linux 下 启动tomcat 报：
Neither the JAVA_HOME nor the JRE_HOME environment variable is defined
At least one of these environment variable is needed to run this program
先看Tomcat的startup.bat，它调用了catalina.bat,而catalina.bat则调用了setclasspath.bat。只要在setclasspath.bat的开头声明环境变量，打开tomcat的bin目录下面的setclasspath.sh，添加红色部分，路径自己修改。windows 下用set。
#!/bin/sh
# -----------------------------------------------------------------------------
# Set CLASSPATH and Java options
#
# $Id: setclasspath.sh 467182 2006-10-23 23:47:06Z markt $
# -----------------------------------------------------------------------------
export JAVA_HOME=/usr/lib/jvm/java-7-sun
export JRE_HOME=$JAVA_HOME/jre
# First clear out the user classpath
CLASSPATH=
# Make sure prerequisite environment variables are set
另查看JAVA_HOME用 which java 命令,如/usr/local/jdk1.7.0_13/bin/java