MyBatis的应用

a）首先先导入固定的jar包

b）添加mybatis配置文件mybatis-config.xml

1、添加mybatis配置文件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>
     <settings>
         <setting name="cacheEnabled" value="true" />  <!-- 缓存 -->
        <setting name="useGeneratedKeys" value="true" /> <!--  自动获取主键 -->
        <setting name="defaultExecutorType" value="REUSE" />
     </settings>
    <!-- 配置别名 -->
     <typeAliases>
         <typeAlias alias="User" type="com.sdtg.system.bean.User"/>
         <typeAlias alias="Dept" type="com.sdtg.system.bean.Dept"/>
         <typeAlias alias="UserDept" type="com.sdtg.system.bean.UserDept"/>
         <typeAlias alias="Module" type="com.sdtg.system.bean.Module"/>
         <typeAlias alias="Privilege" type="com.sdtg.system.bean.Privilege"/>
         <typeAlias alias="Role" type="com.sdtg.system.bean.Role"/>
         <typeAlias alias="RolePrivilege" type="com.sdtg.system.bean.RolePrivilege"/>
         <typeAlias alias="OperateLog" type="com.sdtg.system.bean.OperateLog"/>
         <typeAlias alias="UserPrivilege" type="com.sdtg.system.bean.UserPrivilege"/>
         <typeAlias alias="WorkPlan" type="com.sdtg.plan.bean.WorkPlan"/>
         <typeAlias alias="Notepad" type="com.sdtg.office.bean.Notepad"/>
         <typeAlias alias="Onduty" type="com.sdtg.office.bean.Onduty"/>
         <typeAlias alias="Company" type="com.sdtg.contacts.bean.Company"/>
         <typeAlias alias="News" type="com.sdtg.contacts.bean.News"/>
         <typeAlias alias="Customer" type="com.sdtg.contacts.bean.Customer"/>
         <typeAlias alias="Files" type="com.sdtg.file.bean.Files"/>
     </typeAliases>
     <!-- 配置mappers -->
     <!-- mappers元素是包含所有mapper（映射器）的列表，这些mapper的XML文件包含SQL代码和映射定义信息。 -->
     <mappers>
         <mapper resource="com/sdtg/system/dao/User.xml"/>
        <mapper resource="com/sdtg/system/dao/Dept.xml"/>
        <mapper resource="com/sdtg/system/dao/Module.xml"/>
        <mapper resource="com/sdtg/system/dao/Privilege.xml"/>
        <mapper resource="com/sdtg/system/dao/Role.xml"/>
        <mapper resource="com/sdtg/system/dao/OperateLog.xml"/>
        <mapper resource="com/sdtg/plan/dao/WorkPlan.xml"/>
        <mapper resource="com/sdtg/office/dao/Notepad.xml"/>
        <mapper resource="com/sdtg/office/dao/Onduty.xml"/>
        <mapper resource="com/sdtg/contacts/dao/Company.xml"/>
        <mapper resource="com/sdtg/contacts/dao/News.xml"/>
        <mapper resource="com/sdtg/contacts/dao/Customer.xml"/>
        <mapper resource="com/sdtg/file/dao/Files.xml"/>
     </mappers>
 </configuration>

2、创建对应的实体对象

对应的java代码

 package com.sdtg.contacts.bean;

 import java.io.Serializable;

 import javax.persistence.Column;
 import javax.persistence.Entity;
 import javax.persistence.GeneratedValue;
 import javax.persistence.Id;
 import javax.persistence.Table;

 import org.hibernate.annotations.GenericGenerator;

 @Entity
 @Table(name = "company") // 映射数据库中表的表名
 public class Company implements Serializable {

     private static final long serialVersionUID = -7746115557660768065L;

     @Id
     @Column(name = "c_id") //映射company表的c_id列
     @GenericGenerator(name = "idGenerator", strategy = "identity")//name属性指定生成器名称，strategy属性指定具体生成器的类名。
     @GeneratedValue(generator = "idGenerator")
     private Integer id;//主键

