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javac option to compile all java files under a given directory recursively
(10 answers)
Closed 9 years ago.
How to compile all java files in all subfolders on Unix, using javac?
On Windows...
Create a batch file:
for /r %%a in (.) do (javac %%a\*.java)
...then execute it in the top-level source folder.
On Linux...
javac $(find ./rootdir/* | grep .java)
Both answers taken from this thread...
http://forums.oracle.com/forums/thread.jspa?threadID=1518437&tstart=15
But as others suggested, a build tool would probably prove helpful.
Use a build tool such as Ant or Maven. Both lets you manage dependencies in a much better way than can be accomplished using e.g. the find UNIX tool. Both And and Maven also lets you define custom tasks to be performed in addition to compilation. Maven furthermore comes with conventions for managing external dependencies in remote repositories, as well as conventions for running unit tests and features that support continuous integration.
Even if you just need to compile your source files once in a while, you'll probably find that setting up a simple Ant build.xml file can be a big time saver in the end.
Finally, most of the popular IDE and code editor applications has some kind of integration with Ant build scripts, so you can run all the Ant tasks from within the editor. NetBeans, Eclipse, IDEA and more also has built-in support for Maven.
Read this first, if you're new to Ant. Below is the example build file from the link:
<project name="MyProject" default="dist" basedir=".">
<description>
simple example build file
</description>
<!-- set global properties for this build -->
<property name="src" location="src"/>
<property name="build" location="build"/>
<property name="dist" location="dist"/>
<target name="init">
<!-- Create the time stamp -->
<tstamp/>
<!-- Create the build directory structure used by compile -->
<mkdir dir="${build}"/>
</target>
<target name="compile" depends="init"
description="compile the source " >
<!-- Compile the java code from ${src} into ${build} -->
<javac srcdir="${src}" destdir="${build}"/>
</target>
<target name="dist" depends="compile"
description="generate the distribution" >
<!-- Create the distribution directory -->
<mkdir dir="${dist}/lib"/>
<!-- Put everything in ${build} into the MyProject-${DSTAMP}.jar file -->
<jar jarfile="${dist}/lib/MyProject-${DSTAMP}.jar" basedir="${build}"/>
</target>
<target name="clean"
description="clean up" >
<!-- Delete the ${build} and ${dist} directory trees -->
<delete dir="${build}"/>
<delete dir="${dist}"/>
</target>
</project>
Once you're familiar with Ant, you'll find it easier to move to Maven.
I don't know if it is the best way, but this should work :
find . -name "*.java" | xargs javac
Use Ant to write a script to compile as many source folders as you want.
Use Maven (as a more modern alternative to Ant).
Use an IDE, like Eclipse (all IDEs I know will happily compile multiple source folders for you)
Another (less flexible) way, if you know how much folder levels there are:
javac *.java */*.java */*/*.java */*/*/*.java */*/*/*/*.java ...
Depending on your shell, you may have to set it to expanding non-matching patterns to nothing, in bash with shopt -s nullglob. For example, I'm using the following shell function to find text in my java files:
function jgrep ()
{
(
shopt -s nullglob
egrep --color=ALWAYS -n "$#" *.tex *.java */*.java */*/*.java */*/*/*.java */*/*/*/*.java */*/*/*/*/*.java
)
}
jgrep String
But really, use an build tool, as the others said.
Related
how to remove java System.out.println from ant script?
(when we compile the code from ant we should remove the existing java class system.out.println & compiled classes should not have the Sys.out.println)
In build.xml file, preparation phase, before the mkdir commands,
provide:
<javac srcdir="exe" includes="SysOutRemove.java"/>
<java fork="true" classname="SysOutRemove" dir="exe" failonerror="true"/>
where SysOutRemove.java is in the exe package of your project.
SysOutRemove.java should iterate through the list of directories and files in them, store the contents of each file to a reader or something, find sysout statements and replace.
We can use this in the ant file.
<replaceregexp match="System.out.println(.*);" replace="" flags="g" byline="true">
<fileset dir="${src.dir}" includes="**/*.java"/>
</replaceregexp>
I have multiple Java eclipse projects. Each of them has "jardesc" file for building jar. It's nice - double click -> finish and jar file is made. But when i have to export several jars it's a pain - i have to repeat procedure several times.
Please tell me, can i use Ant script to run several "jardesc" files at once (and get several jars according to each jardesc file)? How to do it?
