接口开发 – 小飞侠

文章目录

IDEA中新建SpringBoot项目

可能遇到问题：Unable to import maven project，解决方法为：File>Settings，切到Maven项，修改以下三处。
在这里插入图片描述
其中，settings.xml的内容如下：

<?xml version="1.0" encoding="UTF-8"?>
<settings xmlns="http://maven.apache.org/SETTINGS/1.0.0"
          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
          xsi:schemaLocation="http://maven.apache.org/SETTINGS/1.0.0     http://maven.apache.org/xsd/settings-1.0.0.xsd">
    <localRepository>D:\.m2\repository</localRepository>

    <pluginGroups>
    </pluginGroups>
    <proxies>
    </proxies>
    <servers>
    </servers>

    <mirrors>
        <mirror>
            <id>alimaven</id>
            <mirrorOf>central</mirrorOf>
            <name>aliyun maven</name>
            <url>http://maven.aliyun.com/nexus/content/repositories/central</url>
        </mirror>

        <mirror>
            <id>alimaven</id>
            <name>aliyun maven</name>
            <url>http://maven.aliyun.com/nexus/content/groups/public</url>
            <mirrorOf>central</mirrorOf>
        </mirror>

        <mirror>
            <id>central</id>
            <name>Maven Repository Switchboard</name>
            <url>http://repo1.maven.org/maven2</url>
            <mirrorOf>central</mirrorOf>
        </mirror>

        <mirror>
            <id>repo2</id>
            <mirrorOf>central</mirrorOf>
            <name>Human Readable Name for this Mirror.</name>
            <url>http://repo2.maven.org/maven2</url>
        </mirror>

        <mirror>
            <id>ibiblio</id>
            <mirrorOf>central</mirrorOf>
            <name>Human Readable Name for this Mirror.</name>
            <url>http://mirrors.ibiblio.org/pub/mirrors/maven2</url>
        </mirror>

        <mirror>
            <id>jboss-public-repository-group</id>
            <mirrorOf>central</mirrorOf>
            <name>JBoss Public Repository Group</name>
            <url>http://repository.jboss.org/nexus/content/groups/public</url>
        </mirror>

        <mirror>
            <id>google-maven-central</id>
            <name>Google Maven Central</name>
            <url>https://maven-central.storage.googleapis.com
            </url>
            <mirrorOf>central</mirrorOf>
        </mirror>

        <!-- 中央仓库在中国的镜像 -->
        <mirror>
            <id>maven.net.cn</id>
            <name>one of the central mirrors in china</name>
            <url>http://maven.net.cn/content/groups/public</url>
            <mirrorOf>central</mirrorOf>
        </mirror>
    </mirrors>

    <profiles>
        <profile>
            <id>jdk-1.8</id>
            <activation>
                <activeByDefault>true</activeByDefault>
                <jdk>1.8</jdk>
            </activation>
            <properties>
                <maven.compiler.source>1.8</maven.compiler.source>
                <maven.compiler.target>1.8</maven.compiler.target>
                <maven.compiler.compilerVersion>1.8</maven.compiler.compilerVersion>
            </properties>
        </profile>
        <profile>
            <id>repository_set</id>
            <repositories>
                <repository>
                    <snapshots>
                        <enabled>false</enabled>
                    </snapshots>
                    <id>public</id>
                    <name>Public Repository</name>
                    <url>http://maven.aliyun.com/nexus/content/groups/public</url>
                </repository>
            </repositories>
            <pluginRepositories>
                <pluginRepository>
                    <releases>
                        <updatePolicy>never</updatePolicy>
                    </releases>
                    <snapshots>
                        <enabled>false</enabled>
                    </snapshots>
                    <id>public</id>
                    <name>Public Repository</name>
                    <url>http://maven.aliyun.com/nexus/content/groups/public</url>
                </pluginRepository>
            </pluginRepositories>
        </profile>

    </profiles>

</settings>

定义一个接口

新建目录controller，并在该目录下新建类TestController，如下所示，

package com.jepcc.test.controller;

import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class TestController {
    @GetMapping("/test")
    public String test(){
        return "Hello,World!";
    }
}

运行TestApplication.main()后，浏览器访问地址http://localhost:8080/test，返回字符串”Hello,World!”。
在这里插入图片描述

