同样的是两个项目

1.下载文件

　　图片：

　　

 

 

2.异步下载程序

package com.jun.web.okhttp;

import okhttp3.*;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;

public class DownAsynFile {

    public static void main(String[] args) {
        downAsynFile();
    }
    private static void downAsynFile() {
        OkHttpClient okHttpClient= new OkHttpClient();
        String url = "http://localhost:8080/96.png";
        Request request = new Request.Builder().url(url).build();
        okHttpClient.newCall(request).enqueue(new Callback() {
            @Override
            public void onFailure(Call call, IOException e) {
            }
            @Override
            public void onResponse(Call call, Response response) {
                InputStream inputStream = response.body().byteStream();
                FileOutputStream fileOutputStream = null;
                try {
                    fileOutputStream = new FileOutputStream(new File("E:/javafile/test/123.png"));
                    byte[] buffer = new byte[2048];
                    int len = 0;
                    while ((len = inputStream.read(buffer)) != -1) {
                        fileOutputStream.write(buffer, 0, len);
                    }
                    fileOutputStream.flush();
                } catch (IOException e) {
                    e.printStackTrace();
                }
                System.out.println("===");
            }
        });
    }

}