Question

我需要知道Spring启动如何在运行时将URL中的请求参数映射到POJO。

以下是带参数

的示例网址

    http://localhost:8080/api/public/properties?serviceType.in=SALE&title.contains=some text&price.greaterOrEqualThan=500&price.lessOrEqualThan=50000&propertyType.in=HOUSE&locationId.in=1,2&landSize.greaterOrEqualThan=100&landSize.lessOrEqualThan=1000&bedrooms.greaterOrEqualThan=2&bedrooms.lessOrEqualThan=5&bathrooms.greaterOrEqualThan=1&bathrooms.lessOrEqualThan=3&ageType.in=BRAND_NEW

我有许多Criteria类，它们都扩展了PropertyCriteria类。举个例子，如果请求不包含任何参数，我希望控制器使用PropertyCriteria。如果请求包含卧室参数，我希望控制器使用HousePropertyCriteria等。请参阅以下控制器方法示例

@GetMapping("/public/properties")
public ResponseEntity<List<Property>> 
   getAllPropertiesNested(HttpServletRequest request) {

   if (condition1 == true) {
       EntityOnePropertyCriteria c1 = new EntityOnePropertyCriteria();
       //populate c1 using request object

   } else {
       EntityTwoPropertyCriteria c2 = new EntityTwoPropertyCriteria();
       //populate c2 using request object
   }

}

Answer 1

手动执行此操作的两种方法： 1）我想知道在你的项目中你是否可以访问HttpServletRequest对象。如果是这种情况，您可以使用方法request.getParameter（nameParam）来填充您需要的对象。

2）使用beanutils库并使用该方法 BeanUtils.copyProperties（dest，source）使用＆＃34; @RequestParam Map source＆＃34;在您的控制器中并替换您想要填充的目标对象

Answer 2

我在this link找到了答案。

public static void applyMapOntoInstance（Object instance，Map properties）{

    if (properties != null && !properties.isEmpty()) {
        BeanWrapper beanWrapper = PropertyAccessorFactory.forBeanPropertyAccess(instance);
        beanWrapper.setAutoGrowNestedPaths(true);

        for (Iterator<?> iterator = properties.entrySet().iterator(); iterator.hasNext();) {
            Map.Entry<String, ?> entry = (Map.Entry<String, ?>) iterator.next();
            String propertyName = entry.getKey();
            if (beanWrapper.isWritableProperty(propertyName)) {
                beanWrapper.setPropertyValue(propertyName, entry.getValue());
            }
        }
    }
}

我的控制器方法现在看起来像：

@GetMapping("/public/properties")
@Timed
public ResponseEntity<List<Property>> getAllPropertiesNested(HttpServletRequest request) throws IllegalAccessException, NoSuchMethodException, InvocationTargetException {


    HttpHeaders headers = null;
    if (requestContains("bedrooms", request)) {

        HousePropertyCriteria housePropertyCriteria = new HousePropertyCriteria();
        applyMapOntoInstance(housePropertyCriteria, request.getParameterMap());

        Page<HouseProperty> page = housePropertyQueryService.findByCriteriaNested(housePropertyCriteria, pageable);
        headers = PaginationUtil.generatePaginationHttpHeaders(page, "/api/public/properties");
        return new ResponseEntity(page.getContent(), headers, HttpStatus.OK);

    } else {
        Page<Property> page = propertyQueryService.findByCriteriaNested(criteria, pageable);
        headers = PaginationUtil.generatePaginationHttpHeaders(page, "/api/public/properties");
        return new ResponseEntity(page.getContent(), headers, HttpStatus.OK);
    }


}

Spring - 如何在运行时将URL中的请求参数映射到POJO？

2 个答案: