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HarmonyOS
我有一个 Maven 项目从 git repo 分叉并克隆到我的 eclipse 上。它建立在 Java 8 之上。我做的第一件事是执行
mvn clean install
但我收到以下失败消息：
[INFO] Scanning for projects...
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] Building Maven 0.0.1-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[INFO]
[INFO] --- maven-clean-plugin:2.5:clean (default-clean) @ Maven ---
[INFO] Deleting /Users/vshukla/git/Prism/target
[INFO]
[INFO] --- maven-resources-plugin:2.6:resources (default-resources) @ Maven ---
[WARNING] Using platform encoding (UTF-8 actually) to copy filtered resources, i.e. build is platform dependent!
[INFO] skip non existing resourceDirectory /Users/vshukla/git/Prism/src/main/resources
[INFO]
[INFO] --- maven-compiler-plugin:3.1:compile (default-compile) @ Maven ---
[INFO] Changes detected - recompiling the module!
[WARNING] File encoding has not been set, using platform encoding UTF-8, i.e. build is platform dependent!
[INFO] Compiling 66 source files to /Users/vshukla/git/Prism/target/classes
[INFO] -------------------------------------------------------------
[ERROR] COMPILATION ERROR :
[INFO] -------------------------------------------------------------
[ERROR] /Users/vshukla/git/Prism/src/main/java/PrenPost/scanUtility.java:[54,52] diamond operator is not supported in -source 1.5
(use -source 7 or higher to enable diamond operator)
[ERROR] /Users/vshukla/git/Prism/src/main/java/main/AppUtility.java:[87,86] diamond operator is not supported in -source 1.5
(use -source 7 or higher to enable diamond operator)
[ERROR] /Users/vshukla/git/Prism/src/main/java/PrenPost/ComparisionUtility.java:[58,52] diamond operator is not supported in -source 1.5
(use -source 7 or higher to enable diamond operator)
[INFO] 3 errors
[INFO] -------------------------------------------------------------
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 1.266 s
[INFO] Finished at: 2017-03-01T12:11:27+05:30
[INFO] Final Memory: 13M/309M
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.1:compile (default-compile) on project Maven: Compilation failure: Compilation failure:
[ERROR] /Users/vshukla/git/Prism/src/main/java/PrenPost/scanUtility.java:[54,52] diamond operator is not supported in -source 1.5
[ERROR] (use -source 7 or higher to enable diamond operator)
[ERROR] /Users/vshukla/git/Prism/src/main/java/main/AppUtility.java:[87,86] diamond operator is not supported in -source 1.5
[ERROR] (use -source 7 or higher to enable diamond operator)
[ERROR] /Users/vshukla/git/Prism/src/main/java/PrenPost/ComparisionUtility.java:[58,52] diamond operator is not supported in -source 1.5
[ERROR] (use -source 7 or higher to enable diamond operator)
[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
但是，下面是明确设置了 JRE-8 的项目的构建路径详细信息： 
和编译设置：
无论我构建项目多少次，我都会遇到同样的错误。即使在清理项目并从 Eclipse 中刷新它也无济于事。请指导。
更新：
添加属性后设置 maven 编译器插件
<properties>
<maven.compiler.source>1.8</maven.compiler.source>
<maven.compiler.target>1.8</maven.compiler.target>
</properties>
,
我收到以下错误：
[INFO] Scanning for projects...
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] Building Maven 0.0.1-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[INFO]
[INFO] --- maven-clean-plugin:2.5:clean (default-clean) @ Maven ---
[INFO] Deleting /Users/vshukla/git/Prism/target
[INFO]
[INFO] --- maven-resources-plugin:2.6:resources (default-resources) @ Maven ---
[WARNING] Using platform encoding (UTF-8 actually) to copy filtered resources, i.e. build is platform dependent!
[INFO] skip non existing resourceDirectory /Users/vshukla/git/Prism/src/main/resources
[INFO]
[INFO] --- maven-compiler-plugin:3.1:compile (default-compile) @ Maven ---
[INFO] Changes detected - recompiling the module!
[WARNING] File encoding has not been set, using platform encoding UTF-8, i.e. build is platform dependent!
[INFO] Compiling 66 source files to /Users/vshukla/git/Prism/target/classes
[INFO] -------------------------------------------------------------
[WARNING] COMPILATION WARNING :
[INFO] -------------------------------------------------------------
[WARNING] /Users/vshukla/git/Prism/src/main/java/main/MainUITabbed.java: /Users/vshukla/git/Prism/src/main/java/main/MainUITabbed.java uses or overrides a deprecated API.
[WARNING] /Users/vshukla/git/Prism/src/main/java/main/MainUITabbed.java: Recompile with -Xlint:deprecation for details.
[WARNING] /Users/vshukla/git/Prism/src/main/java/main/MainUITabbed.java: Some input files use unchecked or unsafe operations.
[WARNING] /Users/vshukla/git/Prism/src/main/java/main/MainUITabbed.java: Recompile with -Xlint:unchecked for details.
[INFO] 4 warnings
[INFO] -------------------------------------------------------------
[INFO] -------------------------------------------------------------
[ERROR] COMPILATION ERROR :
[INFO] -------------------------------------------------------------
[ERROR] /Users/vshukla/git/Prism/src/main/java/main/MainUITabbed.java:[26,22] package com.apple.eawt does not exist
[ERROR] /Users/vshukla/git/Prism/src/main/java/main/MainUITabbed.java:[93,41] cannot find symbol
symbol: class Application
[ERROR] /Users/vshukla/git/Prism/src/main/java/main/MainUITabbed.java:[93,67] cannot find symbol
symbol: variable Application
[INFO] 3 errors
[INFO] -------------------------------------------------------------
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 2.591 s
[INFO] Finished at: 2017-03-01T13:09:47+05:30
[INFO] Final Memory: 21M/347M
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.1:compile (default-compile) on project Maven: Compilation failure: Compilation failure:
[ERROR] /Users/vshukla/git/Prism/src/main/java/main/MainUITabbed.java:[26,22] package com.apple.eawt does not exist
[ERROR] /Users/vshukla/git/Prism/src/main/java/main/MainUITabbed.java:[93,41] cannot find symbol
[ERROR] symbol: class Application
[ERROR] /Users/vshukla/git/Prism/src/main/java/main/MainUITabbed.java:[93,67] cannot find symbol
[ERROR] symbol: variable Application
[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
这是给出 MainUITabbed 类的编译错误的代码片段：
import com.apple.eawt.Application;
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
Application application = Application.getApplication(); // line 93
ImageIcon imgicon = new ImageIcon(getClass().getResource(
"ICON.jpg"));
Image img = imgicon.getImage();
application.setDockIconImage(img);
MainUITabbed frame = new MainUITabbed();
frame.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
原文由 roger_that 发布，翻译遵循 CC BY-SA 4.0 许可协议
java
发生错误是因为代码不适用于那里使用的默认编译器。在声明依赖关系之后，在根元素结束之前将此代码粘贴到有效的 POM 中，以更改使用的编译器。根据需要调整版本。