import org.springframework.data.querydsl.binding.QuerydslPredicate; //导入依赖的package包/类
/**
 * Obtains the domain type information from the given method parameter. Will
 * favor an explicitly registered on through
 * {@link QuerydslPredicate#root()} but use the actual type of the method's
 * return type as fallback.
 * 
 * @param parameter
 *            must not be {@literal null}.
 * @return
 */
static TypeInformation<?> extractTypeInfo(MethodParameter parameter) {

	QuerydslPredicate annotation = parameter.getParameterAnnotation(QuerydslPredicate.class);

	if (annotation != null && !Object.class.equals(annotation.root())) {
		return ClassTypeInformation.from(annotation.root());
	}

	Class<?> containingClass = parameter.getContainingClass();
	if (ClassUtils.isAssignable(EntityController.class, containingClass)) {
		ResolvableType resolvableType = ResolvableType.forClass(containingClass);
		return ClassTypeInformation.from(resolvableType.as(EntityController.class).getGeneric(0).resolve());
	}

	return detectDomainType(ClassTypeInformation.fromReturnTypeOf(parameter.getMethod()));
}
 

import org.springframework.data.querydsl.binding.QuerydslPredicate; //导入依赖的package包/类
@RequestMapping(value = "/", method = RequestMethod.GET)
String index(Model model, //
		@QuerydslPredicate(root = User.class) Predicate predicate, //
		@PageableDefault(sort = { "lastname", "firstname" }) Pageable pageable, //
		@RequestParam MultiValueMap<String, String> parameters) {

	ServletUriComponentsBuilder builder = ServletUriComponentsBuilder.fromCurrentRequest();
	builder.replaceQueryParam("page", new Object[0]);

	model.addAttribute("baseUri", builder.build().toUri());
	model.addAttribute("users", repository.findAll(predicate, pageable));

	return "index";
}
 

import org.springframework.data.querydsl.binding.QuerydslPredicate; //导入依赖的package包/类
@RequestMapping(value = "search", method = RequestMethod.GET)
  public ModelAndView findDishes(@QuerydslPredicate(root = Dish.class) Predicate predicate, @PageableDefault(sort = {"date"}, direction = Sort.Direction.DESC) Pageable pageable, ModelAndView modelAndView) {
Sort realSort = pageable.getSort().and(new Sort(Sort.Direction.ASC, "id"));
PageRequest pageRequest = new PageRequest(pageable.getPageNumber(), pageable.getPageSize(), realSort);
Page<Dish> page = dishRepo.findAll(predicate, pageRequest);
List<DishWebDTO> dishes = page.getContent().stream().map(dishDtoFactory::create).collect(Collectors.toList());
modelAndView.addObject("page", page);
modelAndView.addObject("dishes", dishes);
modelAndView.addObject("labels", getLabelsFromDishes());
modelAndView.addObject("categories", getCategoriesFromDishes());
modelAndView.addObject("mensas", mensaRepo.findAllByOrderByName());
      modelAndView.setViewName("search");
      return modelAndView;
  }
 

import org.springframework.data.querydsl.binding.QuerydslPredicate; //导入依赖的package包/类
/**
 * Another alternative to QBE via QueryDsl Predicates.
 *
 * @param predicate the Predicate to use to query with
 * @param pageable a Pageable to restrict results
 * @return A paged result of matching Patients
 */
@GetMapping("/search/predicate")
public Page<Patient> getPatientsByPredicate(
		@QuerydslPredicate(root = Patient.class) final Predicate predicate,
		@PageableDefault(size = DEFAULT_PAGE_SZ) final Pageable pageable) {
	Page<Patient> pagedResults = this.patientRepository.findAll(predicate, pageable);

	if (!pagedResults.hasContent()) {
		throw new NotFoundException(Patient.RESOURCE_PATH,
				"No Patients found matching predicate " + predicate);
	}

	return pagedResults;
}
 

import org.springframework.data.querydsl.binding.QuerydslPredicate; //导入依赖的package包/类
@Override
public boolean supportsParameter(MethodParameter parameter) {

	if (Predicate.class.equals(parameter.getParameterType())) {
		return true;
	}

	if (parameter.hasParameterAnnotation(QuerydslPredicate.class)) {
		throw new IllegalArgumentException(
				String.format("Parameter at position %s must be of type Predicate but was %s.",
						parameter.getParameterIndex(), parameter.getParameterType()));
	}

	return false;
}
 

import org.springframework.data.querydsl.binding.QuerydslPredicate; //导入依赖的package包/类
@RequestMapping(method = RequestMethod.GET, value = "/cust")
public Iterable<Customer> find(@QuerydslPredicate(root = Customer.class) Predicate predicate, Pageable pageable,
		@RequestParam MultiValueMap<String, String> parameters) {

	System.out.println();
	System.out.println(predicate);
	System.out.println();

	return customerRepository.findAll(predicate, pageable);
}