Mybatis学习过程报错,麻烦各位帮忙看看解决,十分感谢啊。
package com.beike.test;
import com.beike.mapper.BrandMapper;
import com.beike.pojo.Brand;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.junit.Test;
import java.io.IOException;
import java.io.InputStream;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
public class MyBatisTest {
@Test
public void testSelectAll() throws IOException {
//1.获取SqlSessionFactory
String resource = "mybatis-config.xml";
InputStream inputStream = Resources.getResourceAsStream(resource);
SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
//2.获取SqlSession对象
SqlSession sqlSession = sqlSessionFactory.openSession();
//3。获取Mapper接口的代理对象
BrandMapper brandMapper = sqlSession.getMapper(BrandMapper.class);
//4.执行方法
List brands = brandMapper.selectAll();
System.out.println(brands);
//5.释放资源
sqlSession.close();
}
@Test
public void testSelectById() throws IOException {
//接受参数
int id = 1;
String resource = "mybatis-config.xml";
InputStream inputStream = Resources.getResourceAsStream(resource);
SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
SqlSession sqlSession = sqlSessionFactory.openSession();
BrandMapper brandMapper = sqlSession.getMapper(BrandMapper.class);
Brand brand = brandMapper.selectById(id);
System.out.println(brand);
sqlSession.close();
}
@Test
public void testSelectByCondition() throws IOException {
//接收参数
int status = 1;
String companyName = "华为";
String brandName = "华为";
// 处理参数
companyName = "%" + companyName + "%";
brandName = "%" + brandName + "%";
//封装对象
// Brand brand = new Brand();
// brand.setStatus(status);
// brand.setCompanyName(companyName);
// brand.setBrandName(brandName);
Map map = new HashMap();
map.put("status" , status);
map.put("companyName", companyName);
map.put("brandName" , brandName);
//1. 获取SqlSessionFactory
String resource = "mybatis-config.xml";
InputStream inputStream = Resources.getResourceAsStream(resource);
SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
//2. 获取SqlSession对象
SqlSession sqlSession = sqlSessionFactory.openSession();
//3. 获取Mapper接口的代理对象
BrandMapper brandMapper = sqlSession.getMapper(BrandMapper.class);
//4. 执行方法
//List brands = brandMapper.selectByCondition(status, companyName, brandName);
//List brands = brandMapper.selectByCondition(brand);
List brands = brandMapper.selectByCondition(map);
System.out.println(brands);
//5. 释放资源
sqlSession.close();
}
}
package com.beike.pojo;
/**
* 品牌
*
* alt + 鼠标左键:整列编辑
*
* 在实体类中,基本数据类型建议使用其对应的包装类型
*/
public class Brand {
// id 主键
private Integer id;
// 品牌名称
private String brandName;
// 企业名称
private String companyName;
// 排序字段
private Integer ordered;
// 描述信息
private String description;
// 状态:0:禁用 1:启用
private Integer status;
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getBrandName() {
return brandName;
}
public void setBrandName(String brandName) {
this.brandName = brandName;
}
public String getCompanyName() {
return companyName;
}
public void setCompanyName(String companyName) {
this.companyName = companyName;
}
public Integer getOrdered() {
return ordered;
}
public void setOrdered(Integer ordered) {
this.ordered = ordered;
}
public String getDescription() {
return description;
}
public void setDescription(String description) {
this.description = description;
}
public Integer getStatus() {
return status;
}
public void setStatus(Integer status) {
this.status = status;
}
@Override
public String toString() {
return "Brand{" +
"id=" + id +
", brandName='" + brandName + '\'' +
", companyName='" + companyName + '\'' +
", ordered=" + ordered +
", description='" + description + '\'' +
", status=" + status +
'}';
}
}
代码运行查询数据库的时候,第三个方法参数显示为空了,然后前两个方法报错说“brandName" not found。
package com.beike.mapper;
import com.beike.pojo.Brand;
import org.apache.ibatis.annotations.Param;
import java.util.List;
import java.util.Map;
public interface BrandMapper {
/*
* 查询所有
* */
List selectAll();
/**
* 查看详情
*/
Brand selectById(int id);
//List selectByCondition(@Param("status") int status, @Param("companyName") String companyName,@Param("brandName") String brandName);
//List selectByCondition(Brand brand);
List selectByCondition(Map map);
}
mapper
PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.beike.mapper.BrandMapper">
<select id="selectAll" resultMap="brandResultMap">
select * from tb_brand;
select>
<resultMap id="brandResultMap" type="brand">
<result column="brand_name" property="brandName"/>
<result column="company_name" property="companyName"/>
resultMap>
<select id="selectById" resultMap="brandResultMap">
select * from tb_brand where id = #{id};
select>
<select id="selectByCondition" resultMap="brandResultMap">
select * from tb_brand where status = #{status}
and company_name like #{companyName}
and brand_name like #{brandNmae}
select>
mapper>
改成下边试试
mapper
List selectByCondition(@Param("map") Map map);
mapper.XML
select * from tb_brand where status = #{map.status} and company_name like #{map.companyName} and brand_name like #{map.brandNmae}