标签：java String resultMap id hobby Mybatis import public
1 package com.learn.ssm.chapter3.pojo;
2
3 import java.util.Date;
4 import java.util.List;
5
6 public class Role {
7
8 private Long id;
9 private String roleName;
10 private String note;
11 private Date date;
12 private List<String> hobby;
13
14 /*
15 * public Role(Long id, String roleName, String note, Date date) { super();
16 * this.id = id; this.roleName = roleName; this.note = note; this.date =
17 * date; }
18 */
19 public Long getId() {
20 return id;
21 }
22
23 public void setId(Long id) {
24 this.id = id;
25 }
26
27 public String getRoleName() {
28 return roleName;
29 }
30
31 public void setRoleName(String roleName) {
32 this.roleName = roleName;
33 }
34
35 public String getNote() {
36 return note;
37 }
38
39 public void setNote(String note) {
40 this.note = note;
41 }
42
43 public Date getDate() {
44 return date;
45 }
46
47 public void setDate(Date date) {
48 this.date = date;
49 }
50
51 public List<String> getHobby() {
52 return hobby;
53 }
54
55 public void setHobby(List<String> hobby) {
56 this.hobby = hobby;
57 }
58
59 @Override
60 public String toString() {
61 StringBuilder s = new StringBuilder();
62
63 return "id: " + id + ", roleName: " + roleName + ", note: " + note + ", date: " + date + ", hobby: " + hobby;
64 }
65
66 }
1 package com.learn.ssm.chapter3.mapper;
2
3 import java.util.List;
4
5 import com.learn.ssm.chapter3.pojo.Role;
6
7 public interface RoleMapper {
8
9 public int insertRole(Role role);
10
11 public int deleteRole(Long id);
12
13 public int updateRole(Role role);
14
15 public Role getRole(Long id);
16
17 public List<Role> findRoles(String roleName);
18
19 }
1 <?xml version="1.0" encoding="UTF-8"?>
2 <!DOCTYPE mapper
3 PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
4 "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
5 <mapper namespace="com.learn.ssm.chapter3.mapper.RoleMapper">
6
7
8
9 <resultMap id="userResultMap" type="role">
10 <result typeHandler="com.learn.ssm.chapter3.bean.MyDateTypeHandler"
11 column="date" javaType="java.util.Date" jdbcType="VARCHAR" property="date" />
12 <result property="hobby" column="hobby"
13 typeHandler="com.learn.ssm.chapter3.bean.MyListTypeHandler" />
14
15 <result property="roleName" column="role_name" />
16 </resultMap>
17
18
19
20
21
22 <insert id="insertRole" parameterType="role">
23 insert into
24 t_role(id,role_name,note,date,hobby)
25 values(#{id},#{roleName},#{note},#{date,javaType=Date,jdbcType=VARCHAR,typeHandler=com.learn.ssm.chapter3.bean.MyDateTypeHandler},
26 #{hobby,typeHandler=com.learn.ssm.chapter3.bean.MyListTypeHandler})
27 </insert>
28
29 <delete id="deleteRole" parameterType="Long">
30 delete from t_role where
31 id=#{id}
32 </delete>
33
34 <update id="updateRole" parameterType="role">
35 update t_role set
36 role_name=#{roleName},note=#{note},date=#{date} where id=#{id}
37 </update>
38
39
40
41 <select id="getRole" parameterType="Long" resultMap="userResultMap">
42
43 select * from t_role where id=#{id}
44
45 </select>
46
47
48
49 <select id="findRoles" parameterType="string" resultType="role">
50 select
51 id,rote_name as roleName,note from t_role where role_name like
52 concat('%',#{roleName},'%')
53 </select>
54
55 </mapper>
1 <?xml version="1.0" encoding="UTF-8"?>
2 <!DOCTYPE configuration
3 PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
