如果你无聊，不妨逛逛这些网站

1.菜鸟教程

www.runoob.com

2.W3cshool

www.w3school.com.cn

3.Android

https://howtodoinjava.com/java-tutorials-list-howtodoinjava/

https://www.ibm.com/developerworks/cn/topics/

http://tutorials.jenkov.com    -->https://www.journaldev.com/8988/android-studio-tutorial-hello-world-app

https://docs.oracle.com/javase/tutorial/

https://www.journaldev.com

https://guides.codepath.com/android 

www.tutorialspoint.com/android/

www.vogella.com/tutorials/android.html

https://developer.android.google.cn/training/index.html 

// Android 常用列子网站

https://examples.javacodegeeks.com/category/android/