本系列部落格帶你一步一步的學習Spring Boot,如幫助到你,不勝榮幸,如有錯誤,歡迎指正!
本篇部落格我們講解下在Spring Boot中使用MyBatis訪問MySql資料庫(xml方式)的簡單用法。
本系列其它文章如下所示:
Spring Boot入門(一):使用IDEA建立Spring Boot專案並使用yaml配置檔案
Spring Boot入門(二):使用Profile實現多環境配置管理&如何獲取配置檔案值
Spring Boot入門(三):使用Scheduled註解實現定時任務
Spring Boot入門(四):開發Web Api介面常用註解總結
Spring Boot入門(五):使用JDBC訪問MySql資料庫
Spring Boot入門(六):使用MyBatis訪問MySql資料庫(註解方式)
1. 前期準備
假設你的機器已經安裝好了MySql,我們先執行如下語句建立資料庫和表:
CREATE DATABASE springbootaction_db;
create table author
(
author_id int auto_increment comment '作者id' primary key,
author_name varchar(20) not null comment '姓名',
pen_name varchar(20) not null comment '筆名'
)
comment '作者';
2. 修改pom檔案
pom檔案引入mybatis的starter pom和mysql的驅動,因後面要編寫控制器,因此也引入下阿里巴巴的fastjson:
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>1.1.1</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.35</version>
</dependency>
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>fastjson</artifactId>
<version>1.2.47</version>
</dependency>
說明:引入了mybatis-spring-boot-starter後,可以不再引用spring-boot-starter-jdbc,因為前者已經依賴於後者。
3. 配置資料來源
在resources/application.yml中配置資料來源:
spring:
datasource:
driver-class-name: com.mysql.jdbc.Driver
url: jdbc:mysql://localhost:3306/springbootaction_db
username: root
password:
4. 修改配置檔案
在application.yml中新增mybatis配置:
mybatis:
mapper-locations: classpath:mybatis/*.xml
type-aliases-package: com.zwwhnly.springbootaction.mybatis.entity
其中,mapper-locations為mybatis xml檔案的路徑,type-aliases-package為定義的實體所在的包名。
5. 定義資料庫實體
定義資料庫實體Author:
package com.zwwhnly.springbootaction.mybatis.entity;
import com.alibaba.fastjson.annotation.JSONField;
public class Author {
@JSONField(name = "author_id")
private Integer authorId;
@JSONField(name = "author_name")
private String authorName;
@JSONField(name = "pen_name")
private String penName;
public Integer getAuthorId() {
return authorId;
}
public void setAuthorId(Integer authorId) {
this.authorId = authorId;
}
public String getAuthorName() {
return authorName;
}
public void setAuthorName(String authorName) {
this.authorName = authorName;
}
public String getPenName() {
return penName;
}
public void setPenName(String penName) {
this.penName = penName;
}
}
6. 編寫Dao層程式碼
定義介面AuthorMapperV2:
package com.zwwhnly.springbootaction.mybatis.xml;
import com.zwwhnly.springbootaction.mybatis.entity.Author;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Param;
import java.util.List;
@Mapper
public interface AuthorMapperV2 {
int add(@Param("author_name") String authorName, @Param("pen_name") String penName);
int update(@Param("author_name") String authorName, @Param("pen_name") String penName, @Param("id") Integer id);
int delete(Integer id);
Author findAuthor(@Param("id") Integer id);
List<Author> findAuthorList();
}
注意:介面要新增@Mapper註解。
7. 編寫Service層程式碼
定義類AuthorServiceV2:
package com.zwwhnly.springbootaction.mybatis.xml;
import com.zwwhnly.springbootaction.mybatis.entity.Author;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import java.util.List;
@Service
public class AuthorServiceV2 {
@Autowired
private AuthorMapperV2 authorMapperV2;
public int add(String authorName, String penName) {
return this.authorMapperV2.add(authorName, penName);
}
public int update(String authorName, String penName, Integer id) {
return this.authorMapperV2.update(authorName, penName, id);
}
public int delete(Integer id) {
return this.authorMapperV2.delete(id);
}
public Author findAuthor(Integer id) {
return this.authorMapperV2.findAuthor(id);
}
public List<Author> findAuthorList() {
return this.authorMapperV2.findAuthorList();
}
}
注意:類新增@Service註解。
8. 新增mybatis xml檔案
在resources目錄下,新建mybatis資料夾,然後新建AuthorMapper.xml檔案,分別實現上面定義的新增,修改,刪除,獲取單個作者資訊,獲取作者列表功能:
<?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.zwwhnly.springbootaction.mybatis.xml.AuthorMapperV2">
<resultMap id="authorMap" type="Author">
<result property="authorId" column="author_id"/>
