TaskRestController.java

package org.xmx0632.deliciousfruit.rest;

import java.net.URI;
import java.util.List;
import java.util.Set;

import javax.validation.ConstraintViolation;
import javax.validation.Validator;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.MediaType;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.bind.annotation.ResponseStatus;
import org.springframework.web.util.UriComponentsBuilder;
import org.xmx0632.deliciousfruit.entity.Task;
import org.xmx0632.deliciousfruit.service.task.TaskService;
import org.springside.modules.beanvalidator.BeanValidators;

/**
 * Task的Restful API的Controller.
 * 
 * @author calvin
 */
@Controller
@RequestMapping(value = "/api/v1/task")
public class TaskRestController {

	@Autowired
	private TaskService taskService;

	@Autowired
	private Validator validator;

	@RequestMapping(method = RequestMethod.GET, produces = MediaType.APPLICATION_JSON_VALUE)
	@ResponseBody
	public List<Task> list() {
		return taskService.getAllTask();
	}

	@RequestMapping(value = "/{id}", method = RequestMethod.GET, produces = MediaType.APPLICATION_JSON_VALUE)
	@ResponseBody
	public ResponseEntity<?> get(@PathVariable("id") Long id) {
		Task task = taskService.getTask(id);
		if (task == null) {
			return new ResponseEntity(HttpStatus.NOT_FOUND);
		}
		return new ResponseEntity(task, HttpStatus.OK);
	}

	@RequestMapping(method = RequestMethod.POST, consumes = MediaType.APPLICATION_JSON_VALUE)
	@ResponseBody
	public ResponseEntity<?> create(@RequestBody Task task,
			UriComponentsBuilder uriBuilder) {
		// 调用JSR303 Bean Validator进行校验，如果出错返回含400错误码及json格式的错误信息.
		Set<ConstraintViolation<Task>> failures = validator.validate(task);
		if (!failures.isEmpty()) {
			return new ResponseEntity(
					BeanValidators.extractPropertyAndMessage(failures),
					HttpStatus.BAD_REQUEST);
		}

		// 保存任务
		taskService.saveTask(task);

		// 按照Restful风格约定，创建指向新任务的url, 也可以直接返回id或对象.
		Long id = task.getId();
		URI uri = uriBuilder.path("/api/v1/task/" + id).build().toUri();
		HttpHeaders headers = new HttpHeaders();
		headers.setLocation(uri);

		return new ResponseEntity(headers, HttpStatus.CREATED);
	}

	@RequestMapping(value = "/{id}", method = RequestMethod.PUT, consumes = MediaType.APPLICATION_JSON_VALUE)
	public ResponseEntity<?> update(@RequestBody Task task) {
		// 调用JSR303 Bean Validator进行校验，如果出错返回含400错误码及json格式的错误信息.
		Set<ConstraintViolation<Task>> failures = validator.validate(task);
		if (!failures.isEmpty()) {
			return new ResponseEntity(
					BeanValidators.extractPropertyAndMessage(failures),
					HttpStatus.BAD_REQUEST);
		}

		// 保存
		taskService.saveTask(task);

		// 按Restful约定，返回204状态码, 无内容. 也可以返回200状态码.
		return new ResponseEntity(HttpStatus.NO_CONTENT);
	}

	@RequestMapping(value = "/{id}", method = RequestMethod.DELETE)
	@ResponseStatus(HttpStatus.NO_CONTENT)
	public void delete(@PathVariable("id") Long id) {
		taskService.deleteTask(id);
	}
}