

Class.forName("com.mysql.cj.jdbc.Driver");


//閫氳繃椹卞姩绠＄悊绫昏幏鍙栨暟鎹簱閾炬帴


connection =DriverManager.getConnection("jdbc:mysql://localhost:3306/test_wensong","root", "root");



//瀹氫箟sql璇彞 ? 琛ㄧず鍗犱綅绗?/code>



String sql = " select * from user where username = ?";



//鑾峰彇棰勫鐞唖tatement


preparedStatement = connection.prepareStatement(sql);



//璁剧疆鍙傛暟锛岀?涓弬鏁颁负sql璇彞涓弬鏁扮殑搴忓彿锛堜粠1寮€濮嬶級锛岀?涓弬鏁颁负璁剧疆鐨勫弬鏁板€?/code>



preparedStatement.setString(1, "Tom");



//鍚戞暟鎹簱鍙戝嚭sql鎵?鏌ヨ锛屾煡璇㈠嚭缁撴灉闆?/code>



resultSet = preparedStatement.executeQuery();



List<User> userList = new ArrayList<User>();


//閬嶅巻鏌ヨ缁撴灉闆?/code>



while(resultSet.next()){


User user = new User();


user.setId(resultSet.getInteger("id"));


user.setUsername(resultSet.getString("username"))


user.setSex(resultSet.getString("sex"));


user.setAddress(resultSet.getString("address"));


userList.add(user);


}


} catch (Exception e) {


e.printStackTrace();


}finally{


//閲婃斁璧勬簮


if(resultSet!=null){


try {


resultSet.close();


} catch (SQLException e) {


e.printStackTrace();


}


}


if(preparedStatement!=null){


try {


preparedStatement.close();


} catch (SQLException e) {


e.printStackTrace();


}


}


if(connection!=null){


try {


connection.close();


} catch (SQLException e) {


e.printStackTrace();


}


}


}


}


鍘熷JDBC鎿嶄綔闂鍒嗘瀽
鍘熷 jdbc 寮€鍙戝瓨鍦ㄧ殑闂濡備笅锛?/p>
鈶?nbsp;. 鏁版嵁搴撹繛鎺ュ垱寤恒€侀噴鏀鹃绻侀€犳垚绯荤粺璧勬簮娴垂浠?褰卞搷绯荤粺鎬ц兘 銆?/p>
鈶?nbsp;. sql 璇彞鍦ㄤ唬鐮佷腑纭紪鐮侊紝閫犳垚浠ｇ爜涓嶆槗缁存姢锛屽疄闄呭簲? sql 鍙樺寲鐨勫彲鑳借緝?锛?nbsp;sql 鍙樺姩闇€瑕佹敼鍙?java 浠ｇ爜 銆?/p>
鈶?nbsp;. 鏌ヨ鎿嶄綔鏃堕渶瑕?鍔ㄥ皢缁撴灉闆嗕腑鐨勬暟鎹?鍔ㄥ皝瑁呭埌瀹炰綋涓€傛彃?鎿嶄綔鏃堕渶瑕?鍔ㄥ皢瀹炰綋鐨勬暟鎹缃埌 sql 璇彞鐨勫崰浣嶇浣嶇疆 銆?/p>
 
搴斿涓婅堪闂缁欏嚭鐨勮В鍐?妗堬細
鈶?nbsp;. 浣?鏁版嵁搴撹繛鎺ユ睜鍒濆鍖栬繛鎺ヨ祫婧?銆?/p>
鈶?nbsp;. 灏?nbsp;sql 璇彞鎶藉彇鍒?nbsp;xml 閰嶇疆?浠朵腑 銆?/p>
鈶?nbsp;. 浣?鍙嶅皠绛夊簳灞傛妧鏈紝?鍔ㄥ皢瀹炰綋涓庤〃杩?灞炴€т笌瀛楁鐨?鍔ㄦ槧灏?銆?/p>
 