     @Column(name = "c_name")
     private String name;//名称

     @Column(name = "c_address")
     private String address;//地址

     @Column(name = "c_tel")
     private String tel;//电话

     public Company() {
         super();
     }

     public Integer getId() {
         return id;
     }

     public void setId(Integer id) {
         this.id = id;
     }

     public String getName() {
         return name;
     }

     public void setName(String name) {
         this.name = name;
     }

     public String getAddress() {
         return address;
     }

     public void setAddress(String address) {
         this.address = address;
     }

     public String getTel() {
         return tel;
     }

     public void setTel(String tel) {
         this.tel = tel;
     }

 }

3、创建接口和对应的定义操作company表的sql映射文件Company.xml（以company为例）

接口提供简单的增删改查数据的信息

package com.sdtg.contacts.dao;

import java.util.List;
import java.util.Map;

import org.springframework.stereotype.Repository;

import com.sdtg.contacts.bean.Company;

@Repository //标注一个DAO类组件类
public interface CompanyDao {

    /**
     * 查询
     * @param map
     * @return
     */
    public abstract List<Company> find(Map<String, Object> map);

    /**
     * 分页查询
     * @param map
     * @return
     */
    public abstract List<Company> findPage(Map<String, Object> map);

    /**
     * 查询条数
     * @param map
     * @return
     */
    public abstract Integer findCount(Map<String, Object> map);

    /**
     * id查询
     * @param id
     * @return
     */
    public abstract Company findById(Integer id);

    /**
     * 添加
     * @param company
     */
    public abstract void add(Company company);

    /**
     * 删除
     * @param id
     */
    public abstract void delete(Integer id);

    /**
     * 修改
     * @param company
     */
    public abstract void update(Company company);

}

Company.xml文件运用sql语句进行对数据信息的增删改查

<?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.sdtg.contacts.dao.CompanyDao">

    <!-- 字段 -->
    <sql id="field">
        c.c_id as 'id',
        c.c_name as 'name',
        c.c_address as 'address',
        c.c_tel as 'tel'
    </sql>

    <!-- 条件 -->
    <sql id="sql">
        <if test="name != null and name != ''">
            and (c.c_name like '%${name}%' or c.c_address like '%${name}%' or c.c_tel like '%${name}%')
        </if>
    </sql>

    <!-- 查询 -->
    <select id="find" parameterType="Map" resultType="Company">
        select <include refid="field"/>
        from company c
        where 1=1 <include refid="sql"/>
        order by c.c_id desc
    </select>

    <!-- 分页查询 -->
    <select id="findPage" parameterType="Map" resultType="Company">
        select <include refid="field"/>
        from company c
        where 1=1 <include refid="sql"/>
        order by c.c_id desc
        limit ${startIndex}, ${pageSize}
    </select>

    <!-- 查询条数 -->
    <select id="findCount" parameterType="Map" resultType="Integer">
        select count(c.c_id)
        from company c
        where 1=1 <include refid="sql"/>
    </select>

    <!-- id查询 -->
    <select id="findById" parameterType="Integer" resultType="Company">
        select <include refid="field"/>
        from company c
        where c.c_id = #{id}
    </select>

    <!-- 添加 -->
    <insert id="add" parameterType="Company">
        insert into company(
            c_name,
            c_address,
            c_tel
        )values(
            #{name},
            #{address},
            #{tel}
        )
    </insert>

    <!-- 删除 -->
    <delete id="delete" parameterType="Integer">
        delete from company where c_id = #{id}
    </delete>

    <!-- 修改 -->
    <update id="update" parameterType="Company">
        update company
        <set>
            <if test="name != null">
                c_name = #{name},
            </if>
            <if test="address != null">
                c_address = #{address},
            </if>
            <if test="tel != null">
                c_tel = #{tel},
            </if>
        </set>
        where c_id = #{id}
    </update>

</mapper>

然后映射到mybatis-config.xml配置文件

我连接数据库是运用spring配置文件来连接数据库，运用sqlsessionFactory

<?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"
   xmlns:tx="http://www.springframework.org/schema/tx"
   xmlns:aop="http://www.springframework.org/schema/aop"
   xmlns:mvc="http://www.springframework.org/schema/mvc"
   xsi:schemaLocation="
      http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
      http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd
      http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.0.xsd
      http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.0.xsd
      http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd">

    <!-- 启用Spring注解 -->
    <context:annotation-config/>

    <!-- 自动扫描注解类 -->
    <context:component-scan base-package="com.sdtg"/>

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

    <!-- 自动扫描Mapper接口 -->
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <property name="basePackage" value="com.sdtg"/>
    </bean>

    <!-- 数据源 在spring里面配置数据库  -->
    <bean id="dataSource" class="com.jolbox.bonecp.BoneCPDataSource">
        <property name="driverClass" value="${jdbc.driver}" />
        <property name="jdbcUrl" value="${jdbc.url}" />
        <property name="username" value="${jdbc.username}" />
        <property name="password" value="${jdbc.password}" />
    </bean> 

    <!-- Sql Session工厂 --><!-- 映射到mybatis.xml文件-->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource"/>
        <property name="configLocation" value="classpath:mybatis-config.xml"/>
    </bean>

    <!-- Sql Session -->
    <bean id="sqlSession" class="org.mybatis.spring.SqlSessionTemplate">
        <constructor-arg index="0" ref="sqlSessionFactory" />
    </bean>

    <!-- hibernate 映射实体类里面，用注解的方式实现自动建表的功能 -->
    <bean id="sessionFactory" name="sessionFactory" class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
        <property name="dataSource" ref="dataSource" />
        <property name="packagesToScan" value="com.sdtg" />
        <property name="hibernateProperties">
            <props>
                <!-- Hibernate方言 -->
                <prop key="hibernate.dialect">${hibernate.dialect}</prop>
                <!-- 是否输出Sql语句 -->
                <prop key="hibernate.show_sql">${hibernate.show_sql}</prop>
                <!-- 当前Session策略类 -->
                <prop key="hibernate.current_session_context_class">org.springframework.orm.hibernate4.SpringSessionContext</prop>
                <!-- 格式化Sql语句 -->
                <prop key="hibernate.format_sql">${hibernate.format_sql}</prop>
                <!-- 开启后，Hibernate将收集有助于性能调节的统计数据 -->
                <prop key="hibernate.generate_statistics">${hibernate.generate_statistics}</prop>
                <!-- 自动创建数据库表 -->
                <prop key="hibernate.hbm2ddl.auto">${hibernate.hbm2ddl.auto}</prop>
            </props>
        </property>
    </bean>

    <!-- 事物 -->
    <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="dataSource"/>
    </bean>
    <tx:annotation-driven transaction-manager="transactionManager"/>

</beans>

补充：

service和控制层的源码

package com.sdtg.contacts.service;

import java.util.List;
import java.util.Map;

import javax.annotation.Resource;

import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import com.sdtg.contacts.bean.Company;
import com.sdtg.contacts.dao.CompanyDao;
import com.sdtg.utils.ConvertUtils;
import com.sdtg.utils.Page;

@Service //标注一个业务逻辑组件类
@Transactional
public class CompanyService {

    @Resource
    private CompanyDao dao;

    /**
     * 查询
     * @param map
     * @return
     */
    public List<Company> find(Map<String, Object> map){
        try {

            return dao.find(map);
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * 分页查询
     * @param map
     * @return
     */
    public Page<Company> findPage(Map<String, Object> map){
        try {
            Page<Company> page = new Page<Company>();
            page.setTotalCount(dao.findCount(map));
            page.setCurrPage(ConvertUtils.stringToInteger(map.get("currPage").toString()));
            map.put("startIndex", page.getStartIndex());
            map.put("pageSize", page.getPageSize());
            page.setList(dao.findPage(map));
            return page;
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * id查询
     * @param id
     * @return
     */
    public Company findById(Integer id){
        try {
            return dao.findById(id);
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * 添加
     * @param company
     */
    public Boolean add(Company company){
        try {
            dao.add(company);
            return true;
        } catch (Exception e) {
            e.printStackTrace();
            return false;
        }
    }

