Dynamic Web Module 3.0 requires Java 1.6 or newer.

Java compiler level does not match the version of the installed Java project facet.

JAX-RS (REST Web Services) 2.0 requires Java 1.6 or newer.

One or more constraints have not been satisfied.

添加这行代码

   <plugins>

<plugin>     <groupId>org.apache.maven.plugins</groupId>     <artifactId>maven-compiler-plugin</artifactId>     <version>2.3.2</version>     <configuration>         <source>1.8</source>         <target>1.8</target>     </configuration> </plugin> </plugins>

然后maven ——> update project