I am new to Android development. Can I use my existing Java code developed using JDK 7 in Android?
The functions use xerces dom and xslt and xpathapi. Currently when I installed Android Eclipse ADT environment these functions are not compiling. I would also like to know whether an Android device itself supports JRE 6 or 7?
Originally Android development tools supported only jdk 6 features. But that was changed, first by Android Studio 0.3.2 in October 2013 see: http://tools.android.com/recent/androidstudio032released
Support for language features like the diamond operator, multi-catch, try-with-resources, strings in switches, etc. When creating a new project, you can specify a source language level: Note that you can use all these language features not just with Android KitKat, but with older versions of Android too! There is one exception to that: try-with-resources, which will require minSdkVersion 19. Therefore, Studio will flag any uses in your code of try-with-resources if your minSdkVersion is less than 19:
then by ADT plugin 22.6 in March 2014,see: http://developer.android.com/tools/sdk/eclipse-adt.html
Added support for Java 7 language features like multi-catch, try-with-resources, and the diamond operator. These features require version 19 or higher of the Build Tools. Try-with-resources requires minSdkVersion 19; the rest of the new language features require minSdkVersion 8 or higher. To use the new language features after installing ADT 22.6.0, ensure that you run Eclipse on JDK 7 and change your application project settings to use JDK 7.
Android is not intended to be 100% compatible with any Java SE API version, not 6 nor 8 nor any. this was the reason of the court case of Oracle raised Against Google, accusing Google of fragmenting Java. Some APIs are impossible to implement on android as Swing; Imagine a window with a close button on android ! Others were delayed but implemented : for e.g.: Charset class is in Java SE 1.4 but implemented in android API 9, AutoClosable in Java 7 implemented in Android API level 19 to allow implementation of try-with-resources language feature. Some APIs are existent but for different purpose as Console.