android: 用okhttp通信

一，安装第三方库:

1,库地址:

https://mvnrepository.com/artifact/com.squareup.okhttp3/okhttp

2,安装

在build.gradle的dependencies中增加一行:

implementation 'com.squareup.okhttp3:okhttp:4.12.0'

如下:

dependencies {

    implementation libs.appcompat
    implementation libs.material
    implementation libs.activity
    implementation libs.constraintlayout
    testImplementation libs.junit
    androidTestImplementation libs.ext.junit
    androidTestImplementation libs.espresso.core
    implementation 'com.squareup.okhttp3:okhttp:4.12.0'
}

然后点击 sync now

二，配置权限:

在AndroidManifest.xml中添加权限:

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

否则会报以下错误:

java.lang.SecurityException: Permission denied (missing INTERNET permission?)

三，代码：

package com.example.okdemo1;

import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;

import androidx.activity.EdgeToEdge;
import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.graphics.Insets;
import androidx.core.view.ViewCompat;
import androidx.core.view.WindowInsetsCompat;

import java.io.IOException;

import okhttp3.Call;
import okhttp3.Callback;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        EdgeToEdge.enable(this);
        setContentView(R.layout.activity_main);
        ViewCompat.setOnApplyWindowInsetsListener(findViewById(R.id.main), (v, insets) -> {
            Insets systemBars = insets.getInsets(WindowInsetsCompat.Type.systemBars());
            v.setPadding(systemBars.left, systemBars.top, systemBars.right, systemBars.bottom);
            return insets;
        });
        //给按钮增加点击事件
        Button myButton = findViewById(R.id.apibutton);
        myButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                // 处理点击事件
                doGetData();
             }
        });
    }

    //以get方式访问互联网上的页面，并返回数据
    private void doGetData() {
        Toast.makeText(MainActivity.this, "按钮被点击了！", Toast.LENGTH_LONG).show();
        //1.创建HttpClient对象
        OkHttpClient okHttpClient = new OkHttpClient();
        //2.获取request对象
        Request.Builder builder = new Request.Builder().url("https://www.bilibili.com/");
        Request request = builder.build();
        //3.异步请求发起
        okHttpClient.newCall(request).enqueue(new Callback() {
            @Override
            public void onFailure(@NonNull Call call, @NonNull IOException e) {

            }

            @Override
            public void onResponse(@NonNull Call call, @NonNull Response response) throws IOException {
                try {
                    String result = response.body().string();
                    //如果需要更新主线程的 UI 如果使用 rxjava 以及 retrofit 就不用这样处理了
                    System.out.println("网络请求返回结果:");
                    System.out.println(result);
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
        });
    }
}

 

四，测试效果:

界面:

执行结果: