Android 设置ipv4优先（强制ipv4）策略访问网络

在ipv6环境下可能会出现网络无法加载的情况，我们可以考虑使用ipv4优先的方案设置dns以加快网络加载速度。

1. 设置okhttp优先使用ipv4

/**
 * wifi环境下优先使用ipv4
 */
public class MyDns implements Dns {
    @Override
    public List lookup(String hostname) throws UnknownHostException{
        if (hostname == null){
            throw new UnknownHostException ("hostname == null") ;
        }else{
            try{
                List inetAddressList = new ArrayList<>();
                InetAddress[] inetAddresses = InetAddress.getAllByName (hostname) ;
                for (InetAddress inetAddress: inetAddresses){
                    if (inetAddress instanceof Inet4Address){
                        inetAddressList.add(0, inetAddress) ;
                    }else{
                        inetAddressList.add(inetAddress);
                    }
                }
                return inetAddressList;
            }catch (NullPointerException var4){
                UnknownHostException unknownHostException = new UnknownHostException("Broken system behavior");
                unknownHostException.initCause(var4);
                throw unknownHostException;
            }
        }
    }
}

OkHttpClient.Builder builder = new OkHttpClient.Builder();
builder.dns(new MyDns());
OkHttpClient client = builder.build();

2. 设置图片框架Glide优先ipv4

• 引入

    implementation 'com.github.bumptech.glide:glide:4.11.0'
    annotationProcessor 'com.github.bumptech.glide:compiler:4.11.0'
    implementation "com.github.bumptech.glide:okhttp3-integration:4.11.0"

• 自定义类继承AppGlideModule,添加类注解@GlideModule

@GlideModule
public class OkHttpGlideModule extends AppGlideModule {

    @Override
    public boolean isManifestParsingEnabled() {
        return false;
    }

    @Override
    public void registerComponents(@NonNull Context context, @NonNull Glide glide, @NonNull Registry registry) {
        super.registerComponents(context, glide, registry);

        OkHttpClient.Builder builder = new OkHttpClient.Builder();
        builder.dns(new MyDns());
        builder.followRedirects(true);
        // 设置连接超时
        builder.connectTimeout(10, TimeUnit.SECONDS);
        // 设置socket超时
        builder.readTimeout(60, TimeUnit.SECONDS);
        builder.writeTimeout(60, TimeUnit.SECONDS);
        OkHttpClient okHttpClient = builder.build();
        registry.replace(GlideUrl.class, InputStream.class, new OkHttpUrlLoader.Factory(okHttpClient));
    }
}

• 在AndroidManifest.xml中中添加项，如：

• 混淆

-keep public class * implements com.bumptech.glide.module.GlideModule
-keep public class * extends com.bumptech.glide.module.AppGlideModule
-keep public enum com.bumptech.glide.load.ImageHeaderParser$**{
  **[] $VALUES;
  public *;
}
-keep class com.bumptech.glide.GeneratedAppGlideModuleImpl {*;}