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创建一个tbl_book表


??详细步骤操作?? 点击直接查看
不同版本的搭建项目在我springboot专栏里,本次项目采用的是阿里云版。模块的创建就不用多说了。
注意:选择需要的技术


Lombok开发工具可以简化实体类的开发。

??导入druid的依赖
com.alibaba
druid
1.2.11
??设置服务器端口号:
server:
port: 80
??Lombok注解
常用注解: @Data @setter @Getter
??Book
package com.jkj.domain;
import lombok.*;
//@Setter
//@Getter
@Data
public class Book {
private Integer id;
private String type;
private String name;
private String description;
}
??编写yml
server:
port: 80
spring:
datasource:
url: jdbc:mysql://localhost:3306/springboot?serverTimezone=UTC
username: root
password: root
type: com.alibaba.druid.pool.DruidDataSource
mybatis-plus:
global-config:
db-config:
table-prefix: tbl_
??编写Dao层(采用MyBatis-Plus技术)
package com.jkj.dao;
import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.jkj.domain.Book;
import org.apache.ibatis.annotations.Mapper;
@Mapper
public interface BookMapper extends BaseMapper {
}
??测试MyBatis-Plus的其他操作
package com.jkj.dao;
import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.jkj.domain.Book;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
@SpringBootTest()
public class SsmpTest {
@Autowired
private BookMapper bookMapper;
@Test
void findById() {
System.out.println(bookMapper.selectById(2));
}
@Test
void insert() {
Book book=new Book();
book.setName("springboot");
book.setType("框架");
book.setDescription("好用");
bookMapper.insert(book);
}
@Test
void updateById() {
Book book=new Book();
book.setId(4);
book.setDescription("666");
bookMapper.updateById(book);
}
@Test
void delete() {
bookMapper.deleteById(4);
}
@Test
void findAll() {
bookMapper.selectList(null);
}
}
??注意:在进行添加操作过程中,会爆id自增的问题在yml文件中添加这行代码: id-type: auto
mybatis-plus:
global-config:
db-config:
table-prefix: tbl_
id-type: auto
??编辑yml
mybatis-plus:
global-config:
db-config:
table-prefix: tbl_
id-type: auto
configuration:
log-impl: org.apache.ibatis.logging.stdout.StdOutImpl
??测试类
@Test
void findAll() {
bookMapper.selectList(null);
}

??编写拦截器MPConfig类
package com.jkj.config;
import com.baomidou.mybatisplus.extension.plugins.MybatisPlusInterceptor;
import com.baomidou.mybatisplus.extension.plugins.inner.PaginationInnerInterceptor;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
@Configuration
public class MPConfig {
@Bean
public MybatisPlusInterceptor mybatisPlusInterceptor(){
//定义MP拦截器
MybatisPlusInterceptor interceptor = new MybatisPlusInterceptor();
//添加具体拦截器
interceptor.addInnerInterceptor(new PaginationInnerInterceptor());
return interceptor;
}
}
??分页测试
@Test
void page(){
IPage page = new Page(2,5);
bookMapper.selectPage(page,null);
System.out.println(page.getCurrent());
System.out.println(page.getSize());
System.out.println(page.getTotal());
System.out.println(page.getPages());
System.out.println(page.getRecords());
}

??编写测试类
推荐使用:
使用 QueryWrapper对象封装查询条件,推荐使用LambdaQueryWrapper对象,所有查询操作封装成方法调用。
//推荐使用
@Test
void ByCondition1(){
String name="一";
LambdaQueryWrapper lqw = new LambdaQueryWrapper<>();
//支持动态拼写查询条件
lqw.like(name!=null,Book::getName,name);
bookMapper.selectList(lqw);
}
@Test
void ByCondition(){
QueryWrapper wrapper = new QueryWrapper<>();
wrapper.like(“name”,“一”);
bookMapper.selectList(wrapper);
}

