起因
在工作中，android系统定制开发涉及到导出的功能，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 {
static final String DEFAULT_PAGE_PARAMETER = "page";
private 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
// 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);
}
}
原文：https: //blog.csdn.net/u010634897/article/details/81612124