In this example, we compile our application for Java 7. So to compile your sources, you need only to tell maven until which lifecycle to execute. In order to compile your project for Java 11 add the release configuration to the compiler plugin, a new compiler parameter to replace the source and target version parameters: org.apache.maven.pluginsmaven-compiler-plugin3.8.011 Every project is different so I cannot provide solutions for every problem you will face. The most important plugins for Java 11 are the compiler plugin, surefire (for unit-tests) and failsafe (for integration-tests). To cross-compile correctly, the new -release option replaces three flags: -source, -target and -bootclasspath. As mentioned before the best thing you can do is to migrate all your dependencies to the latest stable versions to make sure everything works fine with Java 11. While most classes are still available without any changes, some are not. The first option is setting the version in compiler plugin properties: The Maven compiler accepts this command with –target and –source versions. Maven - The POM for maven-compiler-plugin:jar:3.8. mvn site : java.lang.ClassNotFoundException: org.a; Maven error: release version 1.13 not supported; How to write a UTF-8 file in Java; How to read a UTF-8 file in Java This means we can't use or configure Spring Boot for the older JDK versions. Then this guide is for you. Update maven-compiler-plugin to version 3.7.0+ with latest asm dependency. If you want to force the plugin using javac, you must configure the plugin option forceJavacCompilerUse. License: Apache 2.0: Categories: Maven Plugins: Date (Mar 23, 2015) Files: pom (11 KB) maven-plugin (45 KB) View All: Repositories: Central Redhat GA Spring Plugins: Used By: 95 artifacts: Note: There is a new version for this artifact. The canonical reference for building a production grade API with Spring. Guide for Supporting Multiple Versions of Java (8, 11, 14) in Your Maven Project - DZone Java Java Zone Here, we’re using Java 11 to compile our source code (-source 11) and we’re targeting to JVM 11 (-target 11).Now, if you do mvn compile, mvn install or any other command which invokes the phrase compile, the Maven Compiler Plugin will be triggered correctly.. Also a lot of libraries are incompatible without migrating to the latest version. Apache Maven Compiler Plugin. This change makes perfectly sense because it prevents line-breaks between the number and the currency symbol in various presentation formats. So you want to migrate to Java 11 but your Maven project is still sitting on Java 8? If your project is a multi-module Maven project then it helps to establish a parent POM and maintain dependencyManagement und pluginManagement in this file. Same problem fixed for me by setting JAVA_HOME environment variable to point to the JDK with right version. My source and destination java version in maven-compiler-plugin were 11, java -version was also on version 11, but my JAVA_HOME was pointing to JDK-1.8. Question: Showing two versions like 49, 52 when I check java major version using javap. After transforming our examples, for the plugin properties we can declare: And for the maven-compiler-plugin starting from the 3.6 version we can write: As we notice, we can add the Java version in a new attribute. However, we can override the default version of the parent by specifying the java.version property: By setting the java.version property we declare that the source and the target Java versions are both equal to 1.9. mvn -T 4 compile compiles all modules in parallel on 4 CPU cores. In Intellij IDEA go to Module Settings -> Project -> SDK. Above all, we should keep in mind that this property is a Spring Boot Specification. While some classes have been moved to additional Java modules other classes can no longer been used in user code, namely classes from sun. Make sure you have the versions plugin configured in your master POM: This plugin helps finding the latest plugin or dependency versions for your modules. Java 11 is the latest long-term-support (LTS) version of Java at the time of writing. Check JAVA_HOME again by using a terminal instead of IDE: The guides on building REST APIs with Spring. In order to migrate your project to the latest Java version 11 it's highly recommended to update as much plugins and dependencies to the latest stable version as possible. You'll see warnings like this when a library tries to illegally access classes via setAccessible(true): Keep in mind that later you probably also have to pass the --illegal-access=permit parameter when starting your application. all those various bytecode enhancement libaries such as javassist, cglib, asm or byte-buddy. 1.8 1.8. When migrating our web project to Java 11 we had to add jaxb and javax.annotations to prevent ClassNotFoundException. Additionally, starting from the Spring Boot 2.0, Java 8 is the minimum version. Before moving ahead, we can check the default JDK version of Maven. Additionally, to compile and run the programs for older Java versions, we also need to specify -bootclasspath option. You don't care much about the new module system (Jigsaw) introduced in Java 9, you just want your application to run on the latest JDK version? The Compiler Plugin is used to compile the sources of your project. With the introduction of the Java module system (Jigsaw) in Java 9 the Java standard libary has been divided into separate modules. We can modify these settings in the configuration element: 1.81.8 <-- other customizations --> Now is a good time to compile your project with JDK 11 for the first time: Hint: You can speed up multi-module Maven projects by using parallel builds, e.g. As of 2019 Oracle Java 8 will no longer receive free security updates. Update all of those plugins to the lastest stable version. Apache Maven Compiler Plugin. This command helps to find outdated dependency versions from your modules: Update as much libaries as possible to the latest stable version. From no experience to actually building stuff. Apache Maven Compiler Plugin » 3.3. Spring Boot applications specify the JDK version inside of the properties tags in the pom.xml file. We can specify the desired Java version in the compiler plugin. Since 3.0, the default compiler is javax.tools.JavaCompiler (if you are using java 1.6) and is used to compile Java sources. In this article, see a guide for supporting multiple versions of Java in your Maven project. Open up the terminal and execute this command to find the plugin versions you have to update: You will see a list of plugins used in your project with newer versions available. In this quick tutorial, we'll show how to set the Java version in Maven. First, we need to add spring-boot-starter-parent as a parent to our project: This parent POM allows us to configure default plugins and multiple properties including the Java version: By default, the Java version is 1.8. Chances are that it just runs fine with Java 11. ... At this point you can compile and run your application with Java 11, but you are not using module system yet. The Compiler Plugin is used to compile the sources of your project. If you want to force the plugin using javac, you must configure the plugin option forceJavacCompilerUse. Before moving ahead, we can check the default JDK version of Maven. Reasonably sure the issue is the runner executable. The first thing you should do before even thinking about upgrading the Java version is to clean up your pom.xml files. I can reproduce the issue if I switch my maven runner to using JDK 1.8, but the issue goes away when going to JDK 11. Basically, I'm configuring the Maven compiler plugin and configuring it for Java 11. Running the mvn -v command will show the Java version in which Maven runs. You will eventually face different compiler errors such as ClassNotFoundException. Also, for the compiled classes to be compatible with JVM 1.8, the –target value should be 1.8. For the logic module, pom.xml will look like the following: Many plugins such as the compiler plugin, surefire or failsafe are not compatible with Java 9 if you use older versions. The following will compile your sources: While many older dependencies might work just fine there's a couple of dependencies where version updates are mandatory, e.g. Also let me know on Twitter if your migration was successful. Running the mvn -vcommand will show the Java version in which Maven runs. I hope these tips are somewhat useful to you and helps you migrating your application from Java 8 to 11. Notice that I defined two modules: logic and gui . License: Apache 2.0: Categories: Maven Plugins: Tags: plugin compiler build build-system maven apache: Used By: 95 artifacts If we want to use the Java 8 language features the –source should be set to 1.8. Java 9 already contains all the information for linking the new language features with JDK 7. By default, the compiler plugin compiles source code compatible with Java 5, and the generated classes also work with Java 5 regardless of the JDK in use. Javas number formats have been modified to use non-breaking spaces instead of normal spaces between the number and the currency symbol. Requesting you to suggest me what could be the wrong? In most cases, the values of both options are the same. If you are using IntelliJ IDEA, the first approach maven.compiler. Here's a few things we had to fix in our project: We've encountered a curious case with number formats for locales such as Locale.GERMANY which let a bunch of our tests fail with a rather strange assertion error: The underlying code uses NumberFormat.getCurrencyInstance(Locale.GERMANY) to format numbers into the german currency format. The goals for the Compiler Plugin are bound to their respective phases in the build lifecycle. By default, the -source and -target options don't guarantee a cross-compilation. The default value for both of them is 1.6 version. Otherwise Tomcat will not start on Java 9 and above and you would see the following error: Also don't forget to eventually add the additional startup parameter --illegal-access=permit to your servlet container. This new argument will automatically configure the compiler to produce class files that will link against the implementation of the given platform version. The javac can accept such command using -source and -target.The Compiler Plugin can also be … In order to compile your project for Java 11 add the release configuration to the compiler plugin, a new compiler parameter to replace the source and target version parameters: Also don't forget to set your IDEs project SDK to same JDK version. Hi, I am using java8 , maven 3.5.2 version and using below configuration in pom.xml for compile java. This means that we cannot run our application on older versions of the platform. That way all your plugins and dependencies are defined in a single file and are not spread across multiple POM files what makes managing versions easier. Focus on the new OAuth2 stack in Spring Security 5. So what the heck is happening here? * packages and also some classes from com.sun.*. When running web applications with Apache Tomcat you need at least Apache Tomcat 7.0.85 or later. Those libraries often come as transitive dependencies so make sure at least those libaries are up-to-date. You have to explicitely define which additional modules your application needs access to or you can just add those modules from the Maven central repository. Learn how to use the Maven compiler plugin, used to compile the source code of a Maven project. Regards, Munivelu. Furthermore, starting from JDK 9 version, we can use a new -release command-line option. If you're unsure whether you need this you can add the argLine later if your tests run into trouble. THE unique Spring Security education if you’re working with Java today. The rest of this article describes solutions to various problems we had to solve in order to run our application with JDK 11. We've added the following libaries as additional Maven dependencies to our POMs: Instead of adding those libaries via Maven we could utilize the –add-modules Java parameter to add additional JDK modules to the project. Since 3.0, the default compiler is javax.tools.JavaCompiler (if you are using java 1.6) and is used to compile Java sources. The Compiler Plugin is used to compile the sources of your project. If you get compiler errors because your code links to classes from those packages you have to remove those imports from your code. After you've updated your plugin versions make sure that your project still compiles and runs properly. Sometimes when you may need to compile a certain project to a different version than what you are currently using. org.apache.maven.plugins maven-compiler-plugin 3.8.0. You can use mvn -N ... from your projects root directory to just check your parent POM in case of multi-module projects. Home » org.apache.maven.plugins » maven-compiler-plugin » 3.6.1 Apache Maven Compiler Plugin » 3.6.1 The Compiler Plugin is used to compile the sources of your project. Please keep in mind, that when you upgrade to Java 9+ you will most likely get more issues, like assuring that all Maven plugins and dependencies your Java project uses, are also Java 9+ compatible. Even more, we don't need a JDK 7 installed in our machine. Notice also that the version of the Maven Java compiler plugin has changed from 3.6.1 to 3.8.0 . In this quick tutorial, we'll show how to set the Java version in Maven. If there's some dependency that you can't update due to compatibility issues in your project than leave it as is. This quick tutorial demonstrates the possible ways of setting Java version in our Maven project. Compiling Your Java Sources. Changing the strings in our tests to use non-breaking spaces (use OPTION SPACE on Mac OSX keyboards) fixed this issue. It includes everything I've learned while migrating our product to Java 11. The command java --list-modules lists all available modules. Alternatively, we can configure the compiler plugin directly: The maven-compiler-plugin also has additional configuration properties that allow us to have more control over the compilation process beyond -source and -target versions. For surefire and failsafe plugins we add an additional argument --illegal-access=permit to allow all reflection access for third party libraries: This is only needed if your dependencies make heavy use of reflection. The Compiler Plugin is used to compile the sources of your project. The high level overview of all the articles on the site. So now is the time to migrate to JDK 11. Learn how to work with Maven profiles to be able to create different build configurations. If you like this guide please consider sharing the link with your followers. Setting the -source and -target of the Java Compiler.