2. Building Java Development environment

Previous--chapter1:1, Java language overview

Download Install JDK

1. Download JDK link from Oracle website

3. After the download is complete run the installation JDK, the personal likes installs under the D disk;

5. JDK Installation directory structure:

   • Bin: a command for storing tools, such as Javac,java;

   • DB: Install javadb path;

   • Include: platform-specific header files;

   • JRE: The JRE environment required to run the Java program;

   • LIB: The relevant jar dependency package;

7. Configure environment variables (WIN10):

   1. Open in turn: Control Panel--System and security--system--Advanced system Setup--environment variable--system variable;

   2. New, variable name: java_home, Variable value: D:\Program files\java\jdk1.8.0_131

   3. Locate path, add:%java_home%\bin (note semicolon)

   4. New, variable name: classpath, Variable value:.; %java_home%\lib\dt.jar;%java_home%\lib\toos.jar; Indicates the current path, used to force the Java interpreter to search for Java classes under the current path, and to separate variables.

      • Note that the Classpath,java command is configured to be recognized, and this place is prone to error, so be sure to pay attention.

8. To verify the installation:

   Shortcut key Win+r Open Run--cmd, enter Java Run command, javac compile command or java-version, if display is successful installation, so easy!!!

   ?! installation Test

   Set up the environment, we come to run a small program, which is what every programmer knows: HelloWorld

   Install JDK with 1:linux environment:

   1. Download the corresponding version of the JDK, usually the tar.gz suffix file;

   2. Upload to the Linux environment/usr directory via XFTP client;

   3. 
      mkdir Java
      CP jdk-8u161-linux-i586.tar.gz java/
      
      

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   4. Configure Environment variables:
   ?
   "' Shell
   Vim/etc/bashrc
   #文件末尾添加
   Export java_home=/usr/java/jdk1.8.0_161
   Export JRE_HOME=${JAVA_HOME}/JRE
   Export Classpath=.:${java_home}/lib:${jre_home}/lib: $CLASSPATH
   Export Java_path=${java_home}/bin:${jre_home}/bin
   Export Path=${java_path}: $PATH

   5. Execute the command to make the configuration effective:source /etc/bashrc

   6. Enter java -version command to view Java version found error:

      -bash:/usr/java/jdk1.8.0_161/bin/java:/lib/ld-linux.so.2:bad ELF interpreter:no such file or directory

      This problem occurs because the JDK and the system version do not match.

   7. Execute command: yum install glibc.i686 Resolve version issue, enter java -version discovery is installed correctly:

      Java Version "1.8.0_161"
      Java (TM) SE Runtime Environment (build 1.8.0_161-b12)
      Java HotSpot (TM) Client VM (build 25.161-b12, Mixed mode)

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   Next--chapter1:3, the first Java program

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2. Building Java Development environment