Code Migration from JDK 1.5 to 1.6

Question

What are the steps to be followed for Migration of code from JDK 1.5 to 1.6.

Steps followed :

1. Changed the build Patch of Project as JDK1.6
2. Changed the Compiler as 6
3. Clean and deploy the Project
4. I was getting Compilation error as

       *** ERROR ***: Thu Apr 01 05:17:06 PDT 2010    org.eclipse.jst.j2ee.commonarchivecore.internal.exception.DeploymentDescriptorLoadException: WEB-INF/web.xml
    Stack trace of nested exception:
    java.lang.ClassCastException: org.eclipse.jst.javaee.web.internal.impl.WebAppDeploymentDescriptorImpl cannot be cast to org.eclipse.jst.j2ee.webapplication.WebApp
        at org.eclipse.jst.j2ee.commonarchivecore.internal.strategy.War22ImportStrategyImpl.loadDeploymentDescriptor(War22ImportStrategyImpl.java:87)
        at org.eclipse.jst.j2ee.commonarchivecore.internal.strategy.War22ImportStrategyImpl.importMetaData(War22ImportStrategyImpl.java:81)
        at org.eclipse.jst.j2ee.commonarchivecore.internal.impl.WARFileImpl.getDeploymentDescriptor(WARFileImpl.java:145)  



*** ERROR ***: Thu Apr 01 05:17:06 PDT 2010    org.eclipse.wst.validation.internal.core.ValidationException: CHKJ3000E: WAR Validation Failed: org.eclipse.jst.j2ee.commonarchivecore.internal.exception.DeploymentDescriptorLoadException: WEB-INF/web.xml
        at org.eclipse.jst.j2ee.model.internal.validation.WarValidator.validateInJob(WarValidator.java:343)
        at org.eclipse.jst.j2ee.internal.web.validation.UIWarValidator.validateInJob(UIWarValidator.java:111)
        at org.eclipse.wst.validation.internal.operations.ValidatorJob.run(ValidatorJob.java:75)
        at org.eclipse.core.internal.jobs.Worker.run(Worker.java:55)

Answer 1

In the vast majority of cases, you don't need to do anything at all. Even recompiling is not strictly necessary.

The few incompatibilities that exist between Java 5.0 and 6.0 are documented in the JDK 6 Adoption Guide.

Answer 2

The code that ran on Java 1.5 will run on 1.6 without any modifications(in you weren't using any internal APIs that is). The public Java api is always forward compatible.

Answer 3

Recompile with new JDK, check warnings (maybe some of classes or methods are deprecated), check if application work as expected.