Springboot Mybatis 整合（完整版）

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正題
本項目使用的環境：

開發工具：Intellij IDEA 2017.1.3
springboot: 1.5.6
jdk：1.8.0_161
maven:3.3.9
額外功能

PageHelper 分頁插件
mybatis generator 自動生成代碼插件
步驟：
1.創建一個springboot項目：

2.創建項目的文件結構以及jdk的版本

3.選擇項目所需要的依賴

然后點擊finish

5.看一下文件的結構：

6.查看一下pom.xml：

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"><modelVersion>4.0.0</modelVersion><groupId>com.winter</groupId><artifactId>springboot-mybatis-demo</artifactId><version>0.0.1-SNAPSHOT</version><packaging>jar</packaging><name>springboot-mybatis-demo</name><description>Demo project for Spring Boot</description><parent><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-parent</artifactId><version>1.5.6.RELEASE</version><relativePath/> <!-- lookup parent from repository --></parent><properties><project.build.sourceEncoding>UTF-8</project.build.sourceEncoding><project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding><java.version>1.7</java.version></properties><dependencies><dependency><groupId>org.mybatis.spring.boot</groupId><artifactId>mybatis-spring-boot-starter</artifactId><version>1.3.0</version></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-thymeleaf</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-test</artifactId><scope>test</scope></dependency><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><version>5.1.35</version></dependency><dependency><groupId>com.fasterxml.jackson.core</groupId><artifactId>jackson-core</artifactId></dependency><dependency><groupId>com.fasterxml.jackson.core</groupId><artifactId>jackson-databind</artifactId></dependency><dependency><groupId>com.fasterxml.jackson.datatype</groupId><artifactId>jackson-datatype-joda</artifactId></dependency><dependency><groupId>com.fasterxml.jackson.module</groupId><artifactId>jackson-module-parameter-names</artifactId></dependency><!-- 分頁插件 --><dependency><groupId>com.github.pagehelper</groupId><artifactId>pagehelper-spring-boot-starter</artifactId><version>1.1.2</version></dependency><!-- alibaba的druid數據庫連接池 --><dependency><groupId>com.alibaba</groupId><artifactId>druid-spring-boot-starter</artifactId><version>1.1.0</version></dependency></dependencies><build><plugins><plugin><groupId>org.springframework.boot</groupId><artifactId>spring-boot-maven-plugin</artifactId></plugin><!-- mybatis generator 自動生成代碼插件 --><plugin><groupId>org.mybatis.generator</groupId><artifactId>mybatis-generator-maven-plugin</artifactId><version>1.3.2</version><configuration><configurationFile>${basedir}/src/main/resources/generator/generatorConfig.xml</configurationFile><overwrite>true</overwrite><verbose>true</verbose></configuration></plugin></plugins></build></project>

7.項目不使用application.properties文件而使用更加簡潔的application.yml文件：
將原有的resource文件夾下的application.properties文件刪除，創建一個新的application.yml配置文件，
文件的內容如下：


server:port: 8080spring:datasource:name: testurl: jdbc:mysql://127.0.0.1:3306/depotusername: rootpassword: root# 使用druid數據源type: com.alibaba.druid.pool.DruidDataSourcedriver-class-name: com.mysql.jdbc.Driverfilters: statmaxActive: 20initialSize: 1maxWait: 60000minIdle: 1timeBetweenEvictionRunsMillis: 60000minEvictableIdleTimeMillis: 300000validationQuery: select 'x'testWhileIdle: truetestOnBorrow: falsetestOnReturn: falsepoolPreparedStatements: truemaxOpenPreparedStatements: 20## 該配置節點為獨立的節點，有很多同學容易將這個配置放在spring 的節點下，導致配置無法被識別
mybatis:mapper-locations: classpath:mapping/*.xml ?#注意：一定要對應mapper映射xml文件的所在路徑type-aliases-package: com.winter.model ?# 注意：對應實體類的路徑#pagehelper分頁插件
pagehelper:helperDialect: mysqlreasonable: truesupportMethodsArguments: trueparams: count=countSql

8.創建數據庫：

CREATE DATABASE mytest;CREATE TABLE t_user(user_id INT NOT NULL PRIMARY KEY AUTO_INCREMENT,user_name VARCHAR(255) NOT NULL ,password VARCHAR(255) NOT NULL ,phone VARCHAR(255) NOT NULL
) ENGINE=INNODB AUTO_INCREMENT=1000 DEFAULT CHARSET=utf8;

