calendarInfos.add(calendarInfo);

}

单数据    {'singer':{'id':1,'name':'tom','gender':'男'}}
多个数据  {'singers':[{'id':'2','name':'tom','gender':'男'},{'id':'3','name':'jerry','gender':'男'},{'id':'4','name':'jim','gender':'男'},{'id':'5','name':'lily','gender':'女'}]}

{
    "singer": {
        "gender": "男",
        "id": 1,
        "name": "tom"
    }
}

{
    "singers": [
        {
            "gender": "男",
            "id": "2",
            "name": "tom"
        },
        {
            "gender": "男",
            "id": "3",
            "name": "jerry"
        },
        {
            "gender": "男",
            "id": "4",
            "name": "jim"
        },
        {
            "gender": "女",
            "id": "5",
            "name": "lily"
        }
    ]
}

public class JsonActivity extends Activity {
    /** Called when the activity is first created. */
    private TextView tvJson;
    private Button btnJson;
    private Button btnJsonMulti;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        tvJson = (TextView) this.findViewById(R.id.tvJson);
        btnJson = (Button) this.findViewById(R.id.btnJson);
        btnJsonMulti = (Button) this.findViewById(R.id.btnJsonMulti);
        btnJson.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                // url
                // String strUrl = "http://10.158.166.110:8080/AndroidServer/JsonServlet";
                String strUrl = ServerPageUtil.getStrUrl(UrlsOfServer.JSON_SINGER);
                //获得返回的Json字符串
                String strResult = connServerForResult(strUrl);
                //解析Json字符串
                parseJson(strResult);
            }
        });
        btnJsonMulti.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String strUrl = ServerPageUtil.getStrUrl(UrlsOfServer.JSON_SINGERS);
                String strResult = connServerForResult(strUrl);
                //获得多个Singer
                parseJsonMulti(strResult);
            }
        });
    }
    private String connServerForResult(String strUrl) {
        // HttpGet对象
        HttpGet httpRequest = new HttpGet(strUrl);
        String strResult = "";
        try {
            // HttpClient对象
            HttpClient httpClient = new DefaultHttpClient();
            // 获得HttpResponse对象
            HttpResponse httpResponse = httpClient.execute(httpRequest);
            if (httpResponse.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
                // 取得返回的数据
                strResult = EntityUtils.toString(httpResponse.getEntity());
            }
        } catch (ClientProtocolException e) {
            tvJson.setText("protocol error");
            e.printStackTrace();
        } catch (IOException e) {
            tvJson.setText("IO error");
            e.printStackTrace();
        }
        return strResult;
    }
    // 普通Json数据解析
    private void parseJson(String strResult) {
        try {
            JSONObject jsonObj = new JSONObject(strResult).getJSONObject("singer");
            int id = jsonObj.getInt("id");
            String name = jsonObj.getString("name");
            String gender = jsonObj.getString("gender");
            tvJson.setText("ID号"+id + ", 姓名：" + name + ",性别：" + gender);
        } catch (JSONException e) {
            System.out.println("Json parse error");
            e.printStackTrace();
        }
    }
    //解析多个数据的Json
    private void parseJsonMulti(String strResult) {
        try {
            JSONArray jsonObjs = new JSONObject(strResult).getJSONArray("singers");
            String s = "";
            for(int i = 0; i < jsonObjs.length() ; i++){
                JSONObject jsonObj = (JSONObject)jsonObjs.get(i);
                int id = jsonObj.getInt("id");
                String name = jsonObj.getString("name");
                String gender = jsonObj.getString("gender");
                s += "ID号"+id + ", 姓名：" + name + ",性别：" + gender+ "\n" ;
            }
            tvJson.setText(s);
        } catch (JSONException e) {
            System.out.println("Jsons parse error !");
            e.printStackTrace();
        }
    }
}