Navicate中新建数据库、表及专有账户


数据库名	test-database
表名	list
专有用户名及密码	test-user/test@123

IDEA里操作数据库

由于社区版IDEA没有Database，所以安装插件Database Navigator，如下图所示，更多内容可以参考这篇文章。
在这里插入图片描述

集成MyBatis

在这里插入图片描述

pom.xml中添加MyBatis、Mysql连接的依赖

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
	<modelVersion>4.0.0</modelVersion>
	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>2.4.5</version>
		<relativePath/> <!-- lookup parent from repository -->
	</parent>
	<groupId>com.jepcc</groupId>
	<artifactId>test</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<name>test</name>
	<description>test for spring boot</description>
	<properties>
		<java.version>1.8</java.version>
	</properties>
	<dependencies>
		<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>
		<!--		集成mybatis-->
		<dependency>
			<groupId>org.mybatis.spring.boot</groupId>
			<artifactId>mybatis-spring-boot-starter</artifactId>
			<version>2.1.3</version>
		</dependency>
		<!--		集成mysql连接-->
		<dependency>
			<groupId>mysql</groupId>
			<artifactId>mysql-connector-java</artifactId>
			<version>8.0.22</version>
		</dependency>

	</dependencies>

	<build>
		<plugins>
			<plugin>
				<groupId>org.springframework.boot</groupId>
				<artifactId>spring-boot-maven-plugin</artifactId>
			</plugin>
		</plugins>
	</build>

</project>

application.properties中添加Mysql连接信息、Mapper层xml文件所在位置

spring.datasource.url=jdbc:mysql://localhost:3306/test-database
spring.datasource.username=test-user
spring.datasource.password=test@123
spring.datasource.driver-class=com.mysql.cj.jdbc.Driver

mybatis.mapper-locations=classpath:/mapper/**/*.xml

TestMapper.xml，Mapper层要执行的sql语句就在这个xml文件里

<?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.jepcc.test.mapper.TestMapper">
    <select id="list" resultType="com.jepcc.test.model.Ebook">
        select `id`,`name`,`passwd` from `list`
    </select>
</mapper>

controller层，com.jepcc.test.controller.TestController

package com.jepcc.test.controller;

import com.jepcc.test.model.Ebook;
import com.jepcc.test.service.TestService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;

@RestController
public class TestController {
    @Autowired
    public TestService testService;

    @GetMapping("/test/list")
    public List<Ebook> list(){
        return testService.list();
    }
}

service层，com.jepcc.test.service.TestService

package com.jepcc.test.service;

import com.jepcc.test.mapper.TestMapper;
import com.jepcc.test.model.Ebook;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

@Service
public class TestService {
    @Autowired
    public TestMapper testMapper;
    public List<Ebook> list(){
        return testMapper.list();
    }
}

mapper层，com.jepcc.test.mapper.TestMapper

package com.jepcc.test.mapper;

import com.jepcc.test.model.Ebook;

import java.util.List;

public interface TestMapper {
    public List<Ebook> list();
}

model层，com.jepcc.test.model.Ebook

package com.jepcc.test.mapper;

import com.jepcc.test.model.Ebook;

import java.util.List;

public interface TestMapper {
    public List<Ebook> list();
}

启动类或主函数，com.jepcc.test.TestApplication

package com.jepcc.test;

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@MapperScan("com.jepcc.test.mapper")
@SpringBootApplication
public class TestApplication {

	public static void main(String[] args) {
		SpringApplication.run(TestApplication.class, args);
	}
}

在这里插入图片描述

集成Mybatis Generator

Navicate中新建表users
pom.xml添加Mybatis Generator、Java连接Mysql的驱动包

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
	<modelVersion>4.0.0</modelVersion>
	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>2.4.4</version>
		<relativePath/> <!-- lookup parent from repository -->
	</parent>
	<groupId>com.jepcc</groupId>
	<artifactId>wiki</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<name>wiki</name>
	<description>Jepcc Wiki</description>
	<properties>
		<java.version>1.8</java.version>
	</properties>
	<dependencies>
		<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>org.springframework.boot</groupId>
			<artifactId>spring-boot-devtools</artifactId>
		</dependency>
<!--		集成mybatis-->
		<dependency>
			<groupId>org.mybatis.spring.boot</groupId>
			<artifactId>mybatis-spring-boot-starter</artifactId>
			<version>2.1.3</version>
		</dependency>
<!--		集成mysql连接-->
		<dependency>
			<groupId>mysql</groupId>
			<artifactId>mysql-connector-java</artifactId>
			<version>8.0.22</version>
		</dependency>

