我想使用@RestController和@RequestMapping创建一个restfull api服务项目，但是当我使用appDao.findAll（）来获取所有应用程序时，除了嵌套之外，代码如下：
App.java
@Entity
@Table(name = "apps")
public class App {
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private long id;
@NotNull
private String name;
public App() { }
public App(String name, User user) {
this.name = name;
this.user = user;
}
public long getId() {
return id;
}
public void setId(long id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
@ManyToOne(fetch=FetchType.LAZY)
@JoinColumn(name = "user_id")
private User user;
public User getUser(){
return user;
}
public void setUser(User user) {
this.user = user;
}
@Override
public String toString(){
return "AppName: " + name;
}
}
User.java
@Entity
@Table(name = "users")
public class User {
// ------------------------
// PRIVATE FIELDS
// ------------------------
// An autogenerated id (unique for each user in the db)
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private long id;
// The user's email
@NotNull
private String email;
// The user's name
@NotNull
private String name;
@NotNull
private Integer age;
// ------------------------
// PUBLIC METHODS
// ------------------------
public User() { }
public User(long id) {
this.id = id;
}
public User(String name) {
this.name = name;
}
public User(String email, String name, Integer age) {
this.email = email;
this.name = name;
this.age = age;
}
// Getter and setter methods
public long getId() {
return id;
}
public void setId(long value) {
this.id = value;
}
public String getEmail() {
return email;
}
public void setEmail(String value) {
this.email = value;
}
public String getName() {
return name;
}
public void setName(String value) {
this.name = value;
}
public Integer getAge() {
return age;
}
public void setAge(Integer value) {
this.age = value;
}
@OneToOne(cascade = CascadeType.ALL)
@JoinColumn(name = "car_id")
private Car car;
public Car getCar() {
return car;
}
public void setCar(Car car) {
this.car = car;
}
@OneToMany(targetEntity=App.class, mappedBy="user", fetch=FetchType.EAGER, cascade=CascadeType.ALL)
private Set<App> apps;
public Set<App> getApps() {
return apps;
}
public void setApps(Set<App> apps) {
this.apps= apps;
}
public void addApps(Set<App> apps) {
this.apps.addAll(apps);
}
@Override
public String toString() {
String result = String.format(
"User[id=%d, name='%s']%n",
id, name);
if (apps != null) {
for(App app : apps) {
result += String.format(
"app[id=%d, name='%s']%n",
app.getId(), app.getName());
}
}
return result;
}
} // class User
AppDao.java
@Transactional
public interface AppDao extends JpaRepository<App, Long> {
/**
* This method will find an User instance in the database by its email.
* Note that this method is not implemented and its working code will be
* automagically generated from its signature by Spring Data JPA.
*/
}
AppController.java
@RestController
@RequestMapping("/apps")
public class AppController {
@Autowired
private AppDao appDao;
@RequestMapping("/")
public List<App> getAll() {
List<App> apps = appDao.findAll();
return apps;
}
}
主Java：
@SpringBootApplication
@EnableAutoConfiguration
public class MysqlDemoApplication implements CommandLineRunner {
public static void main(String[] args) {
SpringApplication.run(MysqlDemoApplication.class, args);
}
@Override
@Transactional
public void run(String... strings) throws Exception {
}
}
然后访问：http://localhost:8080/apps/获得嵌套异常：为什么？
回溯：
com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:24) ~[jackson-databind-2.6.6.jar:2.6.6]
at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:693) ~[jackson-databind-2.6.6.jar:2.6.6]
at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:675) ~[jackson-databind-2.6.6.jar:2.6.6]
at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:157) ~[jackson-databind-2.6.6.jar:2.6.6]
at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:693) ~[jackson-databind-2.6.6.jar:2.6.6]
at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:675) ~[jackson-databind-2.6.6.jar:2.6.6]
at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:157) ~[jackson-databind-2.6.6.jar:2.6.6]
