The JDT zip files were obtained from:

http://download.eclipse.org/eclipse/downloads/drops/R-3.7.2-201202080800/download.php?dropFile=org.eclipse.jdt.source-3.7.2.zip
http://download.eclipse.org/eclipse/downloads/drops4/R-4.2.2-201302041200/download.php?dropFile=org.eclipse.jdt.source-4.2.2.zip

The zip files include the sources.