4 "http://mybatis.org/dtd/mybatis-3-config.dtd">
5 <configuration>
6
7 <properties resource="jdbc.properties">
8 </properties>
9
10 <typeAliases>
11 <typeAlias alias="role" type="com.learn.ssm.chapter3.pojo.Role" />
12 </typeAliases>
13
14 <environments default="development">
15 <environment id="development">
16 <transactionManager type="JDBC" />
17 <dataSource type="POOLED">
18 <property name="driver" value="${mysql_driver}" />
19 <property name="url" value="${mysql_url}" />
20 <property name="username" value="${mysql_username}" />
21 <property name="password" value="${mysql_password}" />
22 </dataSource>
23 </environment>
24 </environments>
25
26 <!-- 通过mapp标签加载配置文件 -->
27 <mappers>
28 <mapper resource="com/learn/ssm/chapter3/mapper/RoleMapper.xml" />
29 </mappers>
30 </configuration>
1 package com.learn.ssm.chapter3.utils;
2
3 import java.io.IOException;
4 import java.io.InputStream;
5
6 import org.apache.ibatis.io.Resources;
7 import org.apache.ibatis.session.SqlSession;
8 import org.apache.ibatis.session.SqlSessionFactory;
9 import org.apache.ibatis.session.SqlSessionFactoryBuilder;
10
11 public class SqlSessionFactoryUtils {
12
13 private final static Class<SqlSessionFactoryUtils> Lock = SqlSessionFactoryUtils.class;
14
15 private static SqlSessionFactory sqlSessionFactory = null;
16
17 public static SqlSessionFactory getSessionFactory() {
18 synchronized (Lock) {
19 if (sqlSessionFactory != null) {
20 return sqlSessionFactory;
21 }
22
23 String resource = "mybatis-config.xml";
24 InputStream inputStream;
25
26 try {
27 inputStream = Resources.getResourceAsStream(resource);
28 sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
29 } catch (IOException e) {
30 e.printStackTrace();
31 return null;
32 }
33
34 return sqlSessionFactory;
35
36 }
37 }
38
39 public static SqlSession openSqlSession() {
40 if (sqlSessionFactory == null) {
41 getSessionFactory();
42 }
43 return sqlSessionFactory.openSession();
44 }
45
46 }
1 package com.learn.ssm.chapter3.bean;
2
3 import java.sql.CallableStatement;
4 import java.sql.PreparedStatement;
5 import java.sql.ResultSet;
6 import java.sql.SQLException;
7 import java.util.Date;
8
9 import org.apache.ibatis.type.BaseTypeHandler;
10 import org.apache.ibatis.type.JdbcType;
11 import org.apache.ibatis.type.MappedJdbcTypes;
12 import org.apache.ibatis.type.MappedTypes;
13
14 @MappedJdbcTypes({JdbcType.VARCHAR})
15 @MappedTypes({Date.class})
16 public class MyDateTypeHandler extends BaseTypeHandler<Date>{
17
18 public void setNonNullParameter(PreparedStatement preparedStatement, int i, Date date, JdbcType jdbcType) throws SQLException {
19
20 //将日期格式修改为自1970年算起的毫秒数
21 preparedStatement.setString(i, String.valueOf(date.getTime()));
22 }
23
24 public Date getNullableResult(ResultSet resultSet, String s) throws SQLException {
25 return new Date(resultSet.getLong(s));
26 }
27
28 public Date getNullableResult(ResultSet resultSet, int i) throws SQLException {
29 return new Date(resultSet.getLong(i));
30 }
31
32 public Date getNullableResult(CallableStatement callableStatement, int i) throws SQLException {
33 return callableStatement.getDate(i);
34 }
35
36
37 }
1 package com.learn.ssm.chapter3.bean;
2
3 import java.sql.CallableStatement;
4 import java.sql.PreparedStatement;
5 import java.sql.ResultSet;
6 import java.sql.SQLException;
7 import java.util.ArrayList;
