【Android】OKHttp3發起異步GET和POST請求

一、添加依賴

通過AndroidStudio搜索添加okhttp3，也可以手動添加

implementation 'com.squareup.okhttp3:okhttp:4.2.2'

二、layout佈局

就放了兩個button

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:gravity="center"
    android:orientation="vertical"
    tools:context=".MainActivity">

    <Button
        android:id="@+id/btn_get"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="GET"/>
    <Button
        android:id="@+id/btn_post"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="POST"/>

</LinearLayout>

三、MainActivity代碼

public class MainActivity extends AppCompatActivity implements View.OnClickListener {
    private Button btn_get,btn_post;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        btn_get = findViewById(R.id.btn_get);
        btn_get.setOnClickListener(this);
        btn_post = findViewById(R.id.btn_post);
        btn_post.setOnClickListener(this);
    }

    @Override
    public void onClick(View view) {
        switch (view.getId()){
            case R.id.btn_get:
                request_get();//發起GET請求
                break;
            case R.id.btn_post:
                request_post();//發起POST請求
                break;
             default:
                 break;
        }
    }

四、異步GET

private void request_get(){
        OkHttpClient client = new OkHttpClient();
        Request request = new Request.Builder()
                .url("https://www.baidu.com")
                //.addHeader("User-Agent","xxx")//設置請求頭
                .build();
        Call call = client.newCall(request);
        call.enqueue(new Callback() {
            //請求失敗時調用
            @Override
            public void onFailure(@NotNull Call call, @NotNull IOException e) {
                if (e instanceof SocketTimeoutException){
                    Log.e("OkHttp請求超時異常", "onFailure: "+e.toString());
                }
                if (e instanceof ConnectException){
                    Log.e("OkHttp請求連接異常", "onFailure: "+e.toString());
                }
            }
            //請求成功時調用
            @Override
            public void onResponse(@NotNull Call call, @NotNull Response response) throws IOException {
                String res = response.body().string();//返回字符串
                //InputStream inputStream = response.body().byteStream();//返回流，比如說用於下載圖片等文件
                Log.e("OkHttp GET請求成功", "onFailure: "+res);
            }
        });
    }

五、異步POST

private void request_post(){
        OkHttpClient client = new OkHttpClient();
        RequestBody requestBody = new FormBody.Builder()//創建一個請求體
                .add("name","name")
                .add("password","123456")
                .build();
        Request request = new Request.Builder()
                .url("https://www.baidu.com")
                .post(requestBody) //添加請求體
                .build();
        Call call = client.newCall(request);
        call.enqueue(new Callback() {
            @Override
            public void onFailure(@NotNull Call call, @NotNull IOException e) {
            }

            @Override
            public void onResponse(@NotNull Call call, @NotNull Response response) throws IOException {
                String res = response.body().string();
                Log.e("OkHttp POST請求成功", "onFailure: "+res);
            }
        });
    }

六、添加網絡權限

在Androidmanifest中使用權限

<uses-permission android:name="android.permission.INTERNET"/>

若是Android 9或以上，還需要在application標籤中加入

android:usesCleartextTraffic="true"