cache – 给定命名空间的缓存配置。
cache-ref – 其他命名空间缓存配置的引用。
resultMap – 是最复杂也是最强大的元素，用来描述如何从数据库结果集中来加载对象。
parameterMap – 已废弃！
sql – 可被其他语句引用的可重用语句块。
insert – 映射插入语句
update – 映射更新语句
delete – 映射删除语句
select – 映射查询语
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SqlSession session = factory.openSession();
UserDao dao = session.getMapper(UserDao.class);
//或者可以使用工具类
UserDao userDao =
MyBatisUtil.getSqlSession().getMapper(UserDao.class);
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@Test
  public void TestUpdate(){
    User user = new User(16,"赵六","110");
    userDao.update(user);
  }
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若数据库支持自动生成主键的字段（比如 MySQL 和 SQL Server ），则可以设置`useGeneratedKeys=”true”`，然后再把 keyProperty 设置到目标属性上。
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<insert id="insertEmployee"
insert id="insertEmployee"parameterType="com.atguigu.mybatis.beans.Employee" databaseId="mysql" useGeneratedKeys="true" keyProperty="id">
      insert into tbl_employee(last_name,email,gender) values(#{lastName},#{email},#{gender})
</insert>
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<insert id="insertEmployee" parameterType="com.atguigu.mybatis.beans.Employee" databaseId="oracle">
    <selectKey order="BEFORE" keyProperty="id" resultType="integer">
    select employee_seq.nextval from dual
  </selectKey>
    insert into orcl_employee(id,last_name,email,gender) values(#{id},#{lastName},#{email},#{gender})
</insert>
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<insert id="insertEmployee" parameterType="com.atguigu.mybatis.beans.Employee" databaseId="oracle">
  <selectKey order="AFTER" keyProperty="id" resultType="integer">
    select employee_seq.currval from dual
  </selectKey>
  insert into orcl_employee(id,last_name,email,gender) values(employee_seq.nextval,#{lastName},#{email},#{gender})
</insert>
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//接口中的方法：
User selectById(int id);
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<!--mapper文件-->
<select id="selectById" resultType="com.bjpowernode.domain.Student">
  select id,username,pwd from user where id=#{abcd}
</select>
<!--
  #{abcd} , abcd是自定义的变量名称，可以不和方法参数名相同，但是实际开发中一般是相同的。
-->
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//接口方法
List<User> selectUserByCondition(@Param("username") String username, @Param("pwd") int pwd);
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<!--mapper文件-->
<select id="selectUserByCondition" resultType="com.domain.User">
  select id,username,pwd from student where username = #{username} or pwd = #{pwd}
</select>
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//接口方法
List<User> selectMultiMap(Map<String,Object> map);
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<!--mapper文件-->
<select id="selectMultiMap" resultType="com.domain.User">
  select id,username,pwd from user where username=#{username} or pwd =#{pwd}
</select>
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public User getUserByIdAndUsername
(@Param("id")Integer id, @Param("username")String username);
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public Object getNamedParams(Object[] args) {
        final int paramCount = names.size();
        if (args == null || paramCount == 0) {
            return null;
        } else if (!hasParamAnnotation && paramCount == 1) {
            return args[names.firstKey()];
        } else {
            final Map<String, Object> param = new ParamMap<Object>();
            int i = 0;
            for (Map.Entry<Integer, String> entry : names.entrySet()) {
                param.put(entry.getValue(), args[entry.getKey()]);
        // add generic param names (param1, param2, ...)
