コンソールプロジェクトにログ情報を印刷

package com.jidong.nongmao.util;

import org.apache.log4j.Logger;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import java.io.PrintStream;

public class StdOutErrRedirectServlet extends HttpServlet {

    private static final Logger logger = Logger.getLogger(StdOutErrRedirectServlet.class);

    public void init() throws ServletException {
        tieSystemOutAndErrToLog();
    }

    public static void tieSystemOutAndErrToLog() {
        System.setOut(createLoggingProxy(System.out));
        System.setErr(createLoggingProxy(System.err));
    }

    public static PrintStream createLoggingProxy(final PrintStream realPrintStream) {
        return new PrintStream(realPrintStream) {
            public void print(final String string) {
                realPrintStream.print(string);
                logger.info(string);
            }
        };
    }

}