Why do I get "Note: sun.tools.javac.Main has been deprecated" when compiling my JSP?

I have got this error when I tried to access the Tomcat welcome page at http://localhost:8080 using Tomcat 4.0. Starting service Tomcat-Standalone Apache Tomcat/4.0.1 Starting service Tomcat-Apache Apache Tomcat/4.0.1 java.lang.NoSuchMethodError at org.apache.catalina.connector.ResponseStream.flush(ResponseStream.java:244) at java.io.OutputStreamWriter.flush(OutputStreamWriter.java:245) at java.io.PrintWriter.flush(PrintWriter.java:120) at org.apache.catalina.connector.ResponseWriter.flush(ResponseWriter.java:125) at org.apache.catalina.connector.ResponseBase.finishResponse(ResponseBase.java:481) at org.apache.catalina.connector.HttpResponseBase.finishResponse(HttpResponseBase.java:229) at org.apache.catalina.connector.http.HttpResponseImpl.finishResponse(HttpResponseImpl.java:288) at org.apache.catalina.connector.http.HttpProcessor.process(HttpProcessor.java:1038) at org.apache.catalina.connector.http.HttpProcessor.run(HttpProcessor.java:1106) at java.lang.Thread.run(Thread.java:484) ... more