Xstream之常用方式与常用注解

示例代码 

Java代码  

1. Blog teamBlog = new Blog(new Author("Guilherme Silveira"));  
2. teamBlog.add(new Entry("first","My first blog entry."));  
3. eamBlog.add(new Entry("tutorial","Today we have developed a nice alias tutorial. Tell your friends! NOW!"));  
4. XStream xstream = new XStream();  
5.  System.out.println(xstream.toXML(teamBlog));  

打印结果为: 

Java代码  

1.  <xtream.Blog>  
2.   <writer>  
3.     <name>Guilherme Silveira</name>  
4.   </writer>  
5.   <entries>  
6.     <xtream.Entry>  
7.       <title>first</title>  
8.       <description>My first blog entry.</description>  
9.     </xtream.Entry>  
10.     <xtream.Entry>  
11.       <title>tutorial</title>  
12.       <description>Today we have developed a nice alias tutorial. Tell your friends! NOW!</description>  
13.     </xtream.Entry>  
14.   </entries>  
15. </xtream.Blog>  

以上节点就包含了包名,如包名很长,就很难看了,怎样才能重新命名这个节点呀！ 
以下的1,2设置效果一样 

Java代码  

1. 1 //xstream.aliasPackage("", "xtream");  
2. 2 xstream.alias("blog", Blog.class);  
3. 3 xstream.alias("entry", Entry.class);  

  
通过这样设置就完成了节点名称的设置.如下: 

Java代码  

1. <blog>  
2.   <writer>  
3.     <name>Guilherme Silveira</name>  
4.   </writer>  
5.   <entries>  
6.     <entry>  
7.       <title>first</title>  
8.       <description>My first blog entry.</description>  
9.     </entry>  
10.     <entry>  
11.       <title>tutorial</title>  
12.       <description>Today we have developed a nice alias tutorial. Tell your friends! NOW!</description>  
13.     </entry>  
14.   </entries>  
15. </blog>  

修改子节点属性名称 
将writer属性名称修改为:autor 

Java代码  

1. xstream.aliasField("author", Blog.class, "writer");  

输出如下: 

Java代码  

1. <blog>  
2.   <author>  
3.     <name>Guilherme Silveira</name>  
4.   </author>  
5.   <entries>  
6.     <entry>  
7.       <title>first</title>  
8.       <description>My first blog entry.</description>  
9.     </entry>  
10.     <entry>  
11.       <title>tutorial</title>  
12.       <description>Today we have developed a nice alias tutorial. Tell your friends! NOW!</description>  
13.     </entry>  
14.   </entries>  
15. </blog>  

删除集合节点名称的设置 

Java代码  

1. xstream.addImplicitCollection(Blog.class, "entries");  

输出如下: 

Java代码  

1.  <blog>  
2.   <author>  
3.     <name>Guilherme Silveira</name>  
4.   </author>  
5.   <entry>  
6.     <title>first</title>  
7.     <description>My first blog entry.</description>  
8.   </entry>  
9.   <entry>  
10.     <title>tutorial</title>  
11.     <description>Today we have developed a nice alias tutorial. Tell your friends! NOW!</description>  
12.   </entry>  
13. </blog>  

将Blog类的元素设置为:它的节点属性 
//使用这个属性名作为节点上的元素 

Java代码  

1. xstream.useAttributeFor(Blog.class, "writer");  

//重新命名 

Java代码  

1. xstream.aliasField("author", Blog.class, "writer");  

//注册转换器 

Java代码  

1. xstream.registerConverter(new AuthorConverter());  

转换器: 

Java代码  

1. import com.thoughtworks.xstream.converters.SingleValueConverter;  
2. class AuthorConverter implements SingleValueConverter {  
3.     //显示节点属性值  
4.     public String toString(Object obj) {  
5.         return ((Author) obj).getName();  
6.     }  
7.   
8.     public Object fromString(String name) {  
9.         return new Author(name);  
10.     }  
11.   
12.     public boolean canConvert(Class type) {  
13.         return type.equals(Author.class);  
14.     }  
15. }  

显示结果: 

Java代码  

1. <blog author="Guilherme Silveira">  
2.   <entry>  
3.     <title>first</title>  
4.     <description>My first blog entry.</description>  
5.   </entry>  
6.   <entry>  
7.     <title>tutorial</title>  
8.     <description>Today we have developed a nice alias tutorial. Tell your friends! NOW!</description>  
9.   </entry>  
10. </blog>  

注解的使用方式,使用之前必须加上注解类才有作用: 

Java代码  

1. XStream xstream = new XStream();  
2. xstream.processAnnotations(Blog.class);  
3. xstream.processAnnotations(Entry.class);  

