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java连接mysql底层封装代码实例
时间:2022-06-29 09:03:02 编辑:袖梨 来源:一聚教程网
本篇文章小编给大家分享一下java连接mysql底层封装代码实例,小编觉得挺不错的,现在分享给大家供大家参考,有需要的小伙伴们可以来看看。
具体代码如下:
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 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相关文章
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