Java-----URL网络编程

1.URL：统一资源定位符，对应着互联网的某一资源地址
2.格式：
http://localhost:8080/examples/beauty.jpg?username = Tom
协议 主机名    端口号      资源地址                    参数列表

    public static void main(String[] args){

        try {
            URL url = new URL("http://localhost:8080/examples/beauty.jpg?username = Tom");

//            public String getProtocol( ) 获取该URL的协议名
            System.out.println(url.getProtocol());

//            public String getHost( ) 获取该URL的主机名
            System.out.println(url.getHost());

//            public String getPort( ) 获取该URL的端口号
            System.out.println(url.getPort());

//            public String getPath( ) 获取该URL的文件路径
            System.out.println(url.getPath());

//            public String getFile( ) 获取该URL的文件名
            System.out.println(url.getFile());

//            public String getQuery( ) 获取该URL的查询名
            System.out.println(url.getQuery());


        } catch (MalformedURLException e) {
            e.printStackTrace();
        }

    }

    public static void main(String[] args) {

        HttpURLConnection urlConnection = null;
        InputStream is = null;
        FileOutputStream fos = null;
        try {
            URL url = new URL("http://localhost:8080/examples/beauty.jpg");

            urlConnection = (HttpURLConnection) url.openConnection();

            urlConnection.connect();

            is = urlConnection.getInputStream();

            fos = new FileOutputStream("day10\\图片3.jpg");

            byte[] buffer = new byte[1024];
            int len;
            while((len = is.read(buffer)) != -1){
                fos.write(buffer,0,len);
            }

            System.out.println("下载成功");

        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            //关闭资源
            if(is != null){
                try {
                    is.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if(fos != null){
                try {
                    fos.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if(urlConnection != null){
                urlConnection.disconnect();
            }
        }

    }