maven

mysql-connector-java: unknown was not found

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The IntelliJ cannot find the mysql-connector-java dependency and hits error "unknown was not found"? pom.xml <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <scope>runtime</scope> </dependency> Terminal mysql:mysql-connector-java:jar:unknown was not found in https://repo.maven.apache.org/maven2 during a previous attempt. This failure was cached in the local repository and resolution is not reattempted until the update interval of central has elapsed or updates are …

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How to generate Maven Wrapper files (mvnw and mvnw.cmd)

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This article shows how to generate the Maven Wrapper files in a Maven project: mvnw (For Linux or macOS) mvnw.cmd (For Windows) .mvn/wrapper/maven-wrapper.jar .mvn/wrapper/maven-wrapper.properties Table of contents 1. What is Maven Wrapper 2. Generate the mvnw and mvnw.cmd 2.1 Ensure Maven installed 2.2 Navigate to the Maven project 2.3 Generate Maven Wrapper files 2.4 Build …

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IntelliJ IDEA – Cannot connect to the Maven process

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In the IntelliJ IDEA, clicks on the download sources, and it shows the error Cannot connect to the Maven process. Terminal Cannot connect to the Maven process. Try again later. If the problem persists, check the Maven Importing JDK settings and restart IntelliJ IDEA Tested with IntelliJ IDEA 2022.2.1 (Community Edition) Build #IC-222.3739.54, built on …

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Maven error – invalid target release: 17

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We upgraded the project from Java 11 to Java 17, and mvn test hits the Fatal error compiling: error: invalid target release: 17 pom.xml <properties> <java.version>17</java.version> </properties> Terminal mvn test [ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.8.1:compile (default-compile) on project spring-boot-hello: Fatal error compiling: error: invalid target release: 17 -> [Help 1] The Java version is …

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Jersey and Jetty HTTP Server examples

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This article shows how to start a Jetty HTTP Sever to run a JAX-RS or Eclipse Jersey application. Tested with Jersey 3.0.2 Jetty 11 Jackson 2.12.2 JUnit 5.4.0 (unit test) JSONassert 1.5.0 (unit test) Maven 3.8.3 Java 11 Tables of contents 1. Using Jersey with Jetty HTTP Server 2. Project Directory 3. Project dependencies 4. …

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Maven + Quarkus Hello World example

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This article shows how to use the quarkus-maven-plugin to create or scaffold a Maven + Quarkus JAX-RS hello world project. Technologies used: Quarkus 1.11.0 Maven 3.6.3 Java 11 Topics Creating a new Maven + Quartus project Maven + Quarkus Project Structure Quarkus and pom.xml Quarkus Dependencies Quarkus JAX-RX endpoint Quarkus and Dockerfile Run Quarkus in …

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JUnit 5 Tagging and Filtering, @Tag examples

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This article shows you how to use the JUnit 5 tagging and filtering via the @Tag annotation. Tested with JUnit 5.5.2 Maven 3.6.0 Gradle 5.6.2 1. @Tag A simple tagging for demo. TagMethodTest.java package com.mkyong.tags; import org.junit.jupiter.api.Tag; import org.junit.jupiter.api.Test; import static org.junit.jupiter.api.Assertions.assertEquals; @Tag("branch-20") public class TagMethodTest { @Test @Tag("feature-168") void test1Plus1() { assertEquals(2, 1 + …

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Maven error – invalid target release: 1.11

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Maven compiles and hits the following fatal error messages: Terminal mvn compile Fatal error compiling: error: invalid target release: 1.11 pom.xml <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-compiler-plugin</artifactId> <version>3.8.1</version> <configuration> <source>1.11</source> <target>1.11</target> </configuration> </plugin> Solution For maven-compiler-plugin, the correct JDK version is 1.8, 1.9, 1.10, 10, 11, 12 … 17 … pom.xml <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-compiler-plugin</artifactId> <version>3.8.0</version> <configuration> <source>11</source> <target>11</target> …

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Maven – The POM for maven-compiler-plugin:jar:3.8.1 is missing

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Maven compiles and hits the following maven-compiler-plugin error? The POM for org.apache.maven.plugins:maven-compiler-plugin:jar:3.8.1 is missing, no dependency information available pom.xml <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-compiler-plugin</artifactId> <version>3.8.1</version> <configuration> <source>1.8</source> <target>1.8</target> </configuration> </plugin> Terminal > mvn compile [INFO] Scanning for projects… [INFO] [INFO] ——————–< com.mkyong.core:junit5-maven >——————– [INFO] Building junit5-maven 1.0 [INFO] ——————————–[ jar ]——————————— [WARNING] The POM for org.apache.maven.plugins:maven-compiler-plugin:jar:3.8.1 is …

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Java – How to enable the preview language features?