                final String genericParamName = GENERIC_NAME_PREFIX +
                        String.valueOf(i + 1);
        // ensure not to overwrite parameter named with @Param
                if (!names.containsValue(genericParamName)) {
                    param.put(genericParamName, args[entry.getKey()]);
                }
                i++;
            }
            return param;
        }
    }
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<select id="selectMultiObject" resultType="com.domain.User">
select id,username pwd from user
where username=#{username,javaType=string,jdbcType=VARCHAR}
or pwd =#{pwd,javaType=int,jdbcType=INTEGER}
</select>
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<!--mapper文件-->
<select id="selectById" resultType="com.domain.User">
select id,username,pwd from user where id=#{id}
</select>
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//转为 MyBatis 的执行是：
String sql=” select id,username,pwd from user where id=?”;
PreparedStatement ps = conn.prepareStatement(sql);
ps.setInt(1,1005);
//解释：
where id=? 就是 where id=#{id}
ps.setInt(1,1005) , 1005 会替换掉 #{id}
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//需求：使用不同列作为查询条件
//接口方法
User findByDiffField(@Param("col") String colunName,@Param("cval") Object value);
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<!--mapper文件-->
<select id="findByDiffField" resultType="com.domain.User">
select * from user where ${col} = #{cval}
</select>
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public User getUserById(Integer id );
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public List<User> getAllUser();
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public Map<String,Object> getUserByIdReturnMap(Integer id );
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@MapKey("id") // 指定使用对象的哪个属性来充当 map 的 key
public Map<Integer,User> getAllUserReturnMap();
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//接口方法
int countUser();
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<!--mapper 文件-->
<select id="countUser" resultType="int">
  select count(*) from user
</select>
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//接口方法
List<User> selectUsers();
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<!--mapper文件-->
<select id="selectUsers" resultType="com.domain.User">
  select id,username,pwd from user 
</select>
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<!--resultMap: resultMap 标签中的 id 属性值-->
<select id="getEmployeeById" resultMap="myEmp">
  select id, last_name,email, gender from tbl_employee where id =#{id}
</select>
    <!-- 创建 resultMap
    id:自定义的唯一名称，在<select>使用
    type:期望转为的 java 对象的全限定名称或别名
    -->
<resultMap type="com.domain.Employee" id="myEmp">
    <!-- 主键字段使用 id -->
  <id column="id" property="id" />
    <!--非主键字段使用 result-->
  <result column="last_name" property="lastName"/>
  <result column="email" property="email"/>
  <result column="gender" property="gender"/>
</resultMap>
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@Data
public class Department {
  private Integer id ;
  private String departmentName ;
}
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@Data
public class Employee {
  private Integer id ;
  private String lastName;
  private String email ;
  private String gender ;
  private Department dept ;
}
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<select id="getEmployeeAndDept" resultMap="myEmpAndDept" >
  SELECT e.id eid, e.last_name, e.email,e.gender ,d.id did, d.dept_name 
    FROM tbl_employee e , tbl_dept d 
    WHERE e.d_id = d.id 
    AND e.id = #{id}
</select>
<resultMap type="com.domain.Employee" id="myEmpAndDept">
  <id column="eid" property="id"/>
  <result column="last_name" property="lastName"/>
  <result column="email" property="email"/>
  <result column="gender" property="gender"/>
  <association property="dept" javaType="com.domain.Department">
    <id column="did" property="id"/>
    <result column="dept_name" property="departmentName"/>
    </association>
</resultMap>
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<select id="getEmployeeAndDeptStep" resultMap="myEmpAndDeptStep">
  select id, last_name, email,gender,d_id from tbl_employee where id =#{id}
</select>
  <resultMap type="com.atguigu.mybatis.beans.Employee" id="myEmpAndDeptStep">
    <id column="id" property="id" />
    <result column="last_name" property="lastName"/>
    <result column="email" property="email"/>
    <result column="gender" property="gender"/>
    <association property="dept" 
                     select="com.atguigu.mybatis.dao.DepartmentMapper.getDeptById" 
                     column="d_id" 
                     fetchType="eager">
    </association>
</resultMap>
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<!-- 开启延迟加载 -->
<setting name="lazyLoadingEnabled" value="true"/>
<!-- 设置加载的数据是按需还是全部 -->
<setting name="aggressiveLazyLoading" value="false"/> 
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@Data
public class Department {
  private Integer id ;
  private String departmentName ;
  private List<Employee> emps ;
}
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<select id="getDeptAndEmpsById" resultMap="myDeptAndEmps">
  SELECT d.id did, d.dept_name ,e.id eid ,e.last_name ,e.email,e.gender
  FROM tbl_dept d 
  LEFT OUTER JOIN tbl_employee e 
  ON d.id = e.d_id
  WHERE d.id = #{id}
</select>
<resultMap type="com.atguigu.mybatis.beans.Department" id="myDeptAndEmps">
  <id column="did" property="id"/>
