项目实录之集成Mybatis

摘要: 在实际开发中，持久层框架我们都选用Mybatis，感受就是非常好用。本文就是给出一个基本使用demo，希望对大家有所帮助。

阅读本文之前建议先阅读如下两篇文章

项目实录之Maven工程搭建

项目实录之集成Spring MVC

一、创建数据库和表

先创建数据库wangci,再创建一个表user（仅仅测试用）,完成之后随意插几条数据进去。

CREATE TABLE `user` (
`id` bigint(20) NOT NULL AUTO_INCREMENT,
`username` varchar(20) NOT NULL,
`password` varchar(20) NOT NULL,
PRIMARY KEY (`id`,`username`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8

二、pom.xml中加入Mybatis和MySQL相关依赖

<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/maven-v4_0_0.xsd"> <modelVersion>4.0.0</modelVersion>
<groupId>wang.wangci</groupId>
<artifactId>bottae-parent</artifactId>
<packaging>pom</packaging>
<version>1.0</version>
<name>bottae-parent</name>
<url>http://maven.apache.org</url>
<modules>
<module>bottae-common</module>
<module>bottae-dao</module>
<module>bottae-service</module>
<module>bottae-web</module>
</modules>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<spring.version>3.2.3.RELEASE</spring.version>
</properties>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.0</version>
<configuration>
<source>1.6</source>
<target>1.6</target>
<encoding>${project.build.sourceEncoding}</encoding>
</configuration>
</plugin>
<!-- jetty插件 -->
<plugin>
<groupId>org.mortbay.jetty</groupId>
<artifactId>jetty-maven-plugin</artifactId>
<version>8.1.11.v20130520</version>
<configuration>
<scanIntervalSeconds>0</scanIntervalSeconds>
<connectors>
<connector implementation="org.eclipse.jetty.server.nio.SelectChannelConnector">
<port>7777</port>
</connector>
</connectors>
</configuration>
</plugin>
</plugins>
<resources>
<resource>
<directory>src/main/resources</directory>
<filtering>true</filtering>
</resource>
</resources>
</build>
<dependencies>
<!-- spring start -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-core</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-web</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context-support</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-tx</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-jdbc</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-beans</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-orm</artifactId>
<version>${spring.version}</version>
</dependency>
<!-- spring 依賴jackson -->
<dependency>
<groupId>org.codehaus.jackson</groupId>
<artifactId>jackson-mapper-asl</artifactId>
<version>1.9.7</version>
</dependency>
<!-- spring end -->

<dependency>
<groupId>javax</groupId>
<artifactId>javaee-api</artifactId>
<version>6.0</version>
<scope>provided</scope>
</dependency>

<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.25</version>
</dependency>

<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis-spring</artifactId>
<version>1.1.1</version>
</dependency>
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.1.1</version>
</dependency>

<dependency>
<groupId>com.mchange</groupId>
<artifactId>c3p0</artifactId>
<version>0.9.5-pre8</version>
</dependency>
</dependencies>

<profiles>
<profile>
<id>DEV</id>
<properties>
<dao.jdbc.url>10.236.121.48</dao.jdbc.url>
<dao.jdbc.port>3306</dao.jdbc.port>
<dao.jdbc.schema>wangci</dao.jdbc.schema>
<dao.jdbc.user>root</dao.jdbc.user>
<dao.jdbc.password>root</dao.jdbc.password>
</properties>
<activation>
<activeByDefault>true</activeByDefault>
</activation>
</profile>
</profiles>
</project>

三、dao层配置

1、在dao层resources目录下新建文件mybatis-config.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>
</configuration>

2、在resources目录下新建jdbc.properties文件

c3p0.driverClass=com.mysql.jdbc.Driver
c3p0.jdbcUrl=jdbc:mysql://${dao.jdbc.url}:${dao.jdbc.port}/${dao.jdbc.schema}?useUnicode=
true&characterEncoding=utf8&mysqlEncoding=utf8&zeroDateTimeBehavior=convertToNull
c3p0.user=${dao.jdbc.user}
c3p0.password=${dao.jdbc.password}
c3p0.acquireIncrement=1
c3p0.maxIdleTime=30
c3p0.minPoolSize=10
c3p0.maxPoolSize=100
c3p0.initialPoolSize=10

3、修改context-dao.xml，新增数据库相关配置

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:aop="http://www.springframework.org/schema/aop"
xmlns:tx="http://www.springframework.org/schema/tx"
xmlns:jdbc="http://www.springframework.org/schema/jdbc"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation=" http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc-3.0.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.0.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.0.xsd">
<context:annotation-config />

