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java.lang.UnsatisfiedLinkError: for native method called on JSP in Tomcat

Posted on 2014-02-24
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Last Modified: 2014-03-12
I have a native method that works fine in java application. However when the method is accessed via JSP it gives UnsatisfiedLinkError errors. The dll is in tomcat + tomcat/bin  + tomcat/lib folders all the places.

The Library loads fine on JSP but on calling the native method it gives "java.lang.UnsatisfiedLinkError:"  

JSP Code-
<%!  public static native String stringMethod(String text); %>

<% System.loadLibrary("dll_name");
out.print(stringMethod("JGD"));
out.flush();
%>

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exception

org.apache.jasper.JasperException: javax.servlet.ServletException: java.lang.UnsatisfiedLinkError: org.apache.jsp.index_jsp.stringMethod(Ljava/lang/String;)Ljava/lang/String;
	org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:534)
	org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:442)
	org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:391)
	org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
root cause

javax.servlet.ServletException: java.lang.UnsatisfiedLinkError: org.apache.jsp.index_jsp.stringMethod(Ljava/lang/String;)Ljava/lang/String;
	org.apache.jasper.runtime.PageContextImpl.doHandlePageException(PageContextImpl.java:911)
	org.apache.jasper.runtime.PageContextImpl.handlePageException(PageContextImpl.java:840)
	org.apache.jsp.index_jsp._jspService(index_jsp.java:141)
	org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
	org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:419)
	org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:391)
	org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
root cause

java.lang.UnsatisfiedLinkError: org.apache.jsp.index_jsp.stringMethod(Ljava/lang/String;)Ljava/lang/String;
	org.apache.jsp.index_jsp.stringMethod(Native Method)
	org.apache.jsp.index_jsp._jspService(index_jsp.java:94)
	org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
	org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:419)
	org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:391)
	org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:722)

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ServerLogs.txt
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Comment
Question by:jgdvishnu
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4 Comments
 
LVL 20

Assisted Solution

by:chaitu chaitu
chaitu chaitu earned 1500 total points
ID: 39884779
when the  jars are conflicted then you get this erorr.check in the classpath and see this method stringMethod coming from two jars.remove the jars one by one and debug the issue
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Assisted Solution

by:jgdvishnu
jgdvishnu earned 0 total points
ID: 39884939
Thanks chaituu,

The native method that is throwing error is stored in a dll (not JAR) and to me it seems that there is no conflict at the moment .  I cleaned up and the dll is only at the "WEB-INF/lib" folder and it is nowhere in the classpath now. the WEB-INF/lib folder is loaded with the war.

should the dll  be wrapped in a jar file?
How could we debug the native method? the control goes up to the starting of the method and vanishes.

I am also not sure why the root cause is printed twice.


root cause

javax.servlet.ServletException: java.lang.UnsatisfiedLinkError: org.apache.jsp.index_jsp.stringMethod(Ljava/lang/String;)Ljava/lang/String;
	org.apache.jasper.runtime.PageContextImpl.doHandlePageException(PageContextImpl.java:911)
	org.apache.jasper.runtime.PageContextImpl.handlePageException(PageContextImpl.java:840)
	org.apache.jsp.index_jsp._jspService(index_jsp.java:141)
	org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
	org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:419)
	org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:391)
	org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
root cause

java.lang.UnsatisfiedLinkError: org.apache.jsp.index_jsp.stringMethod(Ljava/lang/String;)Ljava/lang/String;
	org.apache.jsp.index_jsp.stringMethod(Native Method)
	org.apache.jsp.index_jsp._jspService(index_jsp.java:94)
	org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
	org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:419)
	org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:391)
	org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:722)

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index-jsp.java
0
 

Accepted Solution

by:
jgdvishnu earned 0 total points
ID: 39905711
The work around was import the class and call the function to get the required data. The JSP will not work as declaring in the JSP method gets overwritten on deployment.
0
 

Author Closing Comment

by:jgdvishnu
ID: 39922892
it was tried and tested
0

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