Service层接口定义与数据层接口定义具有较大区别,不要混用。
package com.jkj.service;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.jkj.domain.Book;
import java.util.List;
public interface BookService {
Boolean save(Book book);
Boolean update(Book book);
Boolean delete(Integer id);
Book selectById(Integer id);
List SelectAll();
IPage getPage(int currentPage,int pageSize);
}
??实现类
package com.jkj.service.impl;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.jkj.dao.BookMapper;
import com.jkj.domain.Book;
import com.jkj.service.BookService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import java.util.List;
@Service
public class BookServiceImpl implements BookService {
@Autowired
private BookMapper bookMapper;
@Override
public Boolean save(Book book) {
return bookMapper.insert(book)>0;
}
@Override
public Boolean update(Book book) {
return bookMapper.updateById(book)>0;
}
@Override
public Boolean delete(Integer id) {
return bookMapper.deleteById(id)>0;
}
@Override
public Book selectById(Integer id) {
return bookMapper.selectById(id);
}
@Override
public List SelectAll() {
return bookMapper.selectList(null);
}
@Override
public IPage getPage(int currentPage, int pageSize) {
IPage page = new Page(currentPage,pageSize);
bookMapper.selectPage(page,null);
return page;
}
}
??测试类
package com.jkj.service;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.jkj.domain.Book;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
@SpringBootTest
public class BookServiceTest {
@Autowired(required = true)
private BookService bookService;
@Test
void testGetById(){
System.out.println(bookService.selectById(1));
}
@Test
void testSave(){
Book book = new Book();
book.setType("测试");
book.setName("测试");
book.setDescription("测试");
bookService.save(book);
}
@Test
void testUpdate(){
Book book = new Book();
book.setId(11);
book.setType("测试1");
book.setName("测试1");
book.setDescription("测试1");
bookService.update(book);
}
@Test
void testDelete(){
bookService.delete(14);
}
@Test
void testGetAll(){
bookService.SelectAll();
}
@Test
void testGetPage(){
IPage page = new Page(2,5);
System.out.println(page.getCurrent());
System.out.println(page.getSize());
System.out.println(page.getTotal());
System.out.println(page.getPages());
System.out.println(page.getRecords());
}
}
使用MyBatisPlus提供有业务层通用接口(ISerivce)与业务层通用实现类(ServiceImpl
在通用类基础上做功能重载或功能追加
注意重载时不要覆盖原始操作,避免原始提供的功能丢失
??service层接口定义
package com.jkj.service;
import com.baomidou.mybatisplus.extension.service.IService;
import com.jkj.domain.Book;
public interface IBookService extends IService {
}
??实现类
package com.jkj.service.impl;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.jkj.dao.BookMapper;
import com.jkj.domain.Book;
import com.jkj.service.IBookService;
import org.springframework.stereotype.Service;
@Service
public class IBookServiceImpl extends ServiceImpl implements IBookService {
}
??测试类
package com.jkj.service;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.jkj.domain.Book;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
@SpringBootTest
public class IBookServiceTest {
@Autowired
private IBookService iBookService;
@Test
void save(){
Book b=new Book();
b.setType("文学");
b.setName("白鹿原");
b.setDescription("好看");
iBookService.save(b);
}
@Test
void update(){
Book b=new Book();
b.setId(15);
b.setType("文学");
b.setName("白鹿原");
b.setDescription("666");
iBookService.updateById(b);
}
@Test
void delete(){
iBookService.removeById(15);
}
@Test
void findById(){
System.out.println(iBookService.getById(1));
}
@Test
void findAll(){
iBookService.list();
}
@Test
void page(){
IPage page = new Page(2,5);
iBookService.page(page);
System.out.println(page.getCurrent());
System.out.println(page.getSize());
System.out.println(page.getTotal());
System.out.println(page.getPages());
System.out.println(page.getRecords());
}
}
??编写Controller类
package com.jkj.controller;
import com.jkj.domain.Book;
import com.jkj.service.BookService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;
import java.util.List;
/*@RestController
@RequestMapping("/book")*/
public class BookController {
@Autowired
private BookService bookService;
@GetMapping
public List selectAll(){
return bookService.SelectAll();
}
@PostMapping
public Boolean save(@RequestBody Book book){
return bookService.save(book);
}
@PutMapping
public Boolean update(@RequestBody Book book){
return bookService.update(book);
}
@DeleteMapping("{id}")
public Boolean delete(@PathVariable Integer id){
return bookService.delete(id);
}
@GetMapping("{id}")
public Book selectById(@PathVariable Integer id){
return bookService.selectById(id);
}
}
??启动postman测试
查全部

通过id查询

添增

修改

修改之后再查询一次

删除

??编写R.java
package com.jkj.controller.utils;
import lombok.Data;
@Data
public class R {
private Boolean flag;
private Object data;
public R(){}
public R(Boolean flag){
this.flag = flag;
}
public R(Boolean flag,Object data){
this.flag = flag;
this.data = data;
}
}
??编写IController类
package com.jkj.controller;
import com.jkj.domain.Book;
import com.jkj.controller.utils.R;
import com.jkj.service.IBookService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;
@RestController
@RequestMapping("/book")
public class IBookController {
@Autowired
private IBookService iBookService;
@GetMapping
public R selectAll(){
return new R(true,iBookService.list());
}
@PostMapping
public R save(@RequestBody Book book){
/*R r = new R();
boolean flag = iBookService.save(book);
r.setFlag(flag);*/
return new R(iBookService.save(book));
}
@PutMapping
public R update(@RequestBody Book book){
return new R(iBookService.updateById(book));
}
@DeleteMapping("{id}")
public R delete(@PathVariable Integer id){
return new R(iBookService.removeById(id));
}
@GetMapping("{id}")
public R selectById(@PathVariable Integer id){
return new R(true,iBookService.getById(id));
}
}
??postman测试,如上。

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