Angular 4 http服务调用无法调用spring rest服务方法

Question

我是Angular 4的初学者以及弹簧靴休息。

我做了一个简单的应用程序，其中Angular 4作为前端，Spring Rest作为API。我试图从Angular http请求中调用Spring Rest控制器方法（Post）。

以下是Angular 4代码。

import { Injectable } from '@angular/core';
import { Http, Headers, Response, RequestOptions } from '@angular/http';


@Injectable()
export class ServerService {

  constructor(private http: Http) { }

    headers = new Headers({"Content-Type": "application/json"});    

  storeServers(students: any[]) {


    const WEBSERVICE_ADDRESS_STUDENT: string = "http://localhost:8080/api/saveStudent"; 



    return this.http.post(WEBSERVICE_ADDRESS_STUDENT,JSON.stringify(students),{ headers: this.headers })
    .subscribe(
          (response) => console.log(response),
          (error) => console.log("error: ", + error)
        );

  }

}

/************* Following is the student Array *******************/

  student =  [
    {
      StudentID: 102,
      Name: 'abc',
      Surname: 'xyz',
      City: 'Space'
    },
    {
      StudentID: 103,
      Name: 'jack',
      Surname: 'th',
      City: 'Ocean'
    }
  ];

以下是我的Spring Rest API：

@RestController
@RequestMapping("api")
public class StudentDetailsController {

	private StudentRepository studentRepositor;
	
	@Autowired
	public StudentDetailsController(StudentRepository theStudentDetailDAO)
	{
		this.studentRepositor = theStudentDetailDAO;
	}
	
	  
	  @RequestMapping(value="/saveStudent", method = RequestMethod.POST,produces = "application/json")
	  public void saveStudent(StudentDetails[] objStudentDetails)
	  { 
		  List<StudentDetails> lstStudentDetais = null; 
		  lstStudentDetais = studentRepositor.findAll();	   
		  
		  studentRepositor.save(objStudentDetails[0]);
		  
	  }

	
}

当我从Angular App点击服务时，它会在我的Java应用程序中抛出以下错误：

java.lang.NoSuchMethodException: [Lcom.springboot.cruddemo.entity.StudentDetails;.<init>()
	at java.lang.Class.getConstructor0(Class.java:3082) ~[na:1.8.0_202]
	at java.lang.Class.getDeclaredConstructor(Class.java:2178) ~[na:1.8.0_202]
	at org.springframework.web.method.annotation.ModelAttributeMethodProcessor.createAttribute(ModelAttributeMethodProcessor.java:216) ~[spring-web-5.1.5.RELEASE.jar:5.1.5.RELEASE]
	at org.springframework.web.servlet.mvc.method.annotation.ServletModelAttributeMethodProcessor.createAttribute(ServletModelAttributeMethodProcessor.java:84) ~[spring-webmvc-5.1.5.RELEASE.jar:5.1.5.RELEASE]
	at org.springframework.web.method.annotation.ModelAttributeMethodProcessor.resolveArgument(ModelAttributeMethodProcessor.java:139) ~[spring-web-5.1.5.RELEASE.jar:5.1.5.RELEASE]
	at org.springframework.web.method.support.HandlerMethodArgumentResolverComposite.resolveArgument(HandlerMethodArgumentResolverComposite.java:126) ~[spring-web-5.1.5.RELEASE.jar:5.1.5.RELEASE]
	at org.springframework.web.method.support.InvocableHandlerMethod.getMethodArgumentValues(InvocableHandlerMethod.java:166) ~[spring-web-5.1.5.RELEASE.jar:5.1.5.RELEASE]
	at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:134) ~[spring-web-5.1.5.RELEASE.jar:5.1.5.RELEASE]
	at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:102) ~[spring-webmvc-5.1.5.RELEASE.jar:5.1.5.RELEASE]
	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:895) ~[spring-webmvc-5.1.5.RELEASE.jar:5.1.5.RELEASE]
	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:800) ~[spring-webmvc-5.1.5.RELEASE.jar:5.1.5.RELEASE]
	at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) ~[spring-webmvc-5.1.5.RELEASE.jar:5.1.5.RELEASE]
	at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1038) ~[spring-webmvc-5.1.5.RELEASE.jar:5.1.5.RELEASE]
	at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:942) ~[spring-webmvc-5.1.5.RELEASE.jar:5.1.5.RELEASE]
	at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1005) ~[spring-webmvc-5.1.5.RELEASE.jar:5.1.5.RELEASE]
	at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:908) ~[spring-webmvc-5.1.5.RELEASE.jar:5.1.5.RELEASE]
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:660) ~[tomcat-embed-core-9.0.16.jar:9.0.16]
	at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:882) ~[spring-webmvc-5.1.5.RELEASE.jar:5.1.5.RELEASE]
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:741) ~[tomcat-embed-core-9.0.16.jar:9.0.16]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) ~[tomcat-embed-core-9.0.16.jar:9.0.16]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.16.jar:9.0.16]
	at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) ~[tomcat-embed-websocket-9.0.16.jar:9.0.16]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.16.jar:9.0.16]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.16.jar:9.0.16]
	at com.luv2code.springboot.cruddemo.rest.CORSFilter.doFilter(CORSFilter.java:31) ~[classes/:na]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.16.jar:9.0.16]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.16.jar:9.0.16]
	at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99) ~[spring-web-5.1.5.RELEASE.jar:5.1.5.RELEASE]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.1.5.RELEASE.jar:5.1.5.RELEASE]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.16.jar:9.0.16]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.16.jar:9.0.16]
	at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:92) ~[spring-web-5.1.5.RELEASE.jar:5.1.5.RELEASE]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.1.5.RELEASE.jar:5.1.5.RELEASE]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.16.jar:9.0.16]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.16.jar:9.0.16]
	at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:93) ~[spring-web-5.1.5.RELEASE.jar:5.1.5.RELEASE]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.1.5.RELEASE.jar:5.1.5.RELEASE]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.16.jar:9.0.16]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.16.jar:9.0.16]
	at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:200) ~[spring-web-5.1.5.RELEASE.jar:5.1.5.RELEASE]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.1.5.RELEASE.jar:5.1.5.RELEASE]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.16.jar:9.0.16]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.16.jar:9.0.16]
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:200) ~[tomcat-embed-core-9.0.16.jar:9.0.16]
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) [tomcat-embed-core-9.0.16.jar:9.0.16]
	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:490) [tomcat-embed-core-9.0.16.jar:9.0.16]
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139) [tomcat-embed-core-9.0.16.jar:9.0.16]
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92) [tomcat-embed-core-9.0.16.jar:9.0.16]
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74) [tomcat-embed-core-9.0.16.jar:9.0.16]
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343) [tomcat-embed-core-9.0.16.jar:9.0.16]
	at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:408) [tomcat-embed-core-9.0.16.jar:9.0.16]
	at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66) [tomcat-embed-core-9.0.16.jar:9.0.16]
	at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:834) [tomcat-embed-core-9.0.16.jar:9.0.16]
	at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1415) [tomcat-embed-core-9.0.16.jar:9.0.16]
	at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) [tomcat-embed-core-9.0.16.jar:9.0.16]
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [na:1.8.0_202]
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [na:1.8.0_202]
	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-9.0.16.jar:9.0.16]
	at java.lang.Thread.run(Thread.java:748) [na:1.8.0_202]

