tomcat bin 中startup.sh中的环境变量配置
JAVA_HOME=/usr/lib/jvm/java-1.7.0-openjdk-amd64
JRE_HOME=/usr/lib/jvm/java-1.7.0-openjdk-amd64/jre
PATH=$JAVA_HOME/bin:$JRE_HOME:$PATH
ClASSPATH=.:/usr/lib/jvm/java-1.7.0-openjdk-amd64/lib/dt.jar:/usr/lib/jvm/java-1.7.0-openjdk-amd64/lib/tools.jar
TOMCAT_HOME=/opt/tomcat7