IDEA下报错：lambda expressions are not supported at this language level
解决：
1. File -> Project Structure -> Project -> Project Language Level 选择“8 Lamdas Type Annotations etc”
2. 如果没有改选项请先安装和配置JDK1.8
3. 如果为Maven项目，请将pom.xml中maven-compiler-plugin中<configuration>中的<source>和<target>配置为1.8
介绍Java SE 8提供的Lambda语法的较好文章：
http://zh.lucida.me/blog/java-8-lambdas-insideout-language-features/
http://lucida.me/blog/java-8-lambdas-insideout-library-features/