Android通过HttpURLConnection访问Http协议网络

Android原生目前支持两种方式访问http协议的网络&＃xff0c;第一种是HttpURLConnection,另外一种是oKHttp,下面来介绍一下用HttpURLConnection来访问访问http协议的方法

在AndroidManifest.xml文件中添加如下权限

http请求需要在 AndroidManifest.xml文件的application节点添加如下属性

android:usesCleartextTraffic&＃61;"true"

第二步&＃xff1a;使用HttpURLConnection访问网络

首先我们需要得到HttpURLConnection的实例&＃xff0c;获取HttpURLConnection的方法如下

URL url &＃61; new URL("http://baidu.com");
HttpURLConnection urlConnection &＃61; (HttpURLConnection) url.openConnection();


拿到HttpURLConnection的实例以后我们可以通过HttpURLConnection的实例来设置一些http请求的方式

urlConnection.setRequestMethod("GET");
urlConnection.setConnectTimeout(8000);
urlConnection.setRequestProperty("key","value");


请求发送出去以后&＃xff0c;我们就可以通过HttpURLConnection的实例拿到请求的返回数据

InputStream inputStream &＃61; urlConnection.getInputStream();// 字节流
Reader reader &＃61; new InputStreamReader(inputStream);//字符流BufferedReader bufferedReader &＃61; new BufferedReader(reader);// 缓存流


然后我们就可以从缓存流bufferedReader中读取数据

StringBuilder result &＃61; new StringBuilder();;String temp;while ((temp &＃61; bufferedReader.readLine()) !&＃61; null) {result.append(temp);}Log.i("MainActivity", result.toString());


读完数据以后不要忘记把数据流关闭哦

if (reader!&＃61;null){try {reader.close();} catch (IOException e) {e.printStackTrace();}}if (inputStream!&＃61;null){try {inputStream.close();} catch (IOException e) {e.printStackTrace();}}if (bufferedReader!&＃61;null){try {bufferedReader.close();} catch (IOException e) {e.printStackTrace();}}if (urlConnection !&＃61; null){urlConnection.disconnect();}


网络请求访问我们还需要放到子线程中去

new Thread(){&＃64;Overridepublic void run() {super.run();getNetwork();}}.start();


把得到的数据切到主线程中用文本展示出来

runOnUiThread(new Runnable() {&＃64;Overridepublic void run() {mTextView.setText(result);}});

代码示例

完整代码如下

MainActivity.java

package com.lucashu.http;import androidx.appcompat.app.AppCompatActivity;import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.net.HttpURLConnection;
import java.net.URL;public class MainActivity extends AppCompatActivity {TextView mTextView;&＃64;Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);Button button &＃61; findViewById(R.id.button);mTextView &＃61; findViewById(R.id.textView);button.setOnClickListener(new View.OnClickListener() {&＃64;Overridepublic void onClick(View v) {new Thread(){&＃64;Overridepublic void run() {super.run();getNetwork();}}.start();}});}private void getNetwork() {InputStream inputStream &＃61; null;Reader reader &＃61; null;BufferedReader bufferedReader &＃61; null;HttpURLConnection urlConnection &＃61; null;try {URL url &＃61; new URL("http://baidu.com");urlConnection &＃61; (HttpURLConnection) url.openConnection();urlConnection.setRequestMethod("GET");urlConnection.setConnectTimeout(8000);urlConnection.setRequestProperty("key","value");inputStream &＃61; urlConnection.getInputStream();// 字节流reader &＃61; new InputStreamReader(inputStream);//字符流bufferedReader &＃61; new BufferedReader(reader);// 缓存流final StringBuilder result &＃61; new StringBuilder();;String temp;while ((temp &＃61; bufferedReader.readLine()) !&＃61; null) {result.append(temp);}Log.i("MainActivity", result.toString());runOnUiThread(new Runnable() {&＃64;Overridepublic void run() {mTextView.setText(result);}});inputStream.close();reader.close();bufferedReader.close();} catch (Exception e) {Log.i("MainActivity", e.getMessage());e.printStackTrace();}finally {if (reader!&＃61;null){try {reader.close();} catch (IOException e) {e.printStackTrace();}}if (inputStream!&＃61;null){try {inputStream.close();} catch (IOException e) {e.printStackTrace();}}if (bufferedReader!&＃61;null){try {bufferedReader.close();} catch (IOException e) {e.printStackTrace();}}if (urlConnection !&＃61; null){urlConnection.disconnect();}}}
}

AndroidManifest.xml

<?xml version&＃61;"1.0" encoding&＃61;"utf-8"?>
<manifest xmlns:android&＃61;"http://schemas.android.com/apk/res/android"package&＃61;"com.lucashu.http"><uses-permission android:name&＃61;"android.permission.INTERNET" /><uses-permission android:name&＃61;"android.permission.ACCESS_NETWORK_STATE" /><applicationandroid:allowBackup&＃61;"true"android:icon&＃61;"&＃64;mipmap/ic_launcher"android:label&＃61;"&＃64;string/app_name"android:roundIcon&＃61;"&＃64;mipmap/ic_launcher_round"android:supportsRtl&＃61;"true"android:theme&＃61;"&＃64;style/AppTheme"android:usesCleartextTraffic&＃61;"true"><activity android:name&＃61;".MainActivity"><intent-filter><action android:name&＃61;"android.intent.action.MAIN" /><category android:name&＃61;"android.intent.category.LAUNCHER" /></intent-filter></activity></application></manifest>


activity_main.xml

<?xml version&＃61;"1.0" encoding&＃61;"utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android&＃61;"http://schemas.android.com/apk/res/android"xmlns:app&＃61;"http://schemas.android.com/apk/res-auto"xmlns:tools&＃61;"http://schemas.android.com/tools"android:layout_width&＃61;"match_parent"android:layout_height&＃61;"match_parent"tools:context&＃61;".MainActivity"><TextViewandroid:id&＃61;"&＃64;&＃43;id/textView"android:layout_width&＃61;"wrap_content"android:layout_height&＃61;"wrap_content"android:text&＃61;"Hello World!"app:layout_constraintBottom_toBottomOf&＃61;"parent"app:layout_constraintLeft_toLeftOf&＃61;"parent"app:layout_constraintRight_toRightOf&＃61;"parent"app:layout_constraintTop_toTopOf&＃61;"parent"app:layout_constraintVertical_bias&＃61;"0.323" /><Buttonandroid:id&＃61;"&＃64;&＃43;id/button"android:layout_width&＃61;"wrap_content"android:layout_height&＃61;"wrap_content"android:layout_marginTop&＃61;"96dp"android:text&＃61;"访问网络数据"app:layout_constraintEnd_toEndOf&＃61;"parent"app:layout_constraintStart_toStartOf&＃61;"parent"app:layout_constraintTop_toTopOf&＃61;"parent" /></androidx.constraintlayout.widget.ConstraintLayout>