Maven报错Please ensure you are using JDK 1.4 or above and not a JRE

在部署Jenkins项目时，用Jenkins调用服务器上脚本时，脚本在服务器上执行没有任何问题，但是在Jenkins上调用时就报错，提示mvn应该使用全路径执行，当加入jdk，jre，maven环境变量时，出现下面错误。

[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:2.3.2:compile (default-compile) on project kpl-model: Compilation failure
[ERROR] Unable to locate the Javac Compiler in:
[ERROR]   /usr/lib/jvm/java-1.8.0-openjdk-1.8.0.171-8.b10.el6_9.x86_64/jre/../lib/tools.jar
[ERROR] Please ensure you are using JDK 1.4 or above and
[ERROR] not a JRE (the com.sun.tools.javac.Main class is required).
[ERROR] In most cases you can change the location of your Java
[ERROR] installation by setting the JAVA_HOME environment variable.
[ERROR] 

而maven编译需要jdk作为运行环境。
因此，我们只要设置为jdk即可，去掉jre环境变量即可。

#!/bin/bash
export JAVA_HOME=/usr/local/jdk
export M2_HOME=/opt/apache-maven
export PATH=$JAVA_HOME/bin:$PATH
export PATH=${M2_HOME}/bin:${PATH}
export CLASSPATH=.:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar

注：使用which java，mvn -v可查询环境变量的家目录