	</dependencies>
	<build>
		<plugins>
			<plugin>
				<groupId>org.springframework.boot</groupId>
				<artifactId>spring-boot-maven-plugin</artifactId>
				<version>2.4.4</version>
			</plugin>
			<plugin>
				<groupId>org.mybatis.generator</groupId>
				<artifactId>mybatis-generator-maven-plugin</artifactId>
				<version>1.4.0</version>
				<configuration>
					<configurationFile>src/main/resources/generator/generator-config.xml</configurationFile>
					<overwrite>true</overwrite>
					<verbose>true</verbose>
				</configuration>
				<dependencies>
					<dependency>
						<groupId>mysql</groupId>
						<artifactId>mysql-connector-java</artifactId>
						<version>8.0.22</version>
					</dependency>
				</dependencies>
			</plugin>
		</plugins>
	</build>
</project>

在src\main\resources目录下定义generatorConfig.xml文件

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE generatorConfiguration
        PUBLIC "-//mybatis.org//DTD MyBatis Generator Configuration 1.0//EN"
        "http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd">

<generatorConfiguration>

    <context id="Mysql" targetRuntime="MyBatis3">
        <jdbcConnection driverClass="com.mysql.cj.jdbc.Driver"
                        connectionURL="jdbc:mysql://localhost:3306/test-database"
                        userId="test-user"
                        password="test@123">
        </jdbcConnection>

        <javaModelGenerator targetPackage="com.jepcc.test.model" targetProject="src\main\java">
        </javaModelGenerator>

        <sqlMapGenerator targetPackage="mapper"  targetProject="src\main\resources">
        </sqlMapGenerator>

        <javaClientGenerator type="XMLMAPPER" targetPackage="com.jepcc.test.mapper"  targetProject="src\main\java">
        </javaClientGenerator>

        <table tableName="users" domainObjectName="User" >
        </table>

    </context>
</generatorConfiguration>

添加并运行命令mybatis-generator:generate -e，生成相应的Model实体类User、Mapper接口文件UserMapper和Mapper配置文件UserMapper.xml

package com.jepcc.test.model;

public class User {
    /**
     *
     * This field was generated by MyBatis Generator.
     * This field corresponds to the database column users.id
     *
     * @mbg.generated Thu May 06 15:12:26 CST 2021
     */
    private Long id;

    /**
     *
     * This field was generated by MyBatis Generator.
     * This field corresponds to the database column users.name
     *
     * @mbg.generated Thu May 06 15:12:26 CST 2021
     */
    private String name;

    /**
     * This method was generated by MyBatis Generator.
     * This method returns the value of the database column users.id
     *
     * @return the value of users.id
     *
     * @mbg.generated Thu May 06 15:12:26 CST 2021
     */
    public Long getId() {
        return id;
    }

    /**
     * This method was generated by MyBatis Generator.
     * This method sets the value of the database column users.id
     *
     * @param id the value for users.id
     *
     * @mbg.generated Thu May 06 15:12:26 CST 2021
     */
    public void setId(Long id) {
        this.id = id;
    }

    /**
     * This method was generated by MyBatis Generator.
     * This method returns the value of the database column users.name
     *
     * @return the value of users.name
     *
     * @mbg.generated Thu May 06 15:12:26 CST 2021
     */
    public String getName() {
        return name;
    }

    /**
     * This method was generated by MyBatis Generator.
     * This method sets the value of the database column users.name
     *
     * @param name the value for users.name
     *
     * @mbg.generated Thu May 06 15:12:26 CST 2021
     */
    public void setName(String name) {
        this.name = name;
    }
}

package com.jepcc.test.mapper;

import com.jepcc.test.model.User;
import com.jepcc.test.model.UserExample;
import java.util.List;
import org.apache.ibatis.annotations.Param;

public interface UserMapper {
    /**
     * This method was generated by MyBatis Generator.
     * This method corresponds to the database table users
     *
     * @mbg.generated Thu May 06 15:12:26 CST 2021
     */
    long countByExample(UserExample example);