  <result column="dept_name" property="departmentName"/>
        <!--
        property: 关联的属性名
        ofType: 集合中元素的类型
        -->
    <collection property="emps" ofType="com.atguigu.mybatis.beans.Employee">
      <id column="eid" property="id"/>
      <result column="last_name" property="lastName"/>
      <result column="email" property="email"/>
      <result column="gender" property="gender"/>
    </collection>
</resultMap>
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<select id="getDeptAndEmpsByIdStep" resultMap="myDeptAndEmpsStep">
  select id ,dept_name from tbl_dept where id = #{id}
</select>
  <resultMap type="com.atguigu.mybatis.beans.Department" id="myDeptAndEmpsStep">
    <id column="id" property="id"/>
    <result column="dept_name" property="departmentName"/>
    <collection property="emps" select="com.atguigu.mybatis.dao.EmployeeMapper.getEmpsByDid" column="id"></collection>
  </resultMap>
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//接口方法
List<User> selectLikeFirst(String username);
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<!--接口文件-->
<select id="selectLikeFirst" resultType="com.domain.User">
select id,username,pwd from user where username like #{username}
</select>
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//接口方法
List<User> selectLikeSecond(String username);
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<!--mapper文件-->
<select id="selectLikeSecond" resultType="com.domain.User">
select id,username,pwd from user where username like "%" #{studentName} "%"
</select>
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<select id="getEmpsByConditionIf" resultType="com.atguigu.mybatis.beans.Employee">
  select id , last_name ,email , gender
  from tbl_employee
    <where>
      <if test="id!=null">
        and id = #{id}
      </if>
      <if test="lastName!=null &amp;&amp; lastName!=&quot;&quot;">
        and last_name = #{lastName}
      </if>
      <if test="email!=null and email.trim()!=''">
        and email = #{email}
      </if>
      <if test="&quot;m&quot;.equals(gender) or &quot;f&quot;.equals(gender)">
        and gender = #{gender}
      </if>
    </where>
</select>
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<select id="getEmpsByConditionTrim" resultType="com.atguigu.mybatis.beans.Employee">
    select id , last_name ,email , gender from tbl_employee
  <trim prefix="where" suffixOverrides="and">
    <if test="id!=null">
      id = #{id} and
    </if>
    <if test="lastName!=null &amp;&amp; lastName!=&quot;&quot;">
      last_name = #{lastName} and
    </if>
    <if test="email!=null and email.trim()!=''">
      email = #{email} and
    </if>
    <if test="&quot;m&quot;.equals(gender) or &quot;f&quot;.equals(gender)">
      gender = #{gender}
    </if>
  </trim>
</select>
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<update id="updateEmpByConditionSet">
  update tbl_employee
  <set>
    <if test="lastName!=null &amp;&amp; lastName!=&quot;&quot;">
      last_name = #{lastName},
    </if>
    <if test="email!=null and email.trim()!=''">
      email = #{email} ,
    </if>
    <if test="&quot;m&quot;.equals(gender) or &quot;f&quot;.equals(gender)">
      gender = #{gender}
    </if>
  </set>
  where id =#{id}
</update>
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<select id="getEmpsByConditionChoose" resultType="com.atguigu.mybatis.beans.Employee">
  select id ,last_name, email,gender from tbl_employee
  <where>
    <choose>
      <when test="id!=null">
        id = #{id}
      </when>
      <when test="lastName!=null">
        last_name = #{lastName}
      </when>
      <when test="email!=null">
        email = #{email}
      </when>
      <otherwise>
        gender = 'm'
      </otherwise>
    </choose>
  </where>
</select>
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<select id="getEmpsByConditionForeach" resultType="com.atguigu.mybatis.beans.Employee">
    select id , last_name, email ,gender from tbl_employee where id in
  <foreach collection="ids" item="curr_id" open="(" close=")" separator="," >
    #{curr_id}
  </foreach>
</select>
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<sql id="selectSQL">
  select id , last_name, email ,gender from tbl_employee
</sql>
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<include refid="selectSQL"></include>
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<?xml version="1.0" encoding="UTF-8"?>
<ehcache xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:noNamespaceSchemaLocation="../config/ehcache.xsd">
<!-- 磁盘保存路径 -->
<diskStore path="D:\atguigu\ehcache" />
<defaultCache
maxElementsInMemory="1000"
maxElementsOnDisk="10000000"
eternal="false"
              overflowToDisk="true"
timeToIdleSeconds="120"
timeToLiveSeconds="120"
diskExpiryThreadIntervalSeconds="120"
memoryStoreEvictionPolicy="LRU">
</defaultCache>
</ehcache>
<!--
属性说明：
l diskStore：指定数据在磁盘中的存储位置。
l defaultCache：当借助CacheManager.add("demoCache")创建Cache时，EhCache
便会采用<defalutCache/>指定的的管理策略
以下属性是必须的：
l maxElementsInMemory - 在内存中缓存的element的最大数目
l maxElementsOnDisk - 在磁盘上缓存的element的最大数目，若是0表示无穷大
l eternal - 设定缓存的elements是否永远不过期。如果为true，则缓存的数据始
终有效，如果为false那么还要根据timeToIdleSeconds，timeToLiveSeconds判断
l overflowToDisk - 设定当内存缓存溢出的时候是否将过期的element缓存到磁
盘上
以下属性是可选的：
l timeToIdleSeconds - 当缓存在EhCache中的数据前后两次访问的时间超过
timeToIdleSeconds的属性取值时，这些数据便会删除，默认值是0,也就是可闲置
时间无穷大
l timeToLiveSeconds - 缓存element的有效生命期，默认是0.,也就是element存活
时间无穷大
diskSpoolBufferSizeMB 这个参数设置DiskStore(磁盘缓存)的缓存区大小.默认
是30MB.每个Cache都应该有自己的一个缓冲区.
