android9.0适配http请求

在将API升级到28的时候http请求就报错

java.net.UnknownServiceException: CLEARTEXT communication ** not permitted by network security policy

google在android P中强制使用https的请求，就跟IOS10一样，解决办法如下

//.在res中的xml目录下新建`network_security_config.xml`文件
<?xml version="1.0" encoding="utf-8"?>
<network-security-config>
    <base-config cleartextTrafficPermitted="true" />
</network-security-config>

然后在manifest中添加，就可以了

        android:networkSecurityConfig="@xml/network_security_config"