9.使用mybatis generator 自動生成代碼：

配置pom.xml中generator 插件所對應的配置文件 ${basedir}/src/main/resources/generator/generatorConfig.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE generatorConfigurationPUBLIC "-//mybatis.org//DTD MyBatis Generator Configuration 1.0//EN""http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd">
<generatorConfiguration><!-- 數據庫驅動:選擇你的本地硬盤上面的數據庫驅動包--><classPathEntry ?location="E:\developer\mybatis-generator-core-1.3.2\lib\mysql-connector-java-5.1.25-bin.jar"/><context id="DB2Tables" ?targetRuntime="MyBatis3"><commentGenerator><property name="suppressDate" value="true"/><!-- 是否去除自動生成的注釋 true：是 ： false:否 --><property name="suppressAllComments" value="true"/></commentGenerator><!--數據庫鏈接URL，用戶名、密碼 --><jdbcConnection driverClass="com.mysql.jdbc.Driver" connectionURL="jdbc:mysql://127.0.0.1/mytest" userId="root" password="root"></jdbcConnection><javaTypeResolver><property name="forceBigDecimals" value="false"/></javaTypeResolver><!-- 生成模型的包名和位置--><javaModelGenerator targetPackage="com.winter.model" targetProject="src/main/java"><property name="enableSubPackages" value="true"/><property name="trimStrings" value="true"/></javaModelGenerator><!-- 生成映射文件的包名和位置--><sqlMapGenerator targetPackage="mapping" targetProject="src/main/resources"><property name="enableSubPackages" value="true"/></sqlMapGenerator><!-- 生成DAO的包名和位置--><javaClientGenerator type="XMLMAPPER" targetPackage="com.winter.mapper" targetProject="src/main/java"><property name="enableSubPackages" value="true"/></javaClientGenerator><!-- 要生成的表 tableName是數據庫中的表名或視圖名 domainObjectName是實體類名--><table tableName="t_user" domainObjectName="User" enableCountByExample="false" enableUpdateByExample="false" enableDeleteByExample="false" enableSelectByExample="false" selectByExampleQueryId="false"></table></context>
</generatorConfiguration>

點擊run-Edit Configurations

添加配置

運行
注意！！！同一張表一定不要運行多次，因為 mapper 的映射文件中會生成多次的代碼，導致報錯，切記

最后生成的文件以及結構：

10. 生成的文件

UserMapper.javapackage com.winter.mapper;import com.winter.model.User;public interface UserMapper {int deleteByPrimaryKey(Integer userId);int insert(User record);int insertSelective(User record);User selectByPrimaryKey(Integer userId);int updateByPrimaryKeySelective(User record);int updateByPrimaryKey(User record);//這個方式我自己加的List<User> selectAllUser();
}

User.java

package com.winter.model;public class User {private Integer userId;private String userName;private String password;private String phone;public Integer getUserId() {return userId;}public void setUserId(Integer userId) {this.userId = userId;}public String getUserName() {return userName;}public void setUserName(String userName) {this.userName = userName == null ? null : userName.trim();}public String getPassword() {return password;}public void setPassword(String password) {this.password = password == null ? null : password.trim();}public String getPhone() {return phone;}public void setPhone(String phone) {this.phone = phone == null ? null : phone.trim();}
}

