在线安装Eclipse插件 ，总是出现这个错误：
An error occurred while collecting items to be installed
session context was:(profile=epp.package.jee, phase=org.eclipse.equinox.internal.p2.engine.phases.Collect, operand=, action=).
Problems downloading artifact: org.eclipse.update.feature,edu.umd.cs.findbugs.plugin.eclipse,3.0.1.20150306-5afe4d1.
MD5 hash is not as expected. Expected: 700c2058d1720a42563e1541991f3b7f and found 3973f280b94a613552621cb99ad8ff0a.
解决办法：
安装的时候，把“Contact all update sites during install to find required software”这个勾去掉。
这样就可以成功在线安装插件了。