Ubuntu 11.04 安裝 Sun Java 6 JDK 及環境變數設定

星期一, 五月 7, 2012 19:13
Posted in category Linux

手動安裝JDK


  1. sudo apt-get install python-software-properties
  2. sudo add-apt-repository ppa:ferramroberto/java
  3. sudo apt-get update
  4. sudo apt-get install sun-java6-jdk


手動安裝JRE

  1. sudo apt-get install python-software-properties
  2. sudo add-apt-repository ppa:ferramroberto/java
  3. sudo apt-get update
  4. sudo apt-get install sun-java6-jre sun-java6-plugin sun-java6-fonts

附加說明

sudo是執行者權限

apt是Linux負責安裝App的程式

apt-add-repository意指加入網址至/etc/apt/sources.list文字檔

apt-get update是更新指令(base on sources.list)

apt-get install是安裝套件(base on sources.list)

apt-cache search則是搜尋套件指令

題外話:
可是系統中還有一個『Openjdk』怎麼辦?

使用切換程式切換過來,

切換前:

$ java -version
java version "1.6.0_22"
OpenJDK Runtime Environment (IcedTea6 1.10.2) (6b22-1.10.2-0ubuntu1~11.04.1)
OpenJDK 64-Bit Server VM (build 20.0-b11, mixed mode)

切換後:

$ sudo update-java-alternatives -s java-6-sun
$ java -version
java version "1.6.0_26"
Java(TM) SE Runtime Environment (build 1.6.0_26-b03)
Java HotSpot(TM) 64-Bit Server VM (build 20.1-b02, mixed mode)

設定環境變數

修改『/etc/environment』

修改前:

PATH=”/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games”



修改後:

JAVA_HOME=”/usr/lib/jvm/java-6-sun”
PATH=”/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/lib/jvm/java-6-sun/bin”
CLASSPATH=”.:/usr/lib/jvm/java-6-sun/lib:/usr/lib/jvm/java-6-sun/lib/dt.jar:/usr/lib/jvm/java-6-sun/lib/tools.jar”





重登入以後測試一下環境變數,


$ echo $CLASSPATH
.:/usr/lib/jvm/java-6-sun/lib:/usr/lib/jvm/java-6-sun/lib/dt.jar:/usr/lib/jvm/java-6-sun/lib/tools.jar
$ echo $PATH
/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/lib/jvm/java-6-sun/bin
$ echo $JAVA_HOME
/usr/lib/jvm/java-6-sun

參考網址:
http://tekibrain.blogspot.com/2011/05/ubuntu-1104-sun-java-6-jdk.html

http://www.dotblogs.com.tw/feeyaorange/archive/2012/04/16/71546.aspx
http://www.mpsstudio.org/2011/09/javainstall-jdk-60-jre-60-on-ubuntu.html

動態調整 PHP script 的最大記憶體上限 (memory_limit)

星期三, 四月 18, 2012 9:39
Posted in category PHP/MYSQL

ERROR:Allowed memory size of 16777216 bytes exhausted (tried to allocate 24 bytes) in ….

可以在 php.ini 設定 memory_limit 的值
也可以在程式的一剛開始 ini_set(”memory_limit”,”2048M”);
這樣就不用為了少數幾支需要比較多記憶體的程式而去調整php.ini裡面的全域設定.

參考網址:http://izero.pixnet.net/blog/post/14054718-%5Btip%5D-%E5%8B%95%E6%85%8B%E8%AA%BF%E6%95%B4-php-script-%E7%9A%84%E6%9C%80%E5%A4%A7%E8%A8%98%E6%86%B6%E9%AB%94%E4%B8%8A%E9%99%90-(memo