at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serializeContents(CollectionSerializer.java:149) ~[jackson-databind-2.6.6.jar:2.6.6]
at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:111) ~[jackson-databind-2.6.6.jar:2.6.6]
at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:24) ~[jackson-databind-2.6.6.jar:2.6.6]
at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:693) ~[jackson-databind-2.6.6.jar:2.6.6]
at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:675) ~[jackson-databind-2.6.6.jar:2.6.6]
at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:157) ~[jackson-databind-2.6.6.jar:2.6.6]
at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:693) ~[jackson-databind-2.6.6.jar:2.6.6]
at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:675) ~[jackson-databind-2.6.6.jar:2.6.6]
at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:157) ~[jackson-databind-2.6.6.jar:2.6.6]
at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serializeContents(CollectionSerializer.java:149) ~[jackson-databind-2.6.6.jar:2.6.6]
at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:111) ~[jackson-databind-2.6.6.jar:2.6.6]
at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:24) ~[jackson-databind-2.6.6.jar:2.6.6]
2016-06-28 11:01:18.675 ERROR 90592 --- [nio-8080-exec-1] o.a.c.c.C.[.[.[/].[dispatcherServlet] : Servlet.service() for servlet dispatcherServlet threw exception
java.lang.IllegalStateException: getOutputStream() has already been called for this response
at org.apache.catalina.connector.Response.getWriter(Response.java:564) ~[tomcat-embed-core-8.0.33.jar:8.0.33]
at org.apache.catalina.connector.ResponseFacade.getWriter(ResponseFacade.java:212) ~[tomcat-embed-core-8.0.33.jar:8.0.33]
at javax.servlet.ServletResponseWrapper.getWriter(ServletResponseWrapper.java:109) ~[tomcat-embed-core-8.0.33.jar:8.0.33]
at org.springframework.boot.autoconfigure.web.ErrorMvcAutoConfiguration$SpelView.render(ErrorMvcAutoConfiguration.java:195) ~[spring-boot-autoconfigure-1.3.5.RELEASE.jar:1.3.5.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1246) ~[spring-webmvc-4.2.6.RELEASE.jar:4.2.6.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.processDispatchResult(DispatcherServlet.java:1029) ~[spring-webmvc-4.2.6.RELEASE.jar:4.2.6.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:973) ~[spring-webmvc-4.2.6.RELEASE.jar:4.2.6.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:895) ~[spring-webmvc-4.2.6.RELEASE.jar:4.2.6.RELEASE]
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:967) ~[spring-webmvc-4.2.6.RELEASE.jar:4.2.6.RELEASE]
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:858) ~[spring-webmvc-4.2.6.RELEASE.jar:4.2.6.RELEASE]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:622) ~[tomcat-embed-core-8.0.33.jar:8.0.33]
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:843) ~[spring-webmvc-4.2.6.RELEASE.jar:4.2.6.RELEASE]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:729) ~[tomcat-embed-core-8.0.33.jar:8.0.33]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:292) ~[tomcat-embed-core-8.0.33.jar:8.0.33]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207) ~[tomcat-embed-core-8.0.33.jar:8.0.33]
at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99) ~[spring-web-4.2.6.RELEASE.jar:4.2.6.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-4.2.6.RELEASE.jar:4.2.6.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240) ~[tomcat-embed-core-8.0.33.jar:8.0.33]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207) ~[tomcat-embed-core-8.0.33.jar:8.0.33]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:101) ~[spring-web-4.2.6.RELEASE.jar:4.2.6.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240) ~[tomcat-embed-core-8.0.33.jar:8.0.33]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207) ~[tomcat-embed-core-8.0.33.jar:8.0.33]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:101) ~[spring-web-4.2.6.RELEASE.jar:4.2.6.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240) ~[tomcat-embed-core-8.0.33.jar:8.0.33]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207) ~[tomcat-embed-core-8.0.33.jar:8.0.33]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:101) ~[spring-web-4.2.6.RELEASE.jar:4.2.6.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240) ~[tomcat-embed-core-8.0.33.jar:8.0.33]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207) ~[tomcat-embed-core-8.0.33.jar:8.0.33]
