当我发送GET请求时，为什么会出现错误500？

Question

我试图发送一个简单的GET请求，因为它是在这里解释：Using java.net.URLConnection to fire and handle HTTP requests

我指向的网页是：https://e-campus.hei.fr/ERP-prod/

而且我得到这个错误HTTP500：

Exception in thread "main" java.io.IOException: Server returned HTTP response code: 500 for URL: https://e-campus.hei.fr/ERP-prod/ 
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1436) 
at sun.net.www.protocol.https.HttpsURLConnectionImpl.getInputStream(HttpsURLConnectionImpl.java:234) 
at GetWebPage.main(GetWebPage.java:14) 

为什么我收到此页错误？我写将返回我任何其他网页的源代码，该代码...

我的代码：

public class GetWebPage { 
public static void main(String args[]) throws MalformedURLException, 
     IOException { 
    URLConnection connection = new URL("https://e-campus.hei.fr/ERP-prod/").openConnection(); 
    connection.setRequestProperty("User-Agent", "Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2.3) Gecko/20100401"); 
    InputStream response = connection.getInputStream(); 

    InputStreamReader isr = new InputStreamReader(response); 
    BufferedReader reader = new BufferedReader(isr); 
    StringBuilder sb = new StringBuilder(); 
    String line = ""; 
    while ((line = reader.readLine()) != null) { 
     sb.append(line + "\n"); 
    } 
    System.out.println(sb.toString()); 

} 

}

Answer 1

错误500表示在服务器端错误。这通常是由服务器上的脚本生成无效响应标头（通常由脚本生成异常导致的）造成的。您的IOException是因为您的代码未设置为处理这些错误代码。

Answer 2

该错误意味着'内部服务器错误'。我认为这可能是由于对SSL主机进行常规请求造成的（请参阅url中的httpS前缀）。您可能未发送有效的HTTPS请求，并且服务器通过引发未处理的错误来处理此错误。

Answer 3

标准java.net.URL类不支持HTTPS协议。 您必须设置系统属性并将新的安全提供程序添加到Security类对象。有多种方法可以做到这两个东西，但试试这个：

System.setProperty("java.protocol.handler.pkgs", 
     "com.sun.net.ssl.internal.www.protocol"); 
    Security.addProvider(new com.sun.net.ssl.internal.ssl.Provider()); 

追加端口号，如果从443

URL url = new URL("https://[your server]:7002"); 

    URLConnection con = URL.openConnection(); 
    //SSLException thrown here if server certificate is invalid 
    con.getInputStream(); 

你必须赶上异常SSLException如果证书不被信任

不同。 ..

最终代码如下所示：

System.setProperty("java.protocol.handler.pkgs", 
     "com.sun.net.ssl.internal.www.protocol"); 
    try 
    { 
    //if we have the JSSE provider available, 
    //and it has not already been 
    //set, add it as a new provide to the Security class. 
    Class clsFactory = Class.forName("com.sun.net.ssl.internal.ssl.Provider"); 
    if((null != clsFactory) && (null == Security.getProvider("SunJSSE"))) 
     Security.addProvider((Provider)clsFactory.newInstance()); 
    } 
    catch(ClassNotFoundException cfe) 
    { 
     throw new Exception("Unable to load the JSSE SSL stream handler." + 
     "Check classpath." + cfe.toString()); 
    } 


    URL url = new URL("https://[your server]:7002"); 
    URLConnection con = URL.openConnection(); 
    //SSLException thrown here if server certificate is invalid 
    con.getInputStream();