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  • jdbc连接案例

    项目案例模板之jdbc两种连接方式

    第一种连接方式

    JDBCUtils.java

     package jdbc;
     ​
             import org.junit.jupiter.api.Test;
     ​
             import java.sql.Connection;
             import java.sql.DriverManager;
             import java.sql.SQLException;
     ​
     public class JDBCUtils {
         public static Connection connection;
         private static String url="jdbc:mysql://localhost:3306/aaa?useUnicode=true&characterEncoding=utf-8";
         private static String username="root";
         private static String password="root";
     ​
         static{
             try {
                 Class.forName("com.mysql.jdbc.Driver");
                 connection = DriverManager.getConnection(url,username,password);
     ​
             } catch (ClassNotFoundException e) {
                 e.printStackTrace();
             } catch (SQLException e) {
                 e.printStackTrace();
             }
         }
     ​
         public static Connection getConnection(){
             return connection;
         }
     ​
         @Test
         public void test(){
             Connection connection = JDBCUtils.getConnection();
             System.out.println(connection);
         }
     }
    

      

    第二种连接方式

    db.properties

     url=jdbc:mysql://localhost:3306/aaa?useUnicode=true&characterEncoding=utf-8
     username=root
     password=root

    JDBCUtils2.java

    package jdbc;
     ​
     import org.junit.jupiter.api.Test;
     ​
     import java.io.FileInputStream;
     import java.io.FileNotFoundException;
     import java.io.IOException;
     import java.sql.Connection;
     import java.sql.DriverManager;
     import java.sql.SQLException;
     import java.util.Properties;
     ​
     public class JDBCUtils2 {
         private static Connection connection;
         private static String url;
         private static String username;
         private static String password;
     ​
         static {
             try {
                 //动态加载驱动
                 Class.forName("com.mysql.jdbc.Driver");
                 //加载配置文件
                 Properties properties = new Properties();
                 properties.load(new FileInputStream("src/main/java/db.properties"));
                 url = properties.getProperty("url");
                 username = properties.getProperty("username");
                 password = properties.getProperty("password");
     ​
                 connection = DriverManager.getConnection(url,username,password);
     ​
     ​
             } catch (ClassNotFoundException e) {
                 e.printStackTrace();
             } catch (FileNotFoundException e) {
                 e.printStackTrace();
             } catch (IOException e) {
                 e.printStackTrace();
             } catch (SQLException e) {
                 e.printStackTrace();
             }
         }
     ​
         public static Connection getConnection(){
             return connection;
         }
     ​
         @Test
         public void test(){
             Connection connection = JDBCUtils2.getConnection();
             System.out.println(connection);
         }
     }
    

      

     

     

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  • 原文地址:https://www.cnblogs.com/zyx110/p/11489716.html
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