Question

我开发了一种休息服务，用于管理与客户有关的原始操作。

现在，我想从我的spring mvc应用程序中调用服务休息，但是当我单击jsp页面中的“更新”按钮时出现以下错误：

org.springframework.web.util.NestedServletException: Request processing failed; nested exception is
  org.springframework.web.client.HttpClientErrorException: 400 null
  org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:982)
  org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:866)
  javax.servlet.http.HttpServlet.service(HttpServlet.java:634)
  org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:851)
  javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
  org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) cause mère
    org.springframework.web.client.HttpClientErrorException: 400 null
    org.springframework.web.client.DefaultResponseErrorHandler.handleError(DefaultResponseErrorHandler.java:94)
    org.springframework.web.client.DefaultResponseErrorHandler.handleError(DefaultResponseErrorHandler.java:79)
    org.springframework.web.client.ResponseErrorHandler.handleError(ResponseErrorHandler.java:63)
    org.springframework.web.client.RestTemplate.handleResponse(RestTemplate.java:766)
    org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:724)
    org.springframework.web.client.RestTemplate.execute(RestTemplate.java:680)
    org.springframework.web.client.RestTemplate.getForObject(RestTemplate.java:332)
    com.luv2code.springdemo.service.CustomerServiceRestClientImpl.getCustomer(CustomerServiceRestClientImpl.java:59)
    com.luv2code.springdemo.controller.CustomerController.showFormForUpdate(CustomerController.java:62)
    sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    java.lang.reflect.Method.invoke(Method.java:498)
    org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:209)
    org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:136)
    org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:102)
    org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:877)
    org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:783)
    org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)
    org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:991)
    org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:925)
    org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:974)
    org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:866)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:634)
    org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:851)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)

这是我的DemoAppConfig类：

package com.luv2code.springdemo.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.PropertySource;
import org.springframework.web.client.RestTemplate;
import org.springframework.web.servlet.ViewResolver;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
import org.springframework.web.servlet.view.InternalResourceViewResolver;

@Configuration
@EnableWebMvc
@ComponentScan("com.luv2code.springdemo")
@PropertySource({ "classpath:application.properties" })
public class DemoAppConfig implements WebMvcConfigurer {

    // define a bean for ViewResolver

    @Bean
    public ViewResolver viewResolver() {

        InternalResourceViewResolver viewResolver = new InternalResourceViewResolver();

        viewResolver.setPrefix("/WEB-INF/view/");
        viewResolver.setSuffix(".jsp");

        return viewResolver;
    }

    // define bean for RestTemplate ... this is used to make client REST calls

    @Bean
    public RestTemplate restTemplate() {
        return new RestTemplate();
    }

    // add resource handler for loading css, images, etc

    @Override
    public void addResourceHandlers(ResourceHandlerRegistry registry) {
        registry
          .addResourceHandler("/resources/**")
          .addResourceLocations("/resources/"); 
    }   
}

这是我的文件application.properties：

#
# The URL for the CRM REST API
# - update to match your local environment
#
crm.rest.url=http://localhost:8080/spring-crm-rest/api/customers

这是我的服务类别：

package com.luv2code.springdemo.service;

import java.util.List;
import java.util.logging.Logger;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.core.ParameterizedTypeReference;
import org.springframework.http.HttpMethod;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Service;
import org.springframework.web.client.RestTemplate;

import com.luv2code.springdemo.model.Customer;

@Service
public class CustomerServiceRestClientImpl implements CustomerService {

    private RestTemplate restTemplate;

    private String crmRestUrl;

    private Logger logger = Logger.getLogger(getClass().getName());

    @Autowired
    public CustomerServiceRestClientImpl(RestTemplate theRestTemplate, 
                                        @Value("${crm.rest.url}") String theUrl) {
        restTemplate = theRestTemplate;
        crmRestUrl = theUrl;

        logger.info("Loaded property:  crm.rest.url=" + crmRestUrl);
    }

    @Override
    public List<Customer> getCustomers() {

        logger.info("in getCustomers(): Calling REST API " + crmRestUrl);

        // make REST call
        ResponseEntity<List<Customer>> responseEntity = 
                                            restTemplate.exchange(crmRestUrl, HttpMethod.GET, null, 
                                                                  new ParameterizedTypeReference<List<Customer>>() {});

