RestTemplate请求的服务实例返回List类型，用数组接收

使用RestTemplate请求的服务实例返回List类型，若使用List类型解析，会出现问题

例 有user类如下

public class User {
private Long id;
private String username;
private String name;
private Short age;
private BigDecimal balance;
public Long getId() {
return this.id;
}
public void setId(Long id) {
this.id = id;
}
public String getUsername() {
return this.username;
}
public void setUsername(String username) {
this.username = username;
}
public String getName() {
return this.name;
}
public void setName(String name) {
this.name = name;
}
public Short getAge() {
return this.age;
}
public void setAge(Short age) {
this.age = age;
}
public BigDecimal getBalance() {
return this.balance;
}
public void setBalance(BigDecimal balance) {
this.balance = balance;
}
}


服务提供端代码如下：

@GetMapping("list-all")
public List<User> listAll() {
ArrayList<User> list = Lists.newArrayList();
User user = new User(1L, "zhangsan");
User user2 = new User(2L, "zhangsan");
User user3 = new User(3L, "zhangsan");
list.add(user);
list.add(user2);
list.add(user3);
return list;
}

 

服务消费端代码如下：

@GetMapping("/test-list-all")
public List<User> listAll() {
List<User> userList = restTemplate.getForObject("http://microservice-provider-user/list-all", List.class);
for (User user : userList) {
System.out.println(user.getId());
}
return userList;
}

在页面请求：服务消费方URL/test-list-all，会出现如下报错：

java.lang.ClassCastException: java.util.LinkedHashMap cannot be cast to com.itmuch.cloud.entity.User
at com.itmuch.cloud.controller.MovieController.listAll(MovieController.java:45) ~[classes/:na]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_161]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_161]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_161]
at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_161]
at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:220) ~[spring-web-4.3.4.RELEASE.jar:4.3.4.RELEASE]
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:134) ~[spring-web-4.3.4.RELEASE.jar:4.3.4.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:116) ~[spring-webmvc-4.3.4.RELEASE.jar:4.3.4.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:827) ~[spring-webmvc-4.3.4.RELEASE.jar:4.3.4.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:738) ~[spring-webmvc-4.3.4.RELEASE.jar:4.3.4.RELEASE]
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85) ~[spring-webmvc-4.3.4.RELEASE.jar:4.3.4.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:963) ~[spring-webmvc-4.3.4.RELEASE.jar:4.3.4.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:897) ~[spring-webmvc-4.3.4.RELEASE.jar:4.3.4.RELEASE]
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970) ~[spring-webmvc-4.3.4.RELEASE.jar:4.3.4.RELEASE]
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:861) ~[spring-webmvc-4.3.4.RELEASE.jar:4.3.4.RELEASE]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:622) ~[tomcat-embed-core-8.5.6.jar:8.5.6]
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846) ~[spring-webmvc-4.3.4.RELEASE.jar:4.3.4.RELEASE]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:729) ~[tomcat-embed-core-8.5.6.jar:8.5.6]

把服务端代码改为数组接收，在将数组转化为List。

@GetMapping("/test2-list-all")
public List<User> listAll2() {
User[] users = restTemplate.getForObject("http://microservice-provider-user/list-all", User[].class);
List<User> userList = Arrays.asList(users);
for (User user : userList) {
System.out.println(user.getId());
}
return userList;
}

如上请求，可以正常获取服务返回的List类型数据。
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版权声明：本文为CSDN博主「horse_well」的原创文章，遵循 CC 4.0 BY-SA 版权协议，转载请附上原文出处链接及本声明。
原文链接：https://blog.csdn.net/horse_well/article/details/88879185