Build The Web Layer

Implementing the controller layer in Spring

Overview

The web/controller layer handles all the incoming REST requests to a service.

Setup Request Handler In The Controller Layer

Follow the steps below to set up the request handler in the controller layer.

1. Make a call to the method in the Service Layer and get the response back from it.

2. Build the responseInfo.

3. Build the final response to be returned to the client.

Sample request handler in controller layer

The controller class reflects the below content -

package digit.web.controllers;


import digit.service.BirthRegistrationService;
import digit.util.ResponseInfoFactory;
import digit.web.models.*;
import com.fasterxml.jackson.databind.ObjectMapper;
import io.swagger.annotations.ApiParam;
import io.swagger.v3.oas.annotations.Parameter;
import io.swagger.v3.oas.annotations.enums.ParameterIn;
import io.swagger.v3.oas.annotations.media.Schema;
import org.egov.common.contract.response.ResponseInfo;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestMapping;
import java.io.IOException;
import java.util.Collections;
import java.util.List;

import jakarta.validation.Valid;
import jakarta.servlet.http.HttpServletRequest;


@jakarta.annotation.Generated(value = "org.egov.codegen.SpringBootCodegen", date = "2024-03-07T11:10:12.732364039+05:30[Asia/Kolkata]")
@Controller
    @RequestMapping("")
    public class BirthApiController{

    private final ObjectMapper objectMapper;

    private final HttpServletRequest request;

    private BirthRegistrationService birthRegistrationService;

    @Autowired
    private ResponseInfoFactory responseInfoFactory;

    @Autowired
    public BirthApiController(ObjectMapper objectMapper, HttpServletRequest request, BirthRegistrationService birthRegistrationService) {
        this.objectMapper = objectMapper;
        this.request = request;
        this.birthRegistrationService = birthRegistrationService;
    }

    @RequestMapping(value="/registration/v1/_create", method = RequestMethod.POST)
    public ResponseEntity<BirthRegistrationResponse> v1RegistrationCreatePost(@ApiParam(value = "Details for the new Birth Registration Application(s) + RequestInfo meta data." ,required=true )  @Valid @RequestBody BirthRegistrationRequest birthRegistrationRequest) {
        List<BirthRegistrationApplication> applications = birthRegistrationService.registerBtRequest(birthRegistrationRequest);
        ResponseInfo responseInfo = responseInfoFactory.createResponseInfoFromRequestInfo(birthRegistrationRequest.getRequestInfo(), true);
        BirthRegistrationResponse response = BirthRegistrationResponse.builder().birthRegistrationApplications(applications).responseInfo(responseInfo).build();
        return new ResponseEntity<>(response, HttpStatus.OK);
    }

    @RequestMapping(value="/v1/registration/_search", method = RequestMethod.POST)
    public ResponseEntity<BirthRegistrationResponse> v1RegistrationSearchPost(@ApiParam(value = "Details for the new Birth Registration Application(s) + RequestInfo meta data." ,required=true )  @Valid @RequestBody BirthApplicationSearchRequest birthApplicationSearchRequest) {
        List<BirthRegistrationApplication> applications = birthRegistrationService.searchBtApplications(birthApplicationSearchRequest.getRequestInfo(), birthApplicationSearchRequest.getBirthApplicationSearchCriteria());
        ResponseInfo responseInfo = responseInfoFactory.createResponseInfoFromRequestInfo(birthApplicationSearchRequest.getRequestInfo(), true);
        BirthRegistrationResponse response = BirthRegistrationResponse.builder().birthRegistrationApplications(applications).responseInfo(responseInfo).build();
        return new ResponseEntity<>(response,HttpStatus.OK);
    }

    @RequestMapping(value="/registration/v1/_update", method = RequestMethod.POST)
    public ResponseEntity<BirthRegistrationResponse> v1RegistrationUpdatePost(@ApiParam(value = "Details for the new (s) + RequestInfo meta data." ,required=true )  @Valid @RequestBody BirthRegistrationRequest birthRegistrationRequest) {
        BirthRegistrationApplication application = birthRegistrationService.updateBtApplication(birthRegistrationRequest);

        ResponseInfo responseInfo = responseInfoFactory.createResponseInfoFromRequestInfo(birthRegistrationRequest.getRequestInfo(), true);
        BirthRegistrationResponse response = BirthRegistrationResponse.builder().birthRegistrationApplications(Collections.singletonList(application)).responseInfo(responseInfo).build();
        return new ResponseEntity<>(response, HttpStatus.OK);
    }


        }

NOTE: At this point, your IDE must be showing a lot of errors but do not worry we will add all dependent layers as we progress through this guide and the errors will go away.

The web layer is now setup.