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This article shows you how to use –enable-preview to enable the preview language features in Java 12, 13 and above. Note Read this JEP 12: Preview Language and VM Features P.S All preview features are disabled by default. On JDK 12: # compile javac Example.java // Do not enable any preview features javac –release 12 …

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JUnit 5 + Maven examples

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This article shows you how to add JUnit 5 in a Maven project, nothing special, just add the JUnit 5 junit-jupiter-engine library and make sure the maven-surefire-plugin is at least version 2.22.0 Technologies used: Maven 3.6 Java 8 JUnit 5.5.2 1. Maven + JUnit 5 1. Add the JUni 5 jupiter engine. pom.xml <dependency> <groupId>org.junit.jupiter</groupId> …

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Maven – source value 1.5 is obsolete and will be removed in a future release

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In IntelliJ IDEA, Maven builds a project, and hits the following warning message? Warning:java: source value 1.5 is obsolete and will be removed in a future release Warning:java: target value 1.5 is obsolete and will be removed in a future release To fix it, add maven-compiler-plugin plugin. pom.xml <build> <plugins> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-compiler-plugin</artifactId> <version>3.8.0</version> <configuration> …

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Maven – How to force re-download project dependencies?

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In Maven, you can use Apache Maven Dependency Plugin, goal dependency:purge-local-repository to remove the project dependencies from the local repository, and re-download it again. Terminal $ mvn dependency:purge-local-repository [INFO] Scanning for projects… [INFO] [INFO] ————–< com.mkyong.examples:maven-code-coverage >————— [INFO] Building maven-code-coverage 1.0-SNAPSHOT [INFO] ——————————–[ jar ]——————————— [INFO] [INFO] — maven-dependency-plugin:2.8:purge-local-repository (default-cli) @ maven-code-coverage — Downloading from …

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Maven – PMD example

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In this article, we will show you how to use Maven PMD Plugin to analyze the Java code. P.S PMD requires Java 1.7 1. Maven PMD Plugin Define the maven-pmd-plugin in the reporting tag, so that mvn site will generate the PMD report. pom.xml <reporting> <plugins> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-pmd-plugin</artifactId> <version>3.11.0</version> </plugin> </plugins> </reporting> 2. Java …

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mvn site : java.lang.ClassNotFoundException: org.apache.maven.doxia.siterenderer.DocumentContent

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Generating a Maven report with mvn site, but hits the following errors java.lang.NoClassDefFoundError: org/apache/maven/doxia/siterenderer/DocumentContent Caused by: java.lang.ClassNotFoundException: org.apache.maven.doxia.siterenderer.DocumentContent [INFO] ———————————————————————— [INFO] BUILD FAILURE [INFO] ———————————————————————— [INFO] Total time: 28.280 s [INFO] Finished at: 2018-11-19T13:20:14+08:00 [INFO] ———————————————————————— [ERROR] Failed to execute goal org.apache.maven.plugins:maven-site-plugin:3.3:site (default-site) on project maven-static-code-analysis: Execution default-site of goal org.apache.maven.plugins:maven-site-plugin:3.3:site failed: A required class …

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Maven – JaCoCo code coverage example

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In this article, we will show you how to use a JaCoCo Maven plugin to generate a code coverage report for a Java project. Tested with Maven 3.5.3 JUnit 5.3.1 jacoco-maven-plugin 0.8.2 Note JaCoCo is an actively developed line coverage tool, that is used to measure how many lines of our code are tested. 1. …

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Maven Profiles example

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In this article, we will show you few Maven profile examples to pass different parameters (server or database parameters) for different environments (dev, test or prod). P.S Tested with Maven 3.5.3 1. Basic Maven Profiles 1.1 A simple profile to skip the unit test. pom.xml <!– skip unit test –> <profile> <id>xtest</id> <properties> <maven.test.skip>true</maven.test.skip> </properties> …

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Maven – How to create a multi module project

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In this tutorial, we will show you how to use Maven to manage a Multi-module project containing four modules : Password module – Interface only. Password md5 module – Password module implementation, MD5 password hashing. Password sha module – Password module implementation, SHA password hashing. Web module – A simple MVC web app to hash …

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No more mvn eclipse:eclipse, what’s next?

