com.nestorledon.employeedirectory.employees.EmployeeController.java Source code

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Here is the source code for com.nestorledon.employeedirectory.employees.EmployeeController.java

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/*
 * Copyright 2014 Nestor E. Ledon (nestorledon@gmail.com)
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.nestorledon.employeedirectory.employees;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

import org.springframework.hateoas.Link;
import org.springframework.http.converter.HttpMessageConverter;
import org.springframework.http.converter.json.MappingJackson2HttpMessageConverter;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.RequestMapping;

import com.nestorledon.employeedirectory.ControllerBase;
import com.nestorledon.employeedirectory.rest.Resource;

/**
 * http://localhost:8079/provider-client/employees
 * @author Nestor E. Ledon (nestorledon@gmail.com)
 *
 */
@Controller
public class EmployeeController extends ControllerBase {

    private List<EmployeeDTO> employees = new ArrayList<EmployeeDTO>();

    @RequestMapping("/employees")
    public String getAllEmployees() {

        String result = null;
        try {
            Resource<EmployeeDTO> resource = restTemplate.getForObject(RESOURCE_URI, Resource.class);

            // Get objects with relation "employee"
            for (Link l : resource.getLinks()) {
                if (l.getRel().equals(REL_EMPLOYEE)) {
                    EmployeeDTO employee = (EmployeeDTO) linkToObject(l);

                    if (employee != null) {
                        employees.add(employee);
                    }
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
            result = "error";
            return result;
        }
        return result;
    }

    /**
     * Converts Link to object <T>.
     * TODO: Make generic.
     * TODO: Move to ControllerBase.
     * @param link - A Spring HATEOAS Link.
     * @return object <T>
     */
    public EmployeeDTO linkToObject(Link link) {
        MappingJackson2HttpMessageConverter converter = new MappingJackson2HttpMessageConverter();
        converter.setObjectMapper(objectMapper);
        restTemplate.setMessageConverters(Collections.<HttpMessageConverter<?>>singletonList(converter));
        EmployeeDTO resource = restTemplate.getForObject(link.getHref(), EmployeeDTO.class);
        return resource;
    }

    @ModelAttribute("employees")
    public List<EmployeeDTO> getEmployees() {
        return employees;
    }

    public void setEmployees(List<EmployeeDTO> employees) {
        this.employees = employees;
    }
}