Some features of Ant 1.7.0

Ant 1.7.0 has just been released. It includes a long
list of fixes and it includes a new resource framework.

Some of the new features that have not got highlighed
are:

1. Support for junit.jar in the <junit> classpath element, this means that there is now no need to place the junit.jar in $ANT_HOME/lib.
2. Support for junit4.
3. Support for javax scripting. This is done by using a 'manager="javax"' attribute in the <script> task.
4. Scripting language jars can now be placed in the <script> classpath element. This means that these jars do not need to be placed in $ANT_HOME/lib. (This does not work for javascript and jython jars - will be fixed in Ant 1.7.1)
5. Script support for conditions, filters, mappers, selectors added.
6. Antversion condition added - scripts can how make sure that they are run by a supported version of ant.
7. Memory leakages plugged for <*ant*>

Javax scripting for ant 1.7.0

It looks like I am be able to persuade my ant
collegues to have javax.scripting in ant 1.7.0.

There are two options to specify javax.scripting
rather than bsf, have an extra attribute on the script
task:

<script language="javascript" engine="jsr">
 print("hello world\n");
</script>

or use a prefix in the language tag:

<script language="jsr:javascript">
 print("hello world\n");
</script>

The nice thing is that with this, one can use
javascript scripting in ant with java6 *without* any configuration.

Multiline strings in java - solved (sort of)

There has been an long outstanding request for
multiline stings in java. See http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4472509
and http://www.mrchucho.net/index.php/archives/2005/06/01/multi-line-strings-in-java/

With all the new 1.5 stuff being added - annotations, printf, varargs
it is quite annoying that java still has to do
"aaa\n"
+ "bbb\n"
...
for multiline strings.
There is especially annoying when - writing unit tests (xml strings for example)
and for doc and SQL annotations.
With JSR Scripting being added in jdk6, it has become completely stupid,
It would be nice to something like the pythonic -

engine = manager.getEngineByName("beanshell");
engine.eval("""
map = new HashMap();
map.put("foo", "bar");

importObject( map );

print( get("foo") ); // bar
""");

With the GPL release of javac, one can have a look at the
javac code - and see what needs to be done to add this much
needed extension.

A quick look at the code shows that it should be relatively easy
to add this - but I do not have the time at the moment
to add """.

However, one can add multiline strings easily
by relaxing the check for NL and CR.

$COMPILER_HOME/src/share/classes/com/sun/tools/javac/parser/Scanner.java
Line: 916 Change to
while (ch != '\"' /*&& ch != CR && ch != LF*/ && bp < buflen)

and presto the following compiles:

public class HelloWorld {
public static void main(String[] args) {
System.out.println("
Hello world
");
}
}

/f/src/compiler > java -jar dist/lib/javac.jar HelloWorld.java
/f/src/compiler > java -cp . HelloWorld

Hello world

/f/src/compiler >

The script example is a little ropy as one needs to escape
the " and \.

import javax.script.*;

public class ScriptExample {
public static void main(String[] args) throws Exception {
ScriptEngineManager m = new ScriptEngineManager();
ScriptEngine engine = m.getEngineByName("javascript");
engine.eval("
print(\"This is the world \");
print(\"calling\\n\");
");
}
}

/f/src/compiler > java -jar dist/lib/javac.jar ScriptExample.java
/f/src/compiler > java -cp . ScriptExample
This is the world calling
/f/src/compiler >