maven编译项目时出错，提示信息如下：
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.1: Compilation failure [ERROR] No compiler is provided in this environment. Perhaps you are running on a JRE rather than a JDK?
在Eclipse的菜单中，进入 Window > Preferences > Java > Installed JREs > Execution Environments，选择JavaSE-1.7, 在右侧选择jdk.
然后在maven菜单中使用 "update project ...".
