windons bat merge files under multiple folders

E:\spring-tool-suite-3.8.1.RELEASE-e4.6-win32-x86_64\sts-bundle\sts-3.8.1.RELEASE\workspace\dmp\src\main\java\com\dmp>for /R %f in (*.java) do type "%f" >> output.txt

Merge text files
Soft copy source code can be used for

reference
http://mos86.com/74553.html/2/