How to install jdk 1.7 on Linux_how to install jdk1.7-优快云博客

本文详细介绍如何在Linux系统上安装Java 7，包括下载并解压JDK包、配置环境变量、设置Java版本以及验证安装是否成功等步骤。

1. Download jdk-7-linux-i586.tar.gz from Oracle'swebsite.

2. Extract tar package.

cd to the directory the tar package is downloaded.

# sudo tar xzvf jdk-7-linux-i586.tar.gz

the extractfolder is jdk1.7.0

# mv jdk1.7.0 /usr/lib/jvm

You can also move the jdk1.7.0 folder to other folders like /usr/lib/jdk.

If there is nojdk folder, you should mkdir a new folder called jdk.

Then change theJAVA_HOME directory to the corresponding directory.

3. Modify environment variable.

# gedit ~/.bashrc

add below itemsand save:

  export JAVA_HOME=/usr/lib/jvm/jdk1.7.0
  export JRE_HOME=${JAVA_HOME}/jre  
  export CLASSPATH=.:${JAVA_HOME}/lib:${JRE_HOME}/lib  
  export PATH=${JAVA_HOME}/bin:$PATH

then souce it.

# source~/.bashrc

4. Change java jdk to jdk7 version.

# sudo update-alternatives --install /usr/bin/java java /usr/lib/jvm/jdk1.7.0/bin/java 300  
# sudo update-alternatives --install /usr/bin/javac javac /usr/lib/jvm/jdk1.7.0/bin/javac 300  
# sudo update-alternatives --install /usr/bin/jar jar /usr/lib/jvm/jdk1.7.0/bin/jar 300

</pre><pre code_snippet_id="313446" snippet_file_name="blog_20140426_7_6675568" name="code" class="plain"># sudo update-alternatives --config java

type selection number, in my environment, jdk 7 is 3, so I type 3.

5. Test if it is ok.

# java -version
# java
# javac

If there is no error, it is done.