        // get the list of customers from response
        List<Customer> customers = responseEntity.getBody();

        logger.info("in getCustomers(): customers" + customers);

        return customers;
    }

    @Override
    public Customer getCustomer(int theId) {

        logger.info("in getCustomer(): Calling REST API " + crmRestUrl);

        // make REST call
        Customer theCustomer = 
                restTemplate.getForObject(crmRestUrl + "/" + theId, 
                                          Customer.class);

        logger.info("in saveCustomer(): theCustomer=" + theCustomer);

        return theCustomer;
    }

    @Override
    public void saveCustomer(Customer theCustomer) {

        logger.info("in saveCustomer(): Calling REST API " + crmRestUrl);

        int employeeId = theCustomer.getId();

        // make REST call
        if (employeeId == 0) {
            // add employee
            restTemplate.postForEntity(crmRestUrl, theCustomer, String.class);          

        } else {
            // update employee
            restTemplate.put(crmRestUrl, theCustomer);
        }

        logger.info("in saveCustomer(): success");  
    }

    @Override
    public void deleteCustomer(int theId) {

        logger.info("in deleteCustomer(): Calling REST API " + crmRestUrl);

        // make REST call
        restTemplate.delete(crmRestUrl + "/" + theId);

        logger.info("in deleteCustomer(): deleted customer theId=" + theId);
    }

}

这是我在休息服务中的控制器：

package com.luv2code.springdemo.rest;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.DeleteMapping;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.PutMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import com.luv2code.springdemo.entity.Customer;
import com.luv2code.springdemo.service.CustomerService;

@RestController
@RequestMapping("/api")
public class CustomerRestController {


    // importer la depende du service

    @Autowired
    private CustomerService customerService;

    // ajout de la methode qui permet de récupérer les customers (clients)

    @GetMapping("/customers")
    public List<Customer> getCustomers(){


        return customerService.getCustomers();
    }


    // récupérer un seul customer avec un id donné en parametre

    @GetMapping("/customer/{customerId}")
    public Customer getCustomer(@PathVariable int customerId) {

        Customer theCustomer = customerService.getCustomer(customerId);

        if(theCustomer == null) {
            throw new CustomerNotFoundException("Le client avec l'id :"+ customerId + " n'est pas trouvé");
        }


        return theCustomer;
    }

    // ajouter la méthode d'ajout d'un nouveau customer

    @PostMapping("/customers")
    public Customer addCustomer(@RequestBody  Customer theCustomer) {

        theCustomer.setId(0);

        customerService.saveCustomer(theCustomer);

        return theCustomer;
    }


    // modification d'un customer existent :

    @PutMapping("/customers")
    public Customer updateCustomer(@RequestBody  Customer theCustomer) {



        customerService.saveCustomer(theCustomer);

        return theCustomer;
    }

    // delete un customer en fonction de l'id donné :

    @DeleteMapping("/customers/{customerId}")
    public String DeleteCustomer(@PathVariable int customerId) {

        Customer theCustomer = customerService.getCustomer(customerId);

        if(theCustomer == null) {
            throw new CustomerNotFoundException("le customer avec l'id donnée n'a pas été trouvé");
        }

        customerService.deleteCustomer(customerId);;

        return "le client avec l'id" + customerId + " a été supprimé";
    }

}

这是想要测试我的应用程序的驱动器链接：

https://drive.google.com/open?id=1Hko4iSjpR1qV7s1kfWVdLbotWzn1Cvx1

有人可以帮我吗？

Answer 1

在错误堆栈跟踪中，您可以看到代码的最后一行是

com.luv2code.springdemo.service.CustomerServiceRestClientImpl.getCustomer(CustomerServiceRestClientImpl.java:59)

在查看该方法时，我找到了这个声明的函数体。

// make REST call
Customer theCustomer = restTemplate.getForObject(crmRestUrl + "/" + theId, 
                                      Customer.class);

400是状态码，因此restTemplate可以正确调用它，但是4xx表示响应服务器说请求来自客户端的格式错误或错误（因此，它不是响应服务器的错误）。因此，我开始查看请求。您正在使用两个参数，theId是输入参数，然后是URL crmRestUrl。

查询这些参数的声明位置时，会发现以下内容。

private String crmRestUrl;

我相信这是null，这可能是您的问题。

如何解决错误：HttpClientErrorException：400 null？

1 个答案: