问题：
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.1:compile (default-compile) on project travel: Compilation failure [ERROR] No compiler is provided in this environment. Perhaps you are running on a JRE rather than a JDK? [ERROR] -> [Help 1]
解决：
第一次使用maven bulid时出现在这个问题，在pom中的dependencies中输入以下的dependency
以后就不会报这个错了。
<dependency>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.1</version>
</dependency>
