1, the JDK

JDK: Java Development Toolkit – the foundation of Java development

Check for installation:

JDK -- CMD -- javac: Check if the compilation environment is included -- CMD -- java-version: Check if the JDK is installed and get the version number

The JDK installation:

Installation process according to the requirements of the next step — customization, the installation directory will be modified

Configure environment variables:

Way one: simple configuration late maintenance trouble

Copy the JDK installation directory subdirectory bin to My Computer right-click to Properties to Advanced System Settings to Environment Variables

-system variable --path variable -- new -- copied directory address (Win10) -path variable puts the copied address to the front and uses ";" Segmentation (Windows 7)

-- OK -- Check to see if the configuration was successful

Method two: configuration trouble later maintenance is relatively easy (Suggestions)

Copy the JDK installation directory into my computer right-click, Properties, Advanced System Settings, Environment Variables, System Variables and create a new variable named JAVA_HOME and the value of the directory address in the directory PATH variable %JAVA_HOME%\bin (Win10) -PATH variable handwriting %JAVA_HOME%\bin; Placed at the front (Windows 7)

-- OK -- Check to see if the configuration was successful

2. JDK Uninstall

-Delete product (installation folder) -Delete service (delete java.exe, javaw.exe and javaws.exe files in Windows\System32 and Windows\SysWOW64 folders on C drive) - delete the registry regedit HKEY_LOCAL_MACHINE/SOFTWARE/JavaSoft remove all contents - clear environment variable - to restart the computer

3. Precautions:

  1. The target of the software installation is in English: the Chinese directory may not be recognized;
  2. Install software as far as possible custom installation, and classification;
  3. Try not to install the software to the system disk C disk;

4. Conclusion:

1. Write special symbol “;” Semicolons are half-angle symbols for English states; Spaces are meaningful

2. Install and uninstall software, and understand the function of each step

3, MyEclipse installation (if you have installed it before, you can have version issues, merge issues)

4. Cracking steps:

  • How it works: Replace the previous one with a new JAR file
  • Operation:

Step 1: After unzipping, double-click the file as shown below: Enter the decoding generating page

Step 2: Type UserCode, which is a custom name, such as ABC1234, and click SystemID. A SystemID will be generated automatically.

Step 3: Click the Active Activation button, OK, at this time we need to crack the various codes have, copy and paste into MyEclipse can be. (You can also replace the previous one with a new JAR file)

-- (***) You must install the JDK before you install MyEclipse, otherwise you will not be able to hack it -- because you are using a JAR to hack it -- you need to use the Java environment to run it