generic not supported in 1.3 error even when java_home point jdk1.7 in maven build

Question

im getting below message when run mvn clean install

[ERROR] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Compilation failure

D:\data\work\extjs.parser\src\main\java\com\model\Component.java:[17,15] error:
generics are not supported in -source 1.3

could not parse error message:   (use -source 5 or higher to enable generics)
D:\data\work\extjs.parser\src\main\java\com\model\Container.java:14: error: gene
rics are not supported in -source 1.3
    private List<Component> items;

the project is simple maven project but wont compile with generics error when i have already set JAVA_HOME to jdk1.7 installation path

however when i add plug in then it works fine. why is it required to explicitly set hava home path.

<plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <configuration>
                <source>1.7</source>
                <target>1.7</target>
                <showDeprecation>true</showDeprecation>
                <showWarnings>true</showWarnings>
                <executable>${env.JAVA_HOME}/bin/javac</executable>
                <fork>true</fork>
            </configuration>
        </plugin>

Answer 1

You need to tell Maven to use JDK 1.5 to compile your source code explicitly. Declare Maven compiler plugin (maven-compiler-plugin) in your pom.xml file, like this:

<project ...>
  <dependencies>
   ...
  </dependencies>
  <build>
    <plugins>
       <plugin>
           <groupId>org.apache.maven.plugins</groupId>
           <artifactId>maven-compiler-plugin</artifactId>
           <version>2.3.1</version>
           <configuration>
               <source>1.5</source>
               <target>1.5</target>
           </configuration>
       </plugin>
    </plugins>
  </build>
</project>

Answer 2

generics are not supported in -source 1.3

The error message is perfectly clear. You've told the compiler to compile in -source 1.3 mode, where there are no generics. So, there are no generics.

Answer 3

its old question. and after waiting for quite some time back then i didnt get answer. however while browsing maven compiler plugin docs i came to know that plugin has default settings. so earlier versions used to use jdk 1.3 as default for source/target and now it uses 1.5 e,g. after reading docs n running "mvn clean install -X" observed that,

• Maven compile goal uses maven-compiler-plugin internally anyway
• In pom, by specifying maven-compiler-plugin in build section, we can override certain configurations like source/target
• if we don't specify then maven will use defaults given by "maven-compiler-plugin" itself which depends on its version.

Hence there was error till "maven-compiler-plugin" and its configurations(source/target) were not specified in pom.