Jackson 框架JSON、XML、List、Map直接相互转换

xsi:schemaLocation="http://maven.apache.org/POM/4.0.0http://maven.apache.org/xsd/maven-4.0.0.xsd">

<modelVersion>4.0.0</modelVersion>

<groupId>com.waegg</groupId>

<artifactId>jacksonTest</artifactId>

<version>0.0.1-SNAPSHOT</version>

<dependencies>

<dependency>

<groupId>junit</groupId>

<artifactId>junit</artifactId>

<version>4.12</version>

</dependency>

<dependency>

<groupId>org.codehaus.jackson</groupId>

<artifactId>jackson-mapper-asl</artifactId>

<version>1.9.13</version>

</dependency>

<dependency>

<groupId>com.fasterxml.jackson.dataformat</groupId>

<artifactId>jackson-dataformat-xml</artifactId>

<version>2.7.1</version>

</dependency>

</dependencies>

<packaging>war</packaging>

</project>

1. packagecom.bugyun.pojo;
3. publicclassAccountBean{
4. privateintid;
5. privateStringname;
6. privateStringemail;
7. privateStringaddress;
8. privateBirthdaybirthday;
10. //getter、setter
12. @Override
13. publicStringtoString(){
14. returnthis.name+"#"+this.id+"#"+this.address+"#"+this.birthday+"#"+this.email;
15. }
17. publicintgetId(){
18. returnid;
19. }
21. publicvoidsetId(intid){
22. this.id=id;
23. }
25. publicStringgetName(){
26. returnname;
27. }
29. publicvoidsetName(Stringname){
30. this.name=name;
31. }
33. publicStringgetEmail(){
34. returnemail;
35. }
37. publicvoidsetEmail(Stringemail){
38. this.email=email;
39. }
41. publicStringgetAddress(){
42. returnaddress;
43. }
45. publicvoidsetAddress(Stringaddress){
46. this.address=address;
47. }
49. publicBirthdaygetBirthday(){
50. returnbirthday;
51. }
53. publicvoidsetBirthday(Birthdaybirthday){
54. this.birthday=birthday;
55. }
56. }

1. packagecom.bugyun.pojo;
3. publicclassBirthday{
4. privateStringbirthday;
6. publicBirthday(Stringbirthday){
7. super();
8. this.birthday=birthday;
9. }
11. //getter、setter
13. publicBirthday(){
14. }
16. publicStringgetBirthday(){
17. returnbirthday;
18. }
20. publicvoidsetBirthday(Stringbirthday){
21. this.birthday=birthday;
22. }
24. @Override
25. publicStringtoString(){
26. returnthis.birthday;
27. }
28. }

