mybatis扩展之自定义类型处理器处理枚举类型
发布时间:2020-12-14 18:02:40 所属栏目:大数据 来源:网络整理
导读:全局配置: typeHandlers typeHandler handler ="com.gong.mybatis.typeHandler.MyEnumEmpStatusTypeHandler" javaType ="com.gong.mybatis.bean.EmpStatus" / !-- typeHandler handler="org.apache.ibatis.type.EnumOrdinalTypeHandler" javaType="com.gong
全局配置: <typeHandlers> typeHandler handler="com.gong.mybatis.typeHandler.MyEnumEmpStatusTypeHandler" javaType="com.gong.mybatis.bean.EmpStatus"/> <!-- <typeHandler handler="org.apache.ibatis.type.EnumOrdinalTypeHandler" javaType="com.gong.mybatis.bean.EmpStatus"/> --> </> MyEnumEmpStatusTypeHandler.java package com.gong.mybatis.typeHandler; import java.sql.CallableStatement; java.sql.PreparedStatement; java.sql.ResultSet; java.sql.SQLException; org.apache.ibatis.type.JdbcType; org.apache.ibatis.type.TypeHandler; com.gong.mybatis.bean.EmpStatus; /** * 1、实现TypeHandler接口。或者继承BaseTypeHandler * * */ public class MyEnumEmpStatusTypeHandler implements TypeHandler<EmpStatus> { * 定义当前数据如何保存到数据库中 */ @Override void setParameter(PreparedStatement ps,int i,EmpStatus parameter,JdbcType jdbcType) throws SQLException { // TODO Auto-generated method stub System.out.println("要保存的状态码:"+parameter.getCode()); ps.setString(i,parameter.getCode().toString()); } @Override public EmpStatus getResult(ResultSet rs,String columnName) TODO Auto-generated method stub 需要根据从数据库中拿到的枚举的状态码返回一个枚举对象 int code = rs.getInt(columnName); System.out.println("从数据库中获取的状态码:"+code); EmpStatus status = EmpStatus.getEmpStatusByCode(code); return status; } @Override public EmpStatus getResult(ResultSet rs,1)"> columnIndex) TODO Auto-generated method stub rs.getInt(columnIndex); System.out.println("从数据库中获取的状态码:"+public EmpStatus getResult(CallableStatement cs,1)"> cs.getInt(columnIndex); System.out.println("从数据库中获取的状态码:"+ status; } } EmpSatus.java com.gong.mybatis.bean; enum EmpStatus { LOGIN(100,"用户登录"),LOGOUT(200,"用户登出"),REMOVE(300,"用户不存在"); private Integer code; String msg; EmpStatus(Integer code,String msg) { this.code = code; this.msg = msg; } Integer getCode() { code; } void setCode(Integer code) { String getMsg() { setMsg(String msg) { static EmpStatus getEmpStatusByCode( code) { switch(code){ case 100: LOGIN; case 200 LOGOUT; case 300 REMOVE; default: LOGOUT; } } } Employee.java Integer id; String lastName; String gender; String email; private EmpStatus empStatus=EmpStatus.LOGOUT; Department dept; 测试: com.gong.mybatis.test; java.io.IOException; java.io.InputStream; java.util.ArrayList; java.util.Arrays; java.util.HashMap; java.util.List; java.util.Map; org.apache.ibatis.io.Resources; org.apache.ibatis.session.SqlSession; org.apache.ibatis.session.SqlSessionFactory; org.apache.ibatis.session.SqlSessionFactoryBuilder; org.junit.Test; com.github.pagehelper.Page; com.github.pagehelper.PageHelper; com.github.pagehelper.PageInfo; com.gong.mybatis.bean.Department; com.gong.mybatis.bean.Employee; com.gong.mybatis.dao.EmployeeMapper; com.gong.mybatis.mapper.EmployeeMapperDynamicSql; class TestMybatis5 { public SqlSessionFactory getSqlSessionFactory() IOException { String resource = "mybatis-config.xml"; InputStream is = Resources.getResourceAsStream(resource); return new SqlSessionFactoryBuilder().build(is); } @Test void test() IOException { SqlSessionFactory sqlSessionFactory = getSqlSessionFactory(); SqlSession openSession = sqlSessionFactory.openSession(); try { EmployeeMapper mapper = openSession.getMapper(EmployeeMapper.); 第一个参数为当前页码,第二个参数是每页的记录数 Page<Object> page = PageHelper.startPage(1,2); List<Employee> emps = mapper.getAllEmp(); 第一个参数为传入的数据,第二个参数为连续显示多少页 PageInfo<Employee> pageInfo = new PageInfo<>(emps,3for(Employee emp:emps) { System.out.println(emp); } System.out.println("当前页码:"+page.getPageNum()); System.out.println("总记录数:"+page.getTotal()); System.out.println("每页几条记录:"+page.getPageSize()); System.out.println("总页码数:"+page.getPages()); System.out.println("当前页码:"+pageInfo.getPageNum()); System.out.println("总记录数:"+pageInfo.getTotal()); System.out.println("每页几条记录:"+pageInfo.getPageSize()); System.out.println("总页码数:"+pageInfo.getPages()); System.out.println("是否第一页:"+pageInfo.isIsFirstPage()); System.out.println("是否最后一页:"+pageInfo.isIsLastPage()); System.out.println("连续显示的页码:"int[] navigatepageNums = pageInfo.getNavigatepageNums(); for (int i = 0; i < navigatepageNums.length; i++) { System.out.println(navigatepageNums[i]); } } finally { TODO: handle finally clause openSession.close(); } } @Test void testEnum() ); Employee employee = Employee(); employee.setLastName("bom"); employee.setGender("1"); employee.setEmail("bom@qq.com"); mapper.addEmp(employee); System.out.println("保存成功:"+employee.getId()); openSession.commit(); } openSession.close(); } } } 结果: DEBUG 01-23 16:02:56,976 ==> Preparing: insert into tbl_employee(last_name,gender,email,empStatus) values(?,?,?) (BaseJdbcLogger.java:145) 要保存的状态码:200 DEBUG 01-23 16:02:57,030 ==> Parameters: bom(String),1(String),bom@qq.com(String),200(String) (BaseJdbcLogger.java:145) DEBUG 01-23 16:02:57,046 == Updates: 1 (BaseJdbcLogger.java:145) 保存成功:11 数据库中: ? 存储的是自己定义的枚举类型中的code。 再进行查询: Employee employee = mapper.getEmpById(11);
System.out.println(employee);
System.out.println(employee.getEmpstatus());
openSession.commit();
输出: DEBUG 01-23 16:11:09,121 ==> Preparing: select id,last_name lastName,empStatus from tbl_employee where id = ? (BaseJdbcLogger.java:145) DEBUG 01-23 16:11:09,180 ==> Parameters: 11(Integer) (BaseJdbcLogger.java:145) 从数据库中获取的状态码:200 DEBUG 01-23 16:11:09,237 == Total: 1 (BaseJdbcLogger.java:145) Employee [id=11,lastName=bom,1)">gender=1,1)">email=bom@qq.com,1)">dept=null] LOGOUT 说明确实是定义成功的。 同时, 2、也可以在处理某个字段的时候告诉MyBatis用什么类型处理器 保存:#{empStatus,typeHandler=xxxx} 查询: <resultMap type="com.atguigu.mybatis.bean.Employee" id="MyEmp"> <id column="id" property="id"/> <result column="empStatus" property="empStatus" typeHandler=""/> </resultMap> 注意:如果在参数位置修改TypeHandler,应该保证保存数据和查询数据用的TypeHandler是一样的。 --> (编辑:李大同) 【声明】本站内容均来自网络,其相关言论仅代表作者个人观点,不代表本站立场。若无意侵犯到您的权利,请及时与联系站长删除相关内容! |