As we all know Java is a programming language, programming language is used to write software. Then the use of Java in the end what can be used to write software? As you know a lot of software written in Java can be used, for example: QQ, Thunder, Taobao, Jingdong, etc., then what good Java compare it? That is our future in the Java development engineers work in the end what kind of software you want to write it?
the answer is:
1. Internet: electricity providers, P2P, and so on;
2. Enterprise applications: ERP, CRM, BOS, OA, and so on.
After the birth of JAVA, through the development and changes in the following versions:
In 1991, Sun's Green Project, Oak
In 1995, the introduction of Java Beta
In 1996, JDK1.0
In 1997, JDK1.1
In 1998, JDK1.2, greatly improved the earlier version of defects, is a revolutionary release, J2SE J2EE J2ME
In 2004, J2SE 5.0 (1.5.0) Tiger Tiger
In 2006, J2SE 6.0 (1.6.0) Mustang Mustang
In 2011, JAVASE7.0
Environmental Considerations JDK installation :()
1. Full English path
2. Recommended install JDK and JRE when placed in the same subdirectory (can not have Chinese, spaces)
3. When you create a file name in all lowercase ( "jdk1.8.0_171)
Configuration environment variable:
Purpose (why):
After writing command to compile the source code for the class file javac, the configuration environment can be executed in any order javac path.
Note: Before you configure the environment variable path in the content of the first backup; After modifying environment variables, open cmd rewrite
steps: Right Computer -> Advanced System Settings -> Environment Variables -> System Variables -> path, put the jdk bin directory path to the configuration, the separator used in the English state between the paths; semicolon
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4.W10 system
JAVA_HOME: (W10 does not seem to need)
Objective: because they do not want to frequent operation path, may modify the error, it will become possible in line with the incoming, the same reservations, a new JAVA_HOME system variable, the value jdk directory
”HelloWorld”：
