------------------------

-----------------------

-----------------------

•  针对HTTP协议的URLConnection类

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;

/*URL:统一资源定位符
可以通过URL对象调用其他相应的方法，将此资源读取*/
public class TestURL {
	
	public static void main(String[] args) {
		/*创建一个URL的对象*/
		URL url;
		try {
			url = new URL("http://127.0.0.1:8080/examples/hello.txt");
			InputStream is=null;
			try {
				is = url.openStream();
				byte[] b=new byte[1024];
				int len;
				while((len=is.read(b))!=-1) {
					System.out.println(new String(b,0,len));
				}
				
				URLConnection urlConnection = url.openConnection();
				InputStream is1=null;
				FileOutputStream fos = null;
				try {
					is1 = urlConnection.getInputStream();
					fos = new FileOutputStream("url.txt");
					while((len=is1.read(b))!=-1) {
						fos.write(b,0,len);
					}
				} catch (Exception e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}finally {
					if(fos!=null) {
						fos.close();
					}
					if(is1!=null) {
						is1.close();
					}
				}
				
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}finally {
				if(is!=null) {
					try {
						is.close();
					} catch (IOException e) {
						// TODO Auto-generated catch block
						e.printStackTrace();
					}
				}
			}
			System.out.println(url.getProtocol());
			System.out.println(url.getHost());
			System.out.println(url.getPort());
			System.out.println(url.getFile());
			System.out.println(url.getRef());
			System.out.println(url.getQuery());
		} catch (MalformedURLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
	
}