1,基本介紹

Restful介面的呼叫，前端一般使用ajax呼叫，後端可以使用的方法比較多，

　　本次介紹三種：

　　　　1.HttpURLConnection實現

　　　　2.HttpClient實現

　　　　3.Spring的RestTemplate 
　　　　

2，HttpURLConnection實現

1. @Controller

2. public class RestfulAction {

3. @Autowired

4. private UserService userService;

5. // 修改

6. @RequestMapping(value = "put/{param}", method = RequestMethod.PUT)

7. public @ResponseBody String put(@PathVariable String param) {

8. return "put:" + param;

9. }

10. // 新增

11. @RequestMapping(value = "post/{param}", method = RequestMethod.POST)

12. public @ResponseBody String post(@PathVariable String param,String id,String name) {

13. System.out.println("id:"+id);

14. System.out.println("name:"+name);

15. return "post:" + param;

16. }

17. // 刪除

18. @RequestMapping(value = "delete/{param}", method = RequestMethod.DELETE)

19. public @ResponseBody String delete(@PathVariable String param) {

20. return "delete:" + param;

21. }

22. // 查詢

23. @RequestMapping(value = "get/{param}", method = RequestMethod.GET)

24. public @ResponseBody String get(@PathVariable String param) {

25. return "get:" + param;

26. }

27. // HttpURLConnection 方式呼叫Restful介面

28. // 呼叫介面

29. @RequestMapping(value = "dealCon/{param}")

30. public @ResponseBody String dealCon(@PathVariable String param) {

31. try {

32. String url = "http://localhost:8080/tao-manager-web/";

33. url+=(param+"/xxx");

34. URL restServiceURL = new URL(url);

35. HttpURLConnection httpConnection = (HttpURLConnection) restServiceURL

36. .openConnection();

37. //param 輸入小寫，轉換成 GET POST DELETE PUT

38. httpConnection.setRequestMethod(param.toUpperCase());

39. // httpConnection.setRequestProperty("Accept", "application/json");

40. if("post".equals(param)){

41. //開啟輸出開關

42. httpConnection.setDoOutput(true);

43. // httpConnection.setDoInput(true);

44. //傳遞引數

45. String input = "&id="+ URLEncoder.encode("abc", "UTF-8");

46. input+="&name="+ URLEncoder.encode("啊啊啊", "UTF-8");

47. OutputStream outputStream = httpConnection.getOutputStream();

48. outputStream.write(input.getBytes());

49. outputStream.flush();

50. }

51. if (httpConnection.getResponseCode() != 200) {

52. throw new RuntimeException(

53. "HTTP GET Request Failed with Error code : "

54. + httpConnection.getResponseCode());

55. }

56. BufferedReader responseBuffer = new BufferedReader(

57. new InputStreamReader((httpConnection.getInputStream())));

58. String output;

59. System.out.println("Output from Server: \n");

60. while ((output = responseBuffer.readLine()) != null) {

61. System.out.println(output);

62. }

63. httpConnection.disconnect();

64. } catch (MalformedURLException e) {

65. e.printStackTrace();

66. } catch (IOException e) {

67. e.printStackTrace();

68. }

69. return "success";

70. }

71. }

    3.HttpClient實現

72. package com.taozhiye.controller;

73. import org.apache.http.HttpEntity;

74. import org.apache.http.HttpResponse;

75. import org.apache.http.NameValuePair;

76. import org.apache.http.client.HttpClient;

77. import org.apache.http.client.entity.UrlEncodedFormEntity;

78. import org.apache.http.client.methods.HttpDelete;

79. import org.apache.http.client.methods.HttpGet;

80. import org.apache.http.client.methods.HttpPost;

81. import org.apache.http.client.methods.HttpPut;

82. import org.apache.http.impl.client.HttpClients;

83. import org.apache.http.message.BasicNameValuePair;

84. import org.springframework.beans.factory.annotation.Autowired;

85. import org.springframework.stereotype.Controller;

86. import org.springframework.web.bind.annotation.PathVariable;

87. import org.springframework.web.bind.annotation.RequestMapping;

88. import org.springframework.web.bind.annotation.RequestMethod;

89. import org.springframework.web.bind.annotation.ResponseBody;

90. import com.fasterxml.jackson.databind.ObjectMapper;

91. import com.taozhiye.entity.User;

92. import com.taozhiye.service.UserService;

93. import java.io.BufferedReader;

94. import java.io.IOException;

95. import java.io.InputStreamReader;

96. import java.io.OutputStream;

97. import java.net.HttpURLConnection;

98. import java.net.MalformedURLException;

99. import java.net.URL;

100. import java.net.URLEncoder;

101. import java.util.ArrayList;

102. import java.util.List;

103. @Controller

104. public class RestfulAction {

105. @Autowired

106. private UserService userService;

107. // 修改

108. @RequestMapping(value = "put/{param}", method = RequestMethod.PUT)

