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This article mainly introduces the relevant knowledge of how to solve the problem of passing GET parameters of Feign calls, the content is detailed and easy to understand, the operation is simple and fast, and has a certain reference value. I believe you will gain something after reading this article on how to solve the problem of passing GET parameters of Feign calls. Let's take a look.

Demand

When the consumer service accesses the service provider's interface through GET, it needs to pass multiple parameters and split them into multiple parameters, which is not suitable for this scenario. It needs to be modified to call the service side's interface in an appropriate way.

Thinking

When splitting into multiple parameters, if the parameters of the GET request are more than 3 or more, it is not applicable to request the service in this way, because the parameters are too bloated and the readability is poor.

If it is transformed into the POST request method, although it solves the problem of too many parameters, it also brings other overhead. The parameters are put in the body and then requested to the interface provided by the server, and the interface of the server is also transformed into the POST mode, which changes the original intention of calling in the GET way, and is not very friendly.

When the consumer invokes the Feign interface, the parameters can be encapsulated into body. When assembling the Feign interface request, the parameters in body are taken out, converted to the parameters requested by GET, the parameters of body are requested, and then the request is initiated, which implements the GET mode to access the interface provided by the server.

The following are the specific implementations of these three call methods. You can use them according to your own business scenarios and choose different methods to request calls:

Request ① in GET mode

Request DTO object:

Package com.springcloud.pojo; import java.util.Date; public class Requets01DTO {private Date startTime; private Date endTime; private String message; @ Override public String toString () {return "Requets01DTO {" + "startTime=" + startTime + ", endTime=" + endTime + ", message='" + message +'\'+'}' } public Date getStartTime () {return startTime;} public void setStartTime (Date startTime) {this.startTime = startTime;} public Date getEndTime () {return endTime;} public void setEndTime (Date endTime) {this.endTime = endTime;} public String getMessage () {return message;} public void setMessage (String message) {this.message = message }}

Consumer's request:

Autowired GetClient01 getClient01; @ GetMapping ("/ request/get/01") public String requestGetOne (Requets01DTO requets01DTO) {return getClient01.queryDataByGetRequest (requets01DTO.getStartTime (), requets01DTO.getEndTime (), requets01DTO.getMessage ());}

Feign interface:

Package com.springcloud.service; import org.springframework.cloud.openfeign.FeignClient;import org.springframework.web.bind.annotation.GetMapping;import org.springframework.web.bind.annotation.RequestParam; import java.util.Date @ FeignClient (value = "provider-8762", contextId = "GetClient01") public interface GetClient01 {/ * GET request ① * * @ param startTime * @ param endTime * @ return * / @ GetMapping ("/ get/01") String queryDataByGetRequest (@ RequestParam ("startTime") Date startTime, @ RequestParam ("endTime") Date endTime @ RequestParam ("message") String message) }

Service provider:

@ RestControllerpublic class RequestProviderController {@ GetMapping ("/ get/01") public String queryDataByGetRequest (@ RequestParam ("startTime") Date startTime, @ RequestParam ("endTime") Date endTime, @ RequestParam ("message") String message) {Requets01DTO requets01DTO = new Requets01DTO (); requets01DTO.setStartTime (startTime); requets01DTO.setEndTime (endTime); requets01DTO.setMessage (message) Return requets01DTO.toString ();}}

Screenshot of the request result:

Request ② in GET mode

The request for Feign call is changed to POST mode

Consumer's request:

@ Autowired GetClient02 getClient02; @ GetMapping ("/ request/get/02") public String requestGetTwo (Requets01DTO requets01DTO) {return getClient02.queryDataByGetRequest (requets01DTO);}

Feign interface:

Package com.springcloud.service; import com.springcloud.pojo.Requets01DTO;import org.springframework.cloud.openfeign.FeignClient;import org.springframework.web.bind.annotation.PostMapping @ FeignClient (value = "provider-8762", contextId = "GetClient02") public interface GetClient02 {/ * GET request ② (the request called by Feign is changed to POST) * * @ param requets01DTO * @ return * / @ PostMapping ("/ post/02") String queryDataByGetRequest (Requets01DTO requets01DTO);}

Service provider:

@ PostMapping ("/ post/02") public String queryDataByGetRequest (@ RequestBody Requets01DTO requets01DTO) {return requets01DTO.toString ();}

Screenshot of the request result:

Request ③ in GET mode

When assembling the Feign API request, take out the parameters in body and convert them to the parameters requested in GET mode.