l diskPersistent - 在VM重启的时候是否启用磁盘保存EhCache中的数据，默认是
false。
l diskExpiryThreadIntervalSeconds - 磁盘缓存的清理线程运行间隔，默认是120
秒。每个120s，相应的线程会进行一次EhCache中数据的清理工作
l memoryStoreEvictionPolicy - 当内存缓存达到最大，有新的element加入的时
候， 移除缓存中element的策略。默认是LRU（最近最少使用），可选的有LFU
（最不常使用）和FIFO（先进先出）
-->
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<cache type="org.mybatis.caches.ehcache.EhcacheCache"></cache>
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<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE generatorConfiguration
PUBLIC "-//mybatis.org//DTD MyBatis Generator Configuration 1.0//EN"
"http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd">
<generatorConfiguration>
<!--
targetRuntime: 执行生成的逆向工程的版本
MyBatis3Simple: 生成基本的CRUD
MyBatis3: 生成带条件的CRUD
-->
<context id="DB2Tables" targetRuntime="MyBatis3">
<jdbcConnection driverClass="com.mysql.jdbc.Driver"
connectionURL="jdbc:mysql://localhost:3306/mybatis_1129"
userId="root"
password="1234">
</jdbcConnection>
<!-- javaBean的生成策略-->
<javaModelGenerator targetPackage="com.atguigu.mybatis.beans"
                    targetProject=".\src">
<property name="enableSubPackages" value="true" />
<property name="trimStrings" value="true" />
</javaModelGenerator>
<!-- SQL映射文件的生成策略 -->
<sqlMapGenerator targetPackage="com.atguigu.mybatis.dao"
targetProject=".\conf">
<property name="enableSubPackages" value="true" />
</sqlMapGenerator>
<!-- Mapper接口的生成策略 -->
<javaClientGenerator type="XMLMAPPER"
targetPackage="com.atguigu.mybatis.dao" targetProject=".\src">
<property name="enableSubPackages" value="true" />
</javaClientGenerator>
<!-- 逆向分析的表 -->
<table tableName="tbl_dept" domainObjectName="Department"></table>
<table tableName="tbl_employee" domainObjectName="Employee"></table>
</context>
</generatorConfiguration>
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@Test
    public void testMBG() throws Exception {
        List<String> warnings = new ArrayList<String>();
        boolean overwrite = true;
        File configFile = new File("mbg.xml");
        ConfigurationParser cp = new ConfigurationParser(warnings);
        Configuration config = cp.parseConfiguration(configFile);
        DefaultShellCallback callback = new DefaultShellCallback(overwrite);
        MyBatisGenerator myBatisGenerator = new MyBatisGenerator(config,
                callback, warnings);
        myBatisGenerator.generate(null);
    }
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@Test
    public void testSelect() throws Exception {
        SqlSessionFactory ssf = getSqlSessionFactory();
        SqlSession session = ssf.openSession();
        try {
            EmployeeMapper mapper =
                    session.getMapper(EmployeeMapper.class);
            List<Employee> emps = mapper.selectAll();
            for (Employee employee : emps) {
                System.out.println(employee);
            }
        } finally {
            session.close();
        }
    }
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@Test
    public void testSelect() throws Exception {
        SqlSessionFactory ssf = getSqlSessionFactory();
        SqlSession session = ssf.openSession();
        try {
            EmployeeMapper mapper =
                    session.getMapper(EmployeeMapper.class);
//条件查询: 名字中带有'张' 并且 email中'j' 或者 did = 2
            EmployeeExample example = new EmployeeExample();
            Criteria criteria = example.createCriteria();
            criteria.andLastNameLike("%张%");
            criteria.andEmailLike("%j%");
//or
            Criteria criteriaOr = example.createCriteria();
            criteriaOr.andDIdEqualTo(2);
            example.or(criteriaOr);
            List<Employee> emps = mapper.selectByExample(example);
            for (Employee employee : emps) {
                System.out.println(employee);
            }
        } finally {
            session.close();
        }
    }
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<plugins>
<plugin interceptor="com.github.pagehelper.PageInterceptor"></plugin>
</plugins>
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@Test
    public void testPageHelper() throws Exception{
        SqlSessionFactory ssf = getSqlSessionFactory();
