在xml文件夹下建network_security_config.xml 文件，network_security_config.xml文件里的代码如下

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

在AndroidManifest.xml 种引用 network_security_config.xml文件

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

    <uses-permission android:name="android.permission.INTERNET"></uses-permission>
       <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:networkSecurityConfig="@xml/network_security_config"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
          <intent-filter>
             <action android:name="android.intent.action.MAIN" />

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

   </manifest>