带有可选参数的Spring @RequestMapping

本文介绍了带有可选参数的Spring @RequestMapping的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我的控制器在请求映射中具有可选参数时出现问题，请在下面的控制器上查看:

I have problem in my controller with optional params in requestmapping, look on my controller below:

@GetMapping(produces = MediaType.APPLICATION_JSON_VALUE) public ResponseEntity<List<Books>> getBooks() { return ResponseEntity.ok().body(booksService.getBooks()); } @GetMapping( produces = MediaType.APPLICATION_JSON_VALUE, params = {"from", "to"} ) public ResponseEntity<List<Books>>getBooksByFromToDate( @RequestParam(value = "from", required = false) String fromDate, @RequestParam(value = "to", required = false) String toDate) { return ResponseEntity.ok().body(bookService.getBooksByFromToDate(fromDate, toDate)); }

现在，当我发送如下请求时:

Now, when I send request like:

/getBooks?from=123&to=123

可以，请求转到"getBooksByFromToDate"方法 但是当我使用发送类似:

it's ok, request goes to "getBooksByFromToDate" method but when I use send something like:

/getBooks?from=123

或

/getBooks?to=123

转到"getAlerts"方法

it goes to "getAlerts" method

是否可以在@RequestMapping中使可选参数= {"from"，"to"}?有提示吗?

Is it possible to make optional params = {"from", "to"} in @RequestMapping ? Any hints?

推荐答案

使用默认值.示例:-

@GetMapping(produces = MediaType.APPLICATION_JSON_VALUE) public ResponseEntity<List<Books>> getBooksByFromToDate(@RequestParam(value = "from", required = false, defaultValue="01/03/2018") String fromDate, @RequestParam(value = "to", required = false, defaultValue="21/03/2018") String toDate) { .... }