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The Apache Maven Eclipse Plugin is retired, no more following commands # support eclipse ide $ mvn eclipse:eclipse # web project $ mvn eclipse:eclipse -Dwtpversion=2.0 What is the equivalent in Eclipse IDE? 1. Solution Please use Eclipse Maven Integration (m2e). Latest Eclipse IDE has bundled the m2e plugin : 2. How to use m2e? The …

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Eclipse IDE – No compiler is provided in this environment. Perhaps you are running on a JRE rather than a JDK?

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Maven compile a project in Eclipse IDE, but hits the following error messages : $ mvn clean compile [ERROR] COMPILATION ERROR : [INFO] ————————————————————- [ERROR] No compiler is provided in this environment. Perhaps you are running on a JRE rather than a JDK? [INFO] 1 error [INFO] ————————————————————- [INFO] ———————————————————————— [INFO] BUILD FAILURE [INFO] ———————————————————————— …

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Maven – List all the project’s plugins

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In Maven, you can use mvn help:effective-pom to list all the current project’s plugins and its version. D:\maven-examples\java-web-project> mvn help:effective-pom [INFO] Scanning for projects… [INFO] [INFO] ——————< com.mkyong.web:java-web-project >——————- [INFO] Building java-web-project Maven Webapp 1.0-SNAPSHOT [INFO] ——————————–[ war ]——————————— [INFO] [INFO] — maven-help-plugin:3.1.0:effective-pom (default-cli) @ java-web-project — [INFO] Effective POMs, after inheritance, interpolation, and profiles …

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How to tell Maven to use Java 8

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In pom.xml, defined this maven.compiler.source properties to tell Maven to use Java 8 to compile the project. 1. Maven Properties Java 8 pom.xml <properties> <maven.compiler.target>1.8</maven.compiler.target> <maven.compiler.source>1.8</maven.compiler.source> </properties> Java 7 pom.xml <properties> <maven.compiler.target>1.7</maven.compiler.target> <maven.compiler.source>1.7</maven.compiler.source> </properties> 2. Compiler Plugin Alternative, configure the plugin directly. pom.xml <build> <plugins> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-compiler-plugin</artifactId> <version>3.6.1</version> <configuration> <source>1.8</source> <target>1.8</target> </configuration> </plugin> </plugins> …

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Spring Boot Hello World Example – JSP

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A Spring Boot web application example, using embedded Tomcat + JSP template, and package as an executable WAR file. Technologies used : Spring Boot 1.4.2.RELEASE Spring 4.3.4.RELEASE Tomcat Embed 8.5.6 Maven 3 Java 8 1. Project Directory Create the following folders manually : 2. Project Dependencies Maven example. Read comments for self-explanatory. pom.xml <?xml version="1.0" …

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Maven and JUnit example

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In Maven, you can declare the JUnit dependency like this: pom.xml <dependencies> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.12</version> <scope>test</scope> </dependency> </dependencies> But, it comes with a bundled copy of hamcrest-core library. $ mvn dependency:tree … [INFO] \- junit:junit:jar:4.12:test [INFO] \- org.hamcrest:hamcrest-core:jar:1.3:test … 1. Maven + JUnit + Hamcrest Note Not a good idea to use the default …

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Maven – Deploy web application to WildFly

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In Maven, we can use the official JBoss WildFly Maven Plugin to deploy a web application (war file) to the WildFly application server. Technologies tested : Maven 3.3.9 WildFly 9.0.2.final WildFly Maven Plugin 1.1.0.Alpha5 P.S This Spring MVC web application will be used for this deployment test. 1. Deploy WAR To WildFly 1.1 Start WildFly …

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Maven – webxml attribute is required

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Maven package a web application and hits the following error message : $ mvn package //… [ERROR] Failed to execute goal org.apache.maven.plugins:maven-war-plugin:2.2:war (default-war) on project spring4-mvc-maven-ajax-example: Error assembling WAR: webxml attribute is required (or pre-existing WEB-INF/web.xml if executing in update mode) -> [Help 1] Solution 1. For servlet container < 3, make sure WEB-INF/web.xml file ...