以下是我的StudentDetails类，我在那里定义了所有必需的构造函数：

package com.luv2code.springboot.cruddemo.entity;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;

@Entity
@Table(name = "StudentDetails")
public class StudentDetails {
	
	@Id
	@GeneratedValue(strategy = GenerationType.IDENTITY) 
	@Column(name="StudentID")
	private Integer StudentID;
	
	@Column(name="Name")
	private String Name;
	
	@Column(name="Surname")
	private String Surname;
	
	@Column(name="City")
	private String City;
	
	public StudentDetails() {}

	public String getName() {
		return Name;
	}

	public void setName(String name) {
		Name = name;
	}

	public String getSurname() {
		return Surname;
	}

	public void setSurname(String surname) {
		Surname = surname;
	}

	public String getCity() {
		return City;
	}

	public void setCity(String city) {
		City = city;
	}

	public StudentDetails(String name, String surname, String city) {
		Name = name;
		Surname = surname;
		City = city;
	}
	
	

	@Override
	public String toString() {
		return "StudentDetails [Name=" + Name + ", Surname=" + Surname + ", City=" + City + "]";
	}
	
	

}

我不明白哪个构造函数错误是指:(

以下是chrome开发人员工具栏说的内容：

error: "Internal Server Error"
message: "No primary or default constructor found for class [Lcom.luv2code.springboot.cruddemo.entity.StudentDetails;"
path: "/api/saveStudent"
status: 500
timestamp: "2019-03-30T06:38:17.757+0000"
trace: "java.lang.IllegalStateException: No primary or default constructor found for class [Lcom.luv2code.springboot.cruddemo.entity.StudentDetails;
↵	at org.springframework.web.method.annotation.ModelAttributeMethodProcessor.createAttribute(ModelAttributeMethodProcessor.java:219)
↵	at org.springframework.web.servlet.mvc.method.annotation.ServletModelAttributeMethodProcessor.createAttribute(ServletModelAttributeMethodProcessor.java:84)
↵	at org.springframework.web.method.annotation.ModelAttributeMethodProcessor.resolveArgument(ModelAttributeMethodProcessor.java:139)
↵	at org.springframework.web.method.support.HandlerMethodArgumentResolverComposite.resolveArgument(HandlerMethodArgumentResolverComposite.java:126)
↵	at org.springframework.web.method.support.InvocableHandlerMethod.getMethodArgumentValues(InvocableHandlerMethod.java:166)
↵	at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:134)
↵	at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:102)
↵	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:895)
↵	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:800)
↵	at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)
↵	at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1038)
↵	at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:942)
↵	at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1005)
↵	at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:908)
↵	at javax.servlet.http.HttpServlet.service(HttpServlet.java:660)
↵	at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:882)
↵	at javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
↵	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
↵	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
↵	at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
↵	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
↵	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
↵	at com.luv2code.springboot.cruddemo.rest.CORSFilter.doFilter(CORSFilter.java:31)
↵	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
↵	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
↵	at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99)
↵	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
↵	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
↵	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
↵	at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:92)
↵	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
↵	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
↵	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
↵	at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:93)
↵	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
↵	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
↵	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
↵	at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:200)
↵	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
↵	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
↵	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
↵	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:200)
↵	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
↵	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:490)
↵	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139)
↵	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
↵	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74)
↵	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343)
↵	at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:408)
↵	at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
↵	at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:834)
↵	at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1415)
↵	at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
↵	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
↵	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
↵	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
↵	at java.lang.Thread.run(Thread.java:748)
↵Caused by: java.lang.NoSuchMethodException: [Lcom.luv2code.springboot.cruddemo.entity.StudentDetails;.<init>()
↵	at java.lang.Class.getConstructor0(Class.java:3082)
↵	at java.lang.Class.getDeclaredConstructor(Class.java:2178)
↵	at org.springframework.web.method.annotation.ModelAttributeMethodProcessor.createAttribute(ModelAttributeMethodProcessor.java:216)
↵	... 56 more
↵"

