import java.net.URL;
import java.net.URLConnection;
import java.io.InputStreamReader;
import java.io.BufferedReader;
import java.net.HttpURLConnection;
/**
客户端仅仅是获取服务端的信息
*/
public class HttpClient{
private String urlString;
public static void main(String[] args) throws Exception{
if(args.length!=1){
System.out.println("控制台参数错误！");
//终止当前运行的Java虚拟机。
System.exit(1);
}
HttpClient client = new HttpClient(args[0]);
client.run();
}
public HttpClient(String url){
this.urlString = url;
}
private void run() throws Exception{
URL url = new URL(this.urlString);
URLConnection conn = url.openConnection();
if(conn instanceof HttpURLConnection){
HttpURLConnection httpConn = (HttpURLConnection)conn;
String key;
String value;
System.out.println("The Headers");
System.out.println("=========================================");
for(int i=1;;i++){
if((key=httpConn.getHeaderFieldKey(i))==null){
break;
}
if((value=httpConn.getHeaderField(i))==null){
break;
}
System.out.println("key["+key+"]");
System.out.println("value["+value+"]");
}
BufferedReader reader = new BufferedReader(new InputStreamReader(httpConn.getInputStream()));
String line;
System.out.println("Content");
System.out.println("=========================================");
while((line=reader.readLine())!=null){
System.out.println(line);
}
}
}
}
执行结果：
G:\maul keyboard\network programming>java HttpClient http://www.google.cn
The Headers
=========================================
key[Accept-Ranges]
value[none]
key[Vary]
value[Accept-Encoding]
key[Content-Type]
value[text/html]
key[Date]
value[Sat, 10 Nov 2018 10:56:42 GMT]
key[Expires]
value[Sat, 10 Nov 2018 10:56:42 GMT]
key[Cache-Control]
value[private, max-age=0]
key[Last-Modified]
value[Thu, 08 Dec 2016 01:00:57 GMT]
key[X-Content-Type-Options]
value[nosniff]
key[Server]
value[sffe]
key[X-XSS-Protection]
value[1; mode=block]
key[Transfer-Encoding]
value[chunked]
Content
=========================================
<!DOCTYPE html>
<html lang="zh">
<meta charset="utf-8">
<title>Google</title>
<style>
html { background: #fff; margin: 0 1em; }
body { font: .8125em/1.5 arial, sans-serif; text-align: center; }
h1 { font-size: 1.5em; font-weight: normal; margin: 1em 0 0; }
p#footer { color: #767676; font-size: .77em; }
p#footer a { background: url(//www.google.cn/intl/zh-CN_cn/images/cn_icp.gif) top right no-repeat; padding: 5px 20px 5px 0; }
...
