生成项目时，libGDX会抛出错误：
FAILURE: Build failed with an exception.
* What went wrong:
Execution failed for task ':core:compileJava'.
> Cannot find System Java Compiler. Ensure that you have installed a JDK (not just a
JRE) and configured your JAVA_HOME system variable to point to the according directory.
* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option
to get more log output.
BUILD FAILED
我的java和jdk版本：
java版＆＃34; 1.7.0_65＆＃34;
OpenJDK运行时环境（IcedTea 2.5.1）（7u65-2.5.1-4ubuntu1~0.14.04.1）
OpenJDK 64位服务器VM（内置24.65-b04，混合模式）
我该怎么办？ 请帮助!!