        SqlSession session = ssf.openSession();
        try {
            EmployeeMapper mapper =
                    session.getMapper(EmployeeMapper.class);
//设置分页信息
            Page<Object> page = PageHelper.startPage(9, 1);
             List<Employee> emps = mapper.getAllEmps();
for (Employee employee : emps) {
        System.out.println(employee);
    }
    System.out.println("=============获取分页相关的信息
        =================");
        System.out.println("当前页: " + page.getPageNum());
    System.out.println("总页码: " + page.getPages());
    System.out.println("总条数: " + page.getTotal());
    System.out.println("每页显示的条数: " + page.getPageSize());
} finally {
        session.close();
        }
      }
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@Test
    public void testPageHelper1() throws Exception{
        SqlSessionFactory ssf = getSqlSessionFactory();
        SqlSession session = ssf.openSession();
        try {
            EmployeeMapper mapper =
                    session.getMapper(EmployeeMapper.class);
//设置分页信息
            Page<Object> page = PageHelper.startPage(9, 1);
            List<Employee> emps = mapper.getAllEmps();
//
            PageInfo<Employee> info = new PageInfo<>(emps,5);
            for (Employee employee : emps) {
                System.out.println(employee);
            }
            System.out.println("=============获取详细分页相关的信息
                    =================");
            System.out.println("当前页: " + info.getPageNum());
            System.out.println("总页码: " + info.getPages());
            System.out.println("总条数: " + info.getTotal());
            System.out.println("每页显示的条数: " + info.getPageSize());
            System.out.println("是否是第一页: " + info.isIsFirstPage());
      System.out.println("是否是最后一页: " + info.isIsLastPage());
      System.out.println("是否有上一页: " + info.isHasPreviousPage());
      System.out.println("是否有下一页: " + info.isHasNextPage());
      System.out.println("============分页逻辑===============");
    int [] nums = info.getNavigatepageNums();
  for (int i : nums) {
        System.out.print(i +" " );
    }
} finally {
        session.close();
        }
        }
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<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns="http://java.sun.com/xml/ns/javaee"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID" version="2.5">
<!-- 字符编码过滤器 -->
<filter>
  <filter-name>CharacterEncodingFilter</filter-name>
  <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
  <init-param>
    <param-name>encoding</param-name>
    <param-value>UTF-8</param-value>
  </init-param>
</filter>
<filter-mapping>
  <filter-name>CharacterEncodingFilter</filter-name>
  <url-pattern>/*</url-pattern>
</filter-mapping>
    <!-- REST 过滤器 -->
<filter>
<filter-name>HiddenHttpMethodFilter</filter-name>
<filter-class>org.springframework.web.filter.HiddenHttpMethodFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>HiddenHttpMethodFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
<!-- 实例化SpringIOC容器的监听器 -->
<context-param>
  <param-name>contextConfigLocation</param-name>
  <param-value>classpath:applicationContext.xml</param-value>
</context-param>
<listener>
  <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>
<!-- Springmvc的前端控制器 -->
<servlet>
  <servlet-name>springDispatcherServlet</servlet-name>
  <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
  <init-param>
    <param-name>contextConfigLocation</param-name>
    <param-value>classpath:springmvc.xml</param-value>
  </init-param>
  <load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
  <servlet-name>springDispatcherServlet</servlet-name>
  <url-pattern>/</url-pattern>
</servlet-mapping>
</web-app>
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<?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:mybatis-spring="http://mybatis.org/schema/mybatis-spring"
       xsi:schemaLocation="http://mybatis.org/schema/mybatis-spring
http://mybatis.org/schema/mybatis-spring-1.2.xsd
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-4.0.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx-4.0.xsd">
    <!-- 组件扫描 -->
    <context:component-scan base-package="com.atguigu.ssm">