109. public @ResponseBody String put(@PathVariable String param) {

110. return "put:" + param;

111. }

112. // 新增

113. @RequestMapping(value = "post/{param}", method = RequestMethod.POST)

114. public @ResponseBody User post(@PathVariable String param,String id,String name) {

115. User u = new User();

116. System.out.println(id);

117. System.out.println(name);

118. u.setName(id);

119. u.setPassword(name);

120. u.setEmail(id);

121. u.setUsername(name);

122. return u;

123. }

124. // 刪除

125. @RequestMapping(value = "delete/{param}", method = RequestMethod.DELETE)

126. public @ResponseBody String delete(@PathVariable String param) {

127. return "delete:" + param;

128. }

129. // 查詢

130. @RequestMapping(value = "get/{param}", method = RequestMethod.GET)

131. public @ResponseBody User get(@PathVariable String param) {

132. User u = new User();

133. u.setName(param);

134. u.setPassword(param);

135. u.setEmail(param);

136. u.setUsername("愛愛啊");

137. return u;

138. }

139. @RequestMapping(value = "dealCon2/{param}")

140. public @ResponseBody User dealCon2(@PathVariable String param) {

141. User user = null;

142. try {

143. HttpClient client = HttpClients.createDefault();

144. if("get".equals(param)){

145. HttpGet request = new HttpGet("http://localhost:8080/tao-manager-web/get/"

146. +"啊啊啊");

147. request.setHeader("Accept", "application/json");

148. HttpResponse response = client.execute(request);

149. HttpEntity entity = response.getEntity();

150. ObjectMapper mapper = new ObjectMapper();

151. user = mapper.readValue(entity.getContent(), User.class);

152. }else if("post".equals(param)){

153. HttpPost request2 = new HttpPost("http://localhost:8080/tao-manager-web/post/xxx");

154. List<NameValuePair> nvps = new ArrayList<NameValuePair>();

155. nvps.add(new BasicNameValuePair("id", "啊啊啊"));

156. nvps.add(new BasicNameValuePair("name", "secret"));

157. UrlEncodedFormEntity formEntity = new UrlEncodedFormEntity(nvps, "GBK");

158. request2.setEntity(formEntity);

159. HttpResponse response2 = client.execute(request2);

160. HttpEntity entity = response2.getEntity();

161. ObjectMapper mapper = new ObjectMapper();

162. user = mapper.readValue(entity.getContent(), User.class);

163. }else if("delete".equals(param)){

164. }else if("put".equals(param)){

165. }

166. } catch (Exception e) {

167. e.printStackTrace();

168. }

169. return user;

170. }

171. }

     4.Spring的RestTemplate

     springmvc.xml增加

172. <!-- 配置RestTemplate -->

173. <!--Http client Factory -->

174. <bean id="httpClientFactory"

175. class="org.springframework.http.client.SimpleClientHttpRequestFactory">

176. <property name="connectTimeout" value="10000" />

177. <property name="readTimeout" value="10000" />

178. </bean>

179. <!--RestTemplate -->

180. <bean id="restTemplate" class="org.springframework.web.client.RestTemplate">

181. <constructor-arg ref="httpClientFactory" />

182. </bean>

     controller

183. @Controller

184. public class RestTemplateAction {

185. @Autowired

186. private RestTemplate template;

187. @RequestMapping("RestTem")

188. public @ResponseBody User RestTem(String method) {

189. User user = null;

190. //查詢

191. if ("get".equals(method)) {

192. user = template.getForObject(

193. "http://localhost:8080/tao-manager-web/get/{id}",

194. User.class, "嗚嗚嗚嗚");

195. //getForEntity與getForObject的區別是可以獲取返回值和狀態、頭等資訊

196. ResponseEntity<User> re = template.

197. getForEntity("http://localhost:8080/tao-manager-web/get/{id}",

198. User.class, "嗚嗚嗚嗚");

199. System.out.println(re.getStatusCode());

200. System.out.println(re.getBody().getUsername());

201. //新增

202. } else if ("post".equals(method)) {

203. HttpHeaders headers = new HttpHeaders();

204. headers.add("X-Auth-Token", UUID.randomUUID().toString());

205. MultiValueMap<String, String> postParameters = new LinkedMultiValueMap<String, String>();

206. postParameters.add("id", "啊啊啊");

207. postParameters.add("name", "部版本");

208. HttpEntity<MultiValueMap<String, String>> requestEntity = new HttpEntity<MultiValueMap<String, String>>(

209. postParameters, headers);

210. user = template.postForObject(

211. "http://localhost:8080/tao-manager-web/post/aaa", requestEntity,

212. User.class);

213. //刪除

214. } else if ("delete".equals(method)) {

215. template.delete("http://localhost:8080/tao-manager-web/delete/{id}","aaa");

216. //修改

217. } else if ("put".equals(method)) {

218. template.put("http://localhost:8080/tao-manager-web/put/{id}",null,"bbb");

219. }

220. return user;

221. }

222. }