Mybatis妗嗘灦浠嬬粛
mybatis 鏄?涓紭绉€鐨勫熀浜?nbsp;java 鐨勬寔涔呭眰妗嗘灦锛屽畠鍐呴儴灏佽浜?nbsp;jdbc 锛屼娇寮€鍙戣€呭彧闇€瑕佸叧娉?nbsp;sql璇彞鏈韩锛?涓嶉渶瑕佽姳璐圭簿?鍘诲鐞嗗姞杞介┍鍔ㄣ€佸垱寤鸿繛鎺ャ€佸垱寤?nbsp;statement 绛夌箒鏉傜殑杩囩▼ 銆?/p>
mybatis 閫氳繃 xml 鎴栨敞瑙ｇ殑?寮忓皢瑕佹墽?鐨勫悇绉?nbsp;statement 閰嶇疆璧锋潵锛屽苟閫氳繃 java 瀵硅薄鍜?nbsp;statement 涓璼ql 鐨勫姩鎬佸弬鏁拌繘?鏄犲皠?鎴愭渶缁堟墽?鐨?nbsp;sql 璇彞 銆?/p>
鏈€鍚?nbsp;mybatis 妗嗘灦鎵? sql 骞跺皢缁撴灉鏄犲皠涓?nbsp;java 瀵硅薄骞惰繑鍥炪€傞噰? ORM鎬濇兂瑙ｅ喅浜嗗疄浣撳拰鏁版嵁搴撴槧灏勭殑闂锛屽 jdbc 杩?浜嗗皝瑁咃紝灞忚斀浜?nbsp;jdbc api 搴曞眰璁块棶缁嗚妭锛屼娇鎴戜滑涓?涓?nbsp;jdbc api 鎵撲氦閬擄紝灏卞彲浠ュ畬鎴愬鏁版嵁搴撶殑鎸佷箙鍖栨搷浣?銆?/p>
MyBatis 瀹?鍦板潃锛?nbsp;https://mybatis.org/mybatis-3/
?
Mybatis 鏋舵瀯
?
1). mybatis 閰嶇疆?浠?/p>
SqlMapConfig.xml 锛屾?浠朵綔涓?nbsp;mybatis 鐨勫叏灞€閰嶇疆?浠讹紝閰嶇疆浜?nbsp;mybatis鐨勮繍?鐜绛変俊鎭€俶apper.xml ?浠跺嵆 sql 鏄犲皠?浠讹紝?浠朵腑閰嶇疆浜嗘搷浣滄暟鎹簱鐨?nbsp;sql璇彞銆傛?浠堕渶瑕佸湪SqlMapConfig.xml 涓姞杞姐€?/p>
2). 閫氳繃 mybatis 鐜绛夐厤缃俊鎭瀯閫?nbsp;SqlSessionFactory 鍗充細璇??
3). 鐢变細璇??鍒涘缓 sqlSession 鍗充細璇濓紝鎿嶄綔鏁版嵁搴撻渶瑕侀€氳繃 sqlSession 杩?銆?/p>
4). mybatis 搴曞眰?瀹氫箟浜?nbsp;Executor 鎵?鍣ㄦ帴?鎿嶄綔鏁版嵁搴擄紝 Executor鎺?鏈変袱涓疄鐜帮紝?涓槸鍩烘湰鎵?鍣?nbsp;BaseExecutor 銆?涓槸缂撳瓨鎵?鍣?nbsp;CachingExecutor 銆?/p>
5). MappedStatement 涔熸槸 mybatis ?涓簳灞傚皝瑁呭璞★紝瀹冨寘瑁呬簡 mybatis 閰嶇疆淇℃伅鍙?nbsp;sql鏄犲皠淇℃伅绛夈€俶apper.xml ?浠朵腑?涓?nbsp;sql 瀵瑰簲?涓?nbsp;MappedStatement 瀵硅薄锛?nbsp;sql 鐨?nbsp;id 鍗虫槸 Mapped statement 鐨?nbsp;id 銆?/p>
6). MappedStatement 瀵?nbsp;sql 鎵?杈?鍙傛暟杩?瀹氫箟锛屽寘鎷?nbsp;HashMap 銆佸熀鏈被鍨嬨€?nbsp;pojo 锛?nbsp;Executor閫氳繃Mapped Statement 鍦ㄦ墽? sql 鍓嶅皢杈?鐨?nbsp;java 瀵硅薄鏄犲皠? sql 涓紝杈?鍙傛暟鏄犲皠灏辨槸 jdbc缂栫▼涓 preparedStatement 璁剧疆鍙傛暟銆?/p>
7). MappedStatement 瀵?nbsp;sql 鎵?杈撳嚭缁撴灉杩?瀹氫箟锛屽寘鎷?nbsp;HashMap 銆佸熀鏈被鍨嬨€?nbsp;pojo 锛?nbsp;Executor閫氳繃Mapped Statement 鍦ㄦ墽? sql 鍚庡皢杈撳嚭缁撴灉鏄犲皠? java 瀵硅薄涓紝杈撳嚭缁撴灉鏄犲皠杩囩▼鐩稿綋浜?nbsp;jdbc缂栫▼涓缁撴灉鐨勮В鏋愬鐞嗚繃绋嬨€?/p>
 
