How to rewrite the Flat Chain example in Java 7

How to rewrite the Flat Chain example in Java 7

e.g.

FlatChain theChain = new FlatChain.Builder()
.withOmmConsumer(ommConsumer)
.withChainName(chainName)
.withServiceName(serviceName)
.withNameGuessingOptimization(nbOfNamesToGuessForOptimization)
.onChainComplete(
(chain) ->
printChain(chain)
)
.onChainError(
(errorMessage, chain) ->
System.out.println("\tError received for <" + chain.getName() + ">: " + errorMessage)
)
.build();

Best Answer

  • Hi @OX,

    This Java 7 porting requires more work than I initially
    expected. Indeed, lambda expressions need to be removed from the FlatChain and
    RecursiveChain interfaces (this is the quick and easy part actually). But the internal
    source code and the example applications also need to be changed as they
    extensively use lambdas and other Java 8 features.

    I’ve done all these changes in a spike solution that I committed in the feature-java7-compatibility branch of the GitHub repository. I built the
    project with JDK 8 (I do not have JDK 7) with the “-target 1.7” and “-source
    1.7” options. I tested it with a JRE 7u67 that I had on my box. Everything,
    seems to work fine. Can you please give it a try in your own environment?

    As you will see in the feature-java7-compatibility branch,
    the ported source code is less elegant and less readable than the Java 8
    version. For these reasons I will not merge these changes into the master
    branch. But at least you have now a Java 7 compatible version that should work for your
    project. You can also use it as an example if you need to port future versions of
    the FlatChain to Java 7.

Answers

  • Hi @OX,

    These lambda expressions can be replaced by instance of
    classes that implement the different interfaces (ElementAddedFunction, ElementChangedFunction…).

    Let me do some tests and I’ll expand on this
    solution.