spring boot简单的小demo(适合于初学者)

import com.example.demo2.com.example.dao.ShopDao;
import com.example.demo2.com.example.entity.Shops;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.bind.annotation.RestController;

import javax.annotation.Resource;
import java.util.List;

@RestController
public class ShopController {

    @Autowired
    private ShopDao shopdao;

    /*
    * 查询
    * */
    @RequestMapping("sele")
    @ResponseBody
    public List test(){
        List<Shops> finl = shopdao.finalAll();
        for (Shops shop : finl){
            System.out.println(shop.getNames());
            System.out.println(shop.getPass());
        }
        return finl;
    }

    /*
    * 添加
    * */

    @RequestMapping("add")
    @ResponseBody
    public String test1(String names,String pass,String sex){
        Shops shop = new Shops();
        shop.setNames(names);
        shop.setPass(pass);
        shop.setSex(sex);
       Integer result = shopdao.add(shop);
       String st = "添加失败";
       if(result>0){
           st = "添加成功";
       }
       return st;
    }

    /*
     *  修改
     * */
    @RequestMapping("upda")
    @ResponseBody
    public String test2(Integer id,String names,String pass,String sex){
        Shops shop = new Shops();
        shop.setId(id);
        shop.setNames(names);
        shop.setPass(pass);
        shop.setSex(sex);
        Integer result = shopdao.updates(shop);
        String st = "修改失败";
        if(result>0){
            st = "修改成功";
        }
        return st;
    }

    /*
     * 删除
     * */
    @RequestMapping("dele")
    @ResponseBody
    public String test3(Integer id){
        Integer result = shopdao.deletes(id);
        String st = "删除失败";
        if(result>0){
            st = "删除成功";
        }
        return st;
    }

}

　　

dao层

import com.example.demo2.com.example.entity.Shops;
import org.apache.ibatis.annotations.Mapper;
import org.springframework.stereotype.Repository;

import java.util.List;

@Mapper//声明是一个Mapper,与springbootApplication中的@MapperScan二选一写上即可
public interface ShopDao {
    //查询
    public List<Shops> finalAll();

    //添加
    public Integer add(Shops shop);

    //修改
    public Integer updates(Shops shop);

    //删除
    public Integer deletes(Integer id);

}

mapper

<?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.example.demo2.com.example.dao.ShopDao">

    <select id="finalAll" resultType="com.example.demo2.com.example.entity.Shops">
       select * from first
    </select>

    <insert id="add" parameterType="com.example.demo2.com.example.entity.Shops" useGeneratedKeys="true">
        INSERT INTO first(names,pass,sex) values(#{names},#{pass},#{sex})
    </insert>

    <update id="updates" parameterType="com.example.demo2.com.example.entity.Shops">
      update first set names =#{names},pass=#{pass},sex=#{sex} where id = #{id}
    </update>

    <delete id="deletes" parameterType="com.example.demo2.com.example.entity.Shops">
      delete from first where id =#{id}
    </delete>

</mapper>

application.yml

server:
  port: 8088
  context-path: /

spring:
    profiles:
        active: dev
    application:
        name: demo-2
    jackson:
        date-format: yyyy-MM-dd HH:mm:ss
        time-zone: GMT+8
        default-property-inclusion: non_null
    datasource:
        url: jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=UTF8
        username: root
        password: root
        # 使用druid数据源
        type: com.alibaba.druid.pool.DruidDataSource
        driver-class-name: com.mysql.jdbc.Driver
        filters: stat
        maxActive: 20
        initialSize: 1
        maxWait: 60000
        minIdle: 1
        timeBetweenEvictionRunsMillis: 60000
        minEvictableIdleTimeMillis: 300000
        validationQuery: select 'x'
        testWhileIdle: true
        testOnBorrow: false
        testOnReturn: false
        poolPreparedStatements: true
        maxOpenPreparedStatements: 20

mybatis:
    typeAliasesPackage: com.example.demo2.com.example.dao
    mapperLocations: classpath:mapper/*.xml

