Using a map to set parameters for rest using a RestTemplate
I am currently using a piece of code to set the parameters and I am making a REST url call using restTemplate, it works fine:
MultiValueMap<String, String> map = new LinkedMultiValueMap<String, String>();
map.add("grant_type", grantType);
map.add("client_id", clientId);
map.add("client_secret", clientSecret);
HttpEntity<?> entity = new HttpEntity<Object>(map);
restTemplate.exchange("myurl", HttpMethod.POST, entity, Void.class);
But if I use LinkedMultiValueMap
because I was looking on the internet;)
And if I replace it with HashMap
, it works too, so can anyone tell me the advantage of using it LinkedMultiValueMap
?
Code with HashMap
:
Map<String, String> map = new HashMap<String, String>();
map.put("grant_type", grantType);
map.put("client_id", clientId);
map.put("client_secret", clientSecret);
HttpEntity<?> entity = new HttpEntity<Object>(map);
restTemplate.exchange("myurl", HttpMethod.POST, entity, Void.class);
I see that we can keep the order of the parameters in LinkedMultiValueMap
, but that doesn't matter in my project ... And so if the order does matter, I can still useLinkedHashMap
EDIT:
Looks like I need MultiValueMap, if I use APPLICATION_FORM_URLENCODED and HashMap this code throws an exception:
Map<String, String> map = new HashMap<String, String>();
map.add("grant_type", grantType);
map.add("client_id", clientId);
map.add("client_secret", clientSecret);
HttpHeaders headers = new HttpHeaders();
headers.setAccept(Arrays.asList(MediaType.APPLICATION_JSON));
headers.setContentType(MediaType.APPLICATION_FORM_URLENCODED);
HttpEntity<?> entity = new HttpEntity<Object>(map, headers);
restTemplate.exchange("myurl", HttpMethod.POST, entity, Void.class);
An exception:
org.springframework.web.client.RestClientException: Could not write request: no suitable HttpMessageConverter found for request type [java.util.HashMap] and content type [application/x-www-form-urlencoded]
at org.springframework.web.client.RestTemplate$HttpEntityRequestCallback.doWithRequest(RestTemplate.java:784)
at org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:567)
at org.springframework.web.client.RestTemplate.execute(RestTemplate.java:530)
at org.springframework.web.client.RestTemplate.exchange(RestTemplate.java:448)
at uk.co.wowcher.marketplace.commons.rest.RestTemplateUtils.getForEntity(RestTemplateUtils.java:54)
at uk.co.wowcher.marketplace.submission.service.ParameterService.getProductParameterVOs(ParameterService.java:38)
at uk.co.wowcher.marketplace.submission.service.ParameterService$$FastClassBySpringCGLIB$$3f87231d.invoke(<generated>)
at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204)
at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:717)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157)
at org.springframework.aop.aspectj.MethodInvocationProceedingJoinPoint.proceed(MethodInvocationProceedingJoinPoint.java:85)
at uk.co.wowcher.marketplace.submission.logging.MarketplaceLogger.logMethodCalls(MarketplaceLogger.java:27)
at sun.reflect.GeneratedMethodAccessor72.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:483)
at org.springframework.aop.aspectj.AbstractAspectJAdvice.invokeAdviceMethodWithGivenArgs(AbstractAspectJAdvice.java:621)
at org.springframework.aop.aspectj.AbstractAspectJAdvice.invokeAdviceMethod(AbstractAspectJAdvice.java:610)
at org.springframework.aop.aspectj.AspectJAroundAdvice.invoke(AspectJAroundAdvice.java:68)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:653)
at uk.co.xxx.marketplace.submission.service.ParameterService$$EnhancerBySpringCGLIB$$a52b80b.getProductParameterVOs(<generated>)
at uk.co.xxx.marketplace.submission.service.SubmissionService.getAgreementData(SubmissionService.java:449)
at uk.co.xxx.marketplace.submission.service.SubmissionService$$FastClassBySpringCGLIB$$92bbe798.invoke(<generated>)
at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204)
at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:717)
So it looks like setting some parameters with a HashMap is not a good idea ... So I removed the accepted answer, expecting more explanation on the matter ... And I have a suitable converter ( converters.add(new FormHttpMessageConverter());
), I mean if I am using MultiValueMap, I have no exception, so the HashMap problem is the problem!
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The only real advantage of using it LinkedMultiValueMap
over other implementations Map
is that it can store multiple values.
This is useful if you need to pass multiple values for the same key (for example, if you need to pass in the values of a formset checkbox).
See JavaDoc here .
In your case, since you only have one value for each key, you should be able to use it safely HashMap
.
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MultiValueMap
is used to store more than one value for one KEY ( Map(key:ArrayOfValues[])
), and LinkedMultiValueMap
does the same, but preserving the insertion order. In your case it HashMap
is enough, because LinkedMultiValueMap
the performance will be slower than HashMap
and HashMap
not required for your scenario.
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This is an old question, but I got into this problem today. You can use https://docs.spring.io/spring-social/docs/current/apidocs/org/springframework/social/support/FormMapHttpMessageConverter.html
Editorial staff:
FormMapHttpMessageConverter.java is part of the spring social project.
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