如何在运行时指定asyncRabbitTemplate.convertSendAndReceiveAsType()的返回类型？
如何在运行时指定asyncRabbitTemplate.convertSendAndReceiveAsType()的返回类型？
提问于 2021-09-23 11:26:28
我一直在努力使用下面的代码。并且不确定如何反序列化它，甚至在运行时传递正确的类型。
代码是：
@Override
public <T, R> R sendAsync(T payload, String routingKey, String exchangeName) {
ListenableFuture<R> listenableFuture =
asyncRabbitTemplate.convertSendAndReceiveAsType(
exchangeName,
routingKey,
payload,
new ParameterizedTypeReference<>() {
}
);
try {
return listenableFuture.get();
} catch (InterruptedException | ExecutionException e) {
LOGGER.error(" [x] Cannot get response.", e);
return null;
}
}假设我只是像下面这样调用该方法
SaveImageResponse response = backendClient.sendAsync( new SaveImageRequest(createQRRequest.getOwner(), qr), RabbitConstants.CREATE_QR_IMAGE_KEY, RabbitConstants.CDN_EXCHANGE);而pojo如下所示：
public class SaveImageResponse {
private String id;
private String message;
public SaveImageResponse() {
}
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getMessage() {
return message;
}
public void setMessage(String message) {
this.message = message;
}
@Override
public String toString() {
return "SaveImageResponse{" +
"id='" + id + '\'' +
", message='" + message + '\'' +
'}';
}
}当前代码抛出以下错误：
Caused by: java.lang.ClassCastException: class java.util.LinkedHashMap cannot be cast to class dev.yafatek.qr.api.responses.SaveImageResponse (java.util.LinkedHashMap is in module java.base of loader 'bootstrap'; dev.yafatek.qr.api.responses.SaveImageResponse is in unnamed module of loader 'app')提前感谢
解决方案：
因此，我最终使用了以下内容：
@Override
public <T, R> R sendAsync(T payload, String routingKey, String exchangeName, Class<R> clazz) {
ListenableFuture<R> listenableFuture =
asyncRabbitTemplate.convertSendAndReceiveAsType(
exchangeName,
routingKey,
payload,
new ParameterizedTypeReference<>() {
}
);
try {
return objectMapper.convertValue(listenableFuture.get(), clazz);
} catch (InterruptedException | ExecutionException e) {
LOGGER.error(" [x] Cannot get response.", e);
return null;
}
}通过使用对象映射器并在使用
Class<POJO> clazz要使用上面的代码：
WebsiteInfoResponse websiteInfoResponse = backendClient.sendAsync(new GetWebsiteInfoReq(createBusinessDetailsRequest.getWebsiteUrlId()), RabbitConstants.GET_WEBSITE_INFO_KEY, RabbitConstants.QR_EXCHANGE, WebsiteInfoResponse.class);回答 1
Stack Overflow用户
发布于 2021-09-23 16:38:33
你不能这么做。
使用ParameterizedTypeReference<Foo>的全部原因是告诉转换器您需要一个Foo；这必须在方法的编译时解决；您不能调用sendAsync()来接收不同的类型。
不提供泛型类型意味着它将转换为Object (通常是一个映射)。
即使是new ParameterizedTypeReference<R>() { }也无法工作，因为( sendAsync()方法的)泛型类型在编译时不能解析R。
您必须自己进行转换。
@SpringBootApplication
public class So69299112Application {
public static void main(String[] args) {
SpringApplication.run(So69299112Application.class, args);
}
@Bean
MessageConverter converter() {
return new Jackson2JsonMessageConverter();
}
ObjectMapper mapper = new ObjectMapper();
@Bean
AsyncRabbitTemplate template(RabbitTemplate template) {
template.setMessageConverter(new SimpleMessageConverter());
return new AsyncRabbitTemplate(template);
}
@Bean
ApplicationRunner runner(Service service) {
return args -> {
byte[] response = service.sendAsync("bar", "foo", "");
Foo foo = this.mapper.readerFor(Foo.class).readValue(response);
System.out.println(foo);
};
}
@RabbitListener(queues = "foo")
public Foo listen(String in) {
return new Foo(in);
}
public static class Foo {
String foo;
public Foo() {
}
public Foo(String foo) {
this.foo = foo;
}
public String getFoo() {
return this.foo;
}
public void setFoo(String foo) {
this.foo = foo;
}
@Override
public String toString() {
return "Foo [foo=" + this.foo + "]";
}
}
}
@Component
class Service {
private static final Logger LOGGER = LoggerFactory.getLogger(Service.class);
AsyncRabbitTemplate asyncRabbitTemplate;
public Service(AsyncRabbitTemplate asyncRabbitTemplate) {
this.asyncRabbitTemplate = asyncRabbitTemplate;
}
public byte[] sendAsync(Object payload, String routingKey, String exchangeName) {
ListenableFuture<byte[]> listenableFuture = asyncRabbitTemplate.convertSendAndReceive(
exchangeName,
routingKey,
payload);
try {
return listenableFuture.get();
}
catch (InterruptedException | ExecutionException e) {
LOGGER.error(" [x] Cannot get response.", e);
return null;
}
}
}页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/69299112
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