    /**
     * 删除
     * @param id
     */
    public Boolean delete(Integer id){
        try {
            dao.delete(id);
            return true;
        } catch (Exception e) {
            e.printStackTrace();
            return false;
        }
    }

    /**
     * 修改
     * @param company
     */
    public Boolean update(Company company){
        try {
            dao.update(company);
            return true;
        } catch (Exception e) {
            e.printStackTrace();
            return false;
        }
    }
}

控制层：

package com.sdtg.contacts.controller;

import java.util.HashMap;
import java.util.Map;

import javax.annotation.Resource;
import javax.servlet.http.HttpServletRequest;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.servlet.ModelAndView;

import com.sdtg.contacts.bean.Company;
import com.sdtg.contacts.service.CompanyService;
import com.sdtg.system.service.OperateLogService;
import com.sdtg.utils.Page;

@Controller  //类似Struts的Action，标注一个控制器组件类
public class CompanyController {

    @Resource  //命名为'setCompanyService'的方法被用来处理名为'ompanyService'的属性。
    private CompanyService companyService;

    @Resource
    private OperateLogService operateLogService;

    /**
     * 查询公司
     * @param request
     * @param result
     * @param currPage
     * @param name
     * @return
     */
    @RequestMapping(value = "companyList") // 请求url地址映射，类似Struts的actiohn-mapping,直接将返回值返回到页面
    public ModelAndView companyList(HttpServletRequest request, String result, String currPage, String name){
        // request和response不必非要出现在方法中，如果用不上的话可以去掉
        // 参数的名称是与页面控件的name相匹配，参数类型会自动被转换
        System.out.println("进入查询功能");

        ModelAndView mav = new ModelAndView();
        Map<String, Object> map = new HashMap<String, Object>();
        map.put("name", name); //在jsp页面中可直通过${name}获得到值, map.put()相当于request.setAttribute方法。
        map.put("currPage", currPage != null ? currPage : 1);

        Page<Company> page = companyService.findPage(map);
        mav.addObject("companyList",page.getList());
        System.out.println("进入分页查询");
        mav.addObject("page",page);

        mav.addObject("result",result);//增删改的结果
        //返回查询条件
        mav.addObject("name",name);

        mav.setViewName("contacts/company");
        return mav;  //
    }

    /**
     * 添加公司
     * @return
     */
    @RequestMapping(value = "companyAdd")
    public ModelAndView companyAdd(){
        ModelAndView mav = new ModelAndView();
        mav.setViewName("contacts/company_form");
        return mav;
    }

    /**
     * 修改公司
     * @param id
     * @return
     */
    @RequestMapping(value = "companyUpdate")
    public ModelAndView companyUpdate(Integer id){
         // 同样支持参数为表单对象，类似于Struts的ActionForm，Integer id不需要任何配置，直接写即可
        ModelAndView mav = new ModelAndView(); // 采用重定向方式跳转页面
        mav.addObject("company", companyService.findById(id));
        mav.setViewName("contacts/company_form");
        return mav;
    }

    /**
     * 保存公司
     * @param request
     * @param company
     * @return
     */
    @RequestMapping(value = "companySave")
    public ModelAndView companySave(HttpServletRequest request, Company company){
        ModelAndView mav = new ModelAndView();
        Boolean flag;
        if(null == company.getId()){//添加
            flag = companyService.add(company);
            operateLogService.add(request, "添加公司："+company.getName());
        } else {//修改
            flag = companyService.update(company);
            operateLogService.add(request, "修改公司：id="+company.getId());
        }
        mav.setViewName("redirect:companyList.do?result="+flag);
        return mav;
    }

    /**
     * 删除公司
     * @param request
     * @param id
     * @return
     */
    @RequestMapping(value = "companyDelete")
    public ModelAndView companyDelete(HttpServletRequest request, Integer id){
        ModelAndView mav = new ModelAndView();
        Boolean flag = companyService.delete(id);
        if(flag){
            operateLogService.add(request, "删除公司：id="+id);
        }
        mav.setViewName("redirect:companyList.do?result="+flag);
        return mav;
    }

}