ssm框架搭建（一）-Dao層搭建-mybatis

首先創建基於maven的web項目。
環境參數：jdk：1.8
Tomcat：tomcat8
myeclipse2016
先看看文件結構：

Dao層主要用於對數據庫的操作（增刪改查），也就是直接對應着sql語句。
首先是pom.xml中的依賴

<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>SSM_TEST</groupId>
  <artifactId>SSM_TEST</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <packaging>war</packaging>
  <name>SSM_TEST</name>
  <description/>
  <properties>
    <webVersion>3.0</webVersion>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
  </properties>
  <dependencies>
    <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.11</version>
            <scope>test</scope>
        </dependency>
        <!-- 日誌 -->
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-api</artifactId>
            <version>1.7.12</version>
        </dependency>
        <!-- 實現slf4j接口並整合 -->
        <dependency>
            <groupId>ch.qos.logback</groupId>
            <artifactId>logback-classic</artifactId>
            <version>1.1.1</version>
        </dependency>
        <!-- 數據庫相關依賴 -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.35</version>
        </dependency>
        <dependency>
            <groupId>c3p0</groupId>
            <artifactId>c3p0</artifactId>
            <version>0.9.1.2</version>
        </dependency>
        <!-- DAO框架：MyBatis -->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.3.0</version>
        </dependency>
        <!-- mybatis自身實現的spring整合依賴 -->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis-spring</artifactId>
            <version>1.2.3</version>
        </dependency>
        <!-- Servlet WEB相關依賴 -->
        <dependency>
            <groupId>taglibs</groupId>
            <artifactId>standard</artifactId>
            <version>1.1.2</version>
        </dependency>
        <dependency>
            <groupId>jstl</groupId>
            <artifactId>jstl</artifactId>
            <version>1.2</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>2.5.5</version>
        </dependency>
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>3.1.0</version>
        </dependency>
        <!-- spring依賴 -->
        <!-- spring核心依賴 -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-core</artifactId>
            <version>4.1.9.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-beans</artifactId>
            <version>4.1.9.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>4.1.9.RELEASE</version>
        </dependency>
        <!-- spring dao層依賴 -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
            <version>4.1.9.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-tx</artifactId>
            <version>4.1.9.RELEASE</version>
        </dependency>
        <!-- spring web 相關依賴 -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-web</artifactId>
            <version>4.1.9.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>4.1.9.RELEASE</version>
        </dependency>
        <!-- spring test相關依賴 -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-test</artifactId>
            <version>4.1.9.RELEASE</version>
        </dependency>
        <!-- redis客戶端 ：Jedis -->
        <dependency>
            <groupId>redis.clients</groupId>
            <artifactId>jedis</artifactId>
            <version>2.7.3</version>
        </dependency>
        <!--prostuff序列化依賴 -->
        <dependency>
            <groupId>com.dyuproject.protostuff</groupId>
            <artifactId>protostuff-core</artifactId>
            <version>1.0.8</version>
        </dependency>
        <dependency>
            <groupId>com.dyuproject.protostuff</groupId>
            <artifactId>protostuff-runtime</artifactId>
            <version>1.0.8</version>
        </dependency>
        <dependency>
            <groupId>com.aliyun.oss</groupId>
            <artifactId>aliyun-sdk-oss</artifactId>
            <version>2.7.0</version>
        </dependency>
  </dependencies>
  <build>
    <plugins>
      <plugin>
        <artifactId>maven-compiler-plugin</artifactId>
        <version>2.3.2</version>
        <configuration>
          <source>1.8</source>
          <target>1.8</target>
        </configuration>
      </plugin>
      <plugin>
        <artifactId>maven-war-plugin</artifactId>
        <version>2.6</version>
        <configuration>
          <failOnMissingWebXml>false</failOnMissingWebXml>
        </configuration>
      </plugin>
    </plugins>
  </build>
</project>

然後是數據庫配置文件jdbc.properties

driver=com.mysql.jdbc.Driver
url=jdbc:mysql://127.0.0.1:3306/user_d?useUnicode=true&characterEncoding=utf8
user=root
password=root

配置日誌文件logback.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/2002/xmlspec/dtd/2.10/xmlspec.dtd">
<configuration debug="true"> 

  <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender"> 
    <!-- encoders are  by default assigned the type
         ch.qos.logback.classic.encoder.PatternLayoutEncoder -->
    <encoder>
      <pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n</pattern>
    </encoder>
  </appender>

  <root level="debug">
    <appender-ref ref="STDOUT" />
  </root>
</configuration>

mybatis配置文件：

<?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>
    <!-- 配置全局屬性 -->
    <settings>
        <!-- 使用jdbc的getGeneratedKeys 獲取數據庫自增主鍵值 -->
        <setting name="useGeneratedKeys" value="true"/>
        <!-- 使用別名替換列名 默認：true -->
        <setting name="useColumnLabel" value="true"/>
        <!-- 開啓駝峯命名轉換 -->
        <setting name="mapUnderscoreToCamelCase" value="true"/>
    </settings>
  </configuration>

