java 获取当前执行项目的路径

如何获取当前执行项目的路径？如何获取 java -jar 获取当前jar的绝对路径？

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( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
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 :: Spring Boot ::        (v2.1.6.RELEASE)

2021-06-18 10:18:57.298  INFO 87404 --- [           main] c.e.s.SpringbootdemoApplication          : Starting SpringbootdemoApplication on zjMacBook-Pro.local with PID 87404 (/opt/jy/work/ta/springbootdemo/target/classes started by zj in /opt/jy/work/ta/springbootdemo)
2021-06-18 10:18:57.301  INFO 87404 --- [           main] c.e.s.SpringbootdemoApplication          : No active profile set, falling back to default profiles: default
2021-06-18 10:18:58.211  INFO 87404 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat initialized with port(s): 8080 (http)

springboot 启动项目能看到如上的日志，可看到已经输出了项目所在路径。

然后mvn clean package 后，使用java -jar 启动，可以看到输出的日志为：

2021-06-18 10:33:38.147  INFO 94484 --- [           main] c.e.s.SpringbootdemoApplication          : Starting SpringbootdemoApplication v0.0.1-SNAPSHOT on zjMacBook-Pro.local with PID 94484 (/opt/jy/work/pa/jarsigned/zjtarget/signed.jar started by zj in /Users/zj) 

日志中已经输出了jar的绝对路径：/opt/jy/work/pa/jarsigned/zjtarget/signed.jar

跟从springboot启动源码，最终找到了获取jar绝对路径的代码，在ApplicationHome.java类中

/**
 * 获取执行代码的绝对路径，获取执行当前jar包的绝对路径
 * @return
 */
String getPath(){
   ApplicationHome applicationHome = new ApplicationHome(SpringbootdemoApplication.class);
   File file = applicationHome.getSource();
   String path = file.getAbsolutePath();
   return path;
}