不再支持ERROR Source选项1.5.使用1.6或更高版本

Question

这一切都发生在我试图构建一个springboot应用程序时 ./mvnw clean install

当我第一次运行install命令时,它会遇到以下问题.

[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 2.749s
[INFO] Finished at: Fri Jun 21 02:14:32 IST 2013
[INFO] Final Memory: 4M/15M
[INFO] ------------------------------------------------------------------------
**[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:2.3.2:compile (default-compile) on project spring-social-twitter4j: Execution default-compile of goal org.apache.maven.plugins:maven-compiler-plugin:2.3.2:compile failed: A required class was missing while executing org.apache.maven.plugins:maven-compiler-plugin:2.3.2:compile: org/codehaus/plexus/compiler/CompilerException**
[ERROR] -----------------------------------------------------
[ERROR] realm =    plugin>org.apache.maven.plugins:maven-compiler-plugin:2.3.2
[ERROR] strategy = org.codehaus.plexus.classworlds.strategy.SelfFirstStrategy
[ERROR] urls[0] = file:/C:/Users/SS%20Computer/.m2/repository/org/apache/maven/plugins/maven-compiler-plugin/2.3.2/maven-compiler-plugin-2.3.2.jar
[ERROR] urls[1] = file:/C:/Users/SS%20Computer/.m2/repository/org/codehaus/plexus/plexus-utils/1.1/plexus-utils-1.1.jar
[ERROR] Number of foreign imports: 1
[ERROR] import: Entry[import  from realm ClassRealm[maven.api, parent: null]]
[ERROR] 
[ERROR] -----------------------------------------------------: org.codehaus.plexus.compiler.CompilerException
[ERROR] -> [Help 1]
[ERROR] 
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR] 
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/PluginContainerException

我在Stackoverflow上搜索了这个问题,并且能够通过帖子解决这个问题

无法执行目标org.apache.maven.plugins:maven-compiler-plugin:2.3.2:compile(default-compile)

然后,我遇到了另一个问题

[ERROR] Source option 1.5 is no longer supported. Use 1.6 or later.
[ERROR] Target option 1.5 is no longer supported. Use 1.6 or later.

我在OS X上.mvn -v显示:

Maven home: /Users/matthuntington/Desktop/apache-maven-3.5.0
Java version: 9, vendor: Oracle Corporation
Java home: /Library/Java/JavaVirtualMachines/jdk-9.jdk/Contents/Home
Default locale: en_US, platform encoding: UTF-8
OS name: "mac os x", version: "10.12.6", arch: "x86_64", family: "mac"

这是我的pom文件

<?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/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.packtpub.restapp</groupId>
    <artifactId>ticket-management</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>ticket-management</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
    </properties>


    <dependencies>
            <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-web</artifactId>
            <version>5.0.1.RELEASE</version>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
            <version>1.5.7.RELEASE</version>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-tomcat</artifactId>
            <version>1.5.7.RELEASE</version>
        </dependency>

        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>2.9.2</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-web</artifactId>
            <version>5.0.0.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>5.0.1.RELEASE</version>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <version>1.5.7.RELEASE</version>                
        </dependency>   
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>


</project>

Answer 1

您可以通过将这些属性添加到pom.xml文件来指定maven源/目标版本

<properties>
    <maven.compiler.source>1.6</maven.compiler.source>
    <maven.compiler.target>1.6</maven.compiler.target>
</properties>

Answer 2

我认为这意味着

• 您正在使用JDK9或更高版本
• 您的项目使用maven-compiler-plugin和旧版本,默认为Java 5.

你有三个选择来解决这个问题

1. 降级为JDK7或JDK8(meh)

2. 使用maven-compiler-plugin版本或更高版本,因为

   注意:从3.8.0开始,默认值已从1.5更改为1.6请参阅https://maven.apache.org/plugins/maven-compiler-plugin/compile-mojo.html#target

   <plugin>
       <groupId>org.apache.maven.plugins</groupId>
       <artifactId>maven-compiler-plugin</artifactId>
       <version>3.8.0</version>
   </plugin>
   

3. 指示maven-compiler-plugin使用源级别6和目标6(或更高版本).

   https://maven.apache.org/plugins/maven-compiler-plugin/推荐的最佳做法

   另请注意,目前默认的源设置为1.6,默认目标设置为1.6,与您运行Maven的JDK无关.强烈建议您通过设置源代码和目标来更改这些默认值,如设置Java编译器的-source和-target中所述.

   <plugin>
       <groupId>org.apache.maven.plugins</groupId>
       <artifactId>maven-compiler-plugin</artifactId>
       <configuration>
           <source>1.6</source>
           <target>1.6</target>
       </configuration>
   </plugin>
   

   或使用

   <properties>
     <maven.compiler.source>1.6</maven.compiler.source>
     <maven.compiler.target>1.6</maven.compiler.target>
   </properties>
   

Answer 3

此错误也可能是针对插件版本的。您可以像下面这样在.POM文件中修复它：

<build>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <version>2.3.1</version>
            <configuration>
                <source>1.6</source>
                <target>1.6</target>
            </configuration>
        </plugin>
    </plugins>
</build>

Answer 4

确保您的pom.xml文件中有以下配置。

<properties>
    <maven.compiler.source>1.8</maven.compiler.source>
    <maven.compiler.target>1.8</maven.compiler.target>
</properties>