Maven Compilation Error, JAVA 7

If you have mistake like this:

[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.1:compile (default-compile) on project HelloWorld: Compilation failure
[ERROR] /C:/Users/Aleksandr/IdeaProjects/HelloWorldWebApp/src/main/java/HelloWorldServlet.java:[22,13] try-with-resources is not supported in -source 1.5

[ERROR] (use -source 7 or higher to enable try-with-resources)

Open pom.xml

Find section <build> and insert:

<plugins>
  <plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-compiler-plugin</artifactId>
    <version>3.3</version>
    <configuration>
      <source>1.7</source>
      <target>1.7</target>
    </configuration>
  </plugin>

</plugins>