1、数据层标准开发
- 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
@Test
void testGetBy2() {
LambdaQueryWrapper<Book> lambdaQueryWrapper = new LambdaQueryWrapper<>();
lambdaQueryWrapper.like(Book::getName, "Spring");
bookDao.selectList(lambdaQueryWrapper);
}
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@Test
void testGetBy() {
QueryWrapper<Book> queryWrapper = new QueryWrapper<>();
queryWrapper.like("name", "Spring");
bookDao.selectList(queryWrapper);
}
- 支持动态拼写查询条件
@Test
void testGetBy2() {
String name = "1";
LambdaQueryWrapper<Book> lambdaQueryWrapper = new LambdaQueryWrapper<>();
//if (name != null) lambdaQueryWrapper.like(Book::getName,name);
lambdaQueryWrapper.like(Strings.isNotEmpty(name), Book::getName, name);
bookDao.selectList(lambdaQueryWrapper);
}
2、业务层标准开发（基础CRUD）
-
Service层接口定义与数据层接口定义具有较大区别，不要混用
selectByUserNameAndPassword(String username,String password); 数据层接口
login(String username,String password); Service层接口 -
接口定义
public interface BookService { Boolean save(Book book); Boolean update(Book book); Boolean delete(Integer id); Book getById(Integer id); List<Book> getAll(); IPage<Book> getPage(int currentPage,int pageSize); } -
实现类定义
@Service
public class BookServiceImpl implements BookService {
@Autowired
private BookDao bookDao;
@Override
public Boolean save(Book book) {
return bookDao.insert(book) > 0;
}
@Override
public Boolean update(Book book) {
return bookDao.updateById(book) > 0;
}
@Override
public Boolean delete(Integer id) {
return bookDao.deleteById(id) > 0;
}
@Override
public Book getById(Integer id) {
return bookDao.selectById(id);
}
@Override
public List<Book> getAll() {
return bookDao.selectList(null);
}
@Override
public IPage<Book> getPage(int currentPage, int pageSize) {
IPage page = new Page(currentPage, pageSize);
bookDao.selectPage(page, null);
return page;
}
}
- 测试类定义
@SpringBootTest
public class BookServiceTestCase {
@Autowired
private BookService bookService;
@Test
void testGetById() {
System.out.println(bookService.getById(4));
}
@Test
void testSave() {
Book book = new Book();
book.setType("测试数据123");
book.setName("测试数据123");
book.setDescription("测试数据123");
bookService.save(book);
}
@Test
void testUpdate() {
Book book = new Book();
book.setId(14);
book.setType("测试数据asfd");
book.setName("测试数据123");
book.setDescription("测试数据123");
bookService.update(book);
}
@Test
void testDelete() {
bookService.delete(14);
}
@Test
void testGetAll() {
System.out.println(bookService.getAll());
}
@Test
void testGetPage() {
IPage<Book> page = bookService.getPage(2, 5);
System.out.println(page.getCurrent());
System.out.println(page.getSize());
System.out.println(page.getPages());
System.out.println(page.getTotal());
System.out.println(page.getRecords());
}
}
3、业务层快速开发（基于MyBatisPlus构建）
-
快速开发方案
使用MyBatisPlus提供有业务层通用接口（ISerivce）与业务层通用实现类（ServiceImpl<M,T>）
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
-
接口定义
public interface IBookService extends IService<Book> {
}
- 接口追加功能
public interface IBookService extends IService<Book> {
// 追加的操作与原始操作通过名称区分，功能类似
Boolean delete(Integer id);
Boolean insert(Book book);
Boolean modify(Book book);
Book get(Integer id);
}
- 实现类定义
@Service
public class BookServiceImpl extends ServiceImpl<BookDao, Book> implements IBookService {
}
- 实现类追加功能
@Service
public class BookServiceImpl extends ServiceImpl<BookDao, Book> implements IBookService {
@Autowired
private BookDao bookDao;
public Boolean insert(Book book) {
return bookDao.insert(book) > 0;
}
public Boolean modify(Book book) {
return bookDao.updateById(book) > 0;
}
public Boolean delete(Integer id) {
return bookDao.deleteById(id) > 0;
}
public Book get(Integer id) {
return bookDao.selectById(id);
}
}
- 测试类定义
@SpringBootTest
public class BookServiceTest {
@Autowired
private IBookService bookService;
@Test
void testGetById() {
System.out.println(bookService.getById(4));
}
@Test
void testSave() {
Book book = new Book();
book.setType("测试数据123");
book.setName("测试数据123");
book.setDescription("测试数据123");
bookService.save(book);
}
@Test
void testUpdate() {
Book book = new Book();
book.setId(14);
book.setType("===========");
book.setName("测试数据123");
book.setDescription("测试数据123");
bookService.updateById(book);
}
@Test
void testDelete() {
bookService.removeById(14);
}
@Test
void testGetAll() {
System.out.println(bookService.list());
}
@Test
void testGetPage() {
IPage<Book> page = new Page<>(2, 5);
bookService.page(page);
System.out.println(page.getCurrent());
System.out.println(page.getSize());
System.out.println(page.getPages());
System.out.println(page.getTotal());
System.out.println(page.getRecords());
}
}
4、表现层标准开发
- 基于Restful进行表现层接口开发
- 使用Postman测试表现层接口功能
@RestController
@RequestMapping("/books")
public class BookController {
@Autowired
private IBookService bookService;
@GetMapping
public List<Book> getAll() {
return bookService.list();
}
@PostMapping
public Boolean save(@RequestBody Book book) {
return bookService.save(book);
}
@PutMapping
public Boolean update(@RequestBody Book book) {
return bookService.modify(book);
}
@DeleteMapping("{id}")
public Boolean delete(@PathVariable Integer id) {
return bookService.delete(id);
}
@GetMapping("{id}")
public Book getById(@PathVariable Integer id) {
return bookService.getById(id);
}
@GetMapping("{currentPage}/{pageSize}")
public IPage<Book> getPage(@PathVariable Integer currentPage, @PathVariable int pageSize) {
return bookService.getPage(currentPage, pageSize);
}
}
添加 分页的业务层方法
IBookService
IPage<Book> getPage(int currentPage,int pageSize);
BookServiceImpl
@Override
public IPage<Book> getPage(int currentPage, int pageSize) {
IPage page = new Page(currentPage, pageSize);
bookDao.selectPage(page, null);
return page;
}
5、分页
分页操作需要设定分页对象IPage
@Test
void testGetPage() {
IPage page = new Page(1, 5);
bookDao.selectPage(page, null);
}
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-
IPage对象中封装了分页操作中的所有数据
数据
当前页码值
每页数据总量
最大页码值
数据总量
-
分页操作是在MyBatisPlus的常规操作基础上增强得到，内部是动态的拼写SQL语句，因此需要增强对应的功能
使用MyBatisPlus拦截器实现
@Configuration
public class MybatisPlusConfig {
@Bean
public MybatisPlusInterceptor mybatisPlusInterceptor() {
//1. 定义 Mp 拦截器
MybatisPlusInterceptor interceptor = new MybatisPlusInterceptor();
//2. 添加具体的拦截器 分页拦截器
interceptor.addInnerInterceptor(new PaginationInnerInterceptor());
return interceptor;
}
}
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测试
@Test
void testGetPage() {
IPage page = new Page(1, 5);
bookDao.selectPage(page, null);
System.out.println(page.getCurrent());
System.out.println(page.getSize());
System.out.println(page.getPages());
System.out.println(page.getTotal());
System.out.println(page.getRecords());