XStream(xml/bean转换)

Posted 2020-10-02 air_balloon

XStream

1. 什么作用
  * 可以把JavaBean转换为（序列化为）xml

2. XStream的jar包
  * 核心JAR包：xstream-1.4.7.jar；
  * 必须依赖包：xpp3_min-1.1.4c（XML Pull Parser，一款速度很快的XML解析器）；

3. 使用步骤
  * XStream xstream = new XStream();
  * String xmlStr = xstream.toXML(javabean);

4. 使用细节
  * 别名：把类型对应的元素名修改了
    > xstream.alias("china", List.class)：让List类型生成的元素名为china
    > xstream.alias("province", Province.class)：让Province类型生成的元素名为province
  * 使用为属性：默认类的成员，生成的是元素的子元素！我们希望让类的成员生成元素的属性
    > xstream.useAttributeFor(Province.class, "name")：把Province类的名为name成员，生成<province>元素的name属性
  * 去除Collection类型的成名：我们只需要Collection的内容，而不希望Collection本身也生成一个元素
    > xstream.addImplicitCollection(Province.class, "cities")：让Province类的名为cities(它是List类型的，它的内容还会生成元素)的成名不生成元素
  * 去除类的指定成名，让其不生成xml元素
    > xstream.omitField(City.class, "description")：在生成的xml中不会出现City类的名为description的对应的元素！

具体实例

[java] view plain copy

 

