《第一行代码》笔记(12)——使用GSON解析json数据

package com.zjw.mynetwork7;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

import com.google.gson.Gson;
import com.google.gson.reflect.TypeToken;

import java.io.IOException;
import java.util.List;

import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;

//9.4.2 p331 使用GSON
//把OkHttp的使用的代码拷一份过来(笔记(8))
//添加依赖compile 'com.google.code.gson:gson:2.8.0'
/*
GSON可以将一段JSON格式的字符串自动映射成一个对象
如:  JSON数据：{"name":"Tom","age":20}
    Person类：name,age两个字段
    解析代码：Gson gson=new Gson();
    Person person=gson.fromJson(jsonDara,Person.class);
    如果是解析JSON数组，需借助TypeToken将期望解析成的数据类型传入到fromJson()方法中
    List<Person> people=gson.fromJson(jsonData,new TypeToken<List<Person>>(){}.getType());
 */
//新增一个App类，加入id,name,version三个字段
public class GSONAnalysisOfJSON extends AppCompatActivity {

    private Button mBtnSendRequest;
    private TextView mTvResponseText;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_gsonanalysis_of_json);

        //找到控件
        mBtnSendRequest = (Button) findViewById(R.id.btn_send_request);
        mTvResponseText = (TextView) findViewById(R.id.tv_response_text);

        //Button点击事件，发送HTTP请求
        mBtnSendRequest.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                //用OkHttp发送HTTP请求
                sendRequestWithOkHttp();
            }
        });
    }

    private void sendRequestWithOkHttp() {
        //开启新线程做耗时操作
        new Thread(new Runnable() {
            @Override
            public void run() {
                try {
                    OkHttpClient client = new OkHttpClient();//创建一个OkHttpClient实例
                    Request request = new Request.Builder()
                            .url("http://10.0.2.2:8080//get_data.json")//设置目标网络地址
                            .build();//创建一个Request对象
                    Response response = client.newCall(request).execute();//发送请求获取服务器返回对象
                    String responseData = response.body().string();
                    paraJSONWithGSON(responseData);
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }).start();
    }

    private void paraJSONWithGSON(String responseData) {
        StringBuilder builder = new StringBuilder();

        Gson gson = new Gson();
        List<App> appList = gson.fromJson(responseData, new TypeToken<List<App>>() {
        }.getType());
        for (App app :
                appList) {
            builder.append("id:" + app.getId() + "\n")
                    .append("name:" + app.getName() + "\n")
                    .append("version:" + app.getVersion() + "\n")
                    .append("-----------------------------\n");
        }

        showResponse(builder.toString());
    }

    //将数据设置给TextView
    private void showResponse(final String s) {
        //在UI线程(主线程)更新UI,因为Android不允许在子线程中进行UI操作
        runOnUiThread(new Runnable() {
            @Override
            public void run() {
                mTvResponseText.setText(s);
            }
        });
    }
}

转载于:https://my.oschina.net/u/3620480/blog/1489822