In "Java" perspective I can see Java code (between "Package Explorer" and "Outline" - depends on your settings, however it's a kind of default I think).
Then I add "DDMS" perspective and I can't see Java code. I have only "Devices" and "Threads", "Heap" etc. No Java editor in between.
How to show Java code in DDMS perspective?
You can simply switch the editor by setting up a keyboard shortcut to really toggle the editor area visibility. Open the Preferences and navigate to General > Keys *(or press Ctrl/Cmd + Shift + L )* twice to jump right to the Keys preferences).
Search the commands for area and then assign a keyboard shortcut to the Toggle Editor Area Visibility command.