java操作数据库的公共类
package com.lzcu.dao;
import java.io.IOException;
import java.io.InputStream;
import java.sql.*;
import java.util.Properties;
public class BaseDao {
private static String driver;
private static String url;
private static String username;
private static String password;
static {
Properties properties = new Properties();
InputStream is = BaseDao.class.getClassLoader().getResourceAsStream("db.properties");
try {
properties.load(is);
} catch (IOException e) {
e.printStackTrace();
}
driver = properties.getProperty("driver");
url = properties.getProperty("url");
username = properties.getProperty("username");
password = properties.getProperty("password");
}
public static Connection getConnection(){
Connection connection = null;
try {
Class.forName(driver);
connection = DriverManager.getConnection(url, username, password);
} catch (Exception e) {
e.printStackTrace();
}
return connection;
}
public static ResultSet execute(Connection connection,PreparedStatement preparedStatement,ResultSet resultSet,String sql,Object[] params) throws SQLException {
preparedStatement = connection.prepareStatement(sql);
for (int i = 0 ; i < params.length ; i++) {
preparedStatement.setObject(i+1, params[i]);
}
resultSet = preparedStatement.executeQuery();
return resultSet;
}
public static int execute(Connection connection,PreparedStatement preparedStatement,
String sql,Object[] params) throws SQLException {
preparedStatement = connection.prepareStatement(sql);
for (int i = 0 ; i <params.length ; i++) {
preparedStatement.setObject(i+1,params[i]);
}
int updateRows = preparedStatement.executeUpdate();
return updateRows;
}
public static boolean closeResource(Connection connection,PreparedStatement preparedStatement,
ResultSet resultSet){
boolean flag = true;
if (resultSet!=null){
try {
resultSet.close();
resultSet = null;
} catch (SQLException e) {
e.printStackTrace();
flag = false;
}
}
if (preparedStatement!=null){
try {
preparedStatement.close();
preparedStatement = null;
} catch (SQLException e) {
e.printStackTrace();
flag = false;
}
}
if (connection!=null){
try {
connection.close();
connection = null;
} catch (SQLException e) {
e.printStackTrace();
flag = false;
}
}
return flag;
}
}
db.properties配置文件
driver=com.mysql.jdbc.Driver
url=jdbc:mysql://localhost:3306/smbms?useSSL=true&useUnicode=true&characterEncoding=utf-8
username=root
password=wsl123