lambda expressions are not supported at this language level intellij

环境：intellij 14.0.2， jdk 1.8

编译错误：lambda expressions are not supported at this language level intellij

操作1：（如果删除了项目文件，如.idea .iml, 下次打开项目需重新配置）

To compile with Java 8 (lambdas etc) in IntelliJ;

• CTRL + ALT + SHIFT + S or File / Project Structure

• Open Project tab

• Set Project SDK to compatible java version (1.8)

• Set Project language level to 8

• Open Modules tab

• Set Language level to 8, click OK

• CTRL + ALT + S or File / Settings

• Build, Execution, Deployment / Compiler / Java Compiler

• Change Target bytecode version to 1.8, click OK

操作2: （一次配置永久生效）

add the following content to pom.xml

<build>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <version>3.6.1</version>
            <configuration>
                <source>1.8</source>
                <target>1.8</target>
            </configuration>
        </plugin>
    </plugins>
</build>

参考：

http://stackoverflow.com/questions/22703412/java-lambda-expressions-not-supported-at-this-language-level