ubuntu 找不到系统 Java 编译器。确保您已经安装了 JDK（不仅仅是 JRE）
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/20715586/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
ubuntu Cannot find System Java Compiler. Ensure that you have installed a JDK (not just a JRE) a
提问by user584910
On ubuntu 12, I am trying to run example program of fuse-jna. I got below error message
在 ubuntu 12 上，我正在尝试运行 fuse-jna 的示例程序。我收到以下错误消息
syed@ubuntu:~/Downloads/fuse-jna-master/examples$ ./hellofs.sh ~/hellofs
:compileJava FAILED
FAILURE: Build failed with an exception.
* What went wrong:
Execution failed for task ':compileJava'.
> Cannot find System Java Compiler. Ensure that you have installed a JDK (not just a JRE) and configured your JAVA_HOME system variable to point to the according directory.
* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.
BUILD FAILED
running java -versioncommand shows me:
运行java -version命令显示我：
syed@ubuntu:~/Downloads/fuse-jna-master/examples$ java -version
java version "1.7.0_15"
OpenJDK Runtime Environment (IcedTea7 2.3.7) (7u15-2.3.7-0ubuntu1~12.10)
OpenJDK Client VM (build 23.7-b01, mixed mode, sharing)
output of javac -version:
的输出javac -version：
syed@ubuntu:~/Downloads/fuse-jna-master/examples$ javac -version
javac 1.6.0_27
these are installed on my system, see the picture here
这些已安装在我的系统上，请在此处查看图片
http://i40.tinypic.com/2hf2j4z.png
http://i40.tinypic.com/2hf2j4z.png
Please guide me to run this program on Ubuntu
请指导我在 Ubuntu 上运行这个程序
采纳答案by user584910
It was a problem with an environment variable. After correcting the java_home environment variable in etc/environment and restarting ubuntu, now it runs ok. Thanks for the guidance.
这是环境变量的问题。更正etc/environment中的java_home环境变量，重启ubuntu后，运行正常。感谢您的指导。
回答by stevedbrown
Install a JDK
安装 JDK
sudo apt-get install openjdk-7-jdk
EDITED: initial answer had package for jre (not jdk)
编辑：初始答案有 jre 包（不是 jdk）
回答by Pawe? Dyda
None of these worked on my Ubuntu, really. Turns out, there is something like/usr/lib/jvm/default-java, which is a symbolic link to installed version of java.
这些都不适用于我的 Ubuntu，真的。原来，有类似的东西/usr/lib/jvm/default-java，它是到已安装的 java 版本的符号链接。
The funny thing, this was pointing out to /usr/lib/jvm/java-7-openjdk-i386(the JDK!), but JAVA_HOMEpointed to completely different location - the location where I have my current, up-to-date JDK8 installation.
有趣的是，这指向/usr/lib/jvm/java-7-openjdk-i386（JDK！），但JAVA_HOME指向完全不同的位置 - 我当前安装最新 JDK8 的位置。
I simply updated the symlink to point to correct location, but it is likely to be overridden with an update of OpenJDK7... I guess I have to get rid of OpenJDK then.
