Linux installation JDK notes

First, install the JDK:

RPM Installation:

# RPM-IVH jdk-8u45-linux-x64.rpm

In the case of a Debian system, tar. Unzip tar.gz to/usr/local/java/and create the corresponding link file. Such as:

$ ll/usr/local/java/Total usage 4lrwxrwxrwx 1 root root 6 June 22:31 Default-latestdrwxr-xr-x 8 UUCP 143 4096 April 11 01:26 jdk1.8.0_45lrwxrwxrwx 1 root root 28 June 22:30 latest-/usr/local/java/jdk1.8.0_45/

Second, the configuration:

Create the/etc/profile.d/java.sh and edit the configuration file:

$ cat/etc/profile.d/java.sh Export Java_home=/usr/local/java/latestexport classpath=.: $JAVA _home/lib/dt.jar: $JAVA _ Home/lib/tools.jarexport jre_home= $JAVA _home/jreexport path= $PATH: $JAVA _home/bin

When other versions of the JDK are installed by default in the system (for example: OPENJDK), the default version needs to be changed.

To view the current binary level version:

$ update-alternatives--display Javajava-Auto mode link currently pointing to/usr/lib/jvm/java-7-openjdk-amd64/jre/bin/java/usr/lib/jvm/ Java-7-openjdk-amd64/jre/bin/java-priority 1071 Slave java.1.gz:/usr/lib/jvm/java-7-openjdk-amd64/jre/man/man1/ Java.1.gz's current "best" version is/usr/lib/jvm/java-7-openjdk-amd64/jre/bin/java. $ update-alternatives--display javacupdate-alternatives: Error: No JAVAC candidates $ update-alternatives--display Jarupdate-alternatives: Error: No jar candidate $ update-alternatives--display javahupdate-alternatives: Error: No Javah candidates $ update-a Lternatives--display javaupdate-alternatives: Error: No JAVAP candidates

Only the Java link file can be modified at this time:

$ sudo update-alternatives--install/usr/bin/java Java/usr/local/java/latest/bin/java 300

Execute again:

$ update-alternatives--display Javajava-Auto mode link currently pointing to/usr/lib/jvm/java-7-openjdk-amd64/jre/bin/java/usr/lib/jvm/ Java-7-openjdk-amd64/jre/bin/java-priority 1071 Slave java.1.gz:/usr/lib/jvm/java-7-openjdk-amd64/jre/man/man1/ Java.1.gz/usr/local/java/latest/bin/java-Priority 300 the current "best" version is/usr/lib/jvm/java-7-openjdk-amd64/jre/bin/java.

To modify the default value:

$ sudo update-alternatives --config java has  2  candidates available for replacement  java  (provides  / Usr/bin/java).    Select         paths                                              Priority     Status------------------------------------------------------------* 0             /usr/lib/jvm/java-7-openjdk-amd64/jre/bin/java   1071        Auto Mode   1             /usr/lib/jvm/java-7-openjdk-amd64/jre/bin/java   1071        Manual Mode   2            /usr/ Local/java/latest/bin/java                   300        Manual mode to maintain the current value [*] press ENTER, or type the number you selected:2update-alternatives:  using /usr/local/java/latest/bin/java to provide /usr/bin/java  (Java)  in  Manual mode

Check default values:

$ update-alternatives--display Javajava-Manual mode link currently pointing to/usr/local/java/latest/bin/java/usr/lib/jvm/ Java-7-openjdk-amd64/jre/bin/java-priority 1071 Slave java.1.gz:/usr/lib/jvm/java-7-openjdk-amd64/jre/man/man1/ Java.1.gz/usr/local/java/latest/bin/java-Priority 300 the current "best" version is/usr/lib/jvm/java-7-openjdk-amd64/jre/bin/java.

Verify:

$ Java-versionjava Version "1.8.0_45" Java (tm) SE Runtime Environment (build 1.8.0_45-b14) Java HotSpot (tm) 64-bit Server V M (build 25.45-b02, Mixed mode)

This article is from the "Silver Kay Blog" blog, make sure to keep this source http://yinkai.blog.51cto.com/3813923/1664067

Linux installation JDK notes