<result property="authorName" column="author_name"/>
<result property="penName" column="pen_name"/>
</resultMap>
<insert id="add">
INSERT INTO author(author_name, pen_name)
VALUES(#{author_name}, #{pen_name});
</insert>
<update id="update">
UPDATE author
SET author_name = #{author_name,jdbcType=VARCHAR},
pen_name = #{pen_name,jdbcType=VARCHAR}
WHERE author_id = #{id,jdbcType=INTEGER};
</update>
<delete id="delete">
DELETE FROM author
WHERE author_id = #{id};
</delete>
<select id="findAuthor" resultMap="authorMap" resultType="Author">
SELECT author_id, author_name, pen_name
FROM author
WHERE author_id = #{id};
</select>
<select id="findAuthorList" resultMap="authorMap">
SELECT author_id, author_name, pen_name
FROM author;
</select>
</mapper>
9. 編寫Controller程式碼
新建控制器AuthorControllerV2:
package com.zwwhnly.springbootaction.controller;
import com.alibaba.fastjson.JSONObject;
import com.zwwhnly.springbootaction.mybatis.entity.Author;
import com.zwwhnly.springbootaction.mybatis.xml.AuthorServiceV2;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
@RestController
@RequestMapping(value = "/mybatis/author")
public class AuthorControllerV2 {
@Autowired
private AuthorServiceV2 authorServiceV2;
/**
* 查詢作者列表
*/
@RequestMapping(value = "getAuthorListV2", method = RequestMethod.GET)
public Map<String, Object> getAuthorList() {
List<Author> authorList = this.authorServiceV2.findAuthorList();
Map<String, Object> param = new HashMap<>();
param.put("total", authorList.size());
param.put("rows", authorList);
return param;
}
/**
* 查詢單個作者資訊
*/
@RequestMapping(value = "/getAuthorV2/{authorId:\\d+}", method = RequestMethod.GET)
public Author getAuthor(@PathVariable Integer authorId) {
Author author = this.authorServiceV2.findAuthor(authorId);
if (author == null) {
throw new RuntimeException("查詢錯誤");
}
return author;
}
/**
* 新增
*/
@RequestMapping(value = "addV2", method = RequestMethod.POST)
public void add(@RequestBody JSONObject jsonObject) {
String authorName = jsonObject.getString("authorName");
String penName = jsonObject.getString("penName");
try {
this.authorServiceV2.add(authorName, penName);
} catch (Exception e) {
e.printStackTrace();
throw new RuntimeException("新增錯誤");
}
}
/**
* 更新
*/
@RequestMapping(value = "/updateV2/{authorId:\\d+}", method = RequestMethod.PUT)
public void update(@PathVariable Integer authorId, @RequestBody JSONObject jsonObject) {
Author author = this.authorServiceV2.findAuthor(authorId);
String authorName = jsonObject.getString("authorName");
String penName = jsonObject.getString("penName");
try {
this.authorServiceV2.update(authorName, penName, author.getAuthorId());
} catch (Exception e) {
e.printStackTrace();
throw new RuntimeException("更新錯誤");
}
}
/**
* 刪除
*/
@RequestMapping(value = "/deleteV2/{authorId:\\d+}", method = RequestMethod.DELETE)
public void delete(@PathVariable Integer authorId) {
try {
this.authorServiceV2.delete(authorId);
} catch (Exception e) {
throw new RuntimeException("刪除錯誤");
}
}
}
10. 使用Postman驗證
10.1 驗證新增
因為新增是Post請求,因此這裡我們使用下Postman工具:
呼叫完介面,發現資料庫新增資料成功。
然後用同樣的方法新增下魯迅的資訊。
10.2 驗證更新
呼叫更新介面將魯迅的名字從周作人修改為周樹人:
呼叫完介面,發現資料庫更新資料成功。
10.3 驗證獲取列表
在瀏覽器訪問http://localhost:8080/mybatis/author/getAuthorListV2,返回資料如下:
{
"total": 2,
"rows": [
{
"authorId": 1,
"authorName": "王衛國",
"penName": "路遙"
},
{
"authorId": 2,
"authorName": "周樹人",
"penName": "魯迅"
}
]
}
10.4 驗證獲取單個資料
在瀏覽器訪問http://localhost:8080/mybatis/author/getAuthorV2/1,返回如下資料:
{
"authorId": 1,
"authorName": "王衛國",
"penName": "路遙"
}
10.5 驗證刪除
呼叫刪除介面,將魯迅的資料刪除:
此時訪問http://localhost:8080/mybatis/author/getAuthorListV2,返回資料只有1條了:
{
"total": 1,
"rows": [
{
"authorId": 1,
"authorName": "王衛國",
"penName": "路遙"
}
]
}
11. 原始碼
原始碼地址:https://github.com/zwwhnly/springboot-action.git,歡迎下載。
12. 參考
Spring Boot 揭祕與實戰(二) 資料儲存篇 - MyBatis整合
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