Java访问sql server数据库工具

Posted 2020-07-04

  1 package com.dao;
  2 
  3 import java.sql.*;
  4 import java.util.ArrayList;
  5 import java.util.List;
  6 
  7 import com.sun.jmx.snmp.Timestamp;
  8 
  9 public abstract class BaseDao {
 10 
 11     String driver = "com.microsoft.sqlserver.jdbc.SQLServerDriver";
 12     String url = "jdbc:sqlserver://localhost:1433;database=NewsManagerSystem";
 13     String user = "sa";
 14     String pwd = "sa";
 15 
 16     private Connection conn;
 17     private PreparedStatement stmt;
 18     private ResultSet rs;
 19     
 20     public abstract Object createModel(ResultSet rs) throws SQLException;
 21 
 22     private Connection getConnection() throws SQLException {
 23         
 24         try {
 25             Class.forName(driver);
 26         } catch (ClassNotFoundException e) {
 27             e.printStackTrace();
 28         }
 29         
 30         return DriverManager.getConnection(url, user, pwd);
 31     }
 32     
 33     private void closeAll(Connection conn, Statement stmt,ResultSet rs) {
 34         
 35         if(rs != null){
 36             try{
 37                 rs.close();
 38             }catch(SQLException e) {
 39                 e.printStackTrace();
 40             }
 41         }
 42         
 43         if (stmt != null) {
 44             try {
 45                 stmt.close();
 46             } catch (SQLException e) {
 47                 e.printStackTrace();
 48             }
 49         }
 50 
 51         if (conn != null) {
 52             try {
 53                 conn.close();
 54             } catch (SQLException e) {
 55                 e.printStackTrace();
 56             }
 57         }
 58     }
 59     
 60     private void preExecute(String sql,Object...args)throws SQLException{
 61         conn = getConnection();
 62         stmt = conn.prepareStatement(sql);
 63         for (int i = 0; i < args.length; i++) {
 64             Object p = args[i];
 65             if(p instanceof java.util.Date){
 66                 if(!p.getClass().getName().startsWith("java.sql.")){
 67                     java.util.Date date = (java.util.Date)p;
 68                     p = new Timestamp(date.getTime());
 69                 }
 70             }
 71             stmt.setObject(i+1, p);
 72         }
 73     }
 74     
 75     private void postExecute() {
 76         closeAll(conn, stmt, rs);
 77         conn = null;
 78         stmt = null;
 79         rs =  null;
 80     }
 81     
 82     protected int executeUpdate(String sql,Object...args){
 83         int res = -1;
 84         
 85         try {
 86             preExecute(sql,args);
 87             res = stmt.executeUpdate();
 88         } catch (SQLException e) {
 89             e.printStackTrace();
 90         } finally{
 91             postExecute();
 92         }
 93         
 94         return res;
 95     }
 96     
 97     protected List executeQuery(String sql,Object...args){
 98         List list = new ArrayList();
 99         
100         try {
101             preExecute(sql,args);
102             rs = stmt.executeQuery();
103             
104             while (rs.next()) {
105                 Object obj = createModel(rs);
106                 list.add(obj);
107             }
108         } catch (SQLException e) {
109             e.printStackTrace();
110         }finally{
111             postExecute();
112         }
113         
114         return list;
115     }
116     
117     protected Object executeQueryFirst(String sql,Object...args){
118         Object obj = null;
119         
120         try {
121             preExecute(sql, args);
122             rs = stmt.executeQuery();
123             
124             if(rs.next()){
125                 obj = createModel(rs);
126             }
127         } catch (SQLException e) {
128             e.printStackTrace();
129         }finally{
130             postExecute();
131         }
132         
133         return obj;
134     }
135     
136     protected Object executeQueryScalar(String sql,Object...args){
137         Object obj = null;
138         
139         try {
140             preExecute(sql, args);
141             rs = stmt.executeQuery();
142             
143             if(rs.next()){
144                 obj = rs.getObject(1);
145             }
146         } catch (SQLException e) {
147             e.printStackTrace();
148         }finally{
149             postExecute();
150         }
151         
152         return obj;
153     }
154     
155 }