at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:720) [tomcat-embed-core-8.0.33.jar:8.0.33]
at org.apache.catalina.core.ApplicationDispatcher.doInclude(ApplicationDispatcher.java:584) [tomcat-embed-core-8.0.33.jar:8.0.33]
at org.apache.catalina.core.ApplicationDispatcher.include(ApplicationDispatcher.java:523) [tomcat-embed-core-8.0.33.jar:8.0.33]
at org.apache.catalina.core.StandardHostValve.custom(StandardHostValve.java:439) [tomcat-embed-core-8.0.33.jar:8.0.33]
at org.apache.catalina.core.StandardHostValve.status(StandardHostValve.java:304) [tomcat-embed-core-8.0.33.jar:8.0.33]
at org.apache.catalina.core.StandardHostValve.throwable(StandardHostValve.java:399) [tomcat-embed-core-8.0.33.jar:8.0.33]
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:179) [tomcat-embed-core-8.0.33.jar:8.0.33]
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79) [tomcat-embed-core-8.0.33.jar:8.0.33]
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88) [tomcat-embed-core-8.0.33.jar:8.0.33]
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:522) [tomcat-embed-core-8.0.33.jar:8.0.33]
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1095) [tomcat-embed-core-8.0.33.jar:8.0.33]
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:672) [tomcat-embed-core-8.0.33.jar:8.0.33]
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1502) [tomcat-embed-core-8.0.33.jar:8.0.33]
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1458) [tomcat-embed-core-8.0.33.jar:8.0.33]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [na:1.8.0_65]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [na:1.8.0_65]
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-8.0.33.jar:8.0.33]
at java.lang.Thread.run(Thread.java:745) [na:1.8.0_65]
2016-06-28 11:01:18.678 ERROR 90592 --- [nio-8080-exec-1] o.a.c.c.C.[Tomcat].[localhost] : Exception Processing ErrorPage[errorCode=0, location=/error]
org.springframework.web.util.NestedServletException: Request processing failed; nested exception is java.lang.IllegalStateException: getOutputStream() has already been called for this response
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:979) ~[spring-webmvc-4.2.6.RELEASE.jar:4.2.6.RELEASE]
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:858) ~[spring-webmvc-4.2.6.RELEASE.jar:4.2.6.RELEASE]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:622) ~[tomcat-embed-core-8.0.33.jar:8.0.33]
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:843) ~[spring-webmvc-4.2.6.RELEASE.jar:4.2.6.RELEASE]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:729) ~[tomcat-embed-core-8.0.33.jar:8.0.33]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:292) ~[tomcat-embed-core-8.0.33.jar:8.0.33]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207) ~[tomcat-embed-core-8.0.33.jar:8.0.33]
at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99) ~[spring-web-4.2.6.RELEASE.jar:4.2.6.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-4.2.6.RELEASE.jar:4.2.6.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240) ~[tomcat-embed-core-8.0.33.jar:8.0.33]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207) ~[tomcat-embed-core-8.0.33.jar:8.0.33]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:101) ~[spring-web-4.2.6.RELEASE.jar:4.2.6.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240) ~[tomcat-embed-core-8.0.33.jar:8.0.33]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207) ~[tomcat-embed-core-8.0.33.jar:8.0.33]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:101) ~[spring-web-4.2.6.RELEASE.jar:4.2.6.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240) ~[tomcat-embed-core-8.0.33.jar:8.0.33]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207) ~[tomcat-embed-core-8.0.33.jar:8.0.33]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:101) ~[spring-web-4.2.6.RELEASE.jar:4.2.6.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240) ~[tomcat-embed-core-8.0.33.jar:8.0.33]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207) ~[tomcat-embed-core-8.0.33.jar:8.0.33]
