java.net.Authenticator：java.net.ProtocolException：服务器重定向太多次（20）

Question

我们正在通过代理设置通过Weblogic服务器（node1 / node2）上的java独立示例代码来调用URL。该代码在节点1上工作正常，但相同的代码在node2服务器上不工作。我们已经检查了代理设置和凭据都很好，但是仍然出现以下错误：

 java.net.ProtocolException: Server redirected too many  times (20)
        at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1323)
        at ProxyCode.start2(ProxyCode.java:54)
        at ProxyCode.main(ProxyCode.java:23)
Exception in thread "Main Thread" java.lang.NullPointerException
        at java.io.Reader.<init>(Reader.java:61)
        at java.io.InputStreamReader.<init>(InputStreamReader.java:55)
        at ProxyCode.readFromInputStream(ProxyCode.java:65)
        at ProxyCode.start2(ProxyCode.java:59)
        at ProxyCode.main(ProxyCode.java:22)

[另外，请在下面找到我的代码段：SimpleAuthenticator.java

import java.net.Authenticator;导入java.net.PasswordAuthentication;

public class SimpleAuthenticator extends Authenticator
{
        private String username;
        private String password;

        public SimpleAuthenticator(String username,String password)
        {
                this.username = username;
                this.password = password;
        }

        protected PasswordAuthentication getPasswordAuthentication()
        {
                return new PasswordAuthentication(
                        username,password.toCharArray());
        }
}

主类：

    String url = "http://www.oracle.com/technetwork/java/readme-2-149793.txt";
    String proxy = "proxyserver";
    String port = "8080";
    String username = "username";
    String password = "password";
    Authenticator.setDefault(new SimpleAuthenticator(username,password));

    URL server = null;
    try {

            CookieHandler.setDefault(new CookieManager(null, CookiePolicy.ACCEPT_ALL));
            server = new URL(url);
    }
    catch (MalformedURLException e) {
            e.printStackTrace();
    }

Properties systemProperties = System.getProperties();
    systemProperties.setProperty("http.proxyHost", proxy);
    systemProperties.setProperty("http.proxyPort", port);

    InputStream in = null;
    URLConnection connection = null;

    try {
            connection = (URLConnection) server.openConnection();
            connection.connect();
            in = connection.getInputStream();
    }
    catch (IOException e) {
            e.printStackTrace();
    }
            System.out.println(readFromInputStream(in));
    }

    public static String readFromInputStream(InputStream in) {
            StringBuffer strBuf = new StringBuffer();
            char ac[];
            BufferedReader buf = new BufferedReader(new InputStreamReader(in));

      try 
     {
            while (buf.ready()) {
                    ac = new char[10000];
                    buf.read(ac);
                    strBuf.append(ac);
     }
            buf.close();
    }
    catch (IOException e) {
            e.printStackTrace();
    }

我们从现在开始就陷入困境，几个月来一直无法获得任何有用的信息。请帮助。谢谢

Answer 1

如果您提供错误的凭据（用户名或密码），则会出现此错误。这是基于Glassfish的网络应用程序发生的。我当时期待401回应。

我认为，身份验证器会多次尝试相同的凭据。