spring+mybatis 是 java 常见 web 框架，由于工作中有用到，但以前没接触过 mybatis，所以学习一下这个部分
连接库表并完成单表查询
本文使用 mysql 数据库
表如下：
SysConfigID | keyName | keyValue | Comments
24 | myKey | myValue | myComment
pom 依赖
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.carl</groupId>
<artifactId>spring_mybatis</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<name>spring_mybatis</name>
<url>http://maven.apache.org</url>
<properties>
<slf4j.version>1.7.21</slf4j.version>
<logback.version>1.1.7</logback.version>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
</properties>
<dependencies>
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.4.5</version>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>3.8.1</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.43</version>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
<version>${slf4j.version}</version>
</dependency>
<dependency>
<groupId>ch.qos.logback</groupId>
<artifactId>logback-classic</artifactId>
<version>${logback.version}</version>
</dependency>
<dependency>
<groupId>ch.qos.logback</groupId>
<artifactId>logback-core</artifactId>
<version>${logback.version}</version>
</dependency>
</dependencies>
</project>
package com.carl.data.config;
import com.carl.beans.SAT_SysConfig;
public interface SysConfig {
public SAT_SysConfig getSysConfig(int SysConfigID);
public List<SAT_SysConfig> getSysConfigList(int SysConfigID);
}
package com.carl.beans;
public class SAT_SysConfig {
private int SysConfigID;
private String KeyName;
private String KeyValue;
private String Comments;
public int getSysConfigID() {
return SysConfigID;
}
public void setSysConfigID(int sysConfigID) {
SysConfigID = sysConfigID;
}
public String getKeyName() {
return KeyName;
}
public void setKeyName(String keyName) {
KeyName = keyName;
}
public String getKeyValue() {
return KeyValue;
}
public void setKeyValue(String keyValue) {
KeyValue = keyValue;
}
public String getComments() {
return Comments;
}
public void setComments(String comments) {
Comments = comments;
}
}
配置数据库连接信息并增加单表映射 mapper
<?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>
<environments default="development">
<environment id="development">
<transactionManager type="JDBC"/>
<dataSource type="POOLED">
<property name="driver" value="com.mysql.jdbc.Driver"/>
<property name="url" value="jdbc:mysql://localhost:3306/dev"/>
<property name="username" value="admin"/>
<property name="password" value="password"/>
</dataSource>
</environment>
</environments>
<mappers>
<mapper resource="com/carl/xml/sysconfigmapper.xml"/>
</mappers>
</configuration>
<?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="com.carl.data.config.SysConfig">
<select id="getSysConfig" parameterType="int" resultType="com.carl.beans.SAT_SysConfig">
<!-- select SysConfigID,KeyName,KeyValue,Comments from SAT_SysConfig where SysConfigID = #{SysConfigID} -->
select * from SAT_SysConfig where SysConfigID = #{SysConfigID}
</select>
<resultMap type="com.carl.beans.SAT_SysConfig" id="getSysConfitResultMap">
<id column="SysConfigID" property="sysConfigID"/><!-- 不区分大小写 -->
<result column="KeyName" property="KeyName"/>
<result column="KeyValue" property="KeyValue"/>
<result column="Comments" property="Comments"/>
</resultMap>
<select id="getSysConfigList" parameterType="int" resultMap="getSysConfitResultMap">
select * from SAT_SysConfig where SysConfigID like concat(concat('%',#{SysConfigID}),'%')
</select>
</mapper>
package com.carl.spring_mybatis;
import java.io.IOException;
import java.io.InputStream;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
public class DataConnection {
private static String resource = "com/carl/xml/dataconfig.xml";
private static SqlSessionFactory sqlSessionFactory = null;
private static SqlSession sqlSession = null;
private DataConnection() {
}
public static SqlSession getSession() {
InputStream inputStream;
try {
if (sqlSessionFactory == null) {
inputStream = Resources.getResourceAsStream(resource);
sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
}
if (sqlSession == null) {
sqlSession = sqlSessionFactory.openSession();
}
} catch (IOException e) {
e.printStackTrace();
}
return sqlSession;
}
}
package com.carl.spring_mybatis;
import com.carl.beans.SAT_SysConfig;
import com.carl.data.config.SysConfig;
public class SysConfigQuery {
public static void main(String[] args) {
SAT_SysConfig sysConfig = DataConnection.getSession().getMapper(SysConfig.class).getSysConfig(24);
System.out.println(sysConfig.getSysConfigID());
List<SAT_SysConfig> sysConfigList = DataConnection.getSession().getMapper(SysConfig.class).getSysConfigList(24);
// System.out.println(sysConfigList.size());
System.out.println(sysConfigList.get(0).getSysConfigID());
System.out.println(sysConfigList.get(1).getSysConfigID());
}
}
19:35:44.268 [main] DEBUG org.apache.ibatis.logging.LogFactory - Logging initialized using 'class org.apache.ibatis.logging.slf4j.Slf4jImpl' adapter.
19:35:44.439 [main] DEBUG org.apache.ibatis.datasource.pooled.PooledDataSource - PooledDataSource forcefully closed/removed all connections.
19:35:44.440 [main] DEBUG org.apache.ibatis.datasource.pooled.PooledDataSource - PooledDataSource forcefully closed/removed all connections.
19:35:44.440 [main] DEBUG org.apache.ibatis.datasource.pooled.PooledDataSource - PooledDataSource forcefully closed/removed all connections.
19:35:44.440 [main] DEBUG org.apache.ibatis.datasource.pooled.PooledDataSource - PooledDataSource forcefully closed/removed all connections.
19:35:44.547 [main] DEBUG org.apache.ibatis.transaction.jdbc.JdbcTransaction - Opening JDBC Connection
19:35:44.796 [main] DEBUG org.apache.ibatis.datasource.pooled.PooledDataSource - Created connection 817406040.
19:35:44.797 [main] DEBUG org.apache.ibatis.transaction.jdbc.JdbcTransaction - Setting autocommit to false on JDBC Connection [com.mysql.jdbc.JDBC4Connection@30b8a058]
19:35:44.799 [main] DEBUG com.carl.data.config.SysConfig.getSysConfig - ==> Preparing: select * from SAT_SysConfig where SysConfigID = ?
19:35:44.860 [main] DEBUG com.carl.data.config.SysConfig.getSysConfig - ==> Parameters: 24(Integer)
19:35:44.882 [main] DEBUG com.carl.data.config.SysConfig.getSysConfig - <== Total: 1
24
19:35:44.883 [main] DEBUG com.carl.data.config.SysConfig.getSysConfigList - ==> Preparing: select * from SAT_SysConfig where SysConfigID like concat(concat('%',?),'%')
19:35:44.884 [main] DEBUG com.carl.data.config.SysConfig.getSysConfigList - ==> Parameters: 24(Integer)
19:35:44.886 [main] DEBUG com.carl.data.config.SysConfig.getSysConfigList - <== Total: 2
24
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深入浅出 mybatis 技术原理与实战