help me to solve this problem,binding a String object to a string

[preethamkumarrai]

Hi All,
I am pretty new to weblogic8.1.I am Getting a error if i try to
concatenate a object to the string in out.println

statement.
For your kind reference progam and error pattern is enclosed.


public class Test extends HttpServlet
{
PrintWriter out;

public void doGet(HttpServletRequest req,HttpServletResponse res)
throws ServletException,IOException
{
out=res.getWriter();
String aaa="Google";
out.println("Hai"+aaa);
} }


ERROR IS:

Error 500--Internal Server Error
java.lang.NoClassDefFoundError: java/lang/StringBuilder
at Test.doGet(Test.java:15)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:740)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at
weblogic.servlet.internal.ServletStubImpl$ServletInvocationAction.run(ServletStubImpl.java:971)
at
weblogic.servlet.internal.ServletStubImpl.invokeServlet(ServletStubImpl.java:402)
at
weblogic.servlet.internal.ServletStubImpl.invokeServlet(ServletStubImpl.java:305)
at

weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.run(WebAppServletContext.java:6350)
at
weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.java:317)
at
weblogic.security.service.SecurityManager.runAs(SecurityManager.java:118)
at
weblogic.servlet.internal.WebAppServletContext.invokeServlet(WebAppServletContext.java:3635)
at
weblogic.servlet.internal.ServletRequestImpl.execute(ServletRequestImpl.java:2585)
at weblogic.kernel.ExecuteThread.execute(ExecuteThread.java:197)
at weblogic.kernel.ExecuteThread.run(ExecuteThread.java:170)

-------------------------------------------------------------------------------------------------------------------------

--

If i use the statement like;
out.println("Hai");
out.println(aaa); ...It works fine

Plz, help me out there.Thanks All.

Prith

 

[Venky]

One reason could be is that the servlet class is compiled using java1.5
compiler and when its running in java 1.4x jvm.. Because in java 1.4x
the string concatenation is done using StringBuffer and in Java 1.5,
its done using StringBuilder class and this class is not available in
java 1.4x..

Before deploying the jar file in weblogic, compile your classes with
java 1.4x compiler or use java 1.5 with weblogic..

 

[ozgwei]

StringBuilder is a new class introduced in Java 5.

I suspect that you use a Java 5 compiler when compiling this Test class
but run it on a JVM of Java 1.4 or lower.

I don't think that WebLogic 8.1 is running Java 5.

Please check.

 

[Roedy Green]

java.lang.NoClassDefFoundError: java/lang/StringBuilder

I have cataloged 31 causes for that error message. I wish Sun would
do something to be more specific.

Happily your cause is #1 on the list.

See http://mindprod.com/jgloss/caq.html

 

[Roedy Green]

-target 1.4 -source 1.4 -bootclasspath /usr/java/j2re1.4.2/lib/rt.jar

the catch is, Javac will happily let you use StringBuilder in -target
1.4 code. It does not know that it is a new class. That why you need
the -bootclasspath to restrict it to old classes.

 

[Thomas Hawtin]

One reason could be is that the servlet class is compiled using java1.5
compiler and when its running in java 1.4x jvm.. Because in java 1.4x
the string concatenation is done using StringBuffer and in Java 1.5,
its done using StringBuilder class and this class is not available in
java 1.4x..

Sun's 1.5 compiler only uses StringBuilder for target of 1.5. So either
the code is being compiled with some buggy compiler or the JRE (possibly
BEA JRockit) is broken in accepting class files with higher version
numbers than it is capable of running. Perhaps more likely, some
ham-fisted intermediate program is rewriting the class file incorrectly.

Before deploying the jar file in weblogic, compile your classes with
java 1.4x compiler or use java 1.5 with weblogic..

Or use

-target 1.4 -source 1.4 -bootclasspath /usr/java/j2re1.4.2/lib/rt.jar

Normally I'd suggest using the latest javac and options similar to
those. However, for the 1.4 to 1.5 jump the compiler was destabilised
considerably.

Tom Hawtin