Rest架构的主要原则

什么是Restful:

为什么会出现Restful

如何使用:

1. package cn.itcast.mybatis.controller;
2.  
3. import org.springframework.beans.factory.annotation.Autowired;
4. import org.springframework.http.HttpStatus;
5. import org.springframework.http.ResponseEntity;
6. import org.springframework.stereotype.Controller;
7. import org.springframework.web.bind.annotation.PathVariable;
8. import org.springframework.web.bind.annotation.RequestMapping;
9. import org.springframework.web.bind.annotation.RequestMethod;
10. import org.springframework.web.bind.annotation.RequestParam;
11. import org.springframework.web.bind.annotation.ResponseBody;
12.  
13. import cn.itcast.mybatis.pojo.User;
14. import cn.itcast.mybatis.service.NewUserService;
15.  
16. @RequestMapping("restful/user")
17. @Controller
18. public class RestUserController {
19.  
20. @Autowired
21. private NewUserService newUserService;
22.  
23. /**
24. * 根据用户id查询用户数据
25. *
26. * @param id
27. * @return
28. */
29. @RequestMapping(value = "{id}", method = RequestMethod.GET)
30. @ResponseBody
31. public ResponseEntity queryUserById(@PathVariable("id") Long id) {
32. try {
33. User user = this.newUserService.queryUserById(id);
34. if (null == user) {
35. // 资源不存在，响应404
36. return ResponseEntity.status(HttpStatus.NOT_FOUND).body(null);
37. }
38. // 200
39. // return ResponseEntity.status(HttpStatus.OK).body(user);
40. return ResponseEntity.ok(user);
41. } catch (Exception e) {
42. e.printStackTrace();
43. }
44. // 500
45. return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR).body(null);
46. }
47.  
48. /**
49. * 新增用户
50. *
51. * @param user
52. * @return
53. */
54. @RequestMapping(method = RequestMethod.POST)
55. public ResponseEntity saveUser(User user) {
56. try {
57. this.newUserService.saveUser(user);
58. return ResponseEntity.status(HttpStatus.CREATED).build();
59. } catch (Exception e) {
60. // TODO Auto-generated catch block
61. e.printStackTrace();
62. }
63. // 500
64. return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR).body(null);
65. }
66.  
67. /**
68. * 更新用户资源
69. *
70. * @param user
71. * @return
72. */
73. @RequestMapping(method = RequestMethod.PUT)
74. public ResponseEntity updateUser(User user) {
75. try {
76. this.newUserService.updateUser(user);
77. return ResponseEntity.status(HttpStatus.NO_CONTENT).build();
78. } catch (Exception e) {
79. e.printStackTrace();
80. }
81. // 500
82. return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR).body(null);
83. }
84.  
85. /**
86. * 删除用户资源
87. *
88. * @param user
89. * @return
90. */
91. @RequestMapping(method = RequestMethod.DELETE)
92. public ResponseEntity deleteUser(@RequestParam(value = "id", defaultValue = "0") Long id) {
93. try {
94. if (id.intValue() == 0) {
95. // 请求参数有误
96. return ResponseEntity.status(HttpStatus.BAD_REQUEST).build();
97. }
98. this.newUserService.deleteUserById(id);
99. // 204
100. return ResponseEntity.status(HttpStatus.NO_CONTENT).build();
101. } catch (Exception e) {
102. e.printStackTrace();
103. }
104. // 500
105. return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR).body(null);
106. }
107. }

HTTP相应状态码:

总结: