谁能帮我解决这个问题。我是 Linux 新手，这里有问题：
gourab@gourab-RV509:/usr/share/java$ cd /
gourab@gourab-RV509:/$ cd usr
gourab@gourab-RV509:/usr$ mkdir JAVA
mkdir: cannot create directory `JAVA': Permission denied
gourab@gourab-RV509:/usr$