jdk 官方下载地址

http://www.oracle.com/technetwork/java/javase/archive-139210.html

JDK 1.6:

http://www.oracle.com/technetwork/java/javase/downloads/java-archive-downloads-javase6-419409.html

JDK 1.7: 

http://www.oracle.com/technetwork/java/javase/downloads/jdk7-downloads-1880260.html

JDK 1.8:

http://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html