1. packagecom.bugyun.test;
3. importjava.io.IOException;
4. importjava.io.StringWriter;
5. importjava.util.ArrayList;
6. importjava.util.HashMap;
7. importjava.util.Iterator;
8. importjava.util.List;
9. importjava.util.Map;
10. importjava.util.Set;
12. importorg.codehaus.jackson.JsonEncoding;
13. importorg.codehaus.jackson.JsonGenerationException;
14. importorg.codehaus.jackson.JsonGenerator;
15. importorg.codehaus.jackson.JsonParseException;
16. importorg.codehaus.jackson.map.JsonMappingException;
17. importorg.codehaus.jackson.map.ObjectMapper;
18. importorg.junit.After;
19. importorg.junit.Before;
20. importorg.junit.Test;
22. importcom.bugyun.pojo.AccountBean;
23. importcom.fasterxml.jackson.dataformat.xml.XmlMapper;
25. /**
26. *项目名称：jacksonTest
27. *类名称：JacksonTest.java
28. *类描述：
29. *创建人：beyond
30. *创建时间：2016年2月24日上午11:24:33
31. *修改人：
32. *修改时间：
33. *修改备注：
34. *@version
35. */
36. publicclassJacksonTest{
38. privateJsonGeneratorjsonGenerator=null;
39. privateObjectMapperobjectMapper=null;
40. privateAccountBeanbean=null;
42. @Before
43. publicvoidinit(){
44. bean=newAccountBean();
45. bean.setAddress("js_wuxi");
46. bean.setEmail("bugyun@hotmail.com");
47. bean.setId(1);
48. bean.setName("bugyun");
50. objectMapper=newObjectMapper();
51. try{
52. jsonGenerator=objectMapper.getJsonFactory().createJsonGenerator(System.out,JsonEncoding.UTF8);
53. }catch(IOExceptione){
54. e.printStackTrace();
55. }
56. }
58. @After
59. publicvoiddestory(){
60. try{
61. if(jsonGenerator!=null){
62. jsonGenerator.flush();
63. }
64. if(!jsonGenerator.isClosed()){
65. jsonGenerator.close();
66. }
67. jsonGenerator=null;
68. objectMapper=null;
69. bean=null;
70. System.gc();
71. }catch(IOExceptione){
72. e.printStackTrace();
73. }
74. }
77. /**
78. *
79. *@description:JavaBean(Entity/Model)转换成JSON
80. *上面分别利用JsonGenerator的writeObject方法和ObjectMapper的writeValue方法完成对Java对象的转换，二者传递的参数及构造的方式不同；
81. *JsonGenerator的创建依赖于ObjectMapper对象。
82. *也就是说如果你要使用JsonGenerator来转换JSON，那么你必须创建一个ObjectMapper。
83. *但是你用ObjectMapper来转换JSON，则不需要JSONGenerator。objectMapper的writeValue方法可以将一个Java对象转换成JSON。
84. *这个方法的参数一，需要提供一个输出流，转换后可以通过这个流来输出转换后的内容。
85. *或是提供一个File，将转换后的内容写入到File中。当然，这个参数也可以接收一个JSONGenerator，然后通过JSONGenerator来输出转换后的信息。
86. *第二个参数是将要被转换的Java对象。如果用三个参数的方法，那么是一个Config。
87. *这个config可以提供一些转换时的规则，过指定的Java对象的某些属性进行过滤或转换等。
88. *
89. *输出：
90. *jsonGenerator{"id":1,"name":"bugyun","email":"bugyun@hotmail.com","address":"js_wuxi","birthday":null}
91. *ObjectMapper{"id":1,"name":"bugyun","email":"bugyun@hotmail.com","address":"js_wuxi","birthday":null}
92. *@returnvoid
93. *@throws
94. *@authorbeyond
95. *@data:2016年2月24日上午11:34:53
96. */
97. @Test
98. publicvoidwriteEntityJSON(){
99. try{
100. System.out.println("jsonGenerator");
101. jsonGenerator.writeObject(bean);
103. System.out.println("\nObjectMapper");
104. objectMapper.writeValue(System.out,bean);
105. }catch(IOExceptione){
106. e.printStackTrace();
107. }
108. }
111. /**
112. *@description:将Map集合转换成Json字符串
113. *输出：
114. *jsonGenerator{"name":"bugyun","account":{"id":1,"name":"bugyun","email":"bugyun@hotmail.com","address":"js_wuxi","birthday":null}}
115. *ObjectMapper{"name":"bugyun","account":{"id":1,"name":"bugyun","email":"bugyun@hotmail.com","address":"js_wuxi","birthday":null}}
116. *@returnvoid
117. *@throws
118. *@authorbeyond
119. *@data:2016年2月24日上午11:41:48
120. */
121. @Test
122. publicvoidwriteMapJSON(){
123. try{
124. Map<String,Object>map=newHashMap<String,Object>();
125. map.put("name",bean.getName());
126. map.put("account",bean);
