maven. lambda expressions are not supported in -source 1.5

You can specify language version in properties section in pom.xml file.

<properties>
    <maven.compiler.source>1.8</maven.compiler.source>
    <maven.compiler.target>1.8</maven.compiler.target>
</properties>

By default, Maven assumes you wrote your code using JDK 1.5 and that you want to compile to that same target. You will need to add the maven-compiler-plugin to your build plugins, in order to tell it to use 1.8.

<build>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <version>3.3</version>
            <configuration>
                <source>1.8</source>
                <target>1.8</target>
            </configuration>
        </plugin>
    </plugins>
</build>

Check out the plugin's docs for more info: http://maven.apache.org/plugins/maven-compiler-plugin/compile-mojo.html

I found possible solution for IntelliJ.

Go into Project settings (ctrl + shift + alt + s). Then you can change language level into higher version.