Android XML Editor cannot process this input

If you open an XML document in Eclipse and you get the error “Android XML Editor can not process this input”, you can solve it by opening the preferences (Window menu -> Preferences) and select General -> Editors -> File Associations, highlight *.xml , and choose XM Editor as default editor, and then no more Android Common XML Editor.

How to add a file .jar to an Android project in Eclipse

Adding a file .jar from the menu of Eclipse, File -> Properties -> Java Build Path -> Libraries -> Add External JARs…, causes an error, the project compiles but at runtime you get the error “NoClassDefFoundError” as if the file .jar was missing in the project.