On Wed, Jun 13, 2012 at 05:32:14PM +0200, Xavier Detant wrote: > Ok, my bad, I didn't explain myself clearly… > I meant, the byte code generated by the compiler is totally independent > from the _kind_ of JVM > that will be used to run it. > > So a code compiled for 1.6 will run on a sun JDK as on a openJDK.
Yes, but will they produce the same result? That's what I must investigate. I want to be able to select a given set of tools (javac, java, etc.), do the build, run the tests; then select another set of tools (different version, different "vendor"), do the build, run the tests, and compare the two outputs. Best, Gilles > > Nevertheless, the code must be compiled for the right version or lesser. So > if you have a 1.6 JVM, you need the code to be compiled for a 1.6 or 1.5 or > 1.4… The JVMs are retro-compatibles (a 1.6 JVM can run a 1.5 byte code). > > Further more, java compiler are also retro-compatibles. It means that a > compiler that can compile a 1.7 code can compile it as a 1.6 code. This is > the difference between : > <source>1.6</source> > and > <target>1.6</target> > in the maven's pom.xml. > > So if you use > <source>1.7</source> > <target>1.5</target> > > You'll need a 1.7 JDK to compile it but only a 1.5 or higher JVM to run it. > Obviously, the source version must be equals or higher than the target > version, and if your code use 1.7 features, the source version must be (at > least) 1.7 or the compiler will raise an error. > > Finally, as said James, if you want to industrialize your tests, you should > use a dedicated tool as Jenkins (I don't know if continuum can do that). If > you want, you can use profiles in Maven to switch easily the versions to > use ( > http://maven.apache.org/guides/introduction/introduction-to-profiles.html). > > > 2012/6/13 Gilles Sadowski <gil...@harfang.homelinux.org> > > > On Wed, Jun 13, 2012 at 03:05:13PM +0200, Xavier Detant wrote: > > > The byte code generated by the compiler is totally independent from the > > JVM > > > that will be used to run it. > > > > Totally independent? Compiling with 1.7 and running with 1.6 will raise > > this > > error: > > Unsupported major.minor version 51.0 > > > > > So I think the point is not «How to compile > > > using the right JDK?» but «How to run with using the right JVM?» Am I > > > wrong? > > > > It is both: compiling _and_ running the tests. > > > > I should be able to do all combinations, i.e.: > > 1. Compile with javac 1.6 and run with java 1.6 > > 2. Compile with javac 1.7 and run with java 1.7 > > 3. Compile with javac 1.6 and run with java 1.7 > > (and similarly with s/6/5/) > > > > > If so, this can't be done at compile time, so it can't be done via > > > maven, unless you use antrun maven's plugin to create a ant task to > > launch > > > your program. > > > > The point is to compile and then _run_ the unit tests, assuming that the > > code conforms to the syntax of Java 5, Java 6, and Java 7, respectively. > > > > In particular, if some source code is Java 5, it should be compatible with > > more recent versions of the Java language, thus be compilable with more > > recent implementations of javac. > > The ultimate goal is to check that the unit tests pass independently of the > > javac and java versions. > > > > > > Best regards, > > Gilles > > > > > > > > 2012/6/13 Gilles Sadowski <gil...@harfang.homelinux.org> > > > > > > > Hello. > > > > > > > > > > > > > > With maven, you can configure the compiler to compile in the version > > you > > > > > want. > > > > > > > > > > Add this to the pom.xml and set the arguments as you which. > > > > > > > > > > <build> > > > > > <pluginManagement> > > > > > <plugin> > > > > > <groupId>org.apache.maven.plugins</groupId> > > > > > <artifactId>maven-compiler-plugin</artifactId> > > > > > <version>2.4</version> > > > > > <configuration> > > > > > <encoding>UTF-8</encoding> > > > > > <source>1.6</source> > > > > > <target>1.6</target> > > > > > <compilerArguments> > > > > > <Xlint:-unchecked /> > > > > > </compilerArguments> > > > > > </configuration> > > > > > </plugin> > > > > > > > > > > See http://maven.apache.org/plugins/maven-compiler-plugin/ for more > > > > > informations. > > > > > > > > I had seen that, but that cannot be the whole story (unless there is > > some > > > > maven magic involved); indeed, how can maven differentiate > > > > java-6-openjdk-amd64 > > > > from > > > > java-6-sun > > > > (since both are Java 1.6)? > > > > > > > > I was thinking that there should be some environment variable(s) whose > > > > setting would somehow activate the above configuration. > > > > > > > > > > > > Regards, > > > > Gilles > > > > > > > > > > > > > > > > > > > 2012/6/13 Gilles Sadowski <gil...