Java Web 應用程序無法作為 maven 項目運行

Question

我是 java 的新手。 I am using apache netbeans 12.2 version to create new project and the java version is 17. I followed the step to create java web application with maven but when I build it and try to run it I am getting following errors in the console window.

Failed to execute goal org.apache.maven.plugins:maven-war-plugin:2.3:war (default-war) on project JavaProject: Execution default-war of goal org.apache.maven.plugins:maven-war-plugin: 2.3:war failed: Unable to load the mojo 'war' in the plugin 'org.apache.maven.plugins:maven-war-plugin:2.3' due to an API incompatibility: org.codehaus.plexus.component.repository.exception .ComponentLookupException：null

我在 pom.xml 文件中檢查了所需的依賴項，但為什么它無法運行？

這是 Pom.xml 代碼。

<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/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.mycompany</groupId>
    <artifactId>JavaProject</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>war</packaging>
    <name>JavaProject-1.0-SNAPSHOT</name>
    
    <properties>
        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>
        <endorsed.dir>${project.build.directory}/endorsed</endorsed.dir>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <failOnMissingWebXml>false</failOnMissingWebXml>
        <jakartaee>8.0</jakartaee>
    </properties>
    
    <dependencies>
        <dependency>
            <groupId>javax</groupId>
            <artifactId>javaee-api</artifactId>
            <version>${jakartaee}</version>
            <scope>provided</scope>
        </dependency>
    </dependencies>
    
     <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.1</version>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                    <compilerArguments>
                        <endorseddirs>${endorsed.dir}</endorseddirs>
                    </compilerArguments>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-war-plugin</artifactId>
                <version>2.3</version>
                <configuration>
                    <failOnMissingWebXml>false</failOnMissingWebXml>
                </configuration>
            </plugin>
           
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-dependency-plugin</artifactId>
                <version>2.6</version>
                <executions>
                    <execution>
                        <phase>validate</phase>
                        <goals>
                            <goal>copy</goal>
                        </goals>
                        <configuration>
                            <outputDirectory>${endorsed.dir}</outputDirectory>
                            <silent>true</silent>
                            <artifactItems>
                                <artifactItem>
                                    <groupId>javax</groupId>
                                    <artifactId>javaee-api</artifactId>
                                    <version>${jakartaee}</version>
                                    <type>jar</type>
                                </artifactItem>
                            </artifactItems>
                        </configuration>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>
</project>

這是帶有錯誤消息的整個控制台。

Failed to execute goal org.apache.maven.plugins:maven-war-plugin:2.3:war (default-war) on project JavaProject: Execution default-war of goal org.apache.maven.plugins:maven-war-plugin:2.3:war failed: Unable to load the mojo 'war' in the plugin 'org.apache.maven.plugins:maven-war-plugin:2.3' due to an API incompatibility: org.codehaus.plexus.component.repository.exception.ComponentLookupException: null
-----------------------------------------------------
realm =    plugin>org.apache.maven.plugins:maven-war-plugin:2.3
strategy = org.codehaus.plexus.classworlds.strategy.SelfFirstStrategy
urls[0] = file:/Users/mohammadhossan/.m2/repository/org/apache/maven/plugins/maven-war-plugin/2.3/maven-war-plugin-2.3.jar
urls[1] = file:/Users/mohammadhossan/.m2/repository/org/apache/maven/reporting/maven-reporting-api/2.0.6/maven-reporting-api-2.0.6.jar
urls[2] = file:/Users/mohammadhossan/.m2/repository/org/apache/maven/doxia/doxia-sink-api/1.0-alpha-7/doxia-sink-api-1.0-alpha-7.jar
urls[3] = file:/Users/mohammadhossan/.m2/repository/commons-cli/commons-cli/1.0/commons-cli-1.0.jar
urls[4] = file:/Users/mohammadhossan/.m2/repository/org/codehaus/plexus/plexus-interactivity-api/1.0-alpha-4/plexus-interactivity-api-1.0-alpha-4.jar
urls[5] = file:/Users/mohammadhossan/.m2/repository/org/apache/maven/maven-archiver/2.5/maven-archiver-2.5.jar
urls[6] = file:/Users/mohammadhossan/.m2/repository/org/codehaus/plexus/plexus-io/2.0.5/plexus-io-2.0.5.jar
urls[7] = file:/Users/mohammadhossan/.m2/repository/org/codehaus/plexus/plexus-archiver/2.2/plexus-archiver-2.2.jar
urls[8] = file:/Users/mohammadhossan/.m2/repository/org/codehaus/plexus/plexus-interpolation/1.15/plexus-interpolation-1.15.jar
urls[9] = file:/Users/mohammadhossan/.m2/repository/junit/junit/3.8.1/junit-3.8.1.jar
urls[10] = file:/Users/mohammadhossan/.m2/repository/com/thoughtworks/xstream/xstream/1.4.3/xstream-1.4.3.jar
urls[11] = file:/Users/mohammadhossan/.m2/repository/xmlpull/xmlpull/1.1.3.1/xmlpull-1.1.3.1.jar
urls[12] = file:/Users/mohammadhossan/.m2/repository/xpp3/xpp3_min/1.1.4c/xpp3_min-1.1.4c.jar
urls[13] = file:/Users/mohammadhossan/.m2/repository/org/codehaus/plexus/plexus-utils/3.0.8/plexus-utils-3.0.8.jar
urls[14] = file:/Users/mohammadhossan/.m2/repository/org/apache/maven/shared/maven-filtering/1.0-beta-2/maven-filtering-1.0-beta-2.jar
Number of foreign imports: 1
import: Entry[import  from realm ClassRealm[maven.api, parent: null]]

-----------------------------------------------------
: ExceptionInInitializerError: Unable to make field private final java.util.Comparator java.util.TreeMap.comparator accessible: module java.base does not "opens java.util" to unnamed module @73bb1337
-> [Help 1]

To see the full stack trace of the errors, re-run Maven with the -e switch.
Re-run Maven using the -X switch to enable full debug logging.

For more information about the errors and possible solutions, please read the following articles:
[Help 1] http://cwiki.apache.org/confluence/display/MAVEN/PluginContainerException

Answer 1

Your version of Java is incompatible with your version of NetBeans because NetBeans 12.2 does not support the use of JDK 17. From the NetBeans 12.2 Release notes Downloading Apache NetBeans 12.2 :

Apache NetBeans 12.2 在 JDK LTS 版本 8 和 11 以及 JDK 15 上運行，即在此 Z69F0F6923BC1F8AAA26B86Z82AFDB 發布時的當前 JDK 版本。

通常，在更改 NetBeans 和/或 Java 的版本時，請確保版本兼容。 這始終記錄在 NetBeans 發行說明中。

您有兩種選擇來解決此問題：

• 升級到支持 Java 17 的 NetBeans 12.6。
• 繼續使用 NetBeans 12.2，但降級到 Java 15 或更低。 也就是說，將 JDK 15（或更低版本）設為 NetBeans 12.2 的默認平台。

當然，您的項目可能還存在其他問題，但在解決此問題之前，不必擔心這些問題。