OkHttp是 HTTP 框架，它支持get 请求和post请求
MainActivity.java端代码：
public class MainActivity extends AppCompatActivity implements View.OnClickListener {
TextView responseText;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button sendRequest=findViewById(R.id.send_request);
responseText=findViewById(R.id.response_text);
sendRequest.setOnClickListener(this);
}
@Override
public void onClick(View v) {
if (v.getId()==R.id.send_request){
sendRequestWithOkHttp();
}
}
//同步请求
private void sendRequestWithOkHttp() {
new Thread(new Runnable() {
@Override
public void run() {
try {
//GET 请求,构造Request对象，用过前两步中的对象构建Call对象，最后通过 execute() 来提交请求
OkHttpClient client=new OkHttpClient();
//Request是OkHttp中访问的请求，Buider是辅助类，Response即 OKHttp中的响应
String url="http://www.lnfvc.edu.cn/newweb/index.asp";
Request request=new Request.Builder().url(url).build();
Response response=client.newCall(request).execute();
String s=response.body().string();
response.body(); //不可执行多次io 读取完流关闭
System.out.println(s);
//POST 请求 ，与GET相比，就是在构造Request 对象时 ，需要多构造一个RequestBody 对象，
// 用它来携带我们要提交的数据。在构造RequestBody 需要指定MediaType,用于描述请求/响应body的内容类型
OkHttpClient client =new OkHttpClient();
String url="http://www.lnfvc.edu.cn/newweb/index.asp";
String s="{\"name\":\"Http权威指南\"}";
//设置请求体Media Type 指定媒体类型
RequestBody body=RequestBody.create(MediaType.parse("application/s;charset=utf-8"),s);
Request request=new Request.Builder()
.url(url)
.post(body) //等同 method（"POST",body）请求方法需要全部大写
.build();
Response response=null;
response=client.newCall(request).execute();
String x=response.body().string();
System.out.println(x);
//异步处理 GET请求
OkHttpClient client=new OkHttpClient();
String url="http://www.lnfvc.edu.cn/newweb/index.asp";
Request request=new Request.Builder().url(url).build();
client.newCall(request).enqueue(new Callback() {
@Override
public void onFailure(Call call, IOException e) {
System.out.println(e);
}
@Override
public void onResponse(Call call, Response response) throws IOException {
String x=response.body().string();
System.out.println(x);
}
});
//POST请求
OkHttpClient client=new OkHttpClient();
String url="http://www.lnfvc.edu.cn/newweb/index.asp";
String s="{\"name\":\"JAVA 核心思想\"}";
RequestBody requestBody=RequestBody.create(MediaType.parse("applicaton/s;charset-uft-8"),s);
Request request=new Request.Builder().method("POST",requestBody).url(url).build();
client.newCall(request).enqueue(new Callback() {
@Override
public void onFailure(Call call, IOException e) {
System.out.println(e);
}
@Override
public void onResponse(Call call, Response response) throws IOException {
String s=response.body().string();
System.out.println(s);
}
});
} catch (Exception e) {
e.printStackTrace();
}
}
}).start();
}
}
<uses-permission android:name="android.permission.INTERNET"></uses-permission>
activity_main.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.lnjr.okhttp.MainActivity"
android:orientation="vertical">
<!--发送HTTP请求-->
<Button
android:id="@+id/send_request"
android:text="send request"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
<!--以滚动的形式查看屏幕外的内容-->
<ScrollView
android:layout_width="match_parent"
android:layout_height="match_parent">
</ScrollView>
<!--将服务器返回的数据显示出来-->
<TextView
android:id="@+id/response_text"
android:layout_width="match_parent"
android:layout_height="wrap_content"
/>
</LinearLayout>