我只是更新了符号链接以指向正确的位置，但它很可能会被 OpenJDK7 的更新覆盖......我想我那时必须摆脱 OpenJDK。
回答by Max Jindal
I was facing the same issue, after seeing this post, I tried doing
我遇到了同样的问题，看到这篇文章后，我尝试做
gradle -v
java -version
javac -version
javac failed. However, ubuntu prompted me to install javac with the following message
javac 失败。但是，ubuntu 提示我安装 javac 并显示以下消息
21:52:17->javac
The program 'javac' can be found in the following packages:
* default-jdk
* ecj
* gcj-4.8-jdk
* openjdk-7-jdk
* gcj-4.6-jdk
* openjdk-6-jdk
Try: sudo apt-get install <selected package>
After installing javac using openjdk-7-jdk and adding the following 2 lines to my bashrc, gradle started working
使用 openjdk-7-jdk 安装 javac 并将以下两行添加到我的 bashrc 后，gradle 开始工作
JAVA_HOME="/usr/lib/jvm/java-7-openjdk-amd64/jre"
PATH="$PATH:$JAVA_HOME/bin"
Here, /usr/lib/jvm/java-7-openjdk-amd64/jre is the directory containing java binary found by doing which java
这里，/usr/lib/jvm/java-7-openjdk-amd64/jre 是包含通过执行 which java 找到的 java 二进制文件的目录
回答by e18r
Install JDK
sudo apt-get install openjdk-7-jdkMake your $JAVA_HOME point to the newly installed JDK
echo $JAVA_HOME # prints nothing sudo echo 'JAVA_HOME=/usr/lib/jvm/java-7-openjdk-amd64' >> /etc/profile source /etc/profile echo $JAVA_HOME # /usr/lib/jvm/java-7-openjdk-amd64Update your java command symlink
java -version # java version "1.6.0_32" # OpenJDK Runtime Environment (IcedTea6 1.13.4) (6b32-1.13.4-1~deb7u1) # OpenJDK 64-Bit Server VM (build 23.25-b01, mixed mode) which java # /usr/bin/java ls -l /usr/bin/java # lrwxrwxrwx 1 root root 22 Sep 20 21:22 /usr/bin/java -> /etc/alternatives/java ls -l /etc/alternatives/java # lrwxrwxrwx 1 root root 42 Sep 21 00:01 /etc/alternatives/java -> /usr/lib/jvm/java-6-openjdk-amd64/jre/bin/java sudo rm /etc/alternatives/java sudo ln -s /usr/lib/jvm/java-7-openjdk-amd64/bin/java /etc/alternatives/java java -version # java version "1.7.0_65" # OpenJDK Runtime Environment (IcedTea 2.5.1) (7u65-2.5.1-5~deb7u1) # OpenJDK 64-Bit Server VM (build 24.65-b04, mixed mode)Try again
gradle compileJava # :compileJava # BUILD SUCCESSFUL # Total time: 9.397 secs
安装JDK
sudo apt-get install openjdk-7-jdk使您的 $JAVA_HOME 指向新安装的 JDK
echo $JAVA_HOME # prints nothing sudo echo 'JAVA_HOME=/usr/lib/jvm/java-7-openjdk-amd64' >> /etc/profile source /etc/profile echo $JAVA_HOME # /usr/lib/jvm/java-7-openjdk-amd64更新您的 java 命令符号链接
java -version # java version "1.6.0_32" # OpenJDK Runtime Environment (IcedTea6 1.13.4) (6b32-1.13.4-1~deb7u1) # OpenJDK 64-Bit Server VM (build 23.25-b01, mixed mode) which java # /usr/bin/java ls -l /usr/bin/java # lrwxrwxrwx 1 root root 22 Sep 20 21:22 /usr/bin/java -> /etc/alternatives/java ls -l /etc/alternatives/java # lrwxrwxrwx 1 root root 42 Sep 21 00:01 /etc/alternatives/java -> /usr/lib/jvm/java-6-openjdk-amd64/jre/bin/java sudo rm /etc/alternatives/java sudo ln -s /usr/lib/jvm/java-7-openjdk-amd64/bin/java /etc/alternatives/java java -version # java version "1.7.0_65" # OpenJDK Runtime Environment (IcedTea 2.5.1) (7u65-2.5.1-5~deb7u1) # OpenJDK 64-Bit Server VM (build 24.65-b04, mixed mode)再试一次
gradle compileJava # :compileJava # BUILD SUCCESSFUL # Total time: 9.397 secs
回答by SallyRothroat
To be more specific try adding a gradle.properties file and specify org.gradle.java.home there. It worked for me when I had this same problem.
更具体地说，尝试添加一个 gradle.properties 文件并在那里指定 org.gradle.java.home 。当我遇到同样的问题时，它对我有用。
https://docs.gradle.org/current/userguide/build_environment.html
https://docs.gradle.org/current/userguide/build_environment.html
