Swing Hacks

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Chapter 11, Native Integration and Packaging

#83 Control iTunes Under Windows

HACK

Working with COM

The Component Object Model (COM) is a standard way for Windows com-

ponents to expose functionality that other programs can call at runtime.

com4j (https://com4j.dev.java.net/) is an open source library that creates

connections from Java programs to COM objects. com4j has two parts: a

command-line program to create the Java interfaces that your program will

call, and a native library that binds your program to the COM object at run-

time.

com4j uses class annotations to do its magic, so you can only

use it with Java 5.0 or greater.

To get started, download the com4j package at https://com4j.dev.java.net/

servlets/ProjectDocumentList. With the com4j stubber and the iTunes exe-

cutable in your current directory, you can generate the interfaces like this:

java -jar tlbimp.jar -o jtunes -p test.jtunes iTunes.exe

This command will load the iTunes executable and look for COM defini-

tions. Once they are located,

tlbimp will generate a bunch of Java interfaces

in the

test.jtunes package and put the .java files into the jtunes directory. If

you look at the generated Java interfaces, you will see a whole slew of meth-

ods and objects for playing, querying tracks, and dealing with virtually every

other feature of iTunes. com4j will also pull out any embedded documenta-

tion and insert the documentation as JavaDoc ...