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

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preethamkumarrai@gmail.com - 29 Jan 2006 10:36 GMT

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

Reply to this Message

Venky - 29 Jan 2006 12:00 GMT

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..

Reply to this Message

Thomas Hawtin - 29 Jan 2006 15:16 GMT

> 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

Signature

Unemployed English Java programmer
http://jroller.com/page/tackline/

Reply to this Message

Roedy Green - 29 Jan 2006 15:31 GMT

On Sun, 29 Jan 2006 15:32:44 +0000, Thomas Hawtin
<usenet@tackline.plus.com> wrote, quoted or indirectly quoted someone
who said :

> -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.

Signature

Canadian Mind Products, Roedy Green.
http://mindprod.com Java custom programming, consulting and coaching.

Reply to this Message

ozgwei - 29 Jan 2006 12:03 GMT

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.

Reply to this Message

Roedy Green - 29 Jan 2006 12:24 GMT

>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

Signature

Canadian Mind Products, Roedy Green.
http://mindprod.com Java custom programming, consulting and coaching.

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

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