如何验证@RequestParams是否为空？

Question

我有一个计算器服务,从用户获取操作类型num1和num2.我需要验证用户是否实际输入了这些值,而不是将其留空.

@RequestMapping(value = "/calculate")
@ResponseBody
public CalculationResult calculate(@RequestParam(name = "op") String operation, @RequestParam(name = "num1") Double num1, @RequestParam(name = "num2") Double num2) {
    System.out.print("Operation:" + operation);
    Double calculate = calculatorService.calculate(operation, num1, num2);
    return new CalculationResult(calculate);
}

我有一个集成测试,我需要传递,因为它当前失败并出现错误:

{\"timestamp \":1488875777084,\"status \":400,\"error \":\"Bad Request \",\"exception \":\"org.springframework.web.method.annotation.MethodArgumentTypeMismatchException\",""message \":\"无法将'java.lang.String'类型的值转换为必需类型'java.lang.Double';

以下是我的测试用例:

@Test
public void validates_all_parameters_are_set() throws Exception {
    ResponseEntity<String> response = template.getForEntity( "/calculate?op=&num1=&num2=",
            String.class);
    assertThat(response.getStatusCode(), equalTo(HttpStatus.BAD_REQUEST));
    assertThat(response.getBody(), equalTo("{\"error\":\"At least one parameter is invalid or not supplied\"}"));
}

我不知道如何验证这一点.

Answer 1

我在这之前很久就回答了类似的问题,你可以按照以下方式编写测试,如下所示:

@Validated
public class CalculationController {

    @RequestMapping(value = "/calculate")
    @ResponseBody
    public CalculationResult calculate(
            @Valid @NotBlank @RequestParam(name = "op") String operation,
            @Valid @NotNull @RequestParam(name = "num1") Double num1,
            @Valid @NotNull @RequestParam(name = "num2") Double num2) {
        System.out.print("Operation:" + operation);
        Double calculate = calculatorService.calculate(operation, num1, num2);
        return new CalculationResult(calculate);
    }
}

应修改相应的@Test以测试"可能不为空"消息的数组,如下所示:

@Test
public void validates_all_parameters_are_set() throws Exception {
    ResponseEntity<String> response = template.getForEntity( "/calculate?op=&num1=&num2=",
                String.class);
    assertThat(response.getStatusCode(), equalTo(HttpStatus.BAD_REQUEST));
    assertThat(response.getBody(), equalTo("{\"error\":[\"may not be null\",\"may not be null\"]}"));
}

Answer 2

您到目前为止还没有检查这些值；你可以将你的代码更改为：

import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;

@RequestMapping(value = "/calculate")
@ResponseBody
public ResponseEntity<CalculationResult> calculate(@RequestParam(name = "op") String operation, 
    @RequestParam(name = "num1") Double num1, 
    @RequestParam(name = "num2") Double num2) {

    if(null == op || null == num1 || null == num2) {
        throw new IllegalArgumentException("{\"error\":\"At least one parameter is invalid or not supplied\"}")
    }

    System.out.print("Operation:" + operation);
    Double calculate = calculatorService.calculate(operation, num1, num2);

    return new ResponseEntity<>(new CalculationResult(calculate), HttpStatus.OK);
}    

@ExceptionHandler(IllegalArgumentException.class)
@ResponseStatus(HttpStatus.BAD_REQUEST)
public final String exceptionHandlerIllegalArgumentException(final IllegalArgumentException e) {
    return '"' + e.getMessage() + '"';
}