1. package cn.itcast.demo1;  
2.   
3. import java.util.ArrayList;  
4. import java.util.List;  
5.   
6. import org.junit.Test;  
7.   
8. import com.thoughtworks.xstream.XStream;  
9.   
10. /** 
11.  * 演示XStream 
12.  * @author cxf 
13.  * 
14.  */  
15. public class Demo1 {  
16.     // 返回javabean集合  
17.     public List<Province> getProinvceList() {  
18.         Province p1 = new Province();  
19.         p1.setName("北京");  
20.         p1.addCity(new City("东城区", "DongChengQu"));  
21.         p1.addCity(new City("昌平区", "ChangPingQu"));  
22.           
23.         Province p2 = new Province();  
24.         p2.setName("辽宁");  
25.         p2.addCity(new City("沈阳", "shenYang"));  
26.         p2.addCity(new City("葫芦岛", "huLuDao"));  
27.           
28.         List<Province> provinceList = new ArrayList<Province>();  
29.         provinceList.add(p1);  
30.         provinceList.add(p2);  
31.           
32.         return provinceList;  
33.     }  
34.       
35.     /** 
36. <list> --> List类型显示list 
37.   <cn.itcast.demo1.Province> --> javabean的类型为Province，它元素的名称为类的完整名 
38.     <name>北京</name> --> javabean的属性名 
39.     <cities> --> javabean的属性名 
40.       <cn.itcast.demo1.City> --> 类名 
41.         <name>东城区</name> --> 属性名 
42.         <description>DongChengQu</description> --> 属性名 
43.       </cn.itcast.demo1.City> 
44.       <cn.itcast.demo1.City> 
45.         <name>昌平区</name> 
46.         <description>ChangPingQu</description> 
47.       </cn.itcast.demo1.City> 
48.     </cities> 
49.   </cn.itcast.demo1.Province> 
50.   <cn.itcast.demo1.Province> 
51.     <name>辽宁</name> 
52.     <cities> 
53.       <cn.itcast.demo1.City> 
54.         <name>沈阳</name> 
55.         <description>shenYang</description> 
56.       </cn.itcast.demo1.City> 
57.       <cn.itcast.demo1.City> 
58.         <name>葫芦岛</name> 
59.         <description>huLuDao</description> 
60.       </cn.itcast.demo1.City> 
61.     </cities> 
62.   </cn.itcast.demo1.Province> 
63. </list> 
64.      */  
65.     @Test  
66.     public void fun1() {  
67.         List<Province> proList = getProinvceList();  
68.         /* 
69.          * 创建XStream对象 
70.          * 调用toXML把集合转换成xml字符串 
71.          */  
72.         XStream xstream = new XStream();  
73.         String s = xstream.toXML(proList);  
74.         System.out.println(s);  
75.     }  
76.       
77.     /* 
78.      * 别名(alias) 
79.      * 希望： 
80.      * * 默认List类型对应<list>元素，希望让List类型对应<china>元素 
81.      * * 默认Province类型对应<cn.itcast.demo1.Province>，希望让它对应<province> 
82.      * * 默认City类型对应<cn.itcast.demo1.City>，希望它对应<city>元素 
83.      */  
84.     /* 
85. <china> 
86.   <province> 
87.     <name>北京</name> 
88.     <cities> 
89.       <city> 
90.         <name>东城区</name> 
91.         <description>DongChengQu</description> 
92.       </city> 
93.       <city> 
94.         <name>昌平区</name> 
95.         <description>ChangPingQu</description> 
96.       </city> 
97.     </cities> 
98.   </province> 
99.   <province> 
100.     <name>辽宁</name> 
101.     <cities> 
102.       <city> 
103.         <name>沈阳</name> 
104.         <description>shenYang</description> 
105.       </city> 
106.       <city> 
107.         <name>葫芦岛</name> 
108.         <description>huLuDao</description> 
109.       </city> 
110.     </cities> 
111.   </province> 
112. </china> 
113.      */  
114.     @Test  
115.     public void fun2() {  
116.         List<Province> proList = getProinvceList();  
117.         XStream xstream = new XStream();  
118.         /* 
119.          * 给指定的类型指定别名 
120.          */  
121.         xstream.alias("china", List.class);//给List类型指定别名为china  
122.         xstream.alias("province", Province.class);//给Province指定别名为province  
123.         xstream.alias("city", City.class);//给City类型指定别名为city  
124.           
125.           
126.         String s = xstream.toXML(proList);  
127.         System.out.println(s);  
128.     }  
129.       
130.     /* 
131.      * 默认javabean的属性都会生成子元素，而现在希望生成元素的属性 
132.      */  
133. /* 
134. <china> 
135.   <province name="北京"> 
136.     <cities> 
137.       <city> 
138.         <name>东城区</name> 
139.         <description>DongChengQu</description> 
140.       </city> 
141.       <city> 
142.         <name>昌平区</name> 
143.         <description>ChangPingQu</description> 
144.       </city> 
145.     </cities> 
146.   </province> 
147.   <province name="辽宁"> 
148.     <cities> 
149.       <city> 
150.         <name>沈阳</name> 
151.         <description>shenYang</description> 
152.       </city> 
153.       <city> 
154.         <name>葫芦岛</name> 
155.         <description>huLuDao</description> 
156.       </city> 
157.     </cities> 
158.   </province> 
159.  */  
160.     @Test  
161.     public void fun3() {  
162.         List<Province> proList = getProinvceList();  
163.         XStream xstream = new XStream();  
164.         xstream.alias("china", List.class);//给List类型指定别名为china  
165.         xstream.alias("province", Province.class);//给Province指定别名为province  
166.         xstream.alias("city", City.class);//给City类型指定别名为city  
167.           
168.           
169.         /* 
170.          * 把Province类型的name属性，生成<province>元素的属性 
171.          */  
172.         xstream.useAttributeFor(Province.class, "name");  
173.           
174.           
175.         String s = xstream.toXML(proList);  
176.         System.out.println(s);        
177.     }  
178.   
179.       
180.     /* 
181.      * 去除List类型的属性，只把list中的元素生成xml元素 
182.      */  
183. /* 
184. <china> 
185.   <province name="北京"> 
186.     <city> 
187.       <name>东城区</name> 
188.       <description>DongChengQu</description> 
189.     </city> 
190.     <city> 
191.       <name>昌平区</name> 
192.       <description>ChangPingQu</description> 
193.     </city> 
194.   </province> 
195.   <province name="辽宁"> 
196.     <city> 
197.       <name>沈阳</name> 
198.       <description>shenYang</description> 
199.     </city> 
200.     <city> 
201.       <name>葫芦岛</name> 
202.       <description>huLuDao</description> 
203.     </city> 
204.   </province> 
205. </china> 
206.  */  
207.     @Test  
208.     public void fun4() {  
209.         List<Province> proList = getProinvceList();  
210.         XStream xstream = new XStream();  
211.         xstream.alias("china", List.class);//给List类型指定别名为china  
212.         xstream.alias("province", Province.class);//给Province指定别名为province  
213.         xstream.alias("city", City.class);//给City类型指定别名为city  
214.         xstream.useAttributeFor(Province.class, "name");//把Province类型的name属性，生成<province>元素的属性  
215.           
216.           
217.         /* 
218.          * 去除<cities>这样的Collection类型的属性 
219.          * 去除Provice类的名为cities的List类型的属性！ 
220.          */  
221.         xstream.addImplicitCollection(Province.class, "cities");  
222.           
223.           
224.         String s = xstream.toXML(proList);  
225.         System.out.println(s);        
226.     }  
227.       
228.     /** 
229.      * 去除不想要的javabean属性 
230.      * 就是让某引起javabean属性，不生成对应的xml元素！ 
231.      */  
232. /* 
233. <china> 
234.   <province name="北京"> 
235.     <city> 
236.       <name>东城区</name> 
237.     </city> 
238.     <city> 
239.       <name>昌平区</name> 
240.     </city> 
241.   </province> 
242.   <province name="辽宁"> 
243.     <city> 
244.       <name>沈阳</name> 
245.     </city> 
246.     <city> 
247.       <name>葫芦岛</name> 
248.     </city> 
249.   </province> 
250. </china> 
251.  */  
252.     @Test  
253.     public void fun5() {  
254.         List<Province> proList = getProinvceList();  
255.         XStream xstream = new XStream();  
256.         xstream.alias("china", List.class);//给List类型指定别名为china  
257.         xstream.alias("province", Province.class);//给Province指定别名为province  
258.         xstream.alias("city", City.class);//给City类型指定别名为city  
259.         xstream.useAttributeFor(Province.class, "name");//把Province类型的name属性，生成<province>元素的属性  
260.         xstream.addImplicitCollection(Province.class, "cities");//去除Provice类的名为cities的List类型的属性！  
261.           
262.           
263.         /* 
264.          * 让City类的，名为description属性不生成对应的xml元素 
265.          */  
266.         xstream.omitField(City.class, "description");  
267.           
268.           
269.         String s = xstream.toXML(proList);  
270.         System.out.println(s);        
271.     }  
272. }