将JDK从6升级到了7（或从其他电脑移植DBV文件夹后），每当启动DbVisualizer 6的时候都会报空指针异常
在官网上找到了相关的方案，如下：
In the DbVisualizer installation directory there is a.install4j directory.
In this directory create a file named pref_jre.cfg if it doesn't already exist.
Open the file in a text editor
Add the complete path to the root directory for the Java installation you want to use.
Example: C:\Program Files\Java\jre6.