ErrorDisplay.java Source code

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Here is the source code for ErrorDisplay.java

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import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class ErrorDisplay extends HttpServlet {

    public void doGet(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException {
        res.setContentType("text/html");
        PrintWriter out = res.getWriter();

        String code = null, message = null, type = null, uri = null;
        Object codeObj, messageObj, typeObj;
        Throwable throwable;

        codeObj = req.getAttribute("javax.servlet.error.status_code");
        messageObj = req.getAttribute("javax.servlet.error.message");
        typeObj = req.getAttribute("javax.servlet.error.exception_type");
        throwable = (Throwable) req.getAttribute("javax.servlet.error.exception");
        uri = (String) req.getAttribute("javax.servlet.error.request_uri");

        if (uri == null) {
            uri = req.getRequestURI(); // in case there's no URI given
        }

        // Convert the attributes to string values
        if (codeObj != null)
            code = codeObj.toString();
        if (messageObj != null)
            message = messageObj.toString();
        if (typeObj != null)
            type = typeObj.toString();

        // The error reason is either the status code or exception type
        String reason = (code != null ? code : type);

        out.println("<HTML>");
        out.println("<HEAD><TITLE>" + reason + ": " + message + "</TITLE></HEAD>");
        out.println("<BODY>");
        out.println("<H1>" + reason + "</H1>");
        out.println("<H2>" + message + "</H2>");
        out.println("<PRE>");
        if (throwable != null) {
            throwable.printStackTrace(out);
        }
        out.println("</PRE>");
        out.println("<HR>");
        out.println("<I>Error accessing " + uri + "</I>");
        out.println("</BODY></HTML>");
    }
}