JSP异常-找不到类（tomcat）

Question

I'm setting up an existing application on a new Tomcat 5.5 server connecting to a Postgres database (running on Debian Lenny). When I access it I get a series of stack traces with the following root cause:

java.lang.ClassNotFoundException: java.sql.SQLClientInfoException
    org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1363)
    org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1209)
    java.lang.Class.forName(libgcj.so.90)
    java.lang.Class.initializeClass(libgcj.so.90)
    java.lang.Class.initializeClass(libgcj.so.90)
    org.postgresql.Driver.makeConnection(Driver.java:382)
    org.postgresql.Driver.connect(Driver.java:260)
    java.sql.DriverManager.getConnection(libgcj.so.90)
    jof.DBConnection.getConnection(DBConnection.java:81)
    jof.BeanInterfaceBase.db(BeanInterfaceBase.java:263)
    jof.BeanInterfaceBase.getStatement(BeanInterfaceBase.java:613)
    jof.HelpInterface.findByNaturalId(HelpInterface.java:81)
    jof.HelpInterface.findByNaturalId(HelpInterface.java:128)
    org.apache.jsp.index_jsp.getHelp(index_jsp.java:162)
    org.apache.jsp.index_jsp._jspService(index_jsp.java:369)
    org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:98)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
    org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:331)
    org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:329)
    org.apache.jasper.servlet.JspServlet.service(JspServlet.java:265)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
    java.lang.reflect.Method.invoke(libgcj.so.90)
    org.apache.catalina.security.SecurityUtil$1.run(SecurityUtil.java:244)
    java.security.AccessController.doPrivileged(libgcj.so.90)
    javax.security.auth.Subject.doAsPrivileged(libgcj.so.90)
    org.apache.catalina.security.SecurityUtil.execute(SecurityUtil.java:276)
    org.apache.catalina.security.SecurityUtil.doAsPrivilege(SecurityUtil.java:162)

What's missing?

Answer 1

 java.lang.ClassNotFoundException: java.sql.SQLClientInfoException 

What's missing?

To be precise: the mentioned class is missing in the runtime classpath. It must be in the runtime classpath as a standalone class file ( *.class ) or packaged in a JAR file ( *.jar ). Alternatively you can also add its actual path to the runtime classpath.

By default the webapp's Webapp/WEB-INF/lib and Webapp/WEB-INF/classes folders are covered by the runtime classpath, as is appserver's Appserver/lib folder and the Java's JRE/lib .

Any 3rd party webapp-specific JAR files ought to be placed in Webapp/WEB-INF/lib . Any webapp-specific classes (servlets, etc..) ought to be placed in Webapp/WEB-INF/classes . Any appserver-specific (or webapp-common) JAR files ought to be placed in Appserver/lib . The Java's JRE/lib folder must be left untouched.

Hope this helps.

Edit : the actual problem is worse: this is indeed a Java 6 only class. Tomcat is apparently running on a Java 5. Review your JAVA_HOME environment variable. It must at least point to root installation folder of Java 6 JRE.

Answer 2

This is a guess, but I see that java.sql.SQLClientInfoException is a class that was introduced in Java6. What version of Java is being used to launch your Tomcat server? Maybe you are developing under Java6 but then deploying to a Tomcat running Java5?