@harfang.homelinux.org> > > > > > > > > > > > On Wed, Jun 13, 2012 at 12:48:31PM +0200, Jochen Wiedmann wrote: > > > > > > > Yes, that switch is called PATH (environment variable). > > > > > > > > > > > > Do you mean that I should change the PATH variable just to build > > > > Commons > > > > > > Math? > > > > > > I surely hope that there is a more flexible way. > > > > > > > > > > > > With "ant", all that's needed is to define JAVA_HOME (another > > > > environment > > > > > > variable, but specific to the task at hand). > > > > > > > > > > > > > On Wed, Jun 13, 2012 at 12:19 PM, Gilles Sadowski > > > > > > > <gil...@harfang.homelinux.org> wrote: > > > > > > > > Hello. > > > > > > > > > > > > > > > > Are there command-line switches that will select a specific > > JDK? > > > > > > > > I.e. I have several of them installed: > > > > > > > > > > > > > > > > $ ls -l /usr/lib/jvm > > > > > > > > total 36 > > > > > > > > lrwxrwxrwx 1 root root 24 Dec 17 11:04 default-java -> > > > > > > java-1.6.0-openjdk-amd64 > > > > > > > > lrwxrwxrwx 1 root root 18 Jan 5 18:27 java-1.5.0-gcj -> > > > > > > java-1.5.0-gcj-4.6 > > > > > > > > drwxr-xr-x 6 root root 4096 Jan 18 15:04 java-1.5.0-gcj-4.4 > > > > > > > > drwxr-xr-x 6 root root 4096 Mar 7 17:33 java-1.5.0-gcj-4.6 > > > > > > > > lrwxrwxrwx 1 root root 23 Aug 11 2010 java-1.5.0-sun -> > > > > > > java-1.5.0-sun-1.5.0.22 > > > > > > > > drwxr-xr-x 10 root root 4096 Aug 11 2010 > > java-1.5.0-sun-1.5.0.22 > > > > > > > > lrwxrwxrwx 1 root root 20 Dec 16 18:51 > > java-1.6.0-openjdk-amd64 > > > > -> > > > > > > java-6-openjdk-amd64 > > > > > > > > lrwxrwxrwx 1 root root 20 May 3 14:00 > > java-1.7.0-openjdk-amd64 > > > > -> > > > > > > java-7-openjdk-amd64 > > > > > > > > drwxr-xr-x 3 root root 4096 Jan 18 15:38 java-6-openjdk > > > > > > > > drwxr-xr-x 7 root root 4096 Mar 7 17:29 java-6-openjdk-amd64 > > > > > > > > drwxr-xr-x 3 root root 4096 Jan 18 15:38 java-6-openjdk-common > > > > > > > > lrwxrwxrwx 1 root root 19 Jun 9 2011 java-6-sun -> > > > > > > java-6-sun-1.6.0.26 > > > > > > > > drwxr-xr-x 8 root root 4096 Jan 18 15:47 java-6-sun-1.6.0.26 > > > > > > > > drwxr-xr-x 7 root root 4096 Jun 5 17:12 java-7-openjdk-amd64 > > > > > > > > drwxr-xr-x 3 root root 4096 Jun 5 17:12 java-7-openjdk-common > > > > > > > > lrwxrwxrwx 1 root root 12 Jan 5 18:27 java-gcj -> > > java-gcj-4.6 > > > > > > > > lrwxrwxrwx 1 root root 18 Apr 29 2010 java-gcj-4.4 -> > > > > > > java-1.5.0-gcj-4.4 > > > > > > > > lrwxrwxrwx 1 root root 18 Nov 14 2011 java-gcj-4.6 -> > > > > > > java-1.5.0-gcj-4.6 > > > > > > > > > > > > > > > > and I'd like to be able to say something like > > > > > > > > -D...=/usr/lib/jvm/java-7-openjdk-amd64 > > > > > > > > so that maven will use the corresponding compiler and JVM. > > > > > > > > > > > > > > > > Does the default configuration already cares for this? If so, > > which > > > > > > are the > > > > > > > > command-lins options? > > > > > > > > > > > > > > > > If not, I guess that this should be defined in a "profile" in > > > > > > > > "settings.xml". If so, could someone post such a profile? > > > > > > > > > > > > > > > > > > > > > > > > Thanks, > > > > > > > > Gilles > > > > > > > > > > > > > > > > > > > > > > --------------------------------------------------------------------- > > > > > > To unsubscribe, e-mail: dev-unsubscr...@commons.apache.org > > > > > > For additional commands, e-mail: dev-h...@commons.apache.org > > > > > > > > > > > > > > > > > > > > > > > > > > > -- > > > > > Xavier DETANT > > > > > > > > --------------------------------------------------------------------- > > > > To unsubscribe, e-mail: dev-unsubscr...@commons.apache.org > > > > For additional commands, e-mail: dev-h...@commons.apache.org > > > > > > > > > > > > > > > > > -- > > > Xavier DETANT > > > > --------------------------------------------------------------------- > > To unsubscribe, e-mail: dev-unsubscr...@commons.apache.org > > For additional commands, e-mail: dev-h...@commons.apache.org > > > > > > > -- > Xavier DETANT --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@commons.apache.org For additional commands, e-mail: dev-h...@commons.apache.org