Add the configuration class for the Feign request:

Package com.springcloud.config; import com.alibaba.fastjson.JSON;import feign.Request;import feign.RequestInterceptor;import feign.RequestTemplate;import org.springframework.context.annotation.Configuration;import org.springframework.http.HttpMethod;import org.springframework.web.context.request.RequestContextHolder;import org.springframework.web.context.request.ServletRequestAttributes; import javax.servlet.http.HttpServletRequest;import java.lang.reflect.Field;import java.util.* @ Configurationpublic class FeignConfiguration implements RequestInterceptor {@ Override public void apply (RequestTemplate requestTemplate) {ServletRequestAttributes attributes = (ServletRequestAttributes) RequestContextHolder.getRequestAttributes (); HttpServletRequest request = attributes.getRequest (); / / convert body data in get into query data if (requestTemplate.method (). Equals (HttpMethod.GET.name ()) & & Objects.nonNull (requestTemplate.body () {String json = requestTemplate.requestBody (). AsString () Map map = JSON.parseObject (json); Set set = map.keySet (); Iterator it = set.iterator (); while (it.hasNext ()) {String key = it.next (); Object values = map.get (key) If (Objects.nonNull (values)) {/ / write the parameters of body to queries requestTemplate.query (key, values.toString ());}} try {Class requestClass = requestTemplate.getClass (); Field field = requestClass.getDeclaredField ("body") Field.setAccessible (true); / / modify body to be empty. Field.set (requestTemplate, Request.Body.empty ());} catch (Exception ex) {System.out.println (ex.fillInStackTrace ());}} Enumeration headerNames = request.getHeaderNames (); if (headerNames! = null) {while (headerNames.hasMoreElements ()) {String name = headerNames.nextElement () String values = request.getHeader (name); / / Skip content-length if (name.equals ("content-length")) {continue;} requestTemplate.header (name, values) } else {System.out.println (String.format ("feign interceptor error header:%s", requestTemplate));}

Add maven dependencies for fastJson:

Com.alibaba fastjson 1.2.74

Consumer's request:

@ Autowired GetClient03 getClient03; @ GetMapping ("/ request/get/03") public String requestGetThree (Requets01DTO requets01DTO) {return getClient03.queryDataByGetRequest (requets01DTO);}

Feign interface:

Package com.springcloud.service; import com.springcloud.config.FeignConfiguration;import com.springcloud.pojo.Requets01DTO;import org.springframework.cloud.openfeign.FeignClient;import org.springframework.web.bind.annotation.GetMapping @ FeignClient (value = "provider-8762", contextId = "GetClient03", configuration = FeignConfiguration.class) public interface GetClient03 {/ * GET request ③ (when assembling the Feign API request, take out the parameters in body and convert them to the parameters requested in GET) * * @ param requets01DTO * @ return * / @ GetMapping ("/ get/03") String queryDataByGetRequest (Requets01DTO requets01DTO);}

Service provider:

@ GetMapping ("/ get/03") public String queryDataByGetRequest03 (Requets01DTO requets01DTO) {return requets01DTO.toString ();}

Screenshot of the request result:

The date of the GET parameter passed by the Feign call. To specify the jsonFormat annotation, when body converts the GET parameter, the date parameter will become a string, and the date format needs to be specified.

@ JsonFormat (pattern = "yyyy-MM-dd HH:mm:ss") @ DateTimeFormat (pattern = "yyyy-MM-dd HH:mm:ss") private Date startTime; @ JsonFormat (pattern = "yyyy-MM-dd HH:mm:ss") @ DateTimeFormat (pattern = "yyyy-MM-dd HH:mm:ss") private Date endTime

* * Screenshot of result: * *

This is the end of the article on "how to solve the problem of passing GET parameters in Feign calls". Thank you for reading! I believe you all have a certain understanding of "how to solve the problem of passing GET parameters in Feign calls". If you want to learn more, you are welcome to follow the industry information channel.

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