at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:720) ~[tomcat-embed-core-8.0.33.jar:8.0.33]
at org.apache.catalina.core.ApplicationDispatcher.doInclude(ApplicationDispatcher.java:584) ~[tomcat-embed-core-8.0.33.jar:8.0.33]
at org.apache.catalina.core.ApplicationDispatcher.include(ApplicationDispatcher.java:523) ~[tomcat-embed-core-8.0.33.jar:8.0.33]
at org.apache.catalina.core.StandardHostValve.custom(StandardHostValve.java:439) [tomcat-embed-core-8.0.33.jar:8.0.33]
at org.apache.catalina.core.StandardHostValve.status(StandardHostValve.java:304) [tomcat-embed-core-8.0.33.jar:8.0.33]
at org.apache.catalina.core.StandardHostValve.throwable(StandardHostValve.java:399) [tomcat-embed-core-8.0.33.jar:8.0.33]
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:179) [tomcat-embed-core-8.0.33.jar:8.0.33]
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79) [tomcat-embed-core-8.0.33.jar:8.0.33]
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88) [tomcat-embed-core-8.0.33.jar:8.0.33]
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:522) [tomcat-embed-core-8.0.33.jar:8.0.33]
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1095) [tomcat-embed-core-8.0.33.jar:8.0.33]
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:672) [tomcat-embed-core-8.0.33.jar:8.0.33]
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1502) [tomcat-embed-core-8.0.33.jar:8.0.33]
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1458) [tomcat-embed-core-8.0.33.jar:8.0.33]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [na:1.8.0_65]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [na:1.8.0_65]
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-8.0.33.jar:8.0.33]
at java.lang.Thread.run(Thread.java:745) [na:1.8.0_65]
Caused by: java.lang.IllegalStateException: getOutputStream() has already been called for this response
at org.apache.catalina.connector.Response.getWriter(Response.java:564) ~[tomcat-embed-core-8.0.33.jar:8.0.33]
at org.apache.catalina.connector.ResponseFacade.getWriter(ResponseFacade.java:212) ~[tomcat-embed-core-8.0.33.jar:8.0.33]
at javax.servlet.ServletResponseWrapper.getWriter(ServletResponseWrapper.java:109) ~[tomcat-embed-core-8.0.33.jar:8.0.33]
at org.springframework.boot.autoconfigure.web.ErrorMvcAutoConfiguration$SpelView.render(ErrorMvcAutoConfiguration.java:195) ~[spring-boot-autoconfigure-1.3.5.RELEASE.jar:1.3.5.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1246) ~[spring-webmvc-4.2.6.RELEASE.jar:4.2.6.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.processDispatchResult(DispatcherServlet.java:1029) ~[spring-webmvc-4.2.6.RELEASE.jar:4.2.6.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:973) ~[spring-webmvc-4.2.6.RELEASE.jar:4.2.6.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:895) ~[spring-webmvc-4.2.6.RELEASE.jar:4.2.6.RELEASE]
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:967) ~[spring-webmvc-4.2.6.RELEASE.jar:4.2.6.RELEASE]
... 37 common frames omitted
答案 0 :(得分：0)
首先，您是否直接从Controller类调用DAO代码？这被认为是一种不好的做法 - 你应该在它们之间有服务类。
其次，您提供的堆栈跟踪是关于错误，而应用程序尝试在路径/错误下呈现错误屏幕，在此之前是否有任何堆栈跟踪？
根据您的问题 - 尝试为您的RequestMapping方法指定http方法，即：
@RequestMapping(path = "/", method = RequestMethod.GET)
如果这不起作用，Spring配置中必定会出现一些错误，您是否正确指定要扫描组件的包？在Spring Boot中，当您使用@SpringBootApplication时，所有要扫描的包都必须在此类注释的下面。
<强> 更新
不要通过REST webservice返回具有循环依赖关系的实体 - 创建新的DTO类，映射从数据库获取的实体并将其返回到webservice中。
此处有更多信息：http://www.baeldung.com/entity-to-and-from-dto-for-a-java-spring-application
当然如果你想要你可以使用另一个地图库，我个人最喜欢的是Orika（http://orika-mapper.github.io/orika-docs/intro.html）
答案 1 :(得分：0)
您似乎使用了错误的接受标头。如果您尝试从Web浏览器请求服务，此请求将具有带 application / xhtml + xml 值的标准标头值，这会导致问题
您需要使用json具有正确的标头值，例如 application / json 。只需使用其他工具来处理邮递员等请求