15 JDK Installation for Microsoft Windows

Downloading the Installer

If you save the self-installing executable file to disk without running it from the download page at the web site, note the file size specified on the download page. After the download has completed, verify that you have downloaded the complete file.

Installing the JDK Silently

Instead of double-clicking or opening the installer, you can perform a silent, non-interactive, JDK installation by using the command-line arguments. The following table lists example installation scenarios and the commands required to perform them. The notation jdk stands for the downloaded installer file base name, such as jdk-8u05-windows-i586.

jdk.exe /s

jdk.exe /s ADDLOCAL="ToolsFeature,SourceFeature"

jdk.exe /s ADDLOCAL="ToolsFeature,SourceFeature,PublicjreFeature"

jdk.exe /s /INSTALLDIRPUBJRE=C:\test\

Updating the PATH Environment Variable

If you do not set the PATH variable, you need to specify the full path to the executable file every time you run it, such as:

C:\> "C:\Program Files\Java\jdk1.8.0\bin\javac" MyClass.java

It is useful to set the PATH variable permanently so it will persist after rebooting.

To set the PATH variable permanently, add the full path of the jdk1.8.0\bin directory to the PATH variable. Typically, this full path looks something like C:\Program Files\Java\jdk1.8.0\bin. Set the PATH variable as follows on Microsoft Windows:

1. Click Start, then Control Panel, then System.

2. Click Advanced, then Environment Variables.

3. Add the location of the bin folder of the JDK installation to the PATH variable in System Variables. The following is a typical value for the PATH variable:

   C:\WINDOWS\system32;C:\WINDOWS;C:\Program Files\Java\jdk1.8.0\bin
   

Note:

• The PATH environment variable is a series of directories separated by semicolons (;) and is not case-sensitive. Microsoft Windows looks for programs in the PATH directories in order, from left to right.

• You should only have one bin directory for a JDK in the path at a time. Those following the first instance are ignored.

• If you are not sure where to add the JDK path, append it.

• The new path takes effect in each new command window you open after setting the PATH variable.

Corrupt Cabinet File

If you see the error message "corrupt cabinet file," then the file you have downloaded is corrupted. Check the file size against the expected file size listed in these instructions. If sizes do not match, try downloading the bundle again. (A cabinet file contains compressed application, data, resource, and DLL files.)

System Error During Decompression

If you see the error message "system error during decompression," then you might not have enough space on the disk that contains your TEMP directory.

Program Cannot Be Run in DOS Mode

If you see the error message "This program cannot be run in DOS mode," then do the following:

1. Open the MS-DOS shell or Command Prompt window.

2. Right-click the title bar.

3. Select Properties.

4. Choose the Program tab.

5. Click the Advanced button.

6. Ensure that the item "Prevent MS-DOS-based programs from detecting Windows" is not selected.

7. Select OK.

8. Select OK again.

9. Exit the MS-DOS shell.

10. Restart your computer.

Private Versus Public JRE

Installing the JDK also installs a private JRE and optionally a public copy. The private JRE is required to run the tools included with the JDK. It has no registry settings and is contained entirely in a jre directory (typically at C:\Program Files\jdk1.8.0\jre) whose location is known only to the JDK. On the other hand, the public JRE can be used by other Java applications, is contained outside the JDK (typically at C:\Program Files\Java\jre1.8.0), is registered with the Windows registry (at HKEY_LOCAL_MACHINE\SOFTWARE\JavaSoft), can be removed using Add/Remove Programs, might be registered with browsers, and might have the java.exe file copied to the Windows system directory (which would make it the default system Java platform).

Source Files in Notepad

In Microsoft Windows, when you create a new file in Microsoft Notepad and then save it for the first time, Notepad usually adds the .txt extension to the file name. Therefore, a file you name Test.java is saved as Test.java.txt. It is important to note that you cannot see the .txt extension unless you turn on the viewing of file extensions (in Microsoft Windows Explorer, unselect "Hide file extensions for known file types" under Folder Options). To prevent the .txt extension, enclose the file name in quotation marks, such as "Test.java", when typing it into the Save As dialog box.

On the other hand, Microsoft WordPad does not add the .txt extension if you specify another extension. However, you must save the file as "Text Document".