Run Ant from Java

Run ant from Java

Is there a tutorial on how to run Ant from Java?

Part of my answer to this question might help:

See this article
and this article:

   File buildFile = new File("build.xml");
   Project p = new Project();
   p.setUserProperty("ant.file", buildFile.getAbsolutePath());
   p.init();
   ProjectHelper helper = ProjectHelper.getProjectHelper();
   p.addReference("ant.projectHelper", helper);
   helper.parse(p, buildFile);
   p.executeTarget(p.getDefaultTarget());

How to run ant command through java program?

A number of things jump out at me.

1. The ant command should be ant.bat under windows
2. You should separate the command from the arguments, so that each argument represents a separate String. This greatly reduces the complexity of arguments that contain spaces, for example...
3. You should really use ProcessBuilder, it will reduce the complexity of using Process

For example...

ProcessBuilder pb = new ProcessBuilder(
    "D:\\installs\\apache-ant-1.9.2\\bin\\ant.bat", 
    "-v");
pb.redirectError();
// This should point to where your build.xml file is...
pb.directory(new File("C:/"));
try {
    Process p = pb.start();
    InputStream is = p.getInputStream();
    int in = -1;
    while ((in = is.read()) != -1) {
        System.out.print((char) in);
    }
    int exitValue = p.waitFor();
    System.out.println("Exited with " + exitValue);
} catch (Exception ex) {
    ex.printStackTrace();
}

I should also point out that ant is a linux/unix shell script, which Windows won't know what to do with ;)

Updated

I've tested this using Windows 7 and Java 7, works just fine

I've tested this using Windows 7 and Java 6, works just fine...

If you do continue to have issues running the ant.bat directly, then you will need run the batch file via the command processor

ProcessBuilder pb = new ProcessBuilder(
    "cmd",
    "/c",
    "D:\\installs\\apache-ant-1.9.2\\bin\\ant.bat", 
    "-v");

Ant: How to execute Ant from Java

You can execute Ant from Java and print the output to System.out as follows (note that -buildfile is the same as -file or -f):

ProcessBuilder builder = new ProcessBuilder("ant", "-f", "/path/to/build.xml", "searchDirectories");
Process process = builder.start();

try (BufferedReader out = new BufferedReader(new InputStreamReader(process.getInputStream()))) {
    out.lines().collect(Collectors.toList()).forEach(System.out::println);
}

If your searchDirectories task produces wrong results, maybe the corresponding <target> contains a bug.

How can I run a java class with a relative path from Ant?

There's several ways you might do this. Perhaps the simplest is to specify a relative value for the dir attribute in your java task, for example:

<java classname="test.XMLCreator" classpathref="compile-classpath" dir=".." fork="true">

You'll need to also use fork for that to work, which may have other side effects.

On your specific question: many tasks support the dir attribute, some use nested filesets, so there you would have to specify the directory on the nested element.

Another approach is to execute a target using the ant task. The directory specified there will be used as the basedir for all tasks in the target.

How to run `ant` build-script without setting any environment variable?

You problem is not concerned with *_HOME variables, but I first answer you question.
Yes you can.

Just configure your PATH variable to (1) dir where java.exe resides (2) where ant.bat resides.
In case when *_HOME defined the path can be written:

PATH=...;%JAVA_HOME%\bin;%ANT_HOME%

Since you have no such variables you need declare:

PATH=...;C:\Program Files\Java\bin;c:\ant\bin

But in real you problem that you try use JRE while ant needs JDK. Just download from oracle site. tools.jar is part of JDK but not JRE.

UPDATE:
You can write you own bat file that lets Windows know where to locate .exe and .bat files. Just create in notepad text file named my-ant.bat And place following there:

set JAVA_HOME=C:\buildscript_required_files_v2\java\jdk64
set PATH=%PATH%;%JAVA_HOME%\bin;C:\buildscript_required_files_v2\apache-ant-1.9.0\bin
rem ** Now we invoke ant **
ant 

Obviously you would like manipulate with command line arguments. That is why instead of last ant line use following:

set my_ant_start=
:setupArgs
if ""%1""=="""" goto doneStart
set my_ant_start=%my_ant_start% %1
shift
goto setupArgs
:doneStart
rem ** Now we invoke ant **
ant %my_ant_start%

How to run ant inside java command

I think the simplest solution is to call org.apache.tools.ant.Main#main just like the ant command line does.

For instance:

Main.main(new String[] { "-f", "path/to/the/build.xml"});

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