You could use the jar target to make the jars for you:
<jar destfile='destination.jar' basedir='source\dir\' />
so your build.xml would look a little like this:
<project default="makejars">
<target name="makejars">
<jar destfile="app1.jar" basedir="app1\src\" />
<jar destfile="app2.jar" basedir="app2\src\" />
<jar destfile="app3.jar" basedir="app3\src\" />
</target>
</project>
then just run ant in the same directory as build.xml, and the jars should be made.
Take a look at subant task in ant. You can create ant-file which would call other files to.
<subant target="create_jar1">
<fileset dir="." includes="jar2.xml"/>
</subant>
<subant target="create_jar2">
<fileset dir="." includes="jar1.xml"/>
</subant>
You can use some loops to create ant parameters however there is no way to loop to create multiple jars (even with ant-commons extension), a copy & paste is the only viable solution unless you want to write an ant plugin (which doesn't really take that much 2 hours reading docs + write simple plugin)
I am using sshexec, which depends on jsch-0.1.48.jar. I can't just put that into the ant/lib directory because other users wishing to use the same build script will have to make a configuration on their machine before they can do so.
What I want to do is to be able to reference jsch-0.1.48.jar as part of the project. Currently, I have it sitting in project/libs directory and I am trying something like:
<property name="lib" location="lib"/>
<taskdef name="sshexec" classname="org.apache.tools.ant.taskdefs.optional.ssh.SSHExec">
<classpath>
<pathelement location="${lib}/jsch-0.1.48.jar"/>
</classpath>
</taskdef>
<target name="sshcmd" description="ssh command">
<sshexec host="X.X.X.X" username="USER" password="PASS" command="cmd" trust="true"/>
</target>
But that's not working:
C:\dev\trunk\project:>ant sshcmd
Buildfile: C:\dev\trunk\project\build.xml
BUILD FAILED
C:\dev\trunk\project\build.xml:275: taskdef A class needed by class org.apache.tools.ant.taskdefs.optional.ssh.SSHExec cannot be found: com/jcraft/jsch/Logger
using the classloader AntClassLoader[C:\dev\trunk\project\lib\jsch-0.1.48.jar]
Total time: 0 seconds
The sshexec task is built into ANT, you do not need to invoke a taskdef operation to use it. All that's missing is the jsch jar.
This can installed using a bootstrap target as follows (from Maven Central):
<target name="bootstrap" description="Install missing jars">
<mkdir dir="${user.home}/.ant/lib"/>
<get src="http://search.maven.org/remotecontent?filepath=com/jcraft/jsch/0.1.48/jsch-0.1.48.jar" dest="${user.home}/.ant/lib/jsch.jar"/>
</target>
This target only needs to be run once, after which the ANT sshexec task will work as expected on the developer's PC.
Update
If you don't want to download jars another mechanism to pass the location of ANT libraries from the command line as follows:
ant -lib /path/to/project/lib/dir ...
For more details on ANT library management, I refer you to the ANT manual
The jsch jar is packaged with my project. So instead of downloading it, I am copying it into the ant library. The build will fail the first time it is run, which is fine for my purposes. It will succeed the second time because the jar will be in the library and would be loaded at start.
<target name="jschset" description="Set the jar">
<copy file="${lib}/jsch-0.1.48.jar" tofile="${ant.home}/lib/jsch-0.1.48.jar"/>
</target>
So I wrote an ant build.xml file where I take the class files from two Java programs, one that extends the other, package them up into two separate jar files, and then, launches them.
<java classname="Main">
<classpath>
<pathelement location="${mainDir}"/>
<pathelement path="${Main-Class}"/>
</classpath>
</java>
Whenever I invoke ant, it says that "Main" can not be found. I can post the rest of the build.xml file if needed but it's really just this part that I'm confused about. I'm pretty sure that I have the classname right but my biggest problem is figuring out what goes in for location and path. Right now I just have dummy variables.
EDIT: Here's the whole file.
<?xml version="1.0"?>
<project default="dist" name="webscarab">
<description>Class</description>
<property name="ClassFiles" location="..\Simple\trunk\dev\Class\bin\" />
<property name="mainClassFiles" location="..\Simple\trunk\dev\main\build\" />
<property name="buildDir" location=".\build" />
<property name="distDir" location=".\dist" />
<property name="mainDir" location="..\Simple\trunk\dev\webscarab\src\" />
<target name="init">
<tstamp/>
<mkdir dir="${buildDir}"/>
<mkdir dir="${distDir}"/>
</target>
<target name="dist" depends="init">
<jar destfile="${distDir}/package${DSTAMP}.jar" basedir="${ ClassFiles}"/>
<jar destfile="${distDir}/package-web-${DSTAMP}.jar" basedir="${mainClassFiles}"/>
<java classname="Main">
<classpath>
<pathelement location="${mainDir}"/>
<pathelement path="${Main-Class}"/>
</classpath>
</java>
</target>
</project>
EDIT 2: I should mention everything is already compiled and I have all the .class files. It's not something I need to do in the Ant file.
The error message about “class cannot be found” is likely due to an incorrect classpath.
The classpath should grant access to all the class and resource files your application requires. It is composed of a set of directories and jar files. location will denote a single directory or path, whereas path will denote multiple, separated by ; or : depending on your platform.
In your case, it seems to me that you want your classpath to either consist of ${pegaFuzzClassFiles} and ${webScarabClassFiles} as directories, or of ${distDir}/package-pega-${DSTAMP}.jar and ${distDir}/package-web-${DSTAMP}.jar as jar files. You could do this using a single <pathelement path="…"/> element, but I'd suggest multiple <pathelement location="…"/> as I consider this to be clearer.
You should also make sure that any third-party libraries used by your application are available on that path as well. You could nest one or more <fileset> into that <classpath>, each of them describing all the jar files in a given directory.
You probably need to change the elements to point to the Jars that are being created, right now the classpath would appear to point to the source, which is not going to work as the classpath needs the compiled .class files or the jars that contain them.
I would also, just as a matter of style, move the task into a separate 'run' or 'run-app' target that depends on the dist target.
You need to Javac task to compile your code and after that you can run your compiled class. For more information about Javac task visit http://ant.apache.org/manual/Tasks/javac.html
The second advice:
The use of the unix slash '/' is strongly recommended, whether you're on
windows or not. Change your mainDir,distDir and buildDir property locations.
I don't have a ton of ant experience, but you might need to explicitly tell java which jar file to run.
<java jar="path-to-jar-file" classname="org.owasp.webscarab.Main">
My Java application has got a package structure similar to this:
src/com/name/app
src/com/name/app/do
src/com/name/utils/db
How would I go about compiling Java files in these directories in to a runnable jar? I need to package required libraries into the generated JAR (jdbc).
I've always done these things in Eclipse but now I need to supply a couple of people with a way to compile the repository without the use of eclipse and I was thinking of making a makefile or a script that invokes the necessary javac pattern.
Take a look at Ant. It's a relatively simple build tool to understand, and provides everything that meets your requirements. Here's a quick skeleton build.xml to get you started:
<project name="my_app_name" default="jar">
<target name="compile">
<javac srcdir="src" destdir="bin">
<classpath>
<fileset dir="lib">
<include name="**/*.jar" />
</fileset>
</classpath>
</javac>
</target>
<target name="jar">
<jar manifest="manifest_file" destfile="dist/my_app_name.jar">
<fileset dir="bin" />
<fileset dir="lib" />
</jar>
</target>
You need to create a manifest file that will tell the java process which class holds the "main" method. Here is a good place to start learning about manifests.
As an alternate that produces really cluttered Ant build files, you can right click on your Eclipse project and choose "Export...", then choose "General > Ant Buildfiles".
Anyway, that should get you started. You can ask more specific questions as you run into them.
First of all, consider using Ant for such a task.
But since you asked for a manual process, you need to first create a manifest file, like so:
Manifest-Version: 1.0
Created-By: 1.6.0 (Sun Microsystems Inc.)
Class-Path: lib/jdbc.jar lib/otherlib.jar
Main-Class: com.name.app.MainClass
Replace the contents of Class-Path with your libs, and Main-Class with the fully qualified name of your main class.
Then, you need to generate the actual .jar, using the following command:
jar cfm app.jar MANIFEST.MF src/com/name/app/*.class src/com/name/app/do/*.class
Where MANIFEST.MF is the previously mentioned manifest file, and the rest is the folders where your .java classes lie in.
Finally, to run your app, you simply execute: java -jar app.jar.
Consider using Ant to do this. http://ant.apache.org/
I recommend that you use Apache Ant to implement your build scripts.
If implemented correctly, Ant is easy to use and the build scripts can be run on any platform that you can install a JDK on. Indeed, with a little bit of work, you can even set up your project so that users don't even need to download / install Ant. (Hint: add the Ant JAR files and a wrapper script to your project distro)