遵循chrome开发人员工具栏关于整个事情的说法：

error: "Internal Server Error"
message: "No primary or default constructor found for class [Lcom.luv2code.springboot.cruddemo.entity.StudentDetails;"
path: "/api/saveStudent"
status: 500
timestamp: "2019-03-30T06:38:17.757+0000"
trace: "java.lang.IllegalStateException: No primary or default constructor found for class [Lcom.luv2code.springboot.cruddemo.entity.StudentDetails;
↵	at org.springframework.web.method.annotation.ModelAttributeMethodProcessor.createAttribute(ModelAttributeMethodProcessor.java:219)
↵	at org.springframework.web.servlet.mvc.method.annotation.ServletModelAttributeMethodProcessor.createAttribute(ServletModelAttributeMethodProcessor.java:84)
↵	at org.springframework.web.method.annotation.ModelAttributeMethodProcessor.resolveArgument(ModelAttributeMethodProcessor.java:139)
↵	at org.springframework.web.method.support.HandlerMethodArgumentResolverComposite.resolveArgument(HandlerMethodArgumentResolverComposite.java:126)
↵	at org.springframework.web.method.support.InvocableHandlerMethod.getMethodArgumentValues(InvocableHandlerMethod.java:166)
↵	at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:134)
↵	at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:102)
↵	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:895)
↵	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:800)
↵	at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)
↵	at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1038)
↵	at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:942)
↵	at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1005)
↵	at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:908)
↵	at javax.servlet.http.HttpServlet.service(HttpServlet.java:660)
↵	at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:882)
↵	at javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
↵	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
↵	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
↵	at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
↵	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
↵	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
↵	at com.luv2code.springboot.cruddemo.rest.CORSFilter.doFilter(CORSFilter.java:31)
↵	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
↵	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
↵	at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99)
↵	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
↵	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
↵	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
↵	at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:92)
↵	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
↵	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
↵	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
↵	at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:93)
↵	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
↵	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
↵	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
↵	at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:200)
↵	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
↵	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
↵	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
↵	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:200)
↵	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
↵	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:490)
↵	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139)
↵	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
↵	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74)
↵	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343)
↵	at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:408)
↵	at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
↵	at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:834)
↵	at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1415)
↵	at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
↵	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
↵	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
↵	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
↵	at java.lang.Thread.run(Thread.java:748)
↵Caused by: java.lang.NoSuchMethodException: [Lcom.luv2code.springboot.cruddemo.entity.StudentDetails;.<init>()
↵	at java.lang.Class.getConstructor0(Class.java:3082)
↵	at java.lang.Class.getDeclaredConstructor(Class.java:2178)
↵	at org.springframework.web.method.annotation.ModelAttributeMethodProcessor.createAttribute(ModelAttributeMethodProcessor.java:216)
↵	... 56 more
↵"

以下是数组中的null元素：

Answer 1

我通过做一些小改动成功执行了上面的代码。

调节器

@RequestMapping(value = "/saveStudent", method = RequestMethod.POST, produces = "application/json")
    public void saveStudent(@RequestBody StudentDetails[] objStudentDetailsList) {
        System.out.println(objStudentDetailsList[0].getName());
    }

实体

@Entity
@Table(name = "StudentDetails")
public class StudentDetails {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long studentId;
    private String name;
    private String surName;
    private String city;
    public Long getStudentId() {
        return studentId;
    }
    public void setStudentId(Long studentId) {
        this.studentId = studentId;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getSurName() {
        return surName;
    }
    public void setSurName(String surName) {
        this.surName = surName;
    }
    public String getCity() {
        return city;
    }
    public void setCity(String city) {
        this.city = city;
    }