使用Spring Boot进行分页

dependencies {
  implementation 'org.springframework.boot:spring-boot-starter-data-jpa'
  implementation 'org.springframework.boot:spring-boot-starter-web'
  compileOnly 'org.projectlombok:lombok'
  annotationProcessor 'org.projectlombok:lombok'
  runtimeOnly 'com.h2database:h2'
  testImplementation('org.junit.jupiter:junit-jupiter:5.4.0')
  testImplementation('org.springframework.boot:spring-boot-starter-test'){
    exclude group: 'junit', module: 'junit'
  }
}

public interface Pageable {
    
  // number of the current page   int getPageNumber();
  
  // size of the pages   int getPageSize();
  
  // sorting parameters   Sort getSort();
    
  // ... more methods }

Pageable pageable = PageRequest.of(0, 5, Sort.by(
    Order.asc("name"),
    Order.desc("id")));

困惑？java.awt.print.Pageable

使用时，您会注意到 IDE 有时会 建议进口代替春天的班。由于我们很可能不需要包中的任何类，因此我们可以 告诉我们的 IDE 完全忽略它。Pageablejava.awt.print.PageablePageablejava.awt

在IntelliJ中，转到设置中的“常规->编辑器->自动导入”，然后添加到标有“从导入和完成中排除”的列表中。java.awt.*

在 Eclipse 中，转到首选项中的“Java -> 外观 -> 类型过滤器”，然后 添加到包列表中。java.awt.*

public interface Page extends Slice{
  
  // total number of pages   int getTotalPages();
  
  // total number of items   long getTotalElements();
  
  // ... more methods   
}

public interface Slice {
  
  // current page number   int getNumber();
    
  // page size   int getSize();
    
  // number of items on the current page   int getNumberOfElements();
    
  // list of items on this page   List getContent();
  
  // ... more methods   
}

Pageable pageable = ...;
List listOfCharacters = ...;
long totalCharacters = 100;
Page page = 
    new PageImpl<>(listOfCharacters, pageable, totalCharacters);

@Configuration
@EnableSpringDataWebSupport
class PaginationConfiguration {
}

java.lang.NoSuchMethodException: org.springframework.data.domain.Pageable.()
java.lang.NoSuchMethodException: org.springframework.data.domain.Sort.()

@RestController
@RequiredArgsConstructor
class PagedController {
 
  private final MovieCharacterRepository characterRepository;
 
  @GetMapping(path = "/characters/page")
  Page loadCharactersPage(Pageable pageable) {
    return characterRepository.findAllPage(pageable);
  }
  
}

@WebMvcTest(controllers = PagedController.class)
class PagedControllerTest {
 
  @MockBean
  private MovieCharacterRepository characterRepository;
 
  @Autowired
  private MockMvc mockMvc;
 
  @Test
  void evaluatesPageableParameter() throws Exception {
 
    mockMvc.perform(get("/characters/page")
        .param("page", "5")
        .param("size", "10")
        .param("sort", "id,desc")   // <-- no space after comma!         .param("sort", "name,asc")) // <-- no space after comma!         .andExpect(status().isOk());
 
    ArgumentCaptor pageableCaptor = 
        ArgumentCaptor.forClass(Pageable.class);
    verify(characterRepository).findAllPage(pageableCaptor.capture());
    PageRequest pageable = (PageRequest) pageableCaptor.getValue();
 
    assertThat(pageable).hasPageNumber(5);
    assertThat(pageable).hasPageSize(10);
    assertThat(pageable).hasSort("name", Sort.Direction.ASC);
    assertThat(pageable).hasSort("id", Sort.Direction.DESC);
  }
}

@RestController
@RequiredArgsConstructor
class PagedController {
 
  private final MovieCharacterRepository characterRepository;
 
  @GetMapping(path = "/characters/sorted")
  List loadCharactersSorted(Sort sort) {
    return characterRepository.findAllSorted(sort);
  }
}

@WebMvcTest(controllers = PagedController.class)
class PagedControllerTest {
 
  @MockBean
  private MovieCharacterRepository characterRepository;
 
  @Autowired
  private MockMvc mockMvc;
 
  @Test
  void evaluatesSortParameter() throws Exception {
 
    mockMvc.perform(get("/characters/sorted")
        .param("sort", "id,desc")   // <-- no space after comma!!!         .param("sort", "name,asc")) // <-- no space after comma!!!         .andExpect(status().isOk());
 
    ArgumentCaptor sortCaptor = ArgumentCaptor.forClass(Sort.class);
    verify(characterRepository).findAllSorted(sortCaptor.capture());
    Sort sort = sortCaptor.getValue();
 
    assertThat(sort).hasSort("name", Sort.Direction.ASC);
    assertThat(sort).hasSort("id", Sort.Direction.DESC);
  }
}

spring.data.web.pageable.size-parameter=size
spring.data.web.pageable.page-parameter=page
spring.data.web.pageable.default-page-size=20
spring.data.web.pageable.one-indexed-parameters=false
spring.data.web.pageable.max-page-size=2000
spring.data.web.pageable.prefix=
spring.data.web.pageable.qualifier-delimiter=_

@RestController
class PagedController {
 
  @GetMapping(path = "/characters/qualifier")
  Page loadCharactersPageWithQualifier(
      @Qualifier("my") Pageable pageable) {
    ...
  }
 
}

spring.data.web.*属性未评估？

如果对上述配置属性的更改不起作用，则 bean 可能未加载到应用程序上下文中。SpringDataWebProperties

其中一个原因可能是您已经激活了分页支持。这将覆盖， 其中创造了沂豆。仅在普通弹簧应用中使用。@EnableSpringDataWebSupportSpringDataWebAutoConfigurationSpringDataWebProperties@EnableSpringDataWebSupport

@RestController
class PagedController {
 
  @GetMapping(path = "/characters/page")
  Page loadCharactersPage(
      @PageableDefault(page = 0, size = 20)
      @SortDefault.SortDefaults({
          @SortDefault(sort = "name", direction = Sort.Direction.DESC),
          @SortDefault(sort = "id", direction = Sort.Direction.ASC)
      }) Pageable pageable) {
    ...
  }
  
}

interface MovieCharacterRepository 
        extends CrudRepository {
 
  List findByMovie(String movieName, Pageable pageable);
  
  @Query("select c from MovieCharacter c where c.movie = :movie")
  List findByMovieCustom(
      @Param("movie") String movieName, Pageable pageable);
  
  @Query("select c from MovieCharacter c where c.movie = :movie")
  List findByMovieSorted(
      @Param("movie") String movieName, Sort sort);
 
}

interface MovieCharacterRepository 
        extends CrudRepository {
 
  Page findByMovie(String movieName, Pageable pageable);
 
  @Query("select c from MovieCharacter c where c.movie = :movie")
  Slice findByMovieCustom(
      @Param("movie") String movieName, Pageable pageable);
 
}