Mybatis蹇€熷叆闂?/h2>
寮€鍙戞楠?/h3>
鈶?nbsp;. 娣诲姞 MyBatis 鐨勫潗鏍?/p>
鈶?nbsp;. 鍑嗗鏁版嵁搴撶幆澧?/p>
鈶?nbsp;. 缂栧啓 User 瀹炰綋绫?/p>
鈶?nbsp;. 缂栧啓鏍??浠?nbsp;SqlMapConfig.xml
鈶?nbsp;. 缂栧啓鏄犲皠?浠?nbsp;UserMapper.xml
鈶?nbsp;. 缂栧啓娴嬭瘯绫?/p>
 
鐜鎼缓
1 瀵?渚濊禆

 



<!--mybatis鍧愭爣-->


<dependency>


<groupId>org.mybatis</groupId>


<artifactId>mybatis</artifactId>


<version>3.4.5</version>


</dependency>


<!--mysql椹卞姩鍧愭爣-->


<dependency>


<groupId>mysql</groupId>


<artifactId>mysql-connector-java</artifactId>


<version>8.0.16</version>


</dependency>


<!--鍗曞厓娴嬭瘯鍧愭爣-->


<dependency>


<groupId>junit</groupId>


<artifactId>junit</artifactId>


<version>4.12</version>


</dependency>


<!--lombok鍧愭爣-->


<dependency>


<groupId>org.projectlombok</groupId>


<artifactId>lombok</artifactId>


<version>1.16.20</version>


</dependency>


<!--?蹇楀潗鏍?->


<dependency>


<groupId>log4j</groupId>


<artifactId>log4j</artifactId>


<version>1.2.17</version>


</dependency>


2鍑嗗鏁版嵁搴撶幆澧?/p>

 



create database mybatis;


use mybatis;


CREATE TABLE `user` (


`id` int(11) NOT NULL AUTO_INCREMENT,


`username` varchar(32) NOT NULL COMMENT 鈥?鎴峰悕绉扳€?


`sex` char(1) DEFAULT NULL COMMENT 鈥樻€у埆鈥?


`address` varchar(256) DEFAULT NULL COMMENT 鈥樺湴鍧€鈥?


PRIMARY KEY (`id`)


) ENGINE=InnoDB DEFAULT CHARSET=utf8;


insert into `user` (`id`, `username`, `sex`, `address`)


values(NULL,鈥楾om鈥?鈥樼敺鈥?鈥樺寳浜€?;


insert into `user` (`id`, `username`, `sex`, `address`)


values(NULL,鈥楯ack鈥?鈥樼敺鈥?鈥樹笂娴封€?;


insert into `user` (`id`, `username`, `sex`, `address`)


values(NULL,鈥楻ose鈥?鈥?鈥?鈥?瀹夆€?;


insert into `user` (`id`, `username`, `sex`, `address`)


values(NULL,鈥楶oll鈥?鈥?鈥?鈥樺埄?浜氣€?;


?
 
