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which -a java

/usr/bin/java

java -version

openjdk version "11.0.17" 2022-10-18 LTS
OpenJDK Runtime Environment (Red_Hat-11.0.17.0.8-2.el9_0) (build 11.0.17+8-LTS)
OpenJDK 64-Bit Server VM (Red_Hat-11.0.17.0.8-2.el9_0) (build 11.0.17+8-LTS, mixed mode, sharing)

sudo dnf search jdk | egrep -- '-17'

Last metadata expiration check: 0:11:17 ago on Mon 19 Dec 2022 11:32:48 PM EST.
java-17-openjdk.x86_64 : OpenJDK 17 Runtime Environment
java-17-openjdk-demo.x86_64 : OpenJDK 17 Demos
java-17-openjdk-devel.x86_64 : OpenJDK 17 Development Environment
java-17-openjdk-headless.x86_64 : OpenJDK 17 Headless Runtime Environment
java-17-openjdk-javadoc.x86_64 : OpenJDK 17 API documentation
java-17-openjdk-javadoc-zip.x86_64 : OpenJDK 17 API documentation compressed in a single archive
java-17-openjdk-jmods.x86_64 : JMods for OpenJDK 17
java-17-openjdk-src.x86_64 : OpenJDK 17 Source Bundle
java-17-openjdk-static-libs.x86_64 : OpenJDK 17 libraries for static linking

sudo dnf install java-17-openjdk java-17-openjdk-devel

which -a javac

/usr/bin/javac

java -version

javac 17.0.5

wget https://download.oracle.com/java/17/latest/jdk-17_linux-x64_bin.rpm

--2022-12-20 00:12:34--  https://download.oracle.com/java/17/latest/jdk-17_linux-x64_bin.rpm
Resolving download.oracle.com (download.oracle.com)... 23.192.208.88
Connecting to download.oracle.com (download.oracle.com)|23.192.208.88|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: 163101336 (156M) [application/x-redhat-package-manager]
Saving to: ‘jdk-17_linux-x64_bin.rpm’
 
jdk-17_linux-x64_bi 100%[===================>] 155.54M  11.1MB/s    in 17s     
 
2022-12-20 00:12:51 (9.01 MB/s) - ‘jdk-17_linux-x64_bin.rpm’ saved [163101336/163101336]

sudo rpm -Uvh jdk-17_linux-x64_bin.rpm

sudo alternatives --config java

There are 3 programs which provide 'java'.
 
  Selection    Command
-----------------------------------------------
   1           java-11-openjdk.x86_64 (/usr/lib/jvm/java-11-openjdk-11.0.17.0.8-2.el9_0.x86_64/bin/java)
   2           java-17-openjdk.x86_64 (/usr/lib/jvm/java-17-openjdk-17.0.5.0.8-2.el9_0.x86_64/bin/java)
*+ 3           /usr/java/jdk-17.0.5/bin/java
 
Enter to keep the current selection[+], or type selection number: 2

java -version

openjdk version "17.0.5" 2022-10-18 LTS
OpenJDK Runtime Environment (Red_Hat-17.0.5.0.8-2.el9_0) (build 17.0.5+8-LTS)
OpenJDK 64-Bit Server VM (Red_Hat-17.0.5.0.8-2.el9_0) (build 17.0.5+8-LTS, mixed mode, sharing)

export set JAVA_HOME="/usr/lib/jvm/java-17-openjdk-17.0.5.0.8-2.el9_0.x86_64/bin"

export set PATH=$PATH:$JAVA_HOME

// Define the Java program.
public class HelloWorld {
  public static void main(String[] args) {
    System.out.println("Hello World!");
  }
}

javac HelloWorld.java

java HelloWorld

Hello World!

sudo dnf install -y mysql-connector-j-8.0.31-1.el9.noarch.rpm

export set CLASSPATH="/usr/share/java/mysql-connector-j.jar:."

// Import classes.
import java.sql.*;
 
/* You can't include the following on Linux without raising an exception. */
// import com.mysql.jdbc.Driver;
 
public class MySQLConnector {
  public MySQLConnector() {
    /* Declare variables that require explicit assignments because
       they're addressed in the finally block. */
    Connection conn = null;
    Statement stmt = null;
    ResultSet rset = null;
 
    /* Declare other variables. */
    String url;
    String username = "student";
    String password = "student";
    String database = "studentdb";
    String hostname = "localhost";
    String port = "3306";
    String sql;
 
    /* Attempt a connection. */
    try {
      // Set URL.
      url = "jdbc:mysql://" + hostname + ":" + port + "/" + database;
 
      // Create instance of MySQLDriver.
      Class.forName ("com.mysql.cj.jdbc.Driver").newInstance();
      conn = DriverManager.getConnection (url, username, password);
 
      // Query the version of the database.
      sql = "SELECT version()";
      stmt = conn.createStatement();
      rset = stmt.executeQuery(sql);
 
      System.out.println ("Database connection established");
 
      // Read row returns for one column.
      while (rset.next()) {
        System.out.println("MySQLDriver Version [" + rset.getString(1) + "]"); }
 
    }
    catch (SQLException e) {
      System.err.println ("Cannot connect to database server:");
      System.out.println(e.getMessage());
    }
    catch (ClassNotFoundException e) {
      System.err.println ("Cannot find MySQL driver class:");
      System.out.println(e.getMessage());
    }
    catch (InstantiationException e) {
      System.err.println ("Cannot instantiate class:");
      System.out.println(e.getMessage());
    }
    catch (IllegalAccessException e) {
      System.err.println ("Illegal access exception:");
      System.out.println(e.getMessage());
    }
    finally {
      if (conn != null) {
        try {
          rset.close();
          stmt.close();
          conn.close();
          System.out.println ("Database connection terminated");
        }
        catch (Exception e) { /* ignore close errors */ }
      }
    }
  }
  /* Unit test. */
  public static void main(String args[]) {
    new MySQLDriver();
  }
}

javac -Xlint:deprecation  MySQLDriver.java

MySQLDriver.java:30: warning: [deprecation] newInstance() in Class has been deprecated
      Class.forName ("com.mysql.cj.jdbc.Driver").newInstance();
                                                ^
  where T is a type-variable:
    T extends Object declared in class Class
1 warning

java MySQLDriver

Database connection established
MySQLDriver Version [8.0.30]
Database connection terminated