===== 环境 =====
  * centos 6.7
  * jdk 1.7

== 第一步：安装 hg ==
sudo yum install hg
== 第2步：下载源码，多下载几次，经常失败 ==
  * hg clone http://hg.openjdk.java.net/jdk7/jdk7 myjdk7
  * sh ./get_source.sh

== 第3步：安装系统依赖 ==
sudo yum install gcc gcc-c++ libXt-devel libXtst-devel libXrender-devel alsa* cups* ant ant-* freetype-devel.x86_64

gcc （4.4.7）

== 第3步：修改时间 ==
vim ./jdk/src/share/classes/java/util/CurrencyData.properties

将如下时间修改到距离当前10年内
AZ=AZM;2005-12-31-20-00-00;AZN  
MZ=MZM;2006-06-30-22-00-00;MZN  
RO=ROL;2005-06-30-21-00-00;RON  
TR=TRL;2004-12-31-22-00-00;TRY  
VE=VEB;2008-01-01-04-00-00;VEF

== 第4步：去掉测试 ==
vim hotspot/make/linux/Makefile
将包含test_gamma的行全部删除

== 第5步：删除 jaf,jaxp,jaxws模块 ==
  * mkdir drop_dir
  * cd drop_dir
  * wget http://download.java.net/glassfish/components/jax-ws/openjdk/jdk7/jdk7-jaxws2_2_4-b03-2011_05_27.zip
  * wget ftp://ftp.usa.openbsd.org/pub/OpenBSD/distfiles/jdk/jdk7-jaf-2010_08_19.zip
  * wget ftp://ftp.usa.openbsd.org/pub/OpenBSD/distfiles/jdk/jaxp145_01.zip

== 第6步：设置环境变量 ==
<code>
export LANG=C
export ALT_BOOTDIR=/usr/local/jdk1.7.0_80/bin/java

export BUILD_HOTSPOT=true
export BUILD_JDK=true
export BUILD_LANGTOOLS=true
# skip jaxws
#export BUILD_JAXWS=false
# skip jaxp
#export BUILD_JAXP=false
# skip corba
#export BUILD_CORBA=false

export SKIP_COMPARE_IMAGES=true
BUILD_DEPLOY=false
BUILD_INSTALL=false
export ARCH_DATA_MODEL=64
export ALLOW_DOWNLOADS=true

unset JAVA_HOME
unset CLASSPATH
</code>
== 第7步：开始编译 ==
编译命令
<code>
sudo make ALT_BOOTDIR=/usr/local/jdk1.7.0_80 ALLOW_DOWNLOADS=true ALT_DROPS_DIR=/home/hadoop/myjdk7/drop_dir
</code>

===== 编译完之后 =====
  * jdk目录：myjdk7/build/linux-amd64/j2sdk-image/
  * hotspot目录：myjdk7/build/linux-amd64/hotspot/outputdir/linux_amd64_compiler2/