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Maven Jetty Plugin Examples

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Few Maven Jetty 8.x and 9.x plugin examples, just for quick reference. 1. Maven Jetty Plugin 9.x Note You need to use Maven 3 and Java 1.7 for Maven Jetty 9.x plugin. 1.1 The ‘groupId’ is org.eclipse.jetty, by default, it runs on port 8080, in root context ‘/’. pom.xml <plugin> <groupId>org.eclipse.jetty</groupId> <artifactId>jetty-maven-plugin</artifactId> <version>9.2.11.v20150529</version> </plugin> To …

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Maven – Display project dependency

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In Maven, you can use mvn dependency:tree to display the project dependencies in tree format. 1. Maven Project Review a simple Maven project, declared Spring and logback dependencies. pom.xml <properties> <spring.version>4.1.6.RELEASE</spring.version> <logback.version>1.1.3</logback.version> <jcl.slf4j.version>1.7.12</jcl.slf4j.version> </properties> <dependencies> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-core</artifactId> <version>${spring.version}</version> <exclusions> <exclusion> <groupId>commons-logging</groupId> <artifactId>commons-logging</artifactId> </exclusion> </exclusions> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-webmvc</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.slf4j</groupId> <artifactId>jcl-over-slf4j</artifactId> <version>${jcl.slf4j.version}</version> …

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Maven – Get source code for Jar

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In Maven, you can get source code for project dependencies in most IDEs like this : $ mvn dependency:sources $ mvn dependency:resolve -Dclassifier=javadoc Get source code for Jar Get javadoc for Jar, normally, developers don’t provide this. 1. Eclipse IDE In Eclipse IDE, it’s better to use the maven eclipse plugin: $ mvn eclipse:eclipse -DdownloadSources=true …

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Create a fat Jar file – Maven Assembly Plugin

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In this tutorial, we will show you how to create a fat/uber jar with Maven Assembly Plugin. Which means create a Jar together with its dependency Jars into a single executable Jar file. Note Maven assembly plugin is not good in producing fat/uber jar, it may cause name conflict issue, it is better to use …

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Maven – Exclude log4j.properties in Jar file

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This example shows you how to use Maven to exclude the log4j.properties file from your Jar file. Note Please, DO NOT include the log4j.properties into the final Jar file, it will cause multiple log4j.properties files in the classpath, if someone is depending on your Jar, you may accidentally override their logging configurations, depends which Jar …

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Create a fat Jar file – Maven Shade Plugin

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In this tutorial, we will show you how to use Maven Shade Plugin to create a Jar together with its dependency Jars into a single executable Jar file, so called fat Jar or uber Jar. Note Maven Shade plugin is a better plugin to create fat/uber jar, if compare with assembly plugin, because it provides …

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Maven – Exclude logback.xml in Jar file

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This example shows you how to use Maven to exclude the logback.xml file from the final Jar file. Note Please, DO NOT include the logback.xml into the final Jar file, it will cause multiple logback.xml files in the classpath, if someone is using your Jar, you may override other’s logging configurations accidentally. pom.xml <project> <build> …

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Maven site build is very slow – dependency report

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Creating a Maven site, but the build is very slow to generate the dependency report. C:\mkyong_projects\>mvn site [INFO] Scanning for projects… [INFO] [INFO] ————————————– [INFO] Building Maven Webapp 1.0-SNAPSHOT [INFO] ————————————– [INFO] //… [INFO] Generating "Project License" report [INFO] Generating "Project Team" report [INFO] Generating "Project Summary" report [INFO] Generating "Dependencies" report //…… Hanging here… …

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Emma – Class x appears to be instrumented already

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Review the “maven-emma-plugin” in pom.xml : pom.xml <project> //… <build> <plugins> <plugin> <groupId>org.codehaus.mojo</groupId> <artifactId>emma-maven-plugin</artifactId> <version>1.0-alpha-3</version> <inherited>true</inherited> <executions> <execution> <phase>process-classes</phase> <goals> <goal>instrument</goal> </goals> </execution> </executions> </plugin> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-surefire-plugin</artifactId> <inherited>true</inherited> <configuration> <forkMode>once</forkMode> <reportFormat>xml</reportFormat> <classesDirectory> ${project.build.directory}/generated-classes/emma/classes </classesDirectory> </configuration> </plugin> </plugins> </build> </project> 1. Problem When I run the command mvn emma:emma to generate the code coverage report, …

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