我正在Ubuntu 12.04上工作。这是我使用URLConnection实现HTTP GET方法的简单代码。
import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import javax.net.ssl.HttpsURLConnection;
public class HttpURLConnectionExample {
private final String USER_AGENT = "Mozilla/5.0";
public static void main(String[] args) throws Exception {
HttpURLConnectionExample http = new HttpURLConnectionExample();
System.out.println("Testing 1 - Send Http GET request");
http.sendGet();
}
// HTTP GET request
private void sendGet() throws Exception {
String url = "https://www.google.com/search?q=flower";
URL obj = new URL(url);
HttpURLConnection con = (HttpURLConnection) obj.openConnection();
// optional default is GET
con.setRequestMethod("GET");
//add request header
con.setRequestProperty("User-Agent", USER_AGENT);
int responseCode = con.getResponseCode();
System.out.println("nSending 'GET' request to URL : " + url);
System.out.println("Response Code : " + responseCode);
BufferedReader in = new BufferedReader(
new InputStreamReader(con.getInputStream()));
String inputLine;
StringBuffer response = new StringBuffer();
while ((inputLine = in.readLine()) != null) {
response.append(inputLine);
}
in.close();
//print result
System.out.println(response.toString());
}
}
但是当我从ubuntu终端编译并运行这段代码时,这段代码的输出并没有给出URL指定的页面的内容。相反,它给出以下输出
Testing 1 - Send Http GET request
Sending 'GET' request to URL : http://www.google.com/search?q=flower
Response Code : 307
<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN"><html><head><title>307 Temporary Redirect</title></head><body><h1>Temporary Redirect</h1><p>The document has moved <a href="https://ifwb.iitb.ac.in/index.php?add=www.google.com/search">here</a>.</p><hr><address>Apache/2.2.22 (Fedora) Server at www.google.com Port 80</address></body></html>
这个问题适用于我在代码中指定的任何URL。此外,我尝试使用telnet客户端访问web内容,如
telnet www.google.comGET/
,它不仅对www.google.com,而且对每个URL都给出了类似的结果。我是印度理工学院孟买分校的一名学生,也许这与https://ifwb.iitb.ac.in有关。我也想坚持java.net,而不是apache httpclient。所以,帮帮我吧
由于请求不完整,您似乎被服务器拒绝了。使用任何嗅探器,如Fiddler或Wireshark来"以身作则"是一个好主意:比较您的请求和来自特定软件(如浏览器)的请求。
下面是一个摘自Wireshark dump的摘录,IE10如何发送GET请求到感兴趣的URL。正如您所看到的,有各种字段描述了客户端的功能和期望,因此被查询的服务器可以以最合适和可使用的形式返回答案。参考Google/RFC查看传入的每个参数的含义:
/搜索吗?q =花HTTP/1.1
接受:text/html, application/xhtml+xml, /
接收语言:en - us
User-Agent: Mozilla/5.0 (compatible;MSIE 10.0;Windows NT 6.1;WOW64;三叉戟/6.0)
Accept-Encoding: gzip, deflate
主持人:www.google.com
DNT: 1
连接:维生
Cookie:[一些私人信息在这里]