!30 gitignore更新

Merge pull request !30 from j3east/master

.gitignore

@@ -27,7 +27,7 @@ target/
 
 ### NetBeans ###
 nbproject/private/
-build/
+build/*
 nbbuild/
 dist/
 nbdist/
@@ -36,4 +36,8 @@ nbdist/
 ######################################################################
 # Others
 *.log
-*.xml.versionsBackup
+*.xml.versionsBackup
+
+!*/build/*.java
+!*/build/*.html
+!*/build/*.xml