java - Spring:实际请求参数不满足参数条件 "loanTitle"

Question

Java Spring MVC。如果没有参数，我无法打开 url。我在互联网上找到了建议( Spring MVC Thymeleaf Error: Parameter conditions not met for actual request parameters ， http://www.baeldung.com/spring-requestmapping )，但它们没有帮助我。

@Controller
@RequestMapping("/loans/")
public class LoanController {

    @Autowired 
    LoanDAO loanDAO;

    @GetMapping(value= "objectloan", params = {"loanTitle"})
    public String index(Model theModel, HttpSession session, @RequestParam(value = "loanTitle", required = false, defaultValue = "") Optional<String> loanTitle)
    {
....
    }

网址有效

http://localhost:8080/college/loans/objectloan?loanTitle=test

网址有错误

http://localhost:8080/college/loans/objectloan

错误:

Type Status Report
Message Parameter conditions "loanTitle" not met for actual request parameters:
Description The server cannot or will not process the request due to something that is perceived to be a client error (e.g., malformed request syntax, invalid request message framing, or deceptive request routing).

Answer 1

由于 loanTitle 可能不会出现在您的查询网址中，因此请尝试在 Controller 方法中删除 params = {"loanTitle"}

    @GetMapping(value= "objectloan")
    public String index(Model theModel, HttpSession session, @RequestParam(value = "loanTitle", required = false, defaultValue = "") Optional<String> loanTitle)
    {
....
    }