java连接mysql底层封装详解

数据运维 2023-04-29 泡泡 手机阅读

本文实例为大家分享了java连接mysql底层封装代码，供大家参考，具体内容如下 连接数据库 package com.dao.db;import java.sql.Connection;import java.sql.SQLException;/* 数据库连接层MYSQL * @author Admini

本文实例为大家分享了java连接mysql底层封装代码，供大家参考，具体内容如下

连接数据库

package com.dao.db;

import java.sql.Connection; import java.sql.SQLException;

/**

  • 数据库连接层MYSQL
  • @author Administrator

  • */ public class DBConnection {

    /**

    • 连接数据库
    • @return */ public static Connection getDBConnection() { // 1. 注册驱动 try { Class.forName("com.mysql.jdbc.Driver"); } catch (ClassNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } // 获取数据库的连接 try { Connection conn = java.sql.DriverManager.getConnection("jdbc:mysql://localhost/mysql?useUnicode=true&characterEncoding=utf-8", "root", "root"); return conn; } catch (SQLException e1) { e1.printStackTrace(); } return null; }

}

数据层封装

package com.dao.db;

import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.ResultSetMetaData; import java.sql.SQLException; import java.sql.Types; import java.util.ArrayList; import java.util.HashMap;

/**

  • MYSQL数据库底层封装
  • @author Administrator

  • */ public class DBManager {

    private PreparedStatement pstmt; private Connection conn; private ResultSet rs;

    /**

    • 打开数据库 */ public DBManager() { conn = DBConnection.getDBConnection(); }

    /**

    • 执行修改添加操作
    • @param coulmn
    • @param type
    • @param sql
    • @return
    • @throws SQLException */ public boolean updateOrAdd(String[] coulmn, int[] type, String sql) throws SQLException { if(!setPstmtParam(coulmn, type, sql)) return false; boolean flag = pstmt.executeUpdate()>0?true:false; closeDB(); return flag; } /**
    • 获取查询结果集
    • @param coulmn
    • @param type
    • @param sql
    • @throws SQLException */ public DataTable getResultData(String[] coulmn, int[] type, String sql) throws SQLException { DataTable dt = new DataTable();

    ArrayList>list = new ArrayList>();

    if(!setPstmtParam(coulmn, type, sql)) return null; rs = pstmt.executeQuery(); ResultSetMetaData rsmd = rs.getMetaData();//取数据库的列名 int numberOfColumns = rsmd.getColumnCount(); while(rs.next()) { HashMap rsTree = new HashMap(); for(int r=1;r

    /**

    • 参数设置
    • @param coulmn
    • @param type
    • @throws SQLException
    • @throws NumberFormatException */ private boolean setPstmtParam(String[] coulmn, int[] type, String sql) throws NumberFormatException, SQLException { if(sql== null) return false; pstmt = conn.prepareStatement(sql); if(coulmn != null && type != null && coulmn.length !=0 && type.length !=0 ) {
      for (int i = 0; i

    /**

    • 关闭数据库
    • @throws SQLException */ private void closeDB() throws SQLException { if(rs != null) { rs.close(); } if(pstmt != null) { pstmt.close(); } if(conn != null) { conn.close(); }

    } }

数据集封装

package com.dao.db;

import java.util.ArrayList; import java.util.HashMap; import java.util.Iterator; import java.util.Map; import java.util.Set;

/**

  • 数据集封装
  • @author Administrator

  • */ public class DataTable {

    public String[] column;//列字段 public String[][] row; //行值 public int rowCount = 0;//行数 public int colCoun = 0;//列数

    public DataTable() { super(); }

    public DataTable(String[] column, String[][] row, int rowCount, int colCoun) { super(); this.column = column; this.row = row; this.rowCount = rowCount; this.colCoun = colCoun; }

    public void setDataTable(ArrayList> list) { rowCount = list.size(); colCoun = list.get(0).size(); column = new String[colCoun]; row = new String[rowCount][colCoun]; for (int i = 0; i < rowCount; i++) { Set> set = list.get(i).entrySet(); int j = 0; for (Iterator> it = set.iterator(); it .hasNext();) { Map.Entry entry = (Map.Entry) it .next(); row[i][j] = entry.getValue(); if (i == rowCount - 1) { column[j] = entry.getKey(); } j++; } } }

    public String[] getColumn() { return column; }

    public void setColumn(String[] column) { this.column = column; }

    public String[][] getRow() { return row; }

    public void setRow(String[][] row) { this.row = row; }

    public int getRowCount() { return rowCount; }

    public void setRowCount(int rowCount) { this.rowCount = rowCount; }

    public int getColCoun() { return colCoun; }

    public void setColCoun(int colCoun) { this.colCoun = colCoun; }

}

测试Demo

package com.bussiness.test;

import java.sql.SQLException; import java.sql.Types;

import com.dao.db.DBManager; import com.dao.db.DataTable;

public class TestBusIness{

static String searchSql = "select * from score"; static String insertSql = "insert into score(name, age, score)values(?,?,?)"; static String deleteSql = "delete from score where id = ?"; static String updateSql = "update score set name = ? where id = ?";

public static void main(String[] args) { intsertData(); searchData(); }

private static void intsertData() { DBManager dm = new DBManager(); String[] coulmn = new String[]{"wyf2", "23", "89.5"}; int[] type = new int[]{Types.CHAR, Types.INTEGER, Types.DOUBLE};

try { boolean flag = dm.updateOrAdd(coulmn, type, insertSql); if(flag) System.out.println("插入成功"); } catch (SQLException e) { e.printStackTrace(); } } private static void searchData() { DBManager dm = new DBManager(); String[] coulmn = null; int[] type = null;

try { DataTable dt = dm.getResultData(coulmn, type, searchSql); if(dt != null && dt.getRowCount()> 0){
for(int i = 0; i

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持每日运维。