Installing ADT and ADK to eclipse

1. After installing the JDK, configure the environment variables:

In order to configure the system variable environment of the JDK, we need to set up three system variables, namely Java_home,path and classpath. Here are the three variables that are set to guard against.

Java_home
Set the system variable name first, and the variable value is the JDK's installation path on your computer: C:\Program files\java\jdk1.8.0_20. Once created, you can use%java_home% as the unified Reference path for the JDK installation directory.
Path
The Path property already exists, can be edited directly, appended with the original variable:;%java_home%\bin;%java_home%\jre\bin.
CLASSPATH
Set the system variable name to: CLASSPATH variable value is:.; %java_home%\lib\dt.jar;%java_home%\lib\tools.jar.
Note the variable value string is preceded by a "." Represents the current directory, the purpose of setting up classpath is to tell the Java execution Environment, in which directories you can find the classes or packages that you need to execute the Java program.

2. Download and install the offline ADT Package

Replace the adt-xx.x.x part of the Http://dl.google.com/android/ADT-xx.x.x.zip address with the ADT version number you want to download, and the ADT version number can be identified in the Android SDK manager. Example: Adt-23.0.6,http://dl.google.com/android/adt-23.0.6.zip

Eclipse:help->install New software ...,

Click "Add ..." in the Pop-up dialog box of location, select Archive ..., select the downloaded ADT Zip file, all items are selected for installation.
After the installation is complete, download the SDK via the Android SDK manager.

Installing ADT and ADK to eclipse