    /**
     * This method was generated by MyBatis Generator.
     * This method corresponds to the database table users
     *
     * @mbg.generated Thu May 06 15:12:26 CST 2021
     */
    int deleteByExample(UserExample example);

    /**
     * This method was generated by MyBatis Generator.
     * This method corresponds to the database table users
     *
     * @mbg.generated Thu May 06 15:12:26 CST 2021
     */
    int deleteByPrimaryKey(Long id);

    /**
     * This method was generated by MyBatis Generator.
     * This method corresponds to the database table users
     *
     * @mbg.generated Thu May 06 15:12:26 CST 2021
     */
    int insert(User record);

    /**
     * This method was generated by MyBatis Generator.
     * This method corresponds to the database table users
     *
     * @mbg.generated Thu May 06 15:12:26 CST 2021
     */
    int insertSelective(User record);

    /**
     * This method was generated by MyBatis Generator.
     * This method corresponds to the database table users
     *
     * @mbg.generated Thu May 06 15:12:26 CST 2021
     */
    List<User> selectByExample(UserExample example);

    /**
     * This method was generated by MyBatis Generator.
     * This method corresponds to the database table users
     *
     * @mbg.generated Thu May 06 15:12:26 CST 2021
     */
    User selectByPrimaryKey(Long id);

    /**
     * This method was generated by MyBatis Generator.
     * This method corresponds to the database table users
     *
     * @mbg.generated Thu May 06 15:12:26 CST 2021
     */
    int updateByExampleSelective(@Param("record") User record, @Param("example") UserExample example);

    /**
     * This method was generated by MyBatis Generator.
     * This method corresponds to the database table users
     *
     * @mbg.generated Thu May 06 15:12:26 CST 2021
     */
    int updateByExample(@Param("record") User record, @Param("example") UserExample example);

    /**
     * This method was generated by MyBatis Generator.
     * This method corresponds to the database table users
     *
     * @mbg.generated Thu May 06 15:12:26 CST 2021
     */
    int updateByPrimaryKeySelective(User record);

    /**
     * This method was generated by MyBatis Generator.
     * This method corresponds to the database table users
     *
     * @mbg.generated Thu May 06 15:12:26 CST 2021
     */
    int updateByPrimaryKey(User record);
}

