gwt-dev.jar conflicts with icu jar on war/lib classpath when using GAE

Question

Ok I have to rewrite my question after further investigation.

I run into below problem in my GWT/GAE project :

java.lang.RuntimeException: Class com.google.appengine.tools.development.agent.runtime.Runtime$21 can not access a member of class com.ibm.icu.text.CollatorServiceShim with modifiers ""
    at com.ibm.icu.text.Collator.getShim(Collator.java:456)
    at com.ibm.icu.text.Collator.getInstance(Collator.java:478)
    at com.google.visualization.datasource.datatable.value.TextValue$1.<init>(TextValue.java:126)
    at com.google.visualization.datasource.datatable.value.TextValue.getTextLocalizedComparator(TextValue.java:125)
    at com.google.visualization.datasource.datatable.value.Value$1.<init>(Value.java:141)
    at com.google.visualization.datasource.datatable.value.Value.getLocalizedComparator(Value.java:140)
    at com.google.visualization.datasource.query.engine.TableRowComparator.<init>(TableRowComparator.java:66)
    at com.google.visualization.datasource.query.engine.QueryEngine.performSort(QueryEngine.java:234)
    at com.google.visualization.datasource.query.engine.QueryEngine.executeQuery(QueryEngine.java:128)
    at com.google.visualization.datasource.DataSourceHelper.applyQuery(DataSourceHelper.java:410)
    at com.klawt.server.resources.chart.InvoicesChartServerResource.retrieve(InvoicesChartServerResource.java:129)

Some more investigation revealed that gwt-dev.jar contains a copy of the icu library :

public abstract class com.ibm.icu.text.Collator implements java.util.Comparator, com.ibm.icu.util.Freezable

is part of gwt-dev.jar

My project has a dependency on icu4j 4.0.1 (for the Google Visualization Datasource library). But GAE SDK insists on using the version included in gwt-dev.jar;

I guess there must a way to setup my development environment so this kinda works, it did before.

I have tried moving GWT SDK to the bottom in the 'Order and export' tab of my build path and the icu jar to the top, but no luck.

Answer 1

Switching from OpenJDK to Oracle JDK fixes it !! It is not the first time I ran into issues with OpenJDK !