关于Springboot初接触

此博非教学，仅仅为本人的学习记录，望酌情参考,环境是Centos的eclipse企业版，自带jee和maven，所以下了个springboot插件，关于开始创建项目的时候遇到一点坑，应对的方法是出问题了就删除/root/.m2/目录下的那个文件夹，在这个目录下还可以创个settings.xml文件配置maven的阿里源，不然创一个项目能等半年。。。内容如下

   <settings xmlns="http://maven.apache.org/SETTINGS/1.1.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
      xsi:schemaLocation="http://maven.apache.org/SETTINGS/1.1.0 http://maven.apache.org/xsd/settings-1.1.0.xsd">
    <mirrors>
      <mirror>
<id>alimaven</id>
<name>aliyun maven</name>
<url>http://maven.aliyun.com/nexus/content/groups/public/</url>
<mirrorOf>central</mirrorOf>
</mirror>
<mirror>
<id>alimaven</id>
<mirrorOf>central</mirrorOf>
<name>aliyun maven</name>
<url>http://maven.aliyun.com/nexus/content/repositories/central/</url>
</mirror>
      </mirrors>
    </settings>

之后进入eclipse里点windows然后preferences,选择maven,然后user setting，把刚刚那个路径写上去，apply并且close，完事。

接下来正题，创好项目后，我的理解是，所有的java文件夹都在demo下面，也就是在Application.java的同一级。

接触的第一个是用mybatis连接我的mysql，在demo下创建一个entity文件夹，新建一个实体类我这里是User,

package com.example.demo.entity;
import java.util.ArrayList;
import java.util.List;

import org.springframework.stereotype.Component;
import lombok.Data;
import lombok.Getter;
import lombok.Setter;
@Data
@Getter
@Setter
@Component
public class User {
private String name;
private String pass;
private String mac1;
private String mac2;
private String mac3;
public String getname()
{
    return this.name;
}
public String getpass()
{
    return this.pass;
}
public List<String> getmac()
{
    List<String> maclist=new ArrayList();
    maclist.add(mac1);
    maclist.add(mac2);
    maclist.add(mac3);
    return maclist;
    
}
}

然后在resources目录下的application.properties,编辑它内容为，最后两行可以不要，我用的注释方法，所以不用配置mapper的xml

spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.datasource.url=jdbc:mysql://localhost:3306/Program?user=zhurui&password=Zhurui@111
mybatis.mapper-locations=classpath:mapper/*.xml
mybatis.configuration.map-underscore-to-camel-case=true

然后demo下创建一个mapper文件夹，下面新建一个UserMapper.java,内容：（用的注释方法）

package com.cun.mapper;

import org.apache.ibatis.annotations.Mapper;
import org.mybatis.spring.annotation.MapperScan;

import com.example.demo.entity.User;

import org.apache.ibatis.annotations.Select;

@Mapper
public interface UserMapper {
//1、查询数据
    @Select("select * from user where name=#{name}")
    User getUser(String username) throws Exception;
}

接着在在demo下创建service文件夹，创建相应的接口类UserService.java

package com.example.demo.service;
import org.springframework.stereotype.Service;
import com.example.demo.entity.User;
//@Service
public interface UserService {
public User getUser(String name)throws Exception;
}

然后是接口对应的实现类，也是demo下创ServiceImpl文件夹，创建UserServiceImpl.java,内容

package com.example.demo.serviceImpl;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import com.cun.mapper.UserMapper;
import com.example.demo.entity.User;
import com.example.demo.service.UserService;
@Service
public class UserSeviceImpl implements UserService{
@Autowired
private UserMapper mapper;
@Override
public User getUser(String name) throws Exception
{
    return mapper.getUser(name);
}
}

，最后是控制类在demo下创建controller文件夹，创建Usercontroller.java

package com.example.demo.controller;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;

import com.example.demo.entity.User;
import com.example.demo.service.UserService;

@Controller
public class Usercontroller {
@Autowired
private UserService service;
@Autowired
private User user;
@RequestMapping(value="/login")
@ResponseBody
public User showlogin() throws Exception
{
    user=service.getUser("zhurui");
    System.out.print(user);
    return user;
}
}

到此，修改一下Application.java里的内容

package com.example.demo;

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@MapperScan("com.cun.mapper")
@SpringBootApplication
public class FirstProgramApplication {

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

}

也就加了一个注释，噢耶，终于成功了，但是我还是个大彩笔，中间配置pom的过程略了，等我把这些内容消化一下，总结个springboot的工作模式，然后再继续学习把。