用两个jdk版本编译Ant项目

Question

I am working on Ant project. I am using GWT for client side. Means both client side and Server-side code is written in java. But now we have to upgrade jdk version from jdk-1.8 to jdk-11 for hibernate upgradation. But jdk-11 does not support GWT or we don't want to upgrade GWT.

Now I have to compile and build client-side code with jdk-1.8 and server-side code with jdk-11 with single command ie "ant war.all". Is it possible? if yes then What will be the procedure for this?

Answer 1

I am using the below method to build both server- and client-side code with JAVA 8 while having default JDK set to JAVA 11. I'm not sure if it would work when compilation of server- and client-side code use different JDKs - give it a try.

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In Ant build.xml you have javac command to compile java source to bytecode. This is the server side.

The javac command has fork and executable parameters which can be used to set the path to the external javac executable.

fork: Whether to execute javac using the JDK compiler externally.

executable: Complete path to the javac executable to use in case of fork is yes.

<javac
       fork="yes"
       executable="/path/to/javac"
       ...

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For the client side the java command is used to execute GWT compiler. The java command also has a fork parameter that triggers the class execution in another JVM (other than the one Ant is currently using), and a jvm parameter - the command used to invoke JVM.

<java
      fork="true"
      jvm="/path/to/java"
      ...