Java-JDBC.mysql 工具类 读取本地文件配置

引用 mysql-connector-jav 的jar

配置文件为  database.propertties .  格式如下

 driverClass=com.mysql.jdbc.Driver
 url=jdbc:mysql://localhost/mydatabase?useUnicode=true&characterEncoding=GBK
 username=root
 password=***

以下是代码

 package JDBCDemo;

 import java.io.FileInputStream;
 import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.io.InputStream;
 import java.sql.DriverManager;
 import java.sql.PreparedStatement;
 import java.sql.ResultSet;
 import java.sql.SQLException;
 import java.util.InputMismatchException;
 import java.util.Properties;

 import com.mysql.jdbc.Connection;
 import com.mysql.jdbc.Statement;

 public class JDBCUtils {
     private void JDBCUtils() {};
     private  static String sqlurl = "";
     private  static String sqluser = "";
     private  static String sqlpwd = "";
     private  static String classforName = "";
     private static  Connection con = null;

     static {
         try {
             initConfig();
             Class.forName(classforName);
             con = (Connection) DriverManager.getConnection(sqlurl, sqluser, sqlpwd);
         } catch (ClassNotFoundException e) {
             System.out.println("数据驱动失败");
             e.printStackTrace();
         } catch (SQLException e) {

             System.out.println("数据连接失败");
             e.printStackTrace();
         }
     }

     private static void initConfig() {
         InputStream inf = JDBCUtils.class.getClassLoader().getResourceAsStream("database.propertties");
         Properties properties = new Properties();
         try {
             properties.load(inf);
             classforName = properties.getProperty("driverClass");
             sqlurl = properties.getProperty("url");
             sqluser = properties.getProperty("username");
             sqlpwd = properties.getProperty("password");
         } catch (IOException e) {
             System.out.println("读取配置文件失败");
         }
     }

     public static Connection getConnection() {
         return con;
     }
     public static void close(Connection con,Statement preparedStatement,ResultSet rs)   {
         if(con !=null) {
             try {
                 con.close();
             } catch (SQLException e) {
                 //e.printStackTrace();
             }

         }
         if (preparedStatement!=null) {
             try {
                 preparedStatement.close();
             } catch (Exception e) {
                 //e.printStackTrace();
             }
         }
         if (rs!=null) {
             try {
                 rs.close();
             } catch (Exception e) {
                 //e.printStackTrace();
             }
         }
     }
 }