3缂栧啓 User 瀹炰綋
 

 



@Data


public class User {


private Integer id;


private String username;


private String sex;


private String address; }


4 缂栧啓 MyBatis鏍稿績鏂囦欢
?浠跺悕 : SqlMapConfig.xml

 



<?xml version="1.0" encoding="UTF-8" ?>


<!DOCTYPE configuration


PUBLIC "-//mybatis.org//DTD Config 3.0//EN"


"http://mybatis.org/dtd/mybatis-3-config.dtd">


<configuration>


<!--閰嶇疆鏁版嵁搴撹繍?鐜-->


<environments default="development">


<environment id="development">


<transactionManager type="JDBC"/>


<dataSource type="POOLED">


<property name="driver" value="com.mysql.cj.jdbc.Driver"/>


<property name="url" value="jdbc:mysql://127.0.0.1:3306/test_wensong"/>


<property name="username" value="root"/>


<property name="password" value="root"/>


</dataSource>


</environment>


</environments>


<!--閰嶇疆鍏宠仈鐨凷QL璇彞鐨勬槧灏?浠?->


<mappers>


<mapper resource="UserMapper.xml"/>


</mappers>


</configuration>


5 缂栧啓 UserMapper 鏄犲皠?浠?/p>
?浠跺悕 : UserMapper.xml

 



<?xml version="1.0" encoding="UTF-8" ?>


<!DOCTYPE mapper


PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"


"http://mybatis.org/dtd/mybatis-3-mapper.dtd">


<mapper namespace="userMapper">


<!--鏌ヨ鎵€鏈?鎴?->


<select id="findAll" resultType="com.wensong.pojo.User">


select * from user


</select>


</mapper>


6 鏌ヨ鎵€鏈夌敤鎴?/p>

 



public class UserTest {


@Test


public void findAllTest() throws IOException {


//鍔犺浇鏍?閰嶇疆?浠?SqlMapConfig.xml


InputStream inputStream = Resources.getResourceAsStream("SqlMapConfig.xml");


//鏋勯€燬QLSessionFactory瀵硅薄


SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);


//鏋勯€燬QLSession瀵硅薄


SqlSession sqlSession = sqlSessionFactory.openSession();


//鎵?鏌ヨ璇彞


List<User> userList = sqlSession.selectList("userMapper.findAll");


for (User user : userList) {


System.out.println("user = " + user);


}


//閲婃斁璧勬簮


sqlSession.close();


}


}


鏌ヨ缁撴灉鏄剧ず锛?/h3>
?
鐭ヨ瘑灏忕粨

 



1). 鎼缓鐜, 瀵?渚濊禆


mybatis , mysql鏁版嵁搴撻┍鍔? junit , lombok



2). 鍑嗗鏁版嵁搴撶幆澧?/code>



3). 缂栧啓瀹炰綋绫籙ser


4). 缂栧啓鏍?閰嶇疆?浠?/code>



A. mybatis鐨勮繍?鐜 -----> <environments>


B. 鍔犺浇鏄犲皠閰嶇疆?浠?-------> <mappers>



5). 缂栧啓鏄犲皠閰嶇疆?浠?/code>



SQL璇彞



6). 缂栧啓娴嬭瘯浠ｇ爜


A. 鍔犺浇Mybatis鐨勬牳?閰嶇疆?浠?/code>



B. 鏋勯€燬qlSessionFactory


C. 鏋勯€燬qlSession


D. 璋?SqlSession涓殑selectList鎵?鏌ヨ


E. 閲婃斁璧勬簮