多线程IO下载图片

小Demo

环境工具:
ideal
maven
jdk1.8
行了,啥也不要了

pom.xml添加依赖(砍树要斧头,下载要IO):

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.it</groupId>
    <artifactId>demo</artifactId>
    <version>1.0-SNAPSHOT</version>

	<!--下载工具-->
    <dependencies>
        <dependency>
            <groupId>commons-io</groupId>
            <artifactId>commons-io</artifactId>
            <version>2.4</version>
        </dependency>
    </dependencies>

</project>

1.创建一个类,继承Thread,重写run方法

package com.it;

import org.apache.commons.io.FileUtils;

import java.io.File;
import java.io.IOException;
import java.net.URL;

/**
 * 多线程下载图片
 */
public class DownloadPicture extends Thread {
     
    @Override
    public void run() {
     

	}
}

2.成员属性

public class DownloadPicture extends Thread {
     
    private  String url;
    private  String name;

    public DownloadPicture(String url, String name){
     
        this.url = url;
        this.name = name;
    }

}

3.下载工具
第一个参数:要下载的图片地址,第二个参数:下载的图片的名称

package com.it;

import org.apache.commons.io.FileUtils;

import java.io.File;
import java.io.IOException;
import java.net.URL;

/**
 * 多线程下载图片
 */
public class DownloadPicture extends Thread {
     
    private  String url;
    private  String name;

    public DownloadPicture(String url, String name){
     
        this.url = url;
        this.name = name;
    }

    class WebDownloader{
     
            //下载工具
            public void downloader(String url,String name){
     
                try {
     
                    FileUtils.copyURLToFile(new URL(url),new File(name));
                } catch (IOException e) {
     
                    System.out.println("IO异常");
                }
            }
    }
}

4.run方法调用下载工具

package com.it;

import org.apache.commons.io.FileUtils;

import java.io.File;
import java.io.IOException;
import java.net.URL;

/**
 * 多线程下载图片
 */
public class DownloadPicture extends Thread {
     
    private  String url;
    private  String name;

    public DownloadPicture(String url, String name){
     
        this.url = url;
        this.name = name;
    }

    @Override
    public void run() {
     
        WebDownloader webDownloader = new WebDownloader();
        webDownloader.downloader(url,name);
        System.out.println("下载图片,名为:" + name);
    }

    class WebDownloader{
     
            //下载工具
            public void downloader(String url,String name){
     
                try {
     
                    FileUtils.copyURLToFile(new URL(url),new File(name));
                } catch (IOException e) {
     
                    System.out.println("IO异常");
                }
            }
    }
}

5.启动三个线程下载三张图片

package com.it;

import org.apache.commons.io.FileUtils;

import java.io.File;
import java.io.IOException;
import java.net.URL;

/**
 * 多线程下载图片
 */
public class DownloadPicture extends Thread {
     
    private  String url;
    private  String name;

    public DownloadPicture(String url, String name){
     
        this.url = url;
        this.name = name;
    }

    @Override
    public void run() {
     
        WebDownloader webDownloader = new WebDownloader();
        webDownloader.downloader(url,name);
        System.out.println("下载图片,名为:" + name);
    }

    public static void main(String[] args) {
     
        DownloadPicture d1 = new DownloadPicture("http://test-pics.56tj.cn/FmvUmrKZHZBv-4ud15UT863l6-1F","图片1.jpg");
        DownloadPicture d2 = new DownloadPicture("http://test-pics.56tj.cn/FqO9C64EvfgiLr_jmtf2uPknrO6C","图片2.jpg");
        DownloadPicture d3 = new DownloadPicture("http://test-pics.56tj.cn/FqQAhFRpM6H_mqbfWw1WKpFU0GnG","图片3.jpg");
        d1.start();
        d2.start();
        d3.start();
    }

    class WebDownloader{
     
            //下载工具
            public void downloader(String url,String name){
     
                try {
     
                    FileUtils.copyURLToFile(new URL(url),new File(name));
                } catch (IOException e) {
     
                    System.out.println("IO异常");
                }
            }
    }
}

结果
第一次执行:

第二次执行:

图片存储在项目下