项目启动文件

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

@SpringBootApplication
@EnableTransactionManagement//开启事务管理
@MapperScan("com.example.demo2.com.example.dao")//与dao层的@Mapper二选一写上即可(主要作用是扫包)
public class Demo2Application {

    public static void main(String[] args) {
        SpringApplication.run(Demo2Application.class, args);
    }
}

pom文件

<?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.example</groupId>
    <artifactId>demo-2</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>demo-2</name>
    <description>Demo project for Spring Boot</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.9.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>1.8</java.version>
　　　　  <!-- 这个可以使用和spring boot的mybatis两个选一  -->
        <!--<mybatis.version>3.3.1</mybatis.version>-->
        <!--<mybatis.spring.version>1.2.4</mybatis.spring.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-aop</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-tomcat</artifactId>
        </dependency>

        <!-- druid -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.0.11</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>

        <!--Mybatis 二选一  -->
        <!--<dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>${mybatis.version}</version>
        </dependency>
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis-spring</artifactId>
            <version>${mybatis.spring.version}</version>
        </dependency>-->
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.1.1</version>
        </dependency>

        <!-- Mybatis Generator -->
        <dependency>
            <groupId>org.mybatis.generator</groupId>
            <artifactId>mybatis-generator-core</artifactId>
            <version>1.3.2</version>
            <scope>compile</scope>
            <optional>true</optional>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

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

</project>

以上是ssm的简单流程

以下是jpa的简单流程

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.autoconfigure.domain.EntityScan;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.data.jpa.repository.config.EnableJpaRepositories;

@ComponentScan(basePackages = {"com.example.demo3.action"})
@EnableJpaRepositories(basePackages = "com.example.demo3.dao")
@EntityScan("com.example.demo3.entity")
@EnableAutoConfiguration
@SpringBootApplication
public class Demo3Application {

    public static void main(String[] args) {
        SpringApplication.run(Demo3Application.class, args);
    }
}

import com.example.demo3.dao.FirstDao;
import com.example.demo3.entity.First;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class Action {

    @Autowired
    private FirstDao firstDao;

    @RequestMapping("hello")
    @ResponseBody
    public First test1(Integer id){

        First first = firstDao.findOne(id);
        return first;

    }

}

import javax.persistence.*;

@Entity
@Table(name="first")
public class First {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "id")
    private  Integer id;

    @Column(name="names")
    private  String names;

    @Column(name="pass")
    private  String pass;

    @Column(name="sex")
    private  String sex;

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getNames() {
        return names;
    }

    public void setNames(String names) {
        this.names = names;
    }

    public String getPass() {
        return pass;
    }

    public void setPass(String pass) {
        this.pass = pass;
    }

    public String getSex() {
        return sex;
    }

    public void setSex(String sex) {
        this.sex = sex;
    }
}

import com.example.demo3.entity.First;
import org.springframework.data.jpa.repository.JpaRepository;

import java.util.List;

public interface FirstDao extends JpaRepository<First,Integer>{

}

spring:
    datasource:
        url: jdbc:mysql:/localhost:3306/test?useUnicode=true&characterEncoding=UTF-8
        username: root
        password: root
        driver-class-name: com.mysql.jdbc.Driver
        type: com.alibaba.druid.pool.DruidDataSource
        filters: stat
        maxActive: 20
        initialSize: 1
        maxWait: 60000
        minIdle: 1
        timeBetweenEvictionRunsMillis: 60000
        minEvictableIdleTimeMillis: 300000
        validationQuery: select 'x'
        testWhileIdle: true
        testOnBorrow: false
        testOnReturn: false
        poolPreparedStatements: true
        maxOpenPreparedStatements: 20
    jpa:
        show-sql: true
        hibernate:
            ddl-auto: create
server:
    port : 8088
    context-path : /

<?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.example</groupId>
    <artifactId>demo-3</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>demo-3</name>
    <description>Demo project for Spring Boot</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.9.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>1.8</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-data-jpa</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-aop</artifactId>
            <version>1.5.4.RELEASE</version>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-tomcat</artifactId>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>

        <!-- druid -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.0.11</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>

    </dependencies>

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

</project>

以上就是全部的demo,中间出现了一些问题,也都慢慢的解决了,有了解的朋友可以加我微信

如可以解决的问题,私信发我.

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