centos升级 java

you can use the

sudo yum install java-1.8.0-openjdk
However, if you want to install a specific version of Java, such as Java 8, you can use the following command:

sudo yum install java-1.8.0-openjdk
To install Java 11, you can use:

sudo yum install java-11-openjdk
To install Java 17, you can use:

sudo yum install java-17-openjdk
Make sure to replace java-1.8.0-openjdk with java-11-openjdk or java-17-openjdk depending on which version of Java you want to install.

After installing the desired Java version, you can verify the installation by running:

java -version
This command will display the version of Java that is currently installed on your system.

If you encounter any issues with the above commands, it might be due to missing or outdated repositories. You can update your system’s repositories and then try the installation again:

sudo yum update
sudo yum upgrade
Then try installing the desired Java version again using one of the above commands. Additionally, if you want to set a specific version of Java as the default, you can use the alternatives system:

sudo alternatives --config java
This command will list all installed Java versions and allow you to select the one you want to use as the default. Follow the prompts to set your preferred version.

Remember to restart your terminal or source your .bashrc file to ensure that the changes take effect:

source ~/.bashrc
or simply restart your terminal session.

The command alternatives --config java will list all installed Java versions and allow you to select the one you want to use as the default. Follow the prompts to set your preferred version. Remember to restart your terminal or source your .bashrc file to ensure that the changes take effect: source ~/.bashrc. Alternatively, you can also set the default Java version using environment variables in your .bashrc or .bash_profile file. This is particularly useful if you need to switch between different Java versions frequently. Here’s how you can do it:

Setting Default Java Version Using Environment Variables in .bashrc or .bash_profile
Open your .bashrc or .bash_profile file in a text editor:

nano ~/.bashrc # or nano ~/.bash_profile if you prefer using .bash_profile

Add the following line to set the default Java version: Replace /path/to/java with the actual path to your Java executable for the version you want to set as default. You can find this path by running update-alternatives --display java. For example, if you want to set Java 11 as default:

export JAVA_HOME=/usr/lib/jvm/java-11-openjdk # Adjust this path based on your actual installation path. You can find it using update-alternatives --display java.
export PATH=$JAV{A}_{H}OME/bin:$PATH

Save and close the file. If you’re using nano, press Ctrl + O to save and Ctrl + X to exit.

Reload your .bashrc or .bash_profile file: This will apply the changes immediately without needing to restart your terminal session. You can do this by running:

source ~/.bashrc # or source ~/.bash_profile if you’re using .bash_profile instead of .bashrc.

Verify that the default Java version is set correctly: Run:

java -version

This should now display the version of Java that you set as default in your .bashrc or .bash_profile. 🎉🎉🎉🎉🎉🎉🎉🎉🎉🎉🎉🎉🎉🎉🎉🎉🎉🎉🎉🎉🎉🎉🎉🎉🎉🎉🎉���