java-9 – Page 3 – Tarik Billa

How to log request/response using java.net.http.HttpClient?

September 20, 2023 by Tarik

You can log request and responses by specifying-Djdk.httpclient.HttpClient.log=requests on the Java command line. As for testing/mocking you might want to have a look at the offline test: http://hg.openjdk.java.net/jdk/jdk/file/tip/test/jdk/java/net/httpclient/offline/ Depending on what you are looking to achieve you could use a “DelegatingHttpClient” to intercept and log requests and responses too. Besides the Java API documentation there’s … Read more

How to resolve module reads package error in java9

September 13, 2023 by Tarik

The problem is that your module path contains the same package (javax.annotation) in different modules (java.xml.ws.annotation and tomcat.embed.core), which the module system forbids in order to make configurations more reliable. This is called a split package. The module system tells you as much when listing all the modules that read (i.e. “see”) that package twice. … Read more

Does Project Lombok support Java 9?

September 11, 2023 by Tarik

The Lombok project has an issue tracking Java 9 support. As of January 9th 2018 and version 1.16.20, Lombok officially supports Java 9. From the changelog: PLATFORM: Better support for jdk9 in the new IntelliJ, Netbeans and for Gradle. BREAKING CHANGE: lombok config key lombok.addJavaxGeneratedAnnotation now defaults to false instead of true. Oracle broke this … Read more

How to shutdown jshell at the end of the script?

September 7, 2023 by Tarik

Inside the script, use the jshell command /exit. This will exit jshell at the end of your script. Check this reference https://docs.oracle.com/javase/9/jshell/introduction-jshell.htm#JSHEL-GUID-465BA4F5-E77D-456F-BCB7-D826AC1E18AE

JSR-305 annotations replacement for Java 9

September 1, 2023 by Tarik

It’s true that two modules cannot, ordinarily, define types in the same package. Until recently, putting jsr305.jar on the class path of a JDK 9 build would have no effect: That JAR file defines types in the javax.annotation package but that package is defined in the platform’s built-in java.xml.ws.annotation module, and the latter takes precedence. Owing … Read more

Correct way to use VarHandle in Java 9?

August 24, 2023 by Tarik

It is used for instance in AtomicReference, where previously in Java 8, sun.misc.Unsafe was used: public final void lazySet(V newValue) { unsafe.putOrderedObject(this, valueOffset, newValue); } public final boolean compareAndSet(V expect, V update) { return unsafe.compareAndSwapObject(this, valueOffset, expect, update); } Here the this pointer is used together with a field offset to access the field. But … Read more

newInstance vs new in jdk-9/jdk-8 and jmh

August 16, 2023 by Tarik

First of all, the problem has nothing to do with the module system (directly). I noticed that even with JDK 9 the first warmup iteration of newInstance was as fast as with JDK 8. # Fork: 1 of 1 # Warmup Iteration 1: 10,578 ns/op <– Fast! # Warmup Iteration 2: 246,426 ns/op # Warmup … Read more

What is an open module in Java 9 and how do I use it?

August 15, 2023 by Tarik

In order to provide reflective access to your module, Java 9 introduced the open keyword. You can create an open module by using the open keyword in the module declaration. An open module grants reflective access to all of its packages to other modules. For example, if you want to use some framework that heavily … Read more

What is the use of Map.ofEntries() instead of Map.of()

August 13, 2023 by Tarik

Any guesses on how would you create a Map of 26 elements? The primary difference between the two factory methods in Map that you already linked is that : Map.ofEntries Returns an immutable map containing keys and values extracted from the given entries (that are not bounded in count) From the JEP-269:Convenience Factory Methods for … Read more

What does “Required filename-based automodules detected.” warning mean?

August 9, 2023 by Tarik

Automatic module recap An explicit module (i.e. one with a module-info.java) can only access code of modules that it requires (ignoring implied readability for a moment). That’s great if all dependencies are modularized, but what if they are not? How to refer to a JAR that isn’t modular? Automatic modules are the answer: Any JAR … Read more