SpringBoot分页Pageable最大size的自定义配置

• 起因

在工作中，涉及到导出的功能，由于导出和搜索的结果是相同的，所以导出和搜索是同一接口。但由于搜索的分页是每页10条，而导出却是没有条数限制的，所以引出下面的问题

• controller方法如下：

  @PostMapping("/orders/search")
  public Page getOrders(@RequestBody @Valid Search search,
                                        @PageableDefault(
                                                sort = {"modifiedDate", "createdDate"},
                                                direction = Sort.Direction.DESC
                                        ) Pageable pageable) {
  
      return preOrderService.getOrders(search, pageable);
  }

  通过前端传递的pagesize来设定分页的大小，在使用中发现无论page的size修改为多大，导出最多只能2000条，于是怀疑源码中可能有最大值的限制，于是跟踪源码发现果真如此，源码如下(仅相关代码)：

  /**
  * Extracts paging information from web requests and thus allows injecting {@link Pageable} instances into controller
  * methods. Request properties to be parsed can be configured. Default configuration uses request parameters beginning
  * with {@link #DEFAULT_PAGE_PARAMETER}{@link #DEFAULT_QUALIFIER_DELIMITER}.
  * 
  * 从Web请求中提取分页信息，从而允许将Pageable实例注入controller方法
  * 可以配置要解析的请求属性，默认配置使用以DEFAULT_PAGE_PARAMETER，DEFAULT_QUALIFIER_DELIMITER开头的请求参数
  *
  * @since 1.6
  * @author Oliver Gierke
  * @author Nick Williams
  * @author Mark Paluch
  */
  public class PageableHandlerMethodArgumentResolver implements PageableArgumentResolver {
  
      private static final String DEFAULT_PAGE_PARAMETER = "page";
      private static final String DEFAULT_SIZE_PARAMETER = "size";
      private static final String DEFAULT_PREFIX = "";
      private static final String DEFAULT_QUALIFIER_DELIMITER = "_";
      // 默认page size最大2000
      private static final int DEFAULT_MAX_PAGE_SIZE = 2000;
      static final Pageable DEFAULT_PAGE_REQUEST = new PageRequest(0, 20);
  
      private Pageable fallbackPageable = DEFAULT_PAGE_REQUEST;
      private SortArgumentResolver sortResolver;
      private String pageParameterName = DEFAULT_PAGE_PARAMETER;
      private String sizeParameterName = DEFAULT_SIZE_PARAMETER;
      private String prefix = DEFAULT_PREFIX;
      private String qualifierDelimiter = DEFAULT_QUALIFIER_DELIMITER;
      // maxPageSize 最大2000
      private int maxPageSize = DEFAULT_MAX_PAGE_SIZE;
  
      @Override
      public Pageable resolveArgument(MethodParameter methodParameter, ModelAndViewContainer mavContainer,
              NativeWebRequest webRequest, WebDataBinderFactory binderFactory) {
  
          assertPageableUniqueness(methodParameter);
  
          Pageable defaultOrFallback = getDefaultFromAnnotationOrFallback(methodParameter);
  
          String pageString = webRequest.getParameter(getParameterNameToUse(pageParameterName, methodParameter));
          // sizeParameterName="size"，从请求中拿到size值
          String pageSizeString = webRequest.getParameter(getParameterNameToUse(sizeParameterName, methodParameter));
  
          boolean pageAndSizeGiven = StringUtils.hasText(pageString) && StringUtils.hasText(pageSizeString);
  
          if (!pageAndSizeGiven && defaultOrFallback == null) {
              return null;
          }
  
          int page = StringUtils.hasText(pageString) ? parseAndApplyBoundaries(pageString, Integer.MAX_VALUE, true)
                  : defaultOrFallback.getPageNumber();
          int pageSize = StringUtils.hasText(pageSizeString) ? parseAndApplyBoundaries(pageSizeString, maxPageSize, false)
                  : defaultOrFallback.getPageSize();
  
          // Limit lower bound
          pageSize = pageSize < 1 ? defaultOrFallback.getPageSize() : pageSize;
          // Limit upper bound
          // 无论上面怎么处理，pageSize>2000的话，pageSize=2000，否则就是pageSize的值
          pageSize = pageSize > maxPageSize ? maxPageSize : pageSize;
  
          Sort sort = sortResolver.resolveArgument(methodParameter, mavContainer, webRequest, binderFactory);
  
          // Default if necessary and default configured
          sort = sort == null && defaultOrFallback != null ? defaultOrFallback.getSort() : sort;
  
          return new PageRequest(page, pageSize, sort);
      }
  }

• 自定义page配置来解决

  自定义size最大为10000

import org.springframework.context.annotation.Configuration;
import org.springframework.data.web.PageableHandlerMethodArgumentResolver;
import org.springframework.web.method.support.HandlerMethodArgumentResolver;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;

import java.util.List;

@Configuration
public class PageConfig extends WebMvcConfigurerAdapter {

    private static final int PMP_MAX_PAGE_SIZE = 10000;

    @Override
    public void addArgumentResolvers(List argumentResolvers) {
        PageableHandlerMethodArgumentResolver resolver = new PageableHandlerMethodArgumentResolver();

        resolver.setMaxPageSize(PMP_MAX_PAGE_SIZE);
        argumentResolvers.add(resolver);
        super.addArgumentResolvers(argumentResolvers);
    }
}