實體類：User.java （在插入或者更新有可能會報找不到構造方法的錯，但是明明有對應的構造方法，這個問題需要添加空的構造方法，爲了避免這樣的問題，建議每個實體類都有添加空的構造方法）

package com.ssm.entity;   
/**  
* @author zx 
* @Date 2017年10月10日 下午3:50:43  
* @Class User.java 
*/
public class User {

    private Integer userId;

    private String userName;

    private String userPassword;

    public User() {
    }

    public User(String userName, String userPassword) {
        this.userName = userName;
        this.userPassword = userPassword;
    }

    public Integer getUserId() {
        return userId;
    }

    public void setUserId(Integer userId) {
        this.userId = userId;
    }

    public String getUserName() {
        return userName;
    }

    public void setUserName(String userName) {
        this.userName = userName;
    }

    public String getUserPassword() {
        return userPassword;
    }

    public void setUserPassword(String userPassword) {
        this.userPassword = userPassword;
    }

    @Override
    public String toString() {
        return "User [userId=" + userId + ", userName=" + userName + ", userPassword=" + userPassword + "]";
    }
}

Dao層接口類：UserDao.java

package com.ssm.dao;

import org.apache.ibatis.annotations.Param;

import com.ssm.entity.User;

/**  
* @author zx 
* @Date 2017年10月10日 下午3:57:28  
* @Class UserDao.java 
*/
public interface UserDao {

    /**
     * 通過userId查詢User
     * @author zx
     * @date 2017年10月10日 下午3:59:40
     * @param userId
     * @return
     */
    User queryUserByuserId(@Param("userId")Integer userId);
}

接口對應的XML文件：UserDao.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="com.ssm.dao.UserDao">
    <!-- 目的：爲dao接口方法提供sql語句配置 -->
    <select id="queryUserByuserId" resultType="User" parameterType="int">
        SELECT *
        FROM user
        WHERE user_id=#{userId}
    </select>
</mapper>

最關鍵的spring-dao.xml

<?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:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">
        <!-- 配置mybatis整合過程 -->
        <!-- 1：配置數據庫參數 -->
        <context:property-placeholder location="classpath:jdbc.properties"/>

        <!-- 數據庫連接池 -->
        <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
            <!--配置連接池屬性-->
        <property name="driverClass" value="${driver}" />

        <!-- 基本屬性 url、user、password -->
        <property name="jdbcUrl" value="${url}" />
        <property name="user" value="${user}" />
        <property name="password" value="${password}" />

        <!--c3p0私有屬性-->
        <property name="maxPoolSize" value="30"/>
        <property name="minPoolSize" value="10"/>
        <!--關閉連接後不自動commit-->
        <property name="autoCommitOnClose" value="false"/>

        <!--獲取連接超時時間-->
        <property name="checkoutTimeout" value="1000"/>
        <!--當獲取連接失敗重試次數-->
        <property name="acquireRetryAttempts" value="2"/>
        </bean>

        <!--約定大於配置-->
    <!--３.配置SqlSessionFactory對象-->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <!--往下才是mybatis和spring真正整合的配置-->
        <!--注入數據庫連接池-->
        <property name="dataSource" ref="dataSource"/>
        <!--配置mybatis全局配置文件:mybatis-config.xml-->
        <property name="configLocation" value="classpath:mybatis-config.xml"/>
        <!--掃描entity包,使用別名,多個用;隔開-->
        <property name="typeAliasesPackage" value="com.ssm.entity"/>
        <!--掃描sql配置文件:mapper需要的xml文件-->
        <property name="mapperLocations" value="classpath:mapper/*.xml"/>
    </bean>

    <!--４:配置掃描Dao接口包,動態實現DAO接口,注入到spring容器-->
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <!--注入SqlSessionFactory-->
        <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"/>
        <!-- 給出需要掃描的Dao接口-->
        <property name="basePackage" value="com.ssm.dao"/>
    </bean>

 </beans>

使用Junit進行單元測試：UserDaoTest.java

package com.ssm.dao;


import org.junit.Test;
import org.junit.runner.RunWith;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

import com.ssm.entity.User;

/**  
* @author zx 
* @Date 2017年10月10日 下午4:07:00  
* @Class UserDaoTest.java 
*/

@RunWith(SpringJUnit4ClassRunner.class)
//告訴junit spring配置文件
@ContextConfiguration({"classpath:spring/spring-dao.xml"})
public class UserDaoTest {

    private Logger logger = LoggerFactory.getLogger(this.getClass());

    @Autowired
    private UserDao userDao; 

    @Test
    public void testQueryUserByuserId() {
        int userId = 1;
        User user = userDao.queryUserByuserId(userId);
        logger.info("user={}", user);
    }

}

這裏有一個自動生成mybatis實體類、接口類和xml的工具。
mybatis工具下載
generatorConfig.xml是需要我們來配置的文件

只需要打開控制檯，進入lib目錄下，執行腳本：
java -jar mybatis-generator-core-1.3.2.jar -configfile generatorConfig.xml -overwrite
即可。