Java tutorial
/** * The MIT License (MIT) * * Copyright (c) 2014 Baldeep Hira * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in all * copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE * SOFTWARE. */ package net.bhira.sample.api.controller; import java.util.HashMap; import java.util.List; import java.util.concurrent.Callable; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import net.bhira.sample.api.service.EmployeeService; import net.bhira.sample.common.JsonUtil; import net.bhira.sample.model.Employee; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.PathVariable; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestMethod; import org.springframework.web.bind.annotation.ResponseBody; import com.google.gson.Gson; import com.google.gson.JsonSyntaxException; /** * Controller class for employee resource. It services all API requests for employee resource. * * @author Baldeep Hira */ @Controller("employeeController") public class EmployeeController { /** * private singleton instance of the SLF4J logger for this class. */ private static final Logger LOG = LoggerFactory.getLogger(EmployeeController.class); @Autowired EmployeeService employeeService; /** * Fetch all the employees for the given company ID. It will return a light weight version of * {@link net.bhira.sample.model.Employee} model without the address and contactInfo objects. * * @param companyId * the ID for {@link net.bhira.sample.model.Company}. * @param response * the http response to which the results will be written. * @return an array of {@link net.bhira.sample.model.Employee} instances as JSON. */ @RequestMapping(value = "/employee/company/{companyId}", method = RequestMethod.GET) @ResponseBody public Callable<String> getEmployeesByCompany(@PathVariable long companyId, HttpServletResponse response) { return new Callable<String>() { public String call() throws Exception { String body = ""; try { LOG.debug("servicing GET employee/company/{}", companyId); List<Employee> list = employeeService.loadByCompany(companyId); int count = (list == null) ? 0 : list.size(); LOG.debug("GET employee/company/{} count = {}", companyId, count); body = JsonUtil.createGson().toJson(list); } catch (Exception ex) { response.setStatus(HttpServletResponse.SC_FORBIDDEN); body = ex.getLocalizedMessage(); LOG.warn("Error loading employee/company/{}. {}", companyId, body); LOG.debug("Load error stacktrace: ", ex); } return body; } }; } /** * Fetch all the employees for the given department ID. It will return a light weight version of * {@link net.bhira.sample.model.Employee} model without the address and contactInfo objects. * * @param departmentId * the ID for {@link net.bhira.sample.model.Department}. * @param response * the http response to which the results will be written. * @return an array of {@link net.bhira.sample.model.Employee} instances as JSON. */ @RequestMapping(value = "/employee/department/{departmentId}", method = RequestMethod.GET) @ResponseBody public Callable<String> getEmployeesByDepartment(@PathVariable long departmentId, HttpServletResponse response) { return new Callable<String>() { public String call() throws Exception { String body = ""; try { LOG.debug("servicing GET employee/department/{}", departmentId); List<Employee> list = employeeService.loadByDepartment(departmentId); int count = (list == null) ? 0 : list.size(); LOG.debug("GET employee/department/{} count = {}", departmentId, count); body = JsonUtil.createGson().toJson(list); } catch (Exception ex) { response.setStatus(HttpServletResponse.SC_FORBIDDEN); body = ex.getLocalizedMessage(); LOG.warn("Error loading employee/department/{}. {}", departmentId, body); LOG.debug("Load error stacktrace: ", ex); } return body; } }; } /** * Fetch the instance of {@link net.bhira.sample.model.Employee} represented by given employeeId * and return it as JSON object. * * @param employeeId * the ID for {@link net.bhira.sample.model.Employee}. * @param response * the http response to which the results will be written. * @return an instance of {@link net.bhira.sample.model.Employee} as JSON. */ @RequestMapping(value = "/employee/{employeeId}", method = RequestMethod.GET) @ResponseBody public Callable<String> getEmployee(@PathVariable long employeeId, HttpServletResponse response) { return new Callable<String>() { public String call() throws Exception { String body = ""; try { LOG.debug("servicing GET employee/{}", employeeId); Employee employee = employeeService.load(employeeId); LOG.debug("GET employee/{}, found = {}", employeeId, employee != null); if (employee == null) { response.setStatus(HttpServletResponse.SC_NOT_FOUND); } else { body = JsonUtil.createGson().toJson(employee); } } catch (Exception ex) { response.setStatus(HttpServletResponse.SC_FORBIDDEN); body = ex.getLocalizedMessage(); LOG.warn("Error loading employee/{}. {}", employeeId, body); LOG.debug("Load error stacktrace: ", ex); } return body; } }; } /** * Save the given instance of {@link net.bhira.sample.model.Employee}. It will create a new * instance of the employee does not exist, otherwise it will update the existing instance. * * @param request * the http request containing JSON payload in its body. * @param response * the http response to which the results will be written. * @return the error message, if save was not successful. */ @RequestMapping(value = "/employee", method = RequestMethod.POST) @ResponseBody public Callable<String> saveEmployee(HttpServletRequest request, HttpServletResponse response) { return new Callable<String>() { public String call() throws Exception { String body = ""; try { LOG.debug("servicing POST employee"); Gson gson = JsonUtil.createGson(); Employee employee = gson.fromJson(request.getReader(), Employee.class); LOG.debug("POST employee received json = {}", gson.toJson(employee)); employeeService.save(employee); HashMap<String, Long> map = new HashMap<String, Long>(); map.put("id", employee.getId()); body = gson.toJson(map); LOG.debug("POST employee/ successful with return ID = {}", employee.getId()); } catch (Exception ex) { if (ex instanceof JsonSyntaxException) { response.setStatus(HttpServletResponse.SC_BAD_REQUEST); } else { response.setStatus(HttpServletResponse.SC_FORBIDDEN); } body = ex.getLocalizedMessage(); LOG.warn("Error saving employee. {}", body); LOG.debug("Save error stacktrace: ", ex); } return body; } }; } /** * Delete the instance of {@link net.bhira.sample.model.Employee} represented by given * employeeId. In case of an error return the error message. * * @param employeeId * the ID for {@link net.bhira.sample.model.Employee}. * @param response * the http response to which the results will be written. * @return the error message, if save was not successful. */ @RequestMapping(value = "/employee/{employeeId}", method = RequestMethod.DELETE) @ResponseBody public Callable<String> deleteEmployee(@PathVariable long employeeId, HttpServletResponse response) { return new Callable<String>() { public String call() throws Exception { LOG.debug("servicing DELETE employee/{}", employeeId); String body = ""; try { boolean success = employeeService.delete(employeeId); LOG.debug("DELETE employee/{} status = {}", employeeId, success); if (!success) { response.setStatus(HttpServletResponse.SC_FORBIDDEN); } } catch (Exception ex) { response.setStatus(HttpServletResponse.SC_FORBIDDEN); body = ex.getLocalizedMessage(); LOG.warn("Error deleting employee/{}. {}", employeeId, body); LOG.debug("Delete error stacktrace: ", ex); } return body; } }; } }