JDBC连接超级标准模板

//STEP 1. Import required packagesimport java.sql.*;public class FirstExample {   // JDBC driver name and database URL   static final String JDBC_DRIVER = "com.mysql.jdbc.Driver";     static final String DB_URL = "jdbc:mysql://localhost/test";   //  Database credentials -- 数据库名和密码自己修改   static final String USER = "username";   static final String PASS = "password";   public static void main(String[] args) {   Connection conn = null;   Statement stmt = null;   try{      //STEP 2: Register JDBC driver      Class.forName("com.mysql.jdbc.Driver");      //STEP 3: Open a connection      System.out.println("Connecting to database...");      conn = DriverManager.getConnection(DB_URL,USER,PASS);      //STEP 4: Execute a query      System.out.println("Creating statement...");      stmt = conn.createStatement();      String sql;      sql = "SELECT id, first, last, age FROM Employees";      ResultSet rs = stmt.executeQuery(sql);      //STEP 5: Extract data from result set      while(rs.next()){         //Retrieve by column name         int id  = rs.getInt("id");         int age = rs.getInt("age");         String first = rs.getString("first");         String last = rs.getString("last");         //Display values         System.out.print("ID: " + id);         System.out.print(", Age: " + age);         System.out.print(", First: " + first);         System.out.println(", Last: " + last);      }      //STEP 6: Clean-up environment      rs.close();      stmt.close();      conn.close();   }catch(SQLException se){      //Handle errors for JDBC      se.printStackTrace();   }catch(Exception e){      //Handle errors for Class.forName      e.printStackTrace();   }finally{      //finally block used to close resources      try{         if(stmt!=null)            stmt.close();      }catch(SQLException se2){      }// nothing we can do      try{         if(conn!=null)            conn.close();      }catch(SQLException se){         se.printStackTrace();      }//end finally try   }//end try   System.out.println("Goodbye!");}//end main}//end FirstExample - by www.yiibai.com