對于 sql 語句這種黃色的背景，真心是看不下去了（解決方案）：

**UserMapper.xml?? ?**

<?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.winter.mapper.UserMapper" ><resultMap id="BaseResultMap" type="com.winter.model.User" ><id column="user_id" property="userId" jdbcType="INTEGER" /><result column="user_name" property="userName" jdbcType="VARCHAR" /><result column="password" property="password" jdbcType="VARCHAR" /><result column="phone" property="phone" jdbcType="VARCHAR" /></resultMap><sql id="Base_Column_List" >user_id, user_name, password, phone</sql><select id="selectByPrimaryKey" resultMap="BaseResultMap" parameterType="java.lang.Integer" >select?<include refid="Base_Column_List" />from t_userwhere user_id = #{userId,jdbcType=INTEGER}</select><!-- 這個方法是我自己加的 --><select id="selectAllUser" resultMap="BaseResultMap">select<include refid="Base_Column_List" />from t_user</select><delete id="deleteByPrimaryKey" parameterType="java.lang.Integer" >delete from t_userwhere user_id = #{userId,jdbcType=INTEGER}</delete><insert id="insert" parameterType="com.winter.model.User" >insert into t_user (user_id, user_name, password,?phone)values (#{userId,jdbcType=INTEGER}, #{userName,jdbcType=VARCHAR}, #{password,jdbcType=VARCHAR},?#{phone,jdbcType=VARCHAR})</insert><insert id="insertSelective" parameterType="com.winter.model.User" >insert into t_user<trim prefix="(" suffix=")" suffixOverrides="," ><if test="userId != null" >user_id,</if><if test="userName != null" >user_name,</if><if test="password != null" >password,</if><if test="phone != null" >phone,</if></trim><trim prefix="values (" suffix=")" suffixOverrides="," ><if test="userId != null" >#{userId,jdbcType=INTEGER},</if><if test="userName != null" >#{userName,jdbcType=VARCHAR},</if><if test="password != null" >#{password,jdbcType=VARCHAR},</if><if test="phone != null" >#{phone,jdbcType=VARCHAR},</if></trim></insert><update id="updateByPrimaryKeySelective" parameterType="com.winter.model.User" >update t_user<set ><if test="userName != null" >user_name = #{userName,jdbcType=VARCHAR},</if><if test="password != null" >password = #{password,jdbcType=VARCHAR},</if><if test="phone != null" >phone = #{phone,jdbcType=VARCHAR},</if></set>where user_id = #{userId,jdbcType=INTEGER}</update><update id="updateByPrimaryKey" parameterType="com.winter.model.User" >update t_userset user_name = #{userName,jdbcType=VARCHAR},password = #{password,jdbcType=VARCHAR},phone = #{phone,jdbcType=VARCHAR}where user_id = #{userId,jdbcType=INTEGER}</update>
</mapper>

11.打開類 SpringbootMybatisDemoApplication.java，這個是 springboot 的啟動類。我們需要添加點東西：

package com.winter;import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;@SpringBootApplication
@MapperScan("com.winter.mapper")//將項目中對應的mapper類的路徑加進來就可以了
public class SpringbootMybatisDemoApplication {public static void main(String[] args) {SpringApplication.run(SpringbootMybatisDemoApplication.class, args);}
}

注意：@MapperScan("com.winter.mapper") 這個注解非常的關鍵，這個對應了項目中 mapper（dao）所對應的包路徑，很多同學就是這里忘了加導致異常的

12.到這里所有的搭建工作都完成了，接下來就是測試的工作，沒使用 junit4 進行測試：
首先看一下完成之后的文件的結構：

現在controller，service層的代碼都寫好：

UserController.java

package com.winter.Controller;import com.winter.model.User;
import com.winter.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;/*** Created by Administrator on 2017/8/16.*/
@Controller
@RequestMapping(value = "/user")
public class UserController {@Autowiredprivate UserService userService;@ResponseBody@RequestMapping(value = "/add", produces = {"application/json;charset=UTF-8"})public int addUser(User user){return userService.addUser(user);}@ResponseBody@RequestMapping(value = "/all/{pageNum}/{pageSize}", produces = {"application/json;charset=UTF-8"})public Object findAllUser(@PathVariable("pageNum") int pageNum, @PathVariable("pageSize") int pageSize){return userService.findAllUser(pageNum,pageSize);}
}

UserService.java

package com.winter.service;import com.winter.model.User;import java.util.List;/*** Created by Administrator on 2017/8/16.*/
public interface UserService {int addUser(User user);List<User> findAllUser(int pageNum, int pageSize);
}

UserServiceImpl.java

package com.winter.service.impl;import com.github.pagehelper.PageHelper;
import com.winter.mapper.UserMapper;
import com.winter.model.User;
import com.winter.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;import java.util.List;/*** Created by Administrator on 2017/8/16.*/
@Service(value = "userService")
public class UserServiceImpl implements UserService {@Autowiredprivate UserMapper userMapper;//這里會報錯，但是并不會影響@Overridepublic int addUser(User user) {return userMapper.insertSelective(user);}/** 這個方法中用到了我們開頭配置依賴的分頁插件pagehelper* 很簡單，只需要在service層傳入參數，然后將參數傳遞給一個插件的一個靜態方法即可；* pageNum 開始頁數* pageSize 每頁顯示的數據條數* */@Overridepublic List<User> findAllUser(int pageNum, int pageSize) {//將參數傳給這個方法就可以實現物理分頁了，非常簡單。PageHelper.startPage(pageNum, pageSize);return userMapper.selectAllUser();}
}

如果強迫癥看不下去那個報錯：（解決方法）

測試我使用了 idea 一個很用心的功能。
可以發 http 請求的插件：

點擊左側的運行按鈕就可以發送請求了；
如果返回值正確說明你已經搭建成功了！

如果出現mapper注入不了的情況，請檢查版本.

轉自：https://blog.csdn.net/winter_chen001/article/details/77249029?
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