[英]How does maven know JAVA_HOME set as an environment variable inUbuntu
When I type mvn --version in ubuntu from the terminal(ubuntu),I get the below output. 当我从终端(ubuntu)在ubuntu中键入mvn --version时,我得到以下输出。
Warning: JAVA_HOME environment variable is not set.
Apache Maven 3.0.5
Maven home: /usr/share/maven
Java version: 1.7.0_79, vendor: Oracle Corporation
Java home: /usr/lib/jvm/java-7-openjdk-amd64/jre
Default locale: en_IN, platform encoding: UTF-8
OS name: "linux", version: "3.13.0-32-generic", arch: "amd64", family: "unix"
When I did not set any JAVA_HOME environment variable , how is maven getting the java home installed path.Is it trying to find this path from the /usr/bin/java command which is installed in my system and if so why is it taking the path till jre. 当我没有设置任何JAVA_HOME环境变量时,maven如何获得java home安装路径。它是否试图从我的系统中安装的/ usr / bin / java命令中找到此路径,如果是这样,为什么要采用直到jre。
PS : Also I could not find any java path in any maven config. PS:我也找不到任何maven配置中的任何java路径。
Thanks. 谢谢。
As showed in the CLIReportingUtils.java
(the maven class that retrieves the Java Home), the value comes from the following call : 如
CLIReportingUtils.java
(检索Java Home的maven类)所示,该值来自以下调用:
System.getProperty( "java.home", "<unknown java home>" )
The java.home
is for the JRE unlike the JAVA_HOME
which is for the JDK. java.home
用于JRE,不同于JDK的JAVA_HOME
。 So Maven is displaying the JRE home. 所以Maven正在展示JRE主页。
I would say there is a difference between JAVA_HOME
environment variable and the output Java home: /usr/lib/jvm/java-7-openjdk-amd64/jre
. 我想说
JAVA_HOME
环境变量和输出Java home: /usr/lib/jvm/java-7-openjdk-amd64/jre
之间有区别Java home: /usr/lib/jvm/java-7-openjdk-amd64/jre
。 The latter is just the output of the installation directory see here . 后者只是安装目录的输出, 请看这里 。
So maven will run Java in background and java knows where its installed. 所以maven将在后台运行Java,java知道它的安装位置。
I think,I understand it now.In the maven script ie (usr/share/maven/bin/mvn) they are trying to find the java installed using a variety of options. 我想,我现在明白了。在maven脚本ie(usr / share / maven / bin / mvn)中,他们试图找到使用各种选项安装的java。
So at one place they are doing the below 所以在一个地方,他们正在做下面的事情
JAVACMD="`which java`"
And now in my system "which java" points to the below 现在在我的系统中“哪个java”指向下面
java -> /usr/lib/jvm/java-7-openjdk-amd64/jre/bin/java
Hope this is how its getting the java path. 希望这是它获取java路径的方式。
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.