<?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.jepcc.test.mapper.UserMapper">
  <resultMap id="BaseResultMap" type="com.jepcc.test.model.User">
    <!--
      WARNING - @mbg.generated
      This element is automatically generated by MyBatis Generator, do not modify.
      This element was generated on Thu May 06 15:12:27 CST 2021.
    -->
    <id column="id" jdbcType="BIGINT" property="id" />
    <result column="name" jdbcType="VARCHAR" property="name" />
  </resultMap>
  <sql id="Example_Where_Clause">
    <!--
      WARNING - @mbg.generated
      This element is automatically generated by MyBatis Generator, do not modify.
      This element was generated on Thu May 06 15:12:27 CST 2021.
    -->
    <where>
      <foreach collection="oredCriteria" item="criteria" separator="or">
        <if test="criteria.valid">
          <trim prefix="(" prefixOverrides="and" suffix=")">
            <foreach collection="criteria.criteria" item="criterion">
              <choose>
                <when test="criterion.noValue">
                  and ${criterion.condition}
                </when>
                <when test="criterion.singleValue">
                  and ${criterion.condition} #{criterion.value}
                </when>
                <when test="criterion.betweenValue">
                  and ${criterion.condition} #{criterion.value} and #{criterion.secondValue}
                </when>
                <when test="criterion.listValue">
                  and ${criterion.condition}
                  <foreach close=")" collection="criterion.value" item="listItem" open="(" separator=",">
                    #{listItem}
                  </foreach>
                </when>
              </choose>
            </foreach>
          </trim>
        </if>
      </foreach>
    </where>
  </sql>
  <sql id="Update_By_Example_Where_Clause">
    <!--
      WARNING - @mbg.generated
      This element is automatically generated by MyBatis Generator, do not modify.
      This element was generated on Thu May 06 15:12:27 CST 2021.
    -->
    <where>
      <foreach collection="example.oredCriteria" item="criteria" separator="or">
        <if test="criteria.valid">
          <trim prefix="(" prefixOverrides="and" suffix=")">
            <foreach collection="criteria.criteria" item="criterion">
              <choose>
                <when test="criterion.noValue">
                  and ${criterion.condition}
                </when>
                <when test="criterion.singleValue">
                  and ${criterion.condition} #{criterion.value}
                </when>
                <when test="criterion.betweenValue">
                  and ${criterion.condition} #{criterion.value} and #{criterion.secondValue}
                </when>
                <when test="criterion.listValue">
                  and ${criterion.condition}
                  <foreach close=")" collection="criterion.value" item="listItem" open="(" separator=",">
                    #{listItem}
                  </foreach>
                </when>
              </choose>
            </foreach>
          </trim>
        </if>
      </foreach>
    </where>
  </sql>
  <sql id="Base_Column_List">
    <!--
      WARNING - @mbg.generated
      This element is automatically generated by MyBatis Generator, do not modify.
      This element was generated on Thu May 06 15:12:27 CST 2021.
    -->
    id, name
  </sql>
  <select id="selectByExample" parameterType="com.jepcc.test.model.UserExample" resultMap="BaseResultMap">
    <!--
      WARNING - @mbg.generated
      This element is automatically generated by MyBatis Generator, do not modify.
      This element was generated on Thu May 06 15:12:27 CST 2021.
    -->
    select
    <if test="distinct">
      distinct
    </if>
    <include refid="Base_Column_List" />
    from users
    <if test="_parameter != null">
      <include refid="Example_Where_Clause" />
    </if>
    <if test="orderByClause != null">
      order by ${orderByClause}
    </if>
  </select>
  <select id="selectByPrimaryKey" parameterType="java.lang.Long" resultMap="BaseResultMap">
    <!--
      WARNING - @mbg.generated
      This element is automatically generated by MyBatis Generator, do not modify.
      This element was generated on Thu May 06 15:12:27 CST 2021.
    -->
    select 
    <include refid="Base_Column_List" />
    from users
    where id = #{id,jdbcType=BIGINT}
  </select>
  <delete id="deleteByPrimaryKey" parameterType="java.lang.Long">
    <!--
      WARNING - @mbg.generated
      This element is automatically generated by MyBatis Generator, do not modify.
      This element was generated on Thu May 06 15:12:27 CST 2021.
    -->
    delete from users
    where id = #{id,jdbcType=BIGINT}
  </delete>
  <delete id="deleteByExample" parameterType="com.jepcc.test.model.UserExample">
    <!--
      WARNING - @mbg.generated
      This element is automatically generated by MyBatis Generator, do not modify.
      This element was generated on Thu May 06 15:12:27 CST 2021.
    -->
    delete from users
    <if test="_parameter != null">
      <include refid="Example_Where_Clause" />
    </if>
  </delete>
  <insert id="insert" parameterType="com.jepcc.test.model.User">
    <!--
      WARNING - @mbg.generated
      This element is automatically generated by MyBatis Generator, do not modify.
      This element was generated on Thu May 06 15:12:27 CST 2021.
    -->
    insert into users (id, name)
    values (#{id,jdbcType=BIGINT}, #{name,jdbcType=VARCHAR})
  </insert>
  <insert id="insertSelective" parameterType="com.jepcc.test.model.User">
    <!--
      WARNING - @mbg.generated
      This element is automatically generated by MyBatis Generator, do not modify.
      This element was generated on Thu May 06 15:12:27 CST 2021.
    -->
    insert into users
    <trim prefix="(" suffix=")" suffixOverrides=",">
      <if test="id != null">
        id,
      </if>
      <if test="name != null">
        name,
      </if>
    </trim>
    <trim prefix="values (" suffix=")" suffixOverrides=",">
      <if test="id != null">
        #{id,jdbcType=BIGINT},
      </if>
      <if test="name != null">
        #{name,jdbcType=VARCHAR},
      </if>
    </trim>
  </insert>
  <select id="countByExample" parameterType="com.jepcc.test.model.UserExample" resultType="java.lang.Long">
    <!--
      WARNING - @mbg.generated
      This element is automatically generated by MyBatis Generator, do not modify.
      This element was generated on Thu May 06 15:12:27 CST 2021.
    -->
    select count(*) from users
    <if test="_parameter != null">
      <include refid="Example_Where_Clause" />
    </if>
  </select>
  <update id="updateByExampleSelective" parameterType="map">
    <!--
      WARNING - @mbg.generated
      This element is automatically generated by MyBatis Generator, do not modify.
      This element was generated on Thu May 06 15:12:27 CST 2021.
    -->
    update users
    <set>
      <if test="record.id != null">
        id = #{record.id,jdbcType=BIGINT},
      </if>
      <if test="record.name != null">
        name = #{record.name,jdbcType=VARCHAR},
      </if>
    </set>
    <if test="_parameter != null">
      <include refid="Update_By_Example_Where_Clause" />
    </if>
  </update>
  <update id="updateByExample" parameterType="map">
    <!--
      WARNING - @mbg.generated
      This element is automatically generated by MyBatis Generator, do not modify.
      This element was generated on Thu May 06 15:12:27 CST 2021.
    -->
    update users
    set id = #{record.id,jdbcType=BIGINT},
      name = #{record.name,jdbcType=VARCHAR}
    <if test="_parameter != null">
      <include refid="Update_By_Example_Where_Clause" />
    </if>
  </update>
  <update id="updateByPrimaryKeySelective" parameterType="com.jepcc.test.model.User">
    <!--
      WARNING - @mbg.generated
      This element is automatically generated by MyBatis Generator, do not modify.
      This element was generated on Thu May 06 15:12:27 CST 2021.
    -->
    update users
    <set>
      <if test="name != null">
        name = #{name,jdbcType=VARCHAR},
      </if>
    </set>
    where id = #{id,jdbcType=BIGINT}
  </update>
  <update id="updateByPrimaryKey" parameterType="com.jepcc.test.model.User">
    <!--
      WARNING - @mbg.generated
      This element is automatically generated by MyBatis Generator, do not modify.
      This element was generated on Thu May 06 15:12:27 CST 2021.
    -->
    update users
    set name = #{name,jdbcType=VARCHAR}
    where id = #{id,jdbcType=BIGINT}
  </update>
</mapper>

