筆者把多年Ubuntu上用Emacs和Maven開發Java應用（包括TestNG和Web application)的技巧總結出來，希望對有志於Linux開發的朋友有幫助。我並不反對用IDE開發，但是很多時候，Emacs能夠帶來更快的速度（同時對機器硬件要求也很小），對Java工程的更透徹了解，更容易和開源領域的工程師交流。我還不怎麼喜歡用鼠標，Emacs讓我能夠解放我的右手。
1.確保你已經安裝了JDK
2.確保你安裝了Maven
3.安裝Emacs:sudo apt-get install emacs
4.下載jdee-bin-2.4.0.1.zip和依賴文件elib-1.0.zip,地址在這裡：http://sourceforge.net/projects/jdee/files/
5.將兩個文件解壓到/opt/emacs_plugins/目錄下面
6.還需要下載ecb-2.40和ecb.el，也放在emacs_plugins目錄下
7.下載javadoc-help的javadoc-help.el文件放在/opt/emacs_plugins/java目錄下面 http://javadochelp.sourceforge.net/
;;JDEE configuration
(add-to-list 'load-path (expand-file-name "/opt/emacs_plugins/jdee-2.4.0.1/lisp"))
(load-file "/opt/emacs_plugins/cedet-1.0pre7/common/cedet.el")
(add-to-list 'load-path (expand-file-name "/opt/emacs_plugins/elib-1.0"))
(add-to-list 'load-path (expand-file-name "/opt/emacs_plugins/ecb-2.40"))
;;(add-to-list 'load-path (expand-file-name "/opt/emacs_plugins/jde-jalopy"))
(load-file (expand-file-name "/opt/emacs_plugins/ecb-2.40/ecb.el"))
(require 'font-lock)
(require 'ecb)
(require 'ecb-autoloads)
(require 'jde)
(custom-set-variables
'(browse-url-browser-function (quote browse-url-generic))
'(browse-url-generic-program "chromium-browser")
'(column-number-mode t)
'(jde-complete-function (quote jde-complete-menu))
'(jde-debugger (quote ("jdb")))
'(jde-jdk-registry (quote (("1.6.0_35" . "/usr/jdk1.6"))))
'(jde-resolve-relative-paths-p t)
'(jde-run-option-debug (quote ("Server" "Socket" "javadebug" nil "5005" t))))
可惜的是javadoc-helper不能檢索jdk文檔。自己在浏覽器裡面保留一個書簽代替吧。
;; Java document support
(add-to-list 'load-path (expand-file-name "/opt/emacs_plugins/java"))
(require 'javadoc-help)
(javadoc-set-predefined-urls '("/opt/java_docs/common-cache-1.0.0-javadoc"
"/opt/java_docs/commons-codec-1.4-javadoc"
"/opt/java_docs/commons-logging-1.1.1-javadoc"
"/opt/java_docs/ehcache-server-1.0.0-javadoc"
"/opt/java_docs/gson-1.7.1-javadoc"
"/opt/java_docs/jcommander-1.12-javadoc"
"/opt/java_docs/jersey-apache-client-1.9.1-javadoc"
"/opt/java_docs/jersey-client-1.9.1-javadoc"
"/opt/java_docs/jersey-core-1.9.1-javadoc"
"/opt/java_docs/joda-time-1.6.2-javadoc"
"/opt/java_docs/junit-4.8.2-javadoc"
"/opt/java_docs/logback-classic-1.0.0-javadoc"
"/opt/java_docs/logback-core-1.0.0-javadoc"
"/opt/java_docs/lombok-0.10.4-javadoc"
"/opt/java_docs/mongo-java-driver-2.7.2-javadoc"
"/opt/java_docs/mybatis-3.0.5-javadoc"
"/opt/java_docs/slf4j-api-1.6.4-javadoc"
"/opt/java_docs/snakeyaml-1.6-javadoc"
"/opt/java_docs/testng-6.1.1-javadoc"))
(global-set-key [(f1)] 'javadoc-lookup) ; F1 to lookup
(global-set-key [(shift f1)] 'javadoc-help) ; Shift-F1 to bring up menu
注意，上面的文檔目錄都是自己從互聯網上下載的，如果使用maven構建項目，可以很方便的用一個腳本文件將文件jar包下載下來，並且復制到/opt/java_docs/目錄下。
mvn clean
mvn dependency:resolve -Dclassifier=javadoc
rm -rf /opt/java_docs
mkdir /opt/java_docs
cp $(find ~/.m2/repository/ -name *javadoc.jar) /opt/java_docs/
下面這個腳本可以幫助我把所有jar文件解壓到同名目錄下。
#!bin/sh
path=/opt/java_docs
for f in $(ls $path/*.jar);
do
name=`basename $f`
name2=`echo $name | sed 's/\.jar//g'`
echo $name2
mkdir $path/$name2
cd $path/$name2
jar xvf $path/$name
done
rm -f *.jar
這個腳本可以生成需要配置的目錄路徑，用在.emacs中。
path=/opt/java_docs
for f in $(ls $path/);
do
name=`basename $f`
echo \"/opt/java_docs/$name\"
done
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Windows 7下硬盤安裝Ubuntu 13.10圖文教程 見 http://www.linuxidc.com/Linux/2013-10/91565.htm
Ubuntu 13.10 下載、安裝、配置 整理匯總 頁面 http://www.linuxidc.com/Linux/2013-10/91564.htm
為Emacs配置newLISP開發環境 http://www.linuxidc.com/Linux/2013-01/78463.htm
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