Upgrading Java on Windows

Java Upgrade Guide

Upgrading your Windows Java Development Kit (JDK) ensures your system benefits from the latest features and security updates. 

This guide provides step-by-step instructions for upgrading to JDK 8u422, setting environment variables, and verifying the installation.

Steps to Upgrade Java to 8u422

1. Stop Dependent Services

• Stop Tomcat:
  • On the OvalEdge Virtual Machine, type "services" in the Windows search bar and press Enter. Locate the Tomcat service in the list and stop it.
    
• Taking Backup:

• • Backup Existing Java Configurations:

• • • Open a Command Prompt as Administrator.
    • Navigate to the bin directory of the Apache Tomcat installation:
      cmd: cd <path_to_tomcat>\bin  

• • Open the Tomcat Configuration Tool:

• • • Run the following command to launch the tomcat9w configuration utility:
      cmd: tomcat9w.exe //ES//<tomcat_servicename>
    • Replace <tomcat_servicename> with the name of your Tomcat service.
      

• • Save Java Configurations:

• • • In the Java tab of the configuration tool, copy all Java options and paths.
      
      
      

• • • Save this information in a text file for future reference.
• Saving Backup Details:

• • Save the configuration details (e.g., paths, Java options) from the Tomcat properties for later use.
    
• Stop Elasticsearch:
  • In the Windows search bar, type "services" and press Enter. Locate the Elasticsearch service in the list, right-click, and select Stop to stop the service running on the machine.
    

2. Remove the Tomcat Service

• • Open a Command Prompt as Administrator.
  • Execute: sc delete <tomcat_servicename>  
  • Replace <tomcat_servicename> with your Tomcat service name.

3. Uninstall Oracle Java

• • Go to Control Panel > Programs and Features.
  • Select the installed Oracle Java version and click Uninstall.
  • Navigate to the Environment Variables:
    • Delete the JAVA_HOME variable.
    • Remove any Java-related paths from the Path variable.
      
      
      
      
      
  • Verify Uninstallation:

• • • Open a Command Prompt and run: java -version  
    • It should throw an error confirming Java is uninstalled.

4. Install OpenJDK Java 8u422

• Download OpenJDK 8u422:
  • Visit the OpenLogic Downloads Page.
  • Download the installer for Windows.
    

• Install OpenJDK:
• • In the Downloads folder, double-click the installer file. Follow the wizard instructions, clicking Next at each step, to complete the installation.
  • Review the End User License Agreement, select the checkbox to accept the terms and conditions, and click Next to proceed.
  • Choose the appropriate Java Development Kit (JDK) version from the options provided and click Next to continue.
    
  • Click on the Install button to begin the installation.
  • Once the installation is completed, click on the Finish button.

• • Navigate to the folder where the OpenJDK is installed and copy that path.

• Set Environment Variables:
  • Navigate to System Properties > Environment Variables.
    
    
    

• • Add a new JAVA_HOME variable pointing to the JDK installation directory.
  • Edit the Path variable:
    • Add a new entry with the path <JAVA_HOME>\bin.
      
      

• Verify Installation:
  • Open a Command Prompt and run: java -version 
  • Ensure the output displays the new version (8u422).
    

5. Reconfigure and Start Tomcat

• • Navigate to the Newly installed Apache-Tomcat bin directory: 
    
  • Open a Command Prompt as shown in the screenshot, and run the following command:
    Replace <tomcat_servicename> with your desired service name.
  • In the same path run the command for the Tomcat service configuration:
    tomcat9w.exe //ES//<tomcat_servicename> 
  • Restore the previously saved Java options paths and memory pools in the Java tab of the Tomcat properties.
    
  • In the Windows search bar, type "services" and press Enter. Locate the newly created Tomcat service in the list, right-click on it, and select Start to initiate the service.
    
    Note: In the Service General Startup type, make it as “Automatic”.
    
    

6. Start Elasticsearch

• • In the Windows search bar, type "services" and press Enter. Locate the Elasticsearch service in the list, right-click, and select Start to start the service running on the machine.

Verification

Open a Command Prompt and run: java -version  

• Ensure the displayed version is 8u422.
• Verify Tomcat and Elasticsearch services are running correctly by accessing their respective endpoints.

This completes the upgrade to Java 8u422 and the reconfiguration of dependent services.

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