Chapter II Building an Android development environment

First, install the JDK
-jdk

Http://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html
Note the correct choice of download version, if the computer is 32-bit, then choose the 32-bit version (usually described as Windows x86), if the computer is 64-bit, then choose 64-bit version (usually described as Windows x64)
-JDK Installation

The JDK is easy to install, which is the next step, and note that the JRE (Java runtime Environment,java Runtime) will be installed at the end.
-Configure Environment variables
Path

%java_home%\bin;

CLASSPATH

.; %java_home%\lib\tools.jar;
Don't miss out on the front. is important


Java_home

Here's the path to write JDK installation path


Ii. installation of Eclipse
Iii. Installing the ADT Plugin

There are two ways to install ADT, both online and offline.
-Online Installation

Step1: Click on the Help menu to install new software

Step2: After opening name can write a name, location input http://dl-ssl.google.com/android/eclipse/then click OK.

Step3: All the way next until finish is finished.
-Offline installation

Because the Great Firewall blocked Google, some of Google's sites are also blocked, which led to our online installation failure. So you need to download the ADT package for offline installation.
Step1: Download ADT Package, HTTP://PAN.BAIDU.COM/S/1BNFITBX, do not need decompression after download
Step2: Installing ADT


Step3: All the way next until finish
Iv. installation of the SDK

There are two ways to install the SDK--online and offline installation
-Install the SDK online

Download the required version via SDK Manager


-Offline Installation SDK

Step1: To download the SDK files in advance, some people who love sharing will share some download resources on the Internet, to download it.
Step2: Configuring the Path
Expand
What is-JDK?

The full name of the JDK is the Java Development Kit (Java Development component), similar to a bunch of bricks, the basic shape for you to define, the rest is to put a great wall or put a day on the door to see your creation. The Android SDK mentioned below is somewhat similar to this.
The difference between-JDK and JRE

JDK is a Java programmer development necessary, because it is a component, it is a building block, no building blocks how to put small house. The JRE is the operating environment of the Java program, the location of the JVM (the Java Virtual Machine), and the Java program is not able to run without it.
-Why to configure environment variables

Bottom line: Let the Java program find its way home. After you install the JDK, equivalent to the Java program to build a home, run Java program, need to have a clear guide, in order to let him find home, otherwise can not find home lost, on the error. Configuring the environment variable is equivalent to pointing a path home to the Java program. Then, since it is to give people pointed home road, this road can not be wrong, so the configuration environment variables, must pay attention to rigorous, can not have shred error.

A more formal explanation:
The reason for configuring path is that you can compile and run your Java program in the console without having to go to the Java program directory to run, such as console commands: Java-version, to execute this command, The console will first find the Java.exe program in the current directory, can not find the path specified in the PATH variable to find this command, if not found will not execute, Java.exe is in the Java program directory in the bin directory, so path will be assigned to the Java Program Bin directory. Path can be said to be mainly for convenience, so that you can directly use Javac and other commands in any directory, or only to the bin directory to execute Javac and Java commands.

The CLASSPATH variable is usually a newly created variable. When compiling, running the Java program will be in its designated directory down to find the class you want to use, but also in this directory to find, and then in the designated directory to find, can not find will be error.

Why not configure in classpath.; It? For example, if we are not configured in Classpath.; Then the Java command is executed with an error because it cannot find the Test.java compiled Test.class file.


-What is ADT

ADT Full name Android development Tools, is essentially an Eclipse plugin for Android development.
-What is the SDK

SDK full name Software Development Kit (software Development Kit). Not only does Android have an SDK, some software that supports third-party custom development has an SDK that allows users to customize the development on top of that.

Chapter II Building an Android development environment