在网络上传输数据时最常用的格式有两种:XML和JSON,今天学习如何解析JSON格式的数据。
接着上一章XML解析。在Apache的htdocs目录下,新建一个get_data.json文件,内容如下:
[{"id":"5","version":"5.5","name":"Clash of Clans"},
{"id":"6","version":"7.0","name":"Boom Beach"},
{"id":"7","version":"3.5","name":"Clash Royale"}]
在浏览器中验证 http://10.39.131.104/get_data.json 可以访问 (IP依据实际情况而定)
1、使用JSONObject
布局文件activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context=".MainActivity"> <Button
android:id="@+id/send_request"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Send Request"/> <ScrollView
android:layout_width="match_parent"
android:layout_height="match_parent"> <TextView
android:id="@+id/response_text"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
</ScrollView></LinearLayout>
主MainActivity
package com.example.networktest;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import org.json.JSONArray;
import org.json.JSONObject;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
import org.xml.sax.XMLReader;
import org.xmlpull.v1.XmlPullParser;
import org.xmlpull.v1.XmlPullParserException;
import org.xmlpull.v1.XmlPullParserFactory;
import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.StringReader;
import java.net.URL;
import javax.net.ssl.HttpsURLConnection;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.parsers.SAXParserFactory;
import okhttp3.FormBody;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.RequestBody;
import okhttp3.Response;
public class MainActivity extends AppCompatActivity {
TextView responseText;
Response response;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final Button sendRequest = (Button) findViewById(R.id.send_request);
responseText = (TextView) findViewById(R.id.response_text);
sendRequest.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
sendRequestWithOkHttp();
}
});
}
private void sendRequestWithOkHttp(){
new Thread(new Runnable() {
@Override
public void run() {
try {
OkHttpClient client = new OkHttpClient();
Request request = new Request.Builder()
.url("http://10.39.131.104/get_data.json")
.build();
response = client.newCall(request).execute();
String responseData = response.body().string();
Log.d("MainActivity", "--responseData--"+responseData);
// parseXMLWithPull(responseData);
// parseXMLWithSAX(responseData);
parseJSONWithJSONObject(responseData);
} catch (IOException e) {
e.printStackTrace();
}
}
}).start();
}
private void parseJSONWithJSONObject(String jsonData){
try {
JSONArray jsonArray = new JSONArray(jsonData);
for (int i = 0 ; i < jsonArray.length(); i++){
JSONObject jsonObject = jsonArray.getJSONObject(i);
String id = jsonObject.getString("id");
String version = jsonObject.getString("version");
String name = jsonObject.getString("name");
Log.d("MainActivity", "id is :"+id);
Log.d("MainActivity", "version is :"+version);
Log.d("MainActivity", "name is :"+name);
}
}catch (Exception e){
e.printStackTrace();
}
}
}
运行效果(点击button)
2、使用GSON
在build.gradle中添加包依赖
dependencies {
......
compile 'com.google.code.gson:gson:2.7'
}
GSON库主要是可以将一段JSON格式字符串自动映射成一个对象,从而不需要我们手动去编写代码去解析。
新建解析类App
package com.example.networktest;
public class App {
private String id;
private String name;
private String version;
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getVersion() {
return version;
}
public void setVersion(String version) {
this.version = version;
}
}
在MainActiity中修改
public class MainActivity extends AppCompatActivity {
......
private void sendRequestWithOkHttp(){
new Thread(new Runnable() {
@Override
public void run() {
try {
OkHttpClient client = new OkHttpClient();
Request request = new Request.Builder()
.url("http://192.168.31.108/get_data.json")
.build();
response = client.newCall(request).execute();
String responseData = response.body().string();
Log.d("MainActivity", "--responseData--"+responseData);
// parseXMLWithPull(responseData);
// parseXMLWithSAX(responseData);
// parseJSONWithJSONObject(responseData);
parseJSONWithGSON(responseData);
} catch (IOException e) {
e.printStackTrace();
}
}
}).start();
}
private void parseJSONWithGSON(String jsonData){
Gson gson = new Gson();
List<App> appList = gson.fromJson(jsonData, new TypeToken<List<App>>()
{}.getType());
for (App app: appList){
Log.d("MainActivity", "id is :"+app.getId());
Log.d("MainActivity", "name is :"+app.getName());
Log.d("MainActivity", "version is :"+app.getVersion());
}
}
}
运行效果