8 import java.util.Arrays;
9 import java.util.List;
10
11 import org.apache.ibatis.type.BaseTypeHandler;
12 import org.apache.ibatis.type.JdbcType;
13
14 public class MyListTypeHandler extends BaseTypeHandler<List<String>> {
15
16 public void setNonNullParameter(PreparedStatement pre, int i, List<String> list, JdbcType jdbcType)
17 throws SQLException {
18 StringBuilder s = new StringBuilder();
19 for (String hobby : list) {
20 s.append(hobby + ";");
21 }
22 pre.setString(i, s.toString().substring(0, s.length() - 1));
23 }
24
25 public List<String> getNullableResult(ResultSet r, int i) throws SQLException {
26 String s = r.getNString(i);
27 String[] stringArry = s.split(";");
28 List<String> hobby = new ArrayList<String>();
29
30 /*
31 * for(int j=0;j<stringArry.length;j++){ hobby.add(stringArry[j]); }
32 */
33 return Arrays.asList(stringArry);
34 }
35
36 public List<String> getNullableResult(ResultSet r, String s) throws SQLException {
37
38 String string = r.getNString(s);
39 String[] stringArry = s.split(";");
40 List<String> hobby = new ArrayList<String>();
41
42 /*
43 * for(int j=0;j<stringArry.length;j++){ hobby.add(stringArry[j]); }
44 */
45 return Arrays.asList(stringArry);
46 }
47
48 public List<String> getNullableResult(CallableStatement call, int i) throws SQLException {
49
50 String[] string = call.getNString(i).split(";");
51 return Arrays.asList(string);
52 }
53
54 }
1 package com.learn.ssm.chapter3.main;
2
3 import java.util.ArrayList;
4 import java.util.Date;
5 import java.util.List;
6
7 import org.apache.ibatis.session.SqlSession;
8 import org.apache.log4j.Logger;
9
10 import com.learn.ssm.chapter3.mapper.RoleMapper;
11 import com.learn.ssm.chapter3.pojo.Role;
12 import com.learn.ssm.chapter3.utils.SqlSessionFactoryUtils;
13
14 public class Chapter3Main {
15
16 public static void main(String[] args) {
17 Logger log = Logger.getLogger(Chapter3Main.class);
18
19 SqlSession sqlSession = null;
20 try {
21 sqlSession = SqlSessionFactoryUtils.openSqlSession();
22 RoleMapper roleMapper = sqlSession.getMapper(RoleMapper.class);
23
24 // 增
25
26 /*
27 * Date date=new Date(); Role r=new Role(); r.setId(11L);
28 * r.setRoleName("AAA"); r.setNote("AAA"); r.setDate(date);
29 * List<String> hobby=new ArrayList<String>(); hobby.add("唱歌");
30 * hobby.add("跳舞"); hobby.add("滑雪"); hobby.add("读书");
31 * r.setHobby(hobby); roleMapper.insertRole(r); sqlSession.commit();
32 */
33
34 // 删
35 /*
36 * roleMapper.deleteRole(6L); sqlSession.commit();
37 */
38
39 // 改
40 /*
41 * Date date=new Date(); roleMapper.updateRole(new
42 * Role(1L,"LiMing","LiMing",date)); sqlSession.commit();
43 *
44 */
45
46 // 查
47
48 Role role = roleMapper.getRole(10L);
49 // log.info(role.getRoleName());
50 System.out.println(role);
51 sqlSession.commit();
52
53 } finally {
54 if (sqlSession != null) {
55 sqlSession.close();
56 }
57 }
58
59 }
60
61 }
运行结果：
注：
如果在resultMap中不进行字段和属性名的映射：
则打印出的结果中，POJO中的属性和数据库中栏位名称不同的元素会显示null
例，POJO中属性roleName
数据库中的栏位 role_name
按道理来说应该对应，但是打印出的结果为：
id: 10, roleName: null, note: AAA, date: Sun Apr 25 17:46:49 GMT+08:00 2021, hobby: {hobby}
你可以将两者设为一样，比如都设置成role_name或者roleName,这样也会打印出想要的结果，但是数据库和java中的命名规则不同，所以还是在配置中纪进行一下映射为好
标签：java,String,resultMap,id,hobby,Mybatis,import,public 来源： https://www.cnblogs.com/Leeyoung888/p/14701942.html
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