添加controller层UserController和service层UserService

package com.jepcc.test.controller;

import com.jepcc.test.model.User;
import com.jepcc.test.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;

@RestController
@RequestMapping("/test")
public class UserController {
    @Autowired
    private UserService userService;
    @GetMapping("/user")
    public List<User> getInfo(){
        return userService.getInfo();
    }
}

package com.jepcc.test.service;

import com.jepcc.test.mapper.TestMapper;
import com.jepcc.test.model.Ebook;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

@Service
public class TestService {
    @Autowired
    public TestMapper testMapper;
    public List<Ebook> list(){
        return testMapper.list();
    }
}

启动主程序，调用接口

使用泛型

Java5引入参数化类型的概念，也称为泛型。
泛型，允许定义类、接口、方法时使用类型形参，在声明变量、创建对象、调用方法时传入实际的类型参数，即类型实参。
本例中，TestController使用了List<Ebook>，UserController使用了List<User>，所以我们使用泛型来尝试下。

新建包resp，在该包下新建泛型类CommonResp

package com.jepcc.test.resp;

public class CommonResp<T> {
    private Boolean success = true;
    private String message;
    private T content;

    public Boolean getSuccess() {
        return success;
    }

    public void setSuccess(Boolean success) {
        this.success = success;
    }

    public String getMessage() {
        return message;
    }

    public void setMessage(String message) {
        this.message = message;
    }

    public T getContent() {
        return content;
    }

    public void setContent(T content) {
        this.content = content;
    }
}

在TestController和UserController中使用泛型类

package com.jepcc.test.controller;

import com.jepcc.test.resp.CommonResp;
import com.jepcc.test.service.TestService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class TestController {
    @Autowired
    public TestService testService;

    @GetMapping("/test/list")
    public CommonResp list(){
        CommonResp resp = new CommonResp();
        resp.setContent(testService.list());
        return resp;
    }
}

package com.jepcc.test.controller;

import com.jepcc.test.resp.CommonResp;
import com.jepcc.test.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequestMapping("/test")
public class UserController {
    @Autowired
    private UserService userService;
    @GetMapping("/user")
    public CommonResp getInfo(){
        CommonResp resp = new CommonResp();
        resp.setContent(userService.getInfo());
        return resp;
    }
}

接口测试

原文链接：https://blog.csdn.net/qzw752890913/article/details/116236502