在ubuntu下安装pycharm后启动是遇到的错误No JDK found. 的错误：No JDK found. Please validate either PYCHARM_JDK, JDK_HOME or JAVA_HOME environment variable points to valid JDK installation.
解决方法如下：
是因为缺少JDK的原因。
教你怎么安装JDK？
Referring to Ask Ubuntu question How to set JAVA_HOME for OpenJDK?,
How to install “Open JDK” (Java developement kit) in Ubuntu (Linux)?
**Open Applicaction -> Accessories -> Terminal**
Type commandline as below...
**sudo apt-get install openjdk-7-jdk**
Type commandline as below...
**apt-cache search jdk**
(Note: openjdk-7-jdk is symbolically used here. You can choose the JDK version as per your requirement.)
For "JAVA_HOME" (Environment Variable) type command as shown below, in "Terminal" using your installation path...
**export JAVA_HOME=/usr/lib/jvm/java-7-openjdk**
(Note: "/usr/lib/jvm/java-7-openjdk" is symbolically used here just for demostration. You should use your path as per your installation.)
For "PATH" (Environment Variable) type command as shown below, in "Terminal" using your installation path...
**export PATH=$PATH:/usr/lib/jvm/java-7-openjdk/bin**
(Note: "/usr/lib/jvm/java-7-openjdk" is symbolically used here just for demostration. You should use your path as per your installation.)
Check for "open jdk" installation, just type command in "Terminal" as shown below
**javac -version**
完成上面步骤之后基本就搞定了。