mysql数据库的驱动jar包：mysql-connector-java-5.1.18-bin.jar
sqlserver数据库的驱动jar包：sqljdbc.jar
orcle数据库的驱动jar包：orcle*.jar,orcle根据数据库不同版本下载不同的驱动jar包
一定要有驱动jar包才能连接数据库
BaseDao类(驱动类)：
package com.dao;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.List;
public class BaseDao {
/**
* 数据库连接Connection
*/
public Connection con;
/**
* 结果集ResultSet
*/
public ResultSet rs;
/**
* JDBC连接数据库路径字符串
*/
private String url;
/**
* JDBC连接数据库账户
*/
private String user;
/**
* JDBC连接数据库密码
*/
private String password;
/**
* 数据库驱动加载类
*/
private String driver;
/**
* 无参构造函数
*/
public BaseDao(){
//连接sqlserver数据库
//this.setBaseDao("com.microsoft.sqlserver.jdbc.SQLServerDriver","jdbc:sqlserver://127.0.0.1;databasename=WebFileSystem","sa","NewPassword");
//连接mysql数据库
this.setBaseDao("com.mysql.jdbc.Driver","jdbc:mysql://127.0.0.1/webfilesystem","root","root");
//连接orcle数据库
this.setBaseDao("oracle.jdbc.driver.OracleDriver","jdbc:oracle://127.0.0.1/webfilesystem","root","root");
}
/**
* 有参构造函数
*/
public BaseDao(String driver, String url, String user, String password){
this.driver = driver;
this.url = url;
this.user = user;
this.password = password;
}
/**
* 设置JDBC连接数据库路径、账号、密码
*/
public void setBaseDao(String driver, String url, String user, String password){
this.driver = driver;
this.url = url;
this.user = user;
this.password = password;
}
/**
* 获取数据库连接对象Connection
*/
public Connection getConnection(){
try {
Class.forName(driver);
con = DriverManager.getConnection(url,user,password);
}catch (ClassNotFoundException e) {
e.printStackTrace();
}catch (SQLException e) {
e.printStackTrace();
}catch (Exception e) {
e.printStackTrace();
}
return con;
}
/**
* 关闭资源的函数
*/
public void closeAll(){
if(rs != null){
try {
rs.close();
} catch (SQLException e) {
e.printStackTrace();
}catch (Exception e) {
e.printStackTrace();
}
}
if(con != null){
try {
con.close();
} catch (SQLException e) {
e.printStackTrace();
}catch (Exception e) {
e.printStackTrace();
}
}
}
/**
* 增加、删除、修改
*/
public int executeUpdate(String sql){
int rows = 0;
try {
getConnection();
PreparedStatement ps = con.prepareStatement(sql);
rows = ps.executeUpdate();
}catch (SQLException e) {
e.printStackTrace();
}catch (Exception e) {
e.printStackTrace();
}finally{
closeAll();
}
return rows;
}
/**
* 增加、删除、修改
*/
public int executeUpdate(String sql, Object[] pre){
int rows = 0;
try{
getConnection();
PreparedStatement ps = con.prepareStatement(sql);
if(pre != null){
for(int i = 0; i < pre.length; i++){
ps.setObject(i+1, pre[i]);
}
}
rows = ps.executeUpdate();
}catch (SQLException e) {
e.printStackTrace();
}catch (Exception e) {
e.printStackTrace();
}finally{
closeAll();
}
return rows;
}
/**
* 增加、删除、修改
*/
public int executeUpdate(String sql, List pre){
int rows = 0;
try{
getConnection();
PreparedStatement ps = con.prepareStatement(sql);
if(pre != null){
for(int i = 0; i < pre.size(); i++){
ps.setObject(i+1, pre.get(i));
}
}
rows = ps.executeUpdate();
}catch (SQLException e) {
e.printStackTrace();
}catch (Exception e) {
e.printStackTrace();
}finally{
closeAll();
}
return rows;
}
/**
* 查询多行多列数据到成员ResultSet对象
*/
public ResultSet executeQuery(String sql){
try{
getConnection();
PreparedStatement ps = con.prepareStatement(sql);
rs = ps.executeQuery();
}catch (SQLException e) {
e.printStackTrace();
}catch (Exception e) {
}
return rs;
}
/**
* 查询多行多列数据到成员ResultSet对象
*/
public ResultSet executeQuery(String sql, Object[] pre){
try{
getConnection();
PreparedStatement ps = con.prepareStatement(sql);
if(pre != null){
for(int i = 0; i < pre.length; i++){
ps.setObject(i+1, pre[i]);
}
}
rs = ps.executeQuery();
}catch (SQLException e) {
e.printStackTrace();
}catch (Exception e) {
e.printStackTrace();
}
return rs;
}
/**
* 查询多行多列数据到成员ResultSet对象
*/
public ResultSet executeQuery(String sql, List pre){
try{
getConnection();
PreparedStatement ps = con.prepareStatement(sql);
if(pre != null){
for(int i = 0; i < pre.size(); i++){
ps.setObject(i+1, pre.get(i));
}
}
rs = ps.executeQuery();
}catch (SQLException e) {
e.printStackTrace();
}catch (Exception e) {
e.printStackTrace();
}
return rs;
}
}
