java連線mysql底層封裝詳解
阿新 • • 發佈：2020-01-07
本文例項為大家分享了java連線mysql底層封裝程式碼，供大家參考，具體內容如下
連線資料庫
package com.dao.db;
import java.sql.Connection;
import java.sql.SQLException;
/**
* 資料庫連線層MYSQL
* @author Administrator
*
*/
public class DBConnection {
/**
* 連線資料庫
* @return
*/
public static Connection getDBConnection()
{
// 1. 註冊驅動
try {
Class.forName("com.mysql.jdbc.Driver");
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
// 獲取資料庫的連線
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;
}
}資料層封裝
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資料庫底層封裝
* @author Administrator
*
*/
public class DBManager {
private PreparedStatement pstmt;
private Connection conn;
private ResultSet rs;
/**
* 開啟資料庫
*/
public DBManager() {
conn = DBConnection.getDBConnection();
}
/**
* 執行修改新增操作
* @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;
}
/**
* 獲取查詢結果集
* @param coulmn
* @param type
* @param sql
* @throws SQLException
*/
public DataTable getResultData(String[] coulmn,String sql) throws SQLException
{
DataTable dt = new DataTable();
ArrayList<HashMap<String,String>>list = new ArrayList<HashMap<String,String>>();
if(!setPstmtParam(coulmn,sql))
return null;
rs = pstmt.executeQuery();
ResultSetMetaData rsmd = rs.getMetaData();//取資料庫的列名
int numberOfColumns = rsmd.getColumnCount();
while(rs.next())
{
HashMap<String,String> rsTree = new HashMap<String,String>();
for(int r=1;r<numberOfColumns+1;r++)
{
rsTree.put(rsmd.getColumnName(r),rs.getObject(r).toString());
}
list.add(rsTree);
}
closeDB();
dt.setDataTable(list);
return dt;
}
/**
* 引數設定
* @param coulmn
* @param type
* @throws SQLException
* @throws NumberFormatException
*/
private boolean setPstmtParam(String[] coulmn,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<type.length; i++) {
switch (type[i]) {
case Types.INTEGER:
pstmt.setInt(i+1,Integer.parseInt(coulmn[i]));
break;
case Types.BOOLEAN:
pstmt.setBoolean(i+1,Boolean.parseBoolean(coulmn[i]));
break;
case Types.CHAR:
pstmt.setString(i+1,coulmn[i]);
break;
case Types.DOUBLE:
pstmt.setDouble(i+1,Double.parseDouble(coulmn[i]));
break;
case Types.FLOAT:
pstmt.setFloat(i+1,Float.parseFloat(coulmn[i]));
break;
default:
break;
}
}
}
return true;
}
/**
* 關閉資料庫
* @throws SQLException
*/
private void closeDB() throws SQLException
{
if(rs != null)
{
rs.close();
}
if(pstmt != null)
{
pstmt.close();
}
if(conn != null)
{
conn.close();
}
}
}資料集封裝
package com.dao.db;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
/**
* 資料集封裝
* @author Administrator
*
*/
public class DataTable {
public String[] column;//列欄位
public String[][] row; //行值
public int rowCount = 0;//行數
public int colCoun = 0;//列數
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<HashMap<String,String>> 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<Map.Entry<String,String>> set = list.get(i).entrySet();
int j = 0;
for (Iterator<Map.Entry<String,String>> it = set.iterator(); it
.hasNext();) {
Map.Entry<String,String> entry = (Map.Entry<String,String>) 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;
}
}測試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,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,searchSql);
if(dt != null && dt.getRowCount()> 0){
for(int i = 0; i<dt.getRowCount(); i++)
{
for(int j = 0; j<dt.getColCoun(); j++)
System.out.printf(dt.getRow()[i][j]+"\t");
System.out.println();
}
}
else
System.out.println("查詢失敗");
} catch (SQLException e) {
e.printStackTrace();
}
}
}
以上就是本文的全部內容，希望對大家的學習有所幫助，也希望大家多多支援我們。