128. System.out.println("jsonGenerator");
129. jsonGenerator.writeObject(map);
131. System.out.println("\nObjectMapper");
132. objectMapper.writeValue(System.out,map);
133. }catch(IOExceptione){
134. e.printStackTrace();
135. }
136. }
139. /**
140. *
141. *@description:将List集合转换成json
142. *外面就是多了个[]中括号；同样Array也可以转换，转换的JSON和上面的结果是一样的
143. *输出：
144. *jsonGenerator[{"id":1,"name":"bugyun","email":"bugyun@hotmail.com","address":"js_wuxi","birthday":null}]
145. *ObjectMapper1###[{"id":1,"name":"bugyun","email":"bugyun@hotmail.com","address":"js_wuxi","birthday":null}]
146. *2###[{"id":1,"name":"bugyun","email":"bugyun@hotmail.com","address":"js_wuxi","birthday":null}]
147. *@returnvoid
148. *@throws
149. *@authorbeyond
150. *@data:2016年2月24日上午11:46:41
151. */
152. @Test
153. publicvoidwriteListJSON(){
154. try{
155. List<AccountBean>list=newArrayList<AccountBean>();
156. list.add(bean);
158. System.out.println("jsonGenerator");
159. jsonGenerator.writeObject(list);
161. System.out.println("\nObjectMapper");
162. System.out.println("1###"+objectMapper.writeValueAsString(list));
164. System.out.print("2###");
165. objectMapper.writeValue(System.out,list);
166. }catch(IOExceptione){
167. e.printStackTrace();
168. }
169. }
172. /**
173. *@description:复杂的Java类型的JSON转换
174. *输出：
175. *{"user":{"name":"jackson","sex":true,"age":22},"infos":[22,"thisisarray"]}
176. *{"user":{"id":1,"name":"haha","email":"email","address":"address","birthday":null},"infos":["a","b","c"]}
177. *@returnvoid
178. *@throws
179. *@authorbeyond
180. *@data:2016年2月24日下午1:08:06
181. */
182. @Test
183. publicvoidwriteOthersJSON(){
184. try{
185. String[]arr={"a","b","c"};
186. //Object
187. jsonGenerator.writeStartObject();//{
188. jsonGenerator.writeObjectFieldStart("user");//user:{
189. jsonGenerator.writeStringField("name","jackson");//name:jackson
190. jsonGenerator.writeBooleanField("sex",true);//sex:true
191. jsonGenerator.writeNumberField("age",22);//age:22
192. jsonGenerator.writeEndObject();//}
194. jsonGenerator.writeArrayFieldStart("infos");//infos:[
195. jsonGenerator.writeNumber(22);//22
196. jsonGenerator.writeString("thisisarray");//thisisarray
197. jsonGenerator.writeEndArray();//]
199. jsonGenerator.writeEndObject();//}
201. //********************************************
202. AccountBeanbean=newAccountBean();
203. bean.setAddress("address");
204. bean.setEmail("email");
205. bean.setId(1);
206. bean.setName("haha");
207. jsonGenerator.writeStartObject();//{
208. jsonGenerator.writeObjectField("user",bean);//user:{bean}
209. jsonGenerator.writeObjectField("infos",arr);//infos:[array]
210. jsonGenerator.writeEndObject();//}
212. }catch(Exceptione){
213. e.printStackTrace();
214. }
215. }
218. /**
219. *@description:将json字符串转换成JavaBean对象
220. *用到了ObjectMapper这个对象的readValue这个方法，这个方法需要提供2个参数。
221. *第一个参数就是解析的JSON字符串，
222. *第二个参数是将这个JSON解析持什么Java对象，Java对象的类型。当然，还有其他相同签名方法。
223. *
224. *输出：
225. *haha
226. *haha#1#address#null#email
227. *@returnvoid
228. *@throws
229. *@authorbeyond
230. *@data:2016年2月24日下午3:37:50
231. */
232. @Test
233. publicvoidreadJson2Entity(){
234. Stringjson="{\"address\":\"address\",\"name\":\"haha\",\"id\":1,\"email\":\"email\"}";
235. try{
236. AccountBeanacc=objectMapper.readValue(json,AccountBean.class);
237. System.out.println(acc.getName());
238. System.out.println(acc);
239. }catch(JsonParseExceptione){
240. e.printStackTrace();
241. }catch(JsonMappingExceptione){
242. e.printStackTrace();
243. }catch(IOExceptione){
244. e.printStackTrace();
245. }
246. }
247. &n