<context:property-placeholder location="classpath:jdbc.properties"
ignore-unresolvable="true" />

<bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
<property name="driverClass" value="${c3p0.driverClass}"></property>
<property name="jdbcUrl" value="${c3p0.jdbcUrl}"></property>
<property name="user" value="${c3p0.user}"></property>
<property name="password" value="${c3p0.password}"></property>
<property name="acquireIncrement" value="${c3p0.acquireIncrement}"></property>
<property name="initialPoolSize" value="${c3p0.initialPoolSize}"></property>
<property name="maxIdleTime" value="${c3p0.maxIdleTime}"></property>
<property name="maxPoolSize" value="${c3p0.maxPoolSize}"></property>
<property name="minPoolSize" value="${c3p0.minPoolSize}"></property>
<property name="acquireRetryDelay" value="1000"></property>
<property name="acquireRetryAttempts" value="60"></property>
<property name="breakAfterAcquireFailure" value="false"></property>
</bean>
<bean id="transactionManager"
class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
<property name="dataSource" ref="dataSource" />
</bean>

<!-- 使用annotation定义事务 @Transactional -->
<tx:annotation-driven transaction-manager="transactionManager" />

<!-- 配置SqlSessionFactoryBean  -->
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
<property name="dataSource" ref="dataSource" />
<property name="configLocation" value="classpath:mybatis-config.xml" />
<property name="mapperLocations" value="classpath:context/mybatis/*Mapper.xml" />
<property name="typeAliasesPackage" value="wang.wangci.bottae.dao.mapper" />
</bean>
<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
<property name="basePackage" value="wang.wangci.bottae.dao.mapper" />
</bean>

</beans>

四、编写代码

1、在dao层新建wang.wangci.bottae.dao.entity.User类

package wang.wangci.bottae.dao.entity;
public class User {
private long id;
private String username;
private String password;
public long getId() {
return id;
}
public void setId(long id) {
this.id = id;
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}

}

2、dao层新增接口wang.wangci.bottae.dao.mapper.UserMapper

package wang.wangci.bottae.dao.mapper;
import java.util.List;
import org.apache.ibatis.annotations.Param;
import wang.wangci.bottae.dao.entity.User;
public interface UserMapper {
public List<User> selects();

public User selectById(@Param("id")long id);

}

3、在dao层resources/context文件夹下新建mybatis文件夹，新建接口UserMapper的映射文件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="wang.wangci.bottae.dao.mapper.UserMapper">

<select id="selects" resultType="wang.wangci.bottae.dao.entity.User">
SELECT *    FROM user
</select>
<select id="selectById" resultType="wang.wangci.bottae.dao.entity.User">
SELECT *    FROM user WHERE id=#{id}
</select>
</mapper>

4、在service层新建wang.wangci.bottae.service.UserService接口

package wang.wangci.bottae.service;
import java.util.List;
import wang.wangci.bottae.dao.entity.User;
public interface UserService {
public List<User> finds();

public User findById(long id);
}

5、在service层新建wang.wangci.bottae.service.impl.UserServiceImpl类

package wang.wangci.bottae.service.impl;
import java.util.List;
import javax.annotation.Resource;
import org.springframework.stereotype.Component;
import wang.wangci.bottae.dao.entity.User;
import wang.wangci.bottae.dao.mapper.UserMapper;
import wang.wangci.bottae.service.UserService;
@Component
public class UserServiceImpl implements UserService {

@Resource
private UserMapper userMapper;
@Override
public List<User> finds() {
return userMapper.selects();
}
@Override
public User findById(long id) {
return userMapper.selectById(id);
}
}

6、在web层新建wang.wangci.bottae.web.controllers.UserController类

package wang.wangci.bottae.web.controllers;
import java.util.List;
import javax.annotation.Resource;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.ResponseBody;
import wang.wangci.bottae.dao.entity.User;
import wang.wangci.bottae.service.UserService;
@Controller
@RequestMapping("/user")
public class UserController {
@Resource
private UserService userService;

@ResponseBody
@RequestMapping("/gets")
public List<User> gets(){
return userService.finds();
}

@ResponseBody
@RequestMapping("/get")
public User get(@RequestParam long id){
return userService.findById(id);
}

}

五、编译运行

命令行下执行下面命令启动服务：

mvn clean install
cd bottae-web
mvn jetty:run

访问http://localhost:7777/user/gets，如果将数据库user查询出来了，说明成功了
访问http://localhost:7777/user/get?id=1，如果将id为1的user查询出来了，说明成功了

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