Using Groovy to update/generate XML file

Recently when I refactored the Android framework in my work, I found I need to generate eclipse .classpath file based on the library file.
I found using Groovy XML library is a lot easier to do this job compare to Java.

1. Add a new library to the current .classpath file.
Problem:  You have a Eclipse .classpath file, which is XML, you need to add another jar file in the class path. for example, adding following into the .classpath:

<classpathentry kind="lib" path="libs/abc.jar"/>

view raw classpath item hosted with ❤ by GitHub

Solution:

	def classpath = new XmlParser().parse('.classpath')
	classpath.each {
	println "${it.@kind} ${it.@path}"
	}
	def newEntry = new Node(classpath, 'classpathentry', [kind:'lib', path:'libs/abc.jar'])
	println "after adding a new entry:"
	classpath.each {
	println "${it.@kind} ${it.@path}"
	}
	String outxml = groovy.xml.XmlUtil.serialize( classpath )
	println outxml

view raw groovy_update_xml.groovy hosted with ❤ by GitHub

 If you want to write the output to file, use the following code snippet:

	def writer = new FileWriter(".classpath")
	groovy.xml.XmlUtil.serialize( classpath,writer )

view raw groovy_write_xml_to_file hosted with ❤ by GitHub

There is another method to print XML, using XmlNodePrinter, like:

new XmlNodePrinter().print(classpath)

view raw xmlnodeprinter hosted with ❤ by GitHub

But I found using XmlNodePrinter will not generate line break, and no xml header either.

2. Generate a new .classpath file
Problem:  iterate the libs folder, add all the jar file name into the .classpath file.
Solution:

	def lib_folder = "libs";
	def jarFiles = []
	new File(lib_folder).eachFile { file ->
	jarFiles << file.name
	}
	builder = new groovy.xml.StreamingMarkupBuilder()
	builder.encoding = "UTF-8"
	xmlDocument = builder.bind {
	mkp.xmlDeclaration()
	classpath {
	classpathentry(kind:"src", path: "src")
	classpathentry(kind:"src", path: "gen")
	classpathentry(kind:"con", path: "com.android.ide.eclipse.adt.ANDROID_FRAMEWORK")
	classpathentry(kind:"output", path: "bin")
	jarFiles.each { file ->
	classpathentry(kind:"lib", path: "libs/${file}")
	}
	}
	}
	def writer = new FileWriter(root + ".classpath")
	groovy.xml.XmlUtil.serialize( xmlDocument, writer)

view raw groovy_generate_xml hosted with ❤ by GitHub