完成一个get请求

1.导入依赖

   implementation("com.squareup.okhttp3:okhttp:3.14.+")

2.开启viewBinding

  android.buildFeatures.viewBinding = true

3.加网络权限 和 http明文请求允许配置文件

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools">

    <uses-permission android:name="android.permission.INTERNET"/>
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
    <application
        android:allowBackup="true"
        android:dataExtractionRules="@xml/data_extraction_rules"
        android:fullBackupContent="@xml/backup_rules"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.OkHttp"
        android:networkSecurityConfig="@xml/network_security_config"
        tools:targetApi="31">
        <activity
            android:name=".MainActivity"
            android:exported="true">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

<?xml version="1.0" encoding="utf-8"?>
<network-security-config>
    <base-config cleartextTrafficPermitted="true" />
</network-security-config>

4.布局文件

<?xml version="1.0" encoding="utf-8"?>
<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"
    android:orientation="vertical"
    tools:context=".MainActivity">


    <Button
        android:id="@+id/btn1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="请求"/>


    <TextView
        android:id="@+id/text"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"/>
</LinearLayout>

5.Activity

package com.tiger.okhttp;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.util.Log;
import android.view.View;

import com.tiger.okhttp.databinding.ActivityMainBinding;

import java.io.IOException;
import java.util.concurrent.TimeUnit;

import okhttp3.Call;
import okhttp3.Callback;
import okhttp3.FormBody;
import okhttp3.MediaType;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.RequestBody;
import okhttp3.Response;
import okhttp3.ResponseBody;

public class MainActivity extends AppCompatActivity {

    ActivityMainBinding binding;

    OkHttpClient okHttpClient;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        //使用ViewBinding
        super.onCreate(savedInstanceState);
        binding = ActivityMainBinding.inflate(getLayoutInflater());
        setContentView(binding.getRoot());

        okHttpClient = new OkHttpClient.Builder().connectTimeout(3, TimeUnit.SECONDS).build();

        binding.btn1.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                testGet();
            }
        });
    }

    private void testGet() {
        //请求方法
        //post表单数据写法

//        FormBody formBody = new FormBody.Builder()
//                .add("start", "0")
//                .add("count", "8")
//                .build();


        RequestBody requestBody = RequestBody.create(MediaType.parse("application/json;charset=utf-8"),"{\"start\":0,\"count\":8}");

        Request request = new Request.Builder()
                .url("http://192.168.202.55:8999/findPost?start=0&count=8")
                .post(requestBody)
                .build();

        //同步请求
//        new Thread(new Runnable() {
//            @Override
//            public void run() {
//                try {
//                    Response response = okHttpClient.newCall(request).execute();
//
//                    ResponseBody body = response.body();
//                    if (body != null) {
//                        String s = body.string();
//
//                        Log.d("ning", s);
//
//
//                        runOnUiThread(() -> {
//                            binding.text.setText(s);
//                        });
//
//                    }
//                } catch (IOException e) {
//                    throw new RuntimeException(e);
//                }
//            }
//        }).start();

        //异步请求
        okHttpClient.newCall(request).enqueue(new Callback() {
            @Override
            public void onFailure(Call call, IOException e) {
                //失败
            }

            @Override
            public void onResponse(Call call, Response response) throws IOException {
                //有相应的情况下

                ResponseBody body = response.body();
                if (body != null) {
                    String s = body.string();
                    Log.d("ning", s);
                    runOnUiThread(() -> {
                        binding.text.setText(s);
                    });

                }
            }
        });


    }


}