jdk1.8下安装jdk1.7后，报Unsupported major.mino?报错

  之前运行没问题，包括tomcat/jetty/maven都正常，jdk为1.8，后为了运行eova，必须用1.7版本，于是又同时安装了jdk1.7,在tomcat和jetty下都报错。jdk、win7、idea15均为64位，错误如下 ：

1、tomcat 运行错误：

。。。。Full details will be found in the appropriate container log file。。。

。。。。 [com.alibaba.druid.proxy.DruidDriver] but failed to unregister it when the web application was stopped. To prevent a memory leak, the JDBC Driver has been forcibly unregistered。。。

log中关键一句：java.lang.UnsatisfiedLinkError:\maven-3.3.9\bin\tcnative-1.dll: Can't load IA 32-bit .dll on a AMD 64-bit platform

貌似说maven不是64位的，可系统中明明是64位呀，之前也一直正常。

2、jetty错误：

Artifact eova:war exploded: Server is not connected. Deploy is not available.
Detected server http port: 8080
Exception in thread "main" java.lang.UnsupportedClassVersionError: org/eclipse/jetty/start/Main : Unsupported major.minor version 52.0 

at java.lang.ClassLoader.defineClass1(Native Method)
按major.minor 52.0错误，属jdk高低版本冲突造成的，但我在idea里，已经全部设置为低版本1.7的了