设计模式——单例模式（饿汉模式）

MyTask类

package com.example.okhttpdemo;

import android.os.Environment;

import java.io.File;

import java.io.IOException;

import java.util.concurrent.TimeUnit;

import okhttp3.Cache;

import okhttp3.CacheControl;

import okhttp3.Call;

import okhttp3.Callback;

import okhttp3.FormBody;

import okhttp3.OkHttpClient;

import okhttp3.Request;

import okhttp3.Response;

/**

* Created by leon on 2017/12/19.

*/

public class MyOkHttp {

private OkHttpClient ok;

private Cache cache;

private long maxSize = 8 * 1024 * 1024 ;

private static MyOkHttp okHttp = new MyOkHttp();

private MyOkHttp(){

//获取手机根目录并在根目录下建一个文件夹：

//Environment是用来管理手机SDCard内存的

File file = new File( Environment.getExternalStorageDirectory() + "/H1706A");

cache = new Cache( file,maxSize );

ok = new OkHttpClient.Builder().cache( cache ).build();

}

public static MyOkHttp getOkHttp(){

return okHttp;

}

//同步get请求：

public String sendGet(String url) throws IOException {

Request request = new Request.Builder().url( url ).build();

Response response = ok.newCall( request ).execute();

String string = response.body().string();

return string;

}

//同步post请求：

public String sendPost(String url, FormBody body) throws IOException {

Request request = new Request.Builder().url( url ).post( body ).build();

Response response = ok.newCall( request ).execute();

String s = response.body().string();

return s;

}

//异步get请求：

public void sendGetAnsy(String url,Callback callback) throws IOException {

Request request = new Request.Builder().url( url ).build();

ok.newCall( request ).enqueue( callback );;

}

//异步post请求：

public void sendPostAnsync(String url,FormBody body,Callback callback){

Request request = new Request.Builder().url( url ).post( body ).build();

ok.newCall( request ).enqueue( callback );

}

//测试缓存：

public String sendCacheGet(String url) throws IOException {

Request request = new Request.Builder().url( url ).cacheControl( new CacheControl.Builder().maxStale( 24*60*60, TimeUnit.DAYS ).build() ).build();

Response response = ok.newCall( request ).execute();

String s = response.body().string();

return s;

}

}