Example analysis of encapsulating JDBC tool class in java

For code that can be reused, our best approach is to encapsulate it, and then call it directly in the next use. What this article will mention is the JDBC tool class, which I believe everyone has come into contact with when learning java. Then for the method of encapsulating it, this article first gives a simple description of the tool class, lists the relevant encapsulation steps, and then brings relevant examples.

1. Description

In the java development process, the code commonly used to some Scanner, Random1-like classes, they are keyboard input, generate random numbers of classes, like a tool 1, in java is called tool class.

2. Steps

Encapsulate the JDBC tool class

Add a method to get the database connection object

Add a method to release the connection

3. Examples

package com.qianfeng.util;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
/**
 * JDBC Tool class 
 *  There is a method to get the connection 
 * @author dushine
 */
public class JDBCUtil {
/**
 *  Method for getting database connection 
 * @return Connection conn
 * @throws SQLException
 */
public static Connection getConnection() throws SQLException {
String url = "jdbc:mysql://localhost:3306/class?useSSL=false";
String user = "root";
String password = "root";
Connection conn = DriverManager.getConnection(url,user,password);
return conn;
}
/**
 *  Method of releasing connection 
 * @param conn
 * @throws SQLException
 */
public static void releaseSourse(Connection conn) throws SQLException {
if (conn != null) {
conn.close();
}
}
/**
 *  Method of releasing connection 
 * @param conn  Database connection object 
 * @param stmt  Execute SQL Object of the statement 
 * @throws SQLException
 */
public static void releaseSourse(Connection conn,Statement stmt) throws SQLException {
if (stmt != null) {
stmt.close();
}
if (conn != null) {
conn.close();
}
}
/**
 *  Method of releasing connection 
 * @param conn  Database connection object 
 * @param stmt  Execute SQL Object of the statement 
 * @param resultSet  Execute SQL The result set returned by the statement 
 * @throws SQLException
 */
public static void releaseSourse(Connection conn,Statement stmt,ResultSet resultSet) throws SQLException {
if (resultSet != null) {
resultSet.close();
}
if (stmt != null) {
stmt.close();
}
if (conn != null) {
conn.close();
}
}
}

Instance extension:

public class JDBCUtil {
  // Connection object 
  private Connection connection = null;
  // Database operation object 
  private PreparedStatement ps = null;
  // Database connection address 
  private static String url = "jdbc:mysql://localhost:3306/";
  // User name 
  private static String user = "root";
  // Password 
  private static String password = "123456";
  // Static code block   Register driver 
  // Class is loaded, only the execution of the 1 Times 
  static{
    try {
      Class.forName("com.mysql.jdbc.Driver");
    } catch (ClassNotFoundException e) {
      e.printStackTrace();
    }
  }

  // Get the connection object 
  public Connection getConnection(){
    //Connection conn = null;
    try {
      connection = DriverManager.getConnection(url,user,password);
    } catch (SQLException e) {
      e.printStackTrace();
      System.out.println(" Database connection failed ....");
    }
    System.out.println(" Database connection succeeded ...");
    return connection;
  }

  // Get the database operation object 
  public PreparedStatement createPreparedStatement(String sql){
    connection = getConnection();
    try {
      ps = connection.prepareStatement(sql);
    } catch (SQLException e) {
      e.printStackTrace();
    }
    return ps;
  }

  // Release resources 
  public void close(){
    // Release the connection object 
    if (connection != null) {
      try {
        connection.close();
      } catch (SQLException e) {
        e.printStackTrace();
      }
    }
    // Release database operation objects 
    if (ps != null) {
      try {
        ps.close();
      } catch (SQLException e) {
        e.printStackTrace();
      }
    }
    System.out.println(" Resource released successfully ...");
  }
  // Overload of method 
  public void close(ResultSet reuslt){
    //  Call the method that releases the resource 
    close();
    //  Release the query result set object 
    if (reuslt != null) {
      try {
        reuslt.close();
      } catch (SQLException e) {
        e.printStackTrace();
      }
    }
  }

}