Unsupported major.minor version 52.0 - Maven Error JAVA

Question

I'm making

mvn install

and i get the error:

[ERROR] Failed to execute goal org.alfresco.maven.plugin:alfresco-maven-plugin:2.1.0:set-version (default-set-version) on project componentX-share: Execution default-set-version of goal org.alfresco.maven.plugin:alfresco-maven-plugin:2.1.0:set-version failed: Unable to load the mojo 'set-version' in the plugin 'org.alfresco.maven.plugin:alfresco-maven-plugin:2.1.0' due to an API incompatibility: org.codehaus.plexus.component.repository.exception.ComponentLookupException: org/alfresco/maven/plugin/VersionMojo : Unsupported major.minor version 52.0

But I already saw if the versions of java are equal, and it's correct.

Like:

which javac -> /usr/lib/jvm/java-1.7.0-openjdk-amd64/bin/javac

which java -> /usr/lib/jvm/java-1.7.0-openjdk-amd64/bin/java

javac -> -version javac 1.7.0_79

java -> -version java version "1.7.0_79" OpenJDK Runtime Environment (IcedTea 2.5.6) (7u79-2.5.6-0ubuntu1.14.04.1) OpenJDK 64-Bit Server VM (build 24.79-b02, mixed mode)

and

mvn -v -> Apache Maven 3.3.3 (7994120775791599e205a5524ec3e0dfe41d4a06; 2015-04-22T12:57:37+01:00) Maven home: /home/patricia/Transferências/apache-maven-3.3.3 Java version: 1.7.0_79, vendor: Oracle Corporation Java home: /usr/lib/jvm/java-7-openjdk-amd64/jre Default locale: pt_PT, platform encoding: UTF-8 OS name: "linux", version: "3.19.0-25-generic", arch: "amd64", family: "unix"

I think all it's correct. And my pom.xml:

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.acme</groupId>
    <artifactId>componentX-share</artifactId>
    <version>1.0-SNAPSHOT</version>
    <name>componentX-share AMP project</name>
    <packaging>amp</packaging>
    <description>Manages the lifecycle of the componentX-share AMP (Alfresco Module Package)</description>

    <parent>
        <groupId>org.alfresco.maven</groupId>
        <artifactId>alfresco-sdk-parent</artifactId>
        <version>2.1.0</version>
    </parent>

    <!-- 
        SDK properties have sensible defaults in the SDK parent,
        but you can override the properties below to use another version.
        For more available properties see the alfresco-sdk-parent POM.
       -->
    <properties>
        <!-- The following are default values for data location and Alfresco version.
             Uncomment if you need to change
        <alfresco.version>${alfresco.community.default.version}</alfresco.version> -->

        <!-- This control the root logging level for all apps uncomment and change, defaults to WARN
            <app.log.root.level>WARN</app.log.root.level>
        -->

        <!-- Set the enviroment to use, this controls which properties will be picked in src/test/properties
             for embedded run, defaults to the 'local' environment. See SDK Parent POM for more info.
        <env>other environment name</env>
        -->

        <!-- The Maven artifact ID to use when loading the Share.WAR that the AMP should be applied to,
                    defaults to the alfresco.war artifact ID, so we need to override here. -->
        <app.amp.client.war.artifactId>${alfresco.share.artifactId}</app.amp.client.war.artifactId>

        <!-- Since Alfresco.WAR (i.e. the Repository) is already running on port 8080, we run Share.WAR on port 8081 -->
        <maven.tomcat.port>8081</maven.tomcat.port>

        <!-- Used in share-config-custom.xml. By default points to local installation of Alfresco Repo -->
        <alfresco.repo.url>http://localhost:8080/alfresco</alfresco.repo.url>
        <maven.compiler.target>1.7</maven.compiler.target>
        <maven.compiler.source>1.7</maven.compiler.source>
    </properties>

    <!-- Here we realize the connection with the Alfresco selected platform 
        (e.g.version and edition) -->
    <dependencyManagement>
        <dependencies>
            <!-- This will import the dependencyManagement for all artifacts in the selected Alfresco version/edition
                (see http://maven.apache.org/guides/introduction/introduction-to-dependency-mechanism.html#Importing_Dependencies) 
                NOTE: You still need to define dependencies in your POM, but you can omit version as it's enforced by this dependencyManagement. NOTE: It defaults 
                to the latest version this SDK pom has been tested with, but alfresco version can/should be overridden in your project's pom -->
            <dependency>
                <groupId>${alfresco.groupId}</groupId>
                <artifactId>alfresco-platform-distribution</artifactId>
                <version>${alfresco.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <!-- Following dependencies are needed for compiling Java code in src/main/java;  -->
    <dependencies>
        <dependency>
            <groupId>${alfresco.groupId}</groupId>
            <artifactId>share</artifactId>
            <version>${alfresco.version}</version>
            <classifier>classes</classifier>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.extensions.surf</groupId>
            <artifactId>spring-surf-api</artifactId>
            <scope>provided</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <!-- Compress JavaScript files and store as *-min.js -->
            <plugin>
                <groupId>net.alchim31.maven</groupId>
                <artifactId>yuicompressor-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

    <profiles>
        <!--
            Brings in the extra Enterprise specific share classes,
            if the 'enterprise' profile has been activated, needs to be activated manually. -->
        <profile>
            <id>enterprise</id>
            <dependencies>
                <dependency>
                    <groupId>${alfresco.groupId}</groupId>
                    <artifactId>share-enterprise</artifactId>
                    <version>${alfresco.version}</version>
                    <classifier>classes</classifier>
                    <scope>provided</scope>
                </dependency>
            </dependencies>
        </profile>
    </profiles>
</project>

I already try to add lines to pom.xml like:

 <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.3</version>
                <configuration>
                    <source>1.7</source>
                    <target>1.7</target>
                </configuration>
            </plugin>

that I saw in other solutions in "stackoverflow" but I can't solve the problem. I don't want to upgrade the version of Java (if it is the solution) I wanted to run in Java 7. Any idea?

If the solution is only upgrade for Java 8, say me too.

Thanks.

Answer 1

Your problem is that Maven Alfresco Plugin 2.1.0 requires JDK 1.8 as shown in the exception (version 52.0). You can se requirements of the plugin here: Maven Alfresco PLugin Requirements

So your options are downgrade alfresco plugin version or upgrade to JDK 1.8.