JAVA连接数据库代码典例

以下是一个简单的Java连接MySQL数据库的代码示例：

import java.sql.*;

public class JDBCExample {

   static final String JDBC_DRIVER = "com.mysql.jdbc.Driver";  
   static final String DB_URL = "jdbc:mysql://localhost/EMP";
   static final String USER = "username";
   static final String PASS = "password";

   public static void main(String[] args) {
      Connection conn = null;
      Statement stmt = null;
      try{
         Class.forName("com.mysql.jdbc.Driver");

         System.out.println("Connecting to database...");
         conn = DriverManager.getConnection(DB_URL,USER,PASS);

         System.out.println("Creating statement...");
         stmt = conn.createStatement();
         String sql;
         sql = "SELECT id, first_name, last_name, age FROM Employees";
         ResultSet rs = stmt.executeQuery(sql);

         while(rs.next()){
            int id  = rs.getInt("id");
            int age = rs.getInt("age");
            String first = rs.getString("first_name");
            String last = rs.getString("last_name");

            System.out.print("ID: " + id);
            System.out.print(", Age: " + age);
            System.out.print(", First: " + first);
            System.out.println(", Last: " + last);
         }
         rs.close();
         stmt.close();
         conn.close();
      }catch(SQLException se){
         se.printStackTrace();
      }catch(Exception e){
         e.printStackTrace();
      }finally{
         try{
            if(stmt!=null)
               stmt.close();
         }catch(SQLException se2){
         }
         try{
            if(conn!=null)
               conn.close();
         }catch(SQLException se){
            se.printStackTrace();
         }
      }
      System.out.println("Goodbye!");
   }
}

这个示例代码使用Java的JDBC API连接到本地MySQL数据库，并执行一个简单的查询，然后输出结果。在实际应用中，需要根据具体的情况修改连接字符串、用户名、密码等参数。