I recently upgraded to Java7 on my Macbook Pro. I downloaded the JDK (not the JRE).
» javac version
javac 1.7.0_17
» echo $JAVA_HOME
/Library/Java/JavaVirtualMachines/jdk1.7.0_17.jdk/Contents/Home
However, when trying to run a build, one of the maven compiler plugins is failing, claiming I have a JRE installed:
» mvn install
[ERROR] execute error
org.apache.maven.plugin.MojoExecutionException: You need to run build with JDK
or have tools.jar on the classpath.
If this occures during eclipse build make sure you run eclipse under JDK as well
at com.mysema.maven.apt.AbstractProcessorMojo.execute(AbstractProcessorMojo.java:263)
at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:101)
I'm confused, as I clearly have a JDK installed. My MAVEN_OPTS don't do anything funny:
» echo $MAVEN_OPTS
-Xmx512m
Trying to debug, I checked the source of the plugin in question, which is doing the following:
try {
JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
if (compiler == null) {
throw new MojoExecutionException("You need to run build with JDK or have tools.jar on the classpath."
+ "If this occures during eclipse build make sure you run eclipse under JDK as well");
}
That seems harmless, so I suspected something wrong on my command line env, and wrote a simple test:
// Main.java
import javax.tools.JavaCompiler;
import javax.tools.ToolProvider;
public class Main {
public static void main(String[] args) {
JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
if (compiler == null)
{
System.out.print("Compiler is null");
} else {
System.out.print("Compiler is not null");
}
}
}
» javac Main.java
Main.java:1: cannot access javax.tools.JavaCompiler
bad class file: /Library/Java/JavaVirtualMachines/jdk1.7.0_17.jdk/Contents/Home/jre/lib/rt.jar(javax/tools/JavaCompiler.class)
class file has wrong version 51.0, should be 49.0
Please remove or make sure it appears in the correct subdirectory of the classpath.
import javax.tools.JavaCompiler;
^
1 error
If I understand that error correctly, it suggests a Java7 compiler running against a Java5 rt.jar?
I'm not sure what's going on here.
I clearly have a Java7 JDK installed, but don't understand:
- Why is the maven plugin is returning null for the compiler?
- Why am I getting class version errors?
Update
Answers are suggesting a messed up JRE / JDK install. I agree this seems likely, but having trouble tracking down where the culprit lies.
Some additional info:
» which javac
/usr/bin/javac
ls -ltra /usr/bin/javac
/usr/bin/javac -> /System/Library/Frameworks/JavaVM.framework/Versions/Current/Commands/javac
cd /System/Library/Frameworks/JavaVM.framework/Versions
ls -ltra
lrwxr-xr-x 1 root wheel 10 18 Feb 08:36 1.6.0 -> CurrentJDK
lrwxr-xr-x 1 root wheel 10 18 Feb 08:36 1.6 -> CurrentJDK
lrwxr-xr-x 1 root wheel 10 18 Feb 08:36 1.5.0 -> CurrentJDK
lrwxr-xr-x 1 root wheel 10 18 Feb 08:36 1.5 -> CurrentJDK
lrwxr-xr-x 1 root wheel 10 18 Feb 08:36 1.4.2 -> CurrentJDK
lrwxr-xr-x 1 root wheel 10 18 Feb 08:36 1.4 -> CurrentJDK
drwxr-xr-x 8 root wheel 272 18 Feb 08:39 A
drwxr-xr-x 11 root wheel 374 18 Feb 08:39 ..
lrwxr-xr-x 1 root wheel 1 14 Jun 11:14 Current -> A
lrwxr-xr-x 1 root wheel 58 14 Jun 11:15 CurrentJDK -> /Library/Java/JavaVirtualMachines/jdk1.7.0_17.jdk/Contents
drwxr-xr-x 11 root wheel 374 14 Jun 11:15 .
So, the javac that is running is the one installed in A/Commands. I'm not sure if this is correct or not. It seems wrong from my windows days, but I'm not familiar enough with how Mac treats Java install to go tinkering.
My $JAVA_HOME points to /Library/Java/JavaVirtualMachines/jdk1.7.0_17.jdk/Contents/Home, which has the following:
drwxrwxr-x 10 root wheel 340 5 Feb 08:10 jre
-rw-rw-r-- 1 root wheel 123324 5 Feb 08:10 THIRDPARTYLICENSEREADME-JAVAFX.txt
drwxrwxr-x 5 root wheel 170 5 Feb 08:10 man
drwxrwxr-x 9 root wheel 306 2 Mar 02:10 db
-rw-rw-r-- 1 root wheel 3339 2 Mar 02:10 COPYRIGHT
drwxrwxr-x 9 root wheel 306 2 Mar 02:10 include
-rw-rw-r-- 1 root wheel 19997030 2 Mar 02:10 src.zip
-rw-rw-r-- 1 root wheel 447 2 Mar 02:10 release
-rw-rw-r-- 1 root wheel 172252 2 Mar 02:10 THIRDPARTYLICENSEREADME.txt
-rw-rw-r-- 1 root wheel 114 2 Mar 02:10 README.html
-rw-rw-r-- 1 root wheel 40 2 Mar 02:10 LICENSE
drwxrwxr-x 5 root wheel 170 2 Mar 02:10 ..
drwxrwxr-x 15 root wheel 510 2 Mar 02:13 .
drwxrwxr-x 13 root wheel 442 2 Mar 02:13 lib
drwxrwxr-x 43 root wheel 1462 2 Mar 02:13 bin
