[root@localhost hadoop-1.0.3]# javac -classpath hadoop-core-1.0.3.jar -d playground/classes playground/src/WordCount.java ----------1. ERROR in playground/src/WordCount.java (at line 20) extends Mapper{ ^^^^^^The type Mapper is not generic; it cannot be parameterized with arguments ----------2. ERROR in playground/src/WordCount.java (at line 20) extends Mapper{ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^Syn..