        <context:exclude-filter type="annotation"
                                expression="org.springframework.stereotype.Controller"/>
    </context:component-scan>
    <!-- 连接池 -->
    <context:property-placeholder location="classpath:db.properties"/>
    <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="driverClass" value="${jdbc.driver}"></property>
        <property name="jdbcUrl" value="${jdbc.url}"></property>
        <property name="user" value="${jdbc.username}"></property>
        <property name="password" value="${jdbc.password}"></property>
    </bean>
    <!-- 事务 -->
    <bean id="dataSourceTransactionManager"
          class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="dataSource"></property>
    </bean>
    <tx:annotation-driven transaction-manager="dataSourceTransactionManager"/>
</beans>
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<?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:mvc="http://www.springframework.org/schema/mvc"
       xsi:schemaLocation="http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd
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-4.0.xsd">
    <!-- 组件扫描 -->
    <context:component-scan base-package="com.atguigu.ssm" use-default-filters="false">
        <context:include-filter type="annotation"
                                expression="org.springframework.stereotype.Controller"/>
    </context:component-scan>
    <!--视图解析器 -->
    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/views/"></property>
        <property name="suffix" value=".jsp"></property>
    </bean>
    <mvc:default-servlet-handler/>
    <mvc:annotation-driven/>
</beans>
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<?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>
    <!-- Spring 整合 MyBatis 后， MyBatis中配置数据源，事务等一些配置都可以
    迁移到Spring的整合配置中。MyBatis配置文件中只需要配置与MyBatis相关
    的即可。
    -->
    <!-- settings: 包含很多重要的设置项 -->
    <settings>
        <!-- 映射下划线到驼峰命名 -->
        <setting name="mapUnderscoreToCamelCase" value="true"/>
        <!-- 设置Mybatis对null值的默认处理 -->
        <setting name="jdbcTypeForNull" value="NULL"/>
        <!-- 开启延迟加载 -->
        <setting name="lazyLoadingEnabled" value="true"/>
        <!-- 设置加载的数据是按需还是全部 -->
        <setting name="aggressiveLazyLoading" value="false"/>
        <!-- 配置开启二级缓存 -->
        <setting name="cacheEnabled" value="true"/>
    </settings>
</configuration>
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<?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.atguigu.ssm.mapper.EmployeeMapper">
    <!-- public List<Employee> getAllEmps(); -->
    <select id="getAllEmps" resultMap="myEmpsAndDept" >
        select e.id eid, e.last_name,e.email,e.gender, d.id did, d.dept_name
        from tbl_employee e ,tbl_dept d
        where e.d_id = d.id
    </select>
    <resultMap type="com.atguigu.ssm.beans.Employee" id="myEmpsAndDept">
        <id column="eid" property="id"/>
        <result column="last_name" property="lastName"/>
        <result column="email" property="email"/>
        <result column="gender" property="gender"/>
        <association property="dept" javaType="com.atguigu.ssm.beans.Department">
            <id column="did" property="id"/>
            <result column="dept_name" property="departmentName"/>
        </association>
    </resultMap>
</mapper>
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<!-- Spring 整合 Mybatis -->
<!--1. SqlSession -->
<bean class="org.mybatis.spring.SqlSessionFactoryBean">
<!-- 指定数据源 -->
<property name="dataSource" ref="dataSource"></property>
<!-- MyBatis的配置文件 -->
<property name="configLocation"
value="classpath:mybatis-config.xml"></property>
<!-- MyBatis的SQL映射文件 -->
<property name="mapperLocations"
value="classpath:mybatis/mapper/*.xml"></property>
<property name="typeAliasesPackage"
value="com.atguigu.ssm.beans"></property>
</bean>
<!-- Mapper接口
MapperScannerConfigurer 为指定包下的Mapper接口批量生成代理实现类.bean
的默认id是接口名首字母小写.
-->
<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
<property name="basePackage" value="com.atguigu.ssm.mapper"></property>
</bean>
<!-- <mybatis-spring:scan base-package="com.atguigu.ssm.mapper"/> -->