Eclipse 中的 maven 更新：无法更新项目

Question

我正在使用 Jersey 进行 REST 的第一步，然后使用m2e。经过对 tomcat 10 和 Java-17 的一些调整后，它在 tomcat 10.1 上部署得很好。

现在，我想做下一步，将新内容添加到 pom.xml 中。但是执行Maven / Update Project ...会导致失败消息：

Could not update project HelloREST configuration
Cannot invoke "org.eclipse.wst.common.componentcore.internal.WorkbenchComponent.findResourcesByRuntimePath(org.eclipse.core.runtime.IPath)"
because "aComponent" is null

此外，错误日志还显示

eclipse.buildId=4.26.0.20221201-1200
java.version=17.0.5
java.vendor=Eclipse Adoptium
BootLoader constants: OS=linux, ARCH=x86_64, WS=gtk, NL=en_US
Framework arguments:  -product org.eclipse.epp.package.jee.product
Command-line arguments:  -os linux -ws gtk -arch x86_64 -product org.eclipse.epp.package.jee.product

org.eclipse.m2e.logback.appender
Error
Tue Feb 07 13:19:45 CET 2023
HelloREST/.settings/org.eclipse.wst.common.component is missing or invalid. Skipping module dependency configuration. Deployment issues may arise.

和

eclipse.buildId=4.26.0.20221201-1200
java.version=17.0.5
java.vendor=Eclipse Adoptium
BootLoader constants: OS=linux, ARCH=x86_64, WS=gtk, NL=en_US
Framework arguments:  -product org.eclipse.epp.package.jee.product
Command-line arguments:  -os linux -ws gtk -arch x86_64 -product org.eclipse.epp.package.jee.product

org.eclipse.wst.common.frameworks
Error
Tue Feb 07 13:19:45 CET 2023
Cannot invoke "org.eclipse.wst.common.componentcore.internal.WorkbenchComponent.getProperties()" because "component" is null

java.lang.NullPointerException: Cannot invoke "org.eclipse.wst.common.componentcore.internal.WorkbenchComponent.getProperties()" because "component" is null
    at org.eclipse.wst.common.componentcore.internal.resources.VirtualComponent.setMetaProperty(VirtualComponent.java:285)
    at org.eclipse.wst.common.componentcore.internal.operation.ServerContextRootUpdateOperation.execute(ServerContextRootUpdateOperation.java:40)
    at org.eclipse.wst.common.frameworks.internal.datamodel.DataModelPausibleOperationImpl$1.run(DataModelPausibleOperationImpl.java:385)
    at org.eclipse.core.internal.resources.Workspace.run(Workspace.java:2380)
    at org.eclipse.core.internal.resources.Workspace.run(Workspace.java:2405)
    at org.eclipse.wst.common.frameworks.internal.datamodel.DataModelPausibleOperationImpl.runOperation(DataModelPausibleOperationImpl.java:410)
    at org.eclipse.wst.common.frameworks.internal.datamodel.DataModelPausibleOperationImpl.runOperation(DataModelPausibleOperationImpl.java:360)
    at org.eclipse.wst.common.frameworks.internal.datamodel.DataModelPausibleOperationImpl.doExecute(DataModelPausibleOperationImpl.java:247)
    at org.eclipse.wst.common.frameworks.internal.datamodel.DataModelPausibleOperationImpl.executeImpl(DataModelPausibleOperationImpl.java:219)
    at org.eclipse.wst.common.frameworks.internal.datamodel.DataModelPausibleOperationImpl.cacheThreadAndContinue(DataModelPausibleOperationImpl.java:89)
    at org.eclipse.wst.common.frameworks.internal.datamodel.DataModelPausibleOperationImpl.execute(DataModelPausibleOperationImpl.java:207)
    at org.eclipse.wst.common.componentcore.internal.util.ComponentUtilities.setServerContextRoot(ComponentUtilities.java:337)
    at org.eclipse.jst.j2ee.internal.project.J2EEProjectUtilities.setServerContextRoot(J2EEProjectUtilities.java:948)
    at org.eclipse.m2e.wtp.WebProjectConfiguratorDelegate.configure(WebProjectConfiguratorDelegate.java:157)
    at org.eclipse.m2e.wtp.AbstractProjectConfiguratorDelegate.configureProject(AbstractProjectConfiguratorDelegate.java:88)
    at org.eclipse.m2e.wtp.WTPProjectConfigurator.configure(WTPProjectConfigurator.java:70)
    at org.eclipse.m2e.core.project.configurator.AbstractLifecycleMapping.configure(AbstractLifecycleMapping.java:123)
    at org.eclipse.m2e.core.internal.project.ProjectConfigurationManager.lambda$6(ProjectConfigurationManager.java:494)
    at org.eclipse.m2e.core.internal.embedder.MavenExecutionContext.executeBare(MavenExecutionContext.java:364)
    at org.eclipse.m2e.core.internal.embedder.MavenExecutionContext.execute(MavenExecutionContext.java:274)
    at org.eclipse.m2e.core.internal.project.ProjectConfigurationManager.updateProjectConfiguration(ProjectConfigurationManager.java:488)
    at org.eclipse.m2e.core.internal.project.ProjectConfigurationManager.lambda$4(ProjectConfigurationManager.java:416)
    at java.base/java.util.Collection.removeIf(Collection.java:576)
    at org.eclipse.m2e.core.internal.project.ProjectConfigurationManager.updateProjectConfiguration0(ProjectConfigurationManager.java:410)
    at org.eclipse.m2e.core.internal.project.ProjectConfigurationManager.lambda$3(ProjectConfigurationManager.java:340)
    at org.eclipse.m2e.core.internal.embedder.MavenExecutionContext.executeBare(MavenExecutionContext.java:364)
    at org.eclipse.m2e.core.internal.embedder.MavenExecutionContext.execute(MavenExecutionContext.java:274)
    at org.eclipse.m2e.core.internal.embedder.MavenExecutionContext.execute(MavenExecutionContext.java:213)
    at org.eclipse.m2e.core.internal.embedder.MavenImpl.execute(MavenImpl.java:1102)
    at org.eclipse.m2e.core.internal.project.ProjectConfigurationManager.updateProjectConfiguration(ProjectConfigurationManager.java:339)
    at org.eclipse.m2e.core.ui.internal.UpdateMavenProjectJob.runInWorkspace(UpdateMavenProjectJob.java:80)
    at org.eclipse.core.internal.resources.InternalWorkspaceJob.run(InternalWorkspaceJob.java:43)
    at org.eclipse.core.internal.jobs.Worker.run(Worker.java:63)

我还没有看到任何其他问题，但它们可能会出现。知道可能是什么原因吗？

当我尝试减少项目时，失败消息不会消失，即使删除 .metadata 并重新启动 Eclipse 也不会消失。

pom.xml：

<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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>net.codejava</groupId>
    <artifactId>HelloREST</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>war</packaging>
    <name>HelloREST</name>
    <build>
        <plugins>
            <plugin>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.8.1</version>
                <configuration>
                    <release>17</release>
                </configuration>
            </plugin>
            <plugin>
                <artifactId>maven-war-plugin</artifactId>
                <version>3.2.3</version>
                <configuration>
                    <warName>HelloREST</warName>
                    <outputDirectory>/opt/tomcat/webapps/</outputDirectory>
                </configuration>
            </plugin>
        </plugins>
    </build>
    <dependencies>
        <dependency>
            <groupId>org.glassfish.jersey.containers</groupId>
            <artifactId>jersey-container-servlet</artifactId>
            <version>3.1.1</version>
        </dependency>
        <dependency>
            <groupId>org.glassfish.jersey.inject</groupId>
            <artifactId>jersey-hk2</artifactId>
            <version>3.1.1</version>
        </dependency>
        <dependency>
            <groupId>jakarta.ws.rs</groupId>
            <artifactId>jakarta.ws.rs-api</artifactId>
            <version>3.1.0</version>
        </dependency>
        <dependency>
            <groupId>jakarta.xml.bind</groupId>
            <artifactId>jakarta.xml.bind-api</artifactId>
            <version>4.0.0</version>
        </dependency>
        <dependency>
            <groupId>org.glassfish.jaxb</groupId>
            <artifactId>jaxb-runtime</artifactId>
            <version>4.0.1</version>
            <scope>runtime</scope>
        </dependency>
    </dependencies>
</project>

Answer 1

以下步骤解决了我的问题：

1. 从 Eclipse Project Explorer 中删除项目，但不从文件系统中删除。
2. 删除文件系统中的.settings文件夹
3. 再次导入项目作为现有 Maven 项目

=====

我调查得更深入一些。我在.settings文件夹中有 2 个文件找到了原因：

1. org.eclipse.wst.common.component
2. org.eclipse.wst.common.project.facet.core.xml

第一个几乎是空的。只是

<?xml version="1.0" encoding="UTF-8"?><project-modules id="moduleCoreId"/>

第二个包含一行

 <installed facet="jst.web" version="5.0"/>

删除该行并重新导入项目，将其替换为

<installed facet="jst.web" version="2.5"/>

并填充第一个文件

<?xml version="1.0" encoding="UTF-8"?><project-modules id="moduleCoreId" project-version="1.5.0">
    <wb-module deploy-name="HelloREST">
        <wb-resource deploy-path="/" source-path="/target/m2e-wtp/web-resources"/>
        <wb-resource deploy-path="/" source-path="/src/main/webapp" tag="defaultRootSource"/>
        <wb-resource deploy-path="/WEB-INF/classes" source-path="/src/main/java"/>
        <property name="context-root" value="HelloREST"/>
        <property name="java-output-path" value="/HelloREST/target/classes"/>
    </wb-module>
</project-modules>

我对此一无所知，但有两个问题仍未得到解答（目前对我来说不是很重要）：

• .settings文件是如何出现乱码的？
• 为什么Eclipse 导入现有 Maven 项目会查看.settings文件，而删除.settings文件时它的工作方式相同？

@nitind：从https://github.com/rolfschumacher/RoS-HelloREST.git您可以git 克隆错误的项目。