打开“window”→“Preferences”，输入“Content Assist”，然后就可以在下面修改啦
java：
“Auto Activation triggers for java”,增加ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz
xml：
“ Prompt when these characters are inserted”，同样增加ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz
