Maven问题：【不支持源选项5。请使用7或更高版本。】问题解决方案

Maven问题：【不支持源选项5。请使用7或更高版本。】问题解决方案

一、问题

不支持源选项5。请使用7或更高版本。不支持目标选项5。请使用7或更高版本

E:\DISK\document\windowsSoftware\xubojavaxiangmu\09-maven\Hello>mvn compile
[INFO] Scanning for projects...
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] Building ch01-maven 1.0-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[INFO]
[INFO] --- maven-resources-plugin:2.6:resources (default-resources) @ ch01-maven ---
Downloading: https://repo.maven.apache.org/maven2/org/codehaus/plexus/plexus-interactivity-api/1.0-alpha-4/plexus-interactivity-api-1.0-alpha-4.jar
Downloading: https://repo.maven.apache.org/maven2/org/apache/maven/maven-monitor/2.0.6/maven-monitor-2.0.6.jar
Downloaded: https://repo.maven.apache.org/maven2/org/apache/maven/maven-monitor/2.0.6/maven-monitor-2.0.6.jar (0 B at 0.0 KB/sec)
Downloaded: https://repo.maven.apache.org/maven2/org/codehaus/plexus/plexus-interactivity-api/1.0-alpha-4/plexus-interactivity-api-1.0-alpha-4.jar (0 B at 0.0 KB/sec)
[WARNING] Using platform encoding (GBK actually) to copy filtered resources, i.e. build is platform dependent!
[INFO] Copying 0 resource
[INFO]
[INFO] --- maven-compiler-plugin:3.1:compile (default-compile) @ ch01-maven ---
[INFO] Changes detected - recompiling the module!
[WARNING] File encoding has not been set, using platform encoding GBK, i.e. build is platform dependent!
[INFO] Compiling 1 source file to E:\DISK\document\windowsSoftware\xubojavaxiangmu\09-maven\Hello\target\classes
[INFO] -------------------------------------------------------------
[ERROR] COMPILATION ERROR :
[INFO] -------------------------------------------------------------
[ERROR] 不再支持源选项 5。请使用 7 或更高版本。
[ERROR] 不再支持目标选项 5。请使用 7 或更高版本。
[INFO] 2 errors
[INFO] -------------------------------------------------------------
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 8.049 s
[INFO] Finished at: 2022-08-14T12:58:52+08:00
[INFO] Final Memory: 12M/44M
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.1:compile (default-compile) on project ch01-maven: Compilation failure: Compilation failure:
[ERROR] 不再支持源选项 5。请使用 7 或更高版本。
[ERROR] 不再支持目标选项 5。请使用 7 或更高版本。
[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/MojoFailureException

二、问题原因

maven的setings.xml文件中默认是JDK1.4版本，需要加载更高版本的JDK才行。

三、解决方法

（1）暂时解决

在pom.xml文件中指定的jdk版本，运行另一个项目，需要在另一个项目的pom.xml文件中再配置一个，每换一个项目，都需要在pom.xml中配置一个，所以是暂时解决的。

<properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <maven.compiler.encoding>UTF-8</maven.compiler.encoding>
        <java.version>1.8</java.version>
        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>
 </properties>

（2）永久解决

在maven配置文件settings.xml文件中在每次运行maven用指定的jdk版本

把下面的代码放到标签的中间才能生效

<profile>  
     <id>jdk-1.8</id>  
     <activation>  
         <activeByDefault>true</activeByDefault>  
         <jdk>1.8</jdk>  
     </activation>
     <properties>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
         <maven.compiler.source>1.8</maven.compiler.source>  
         <maven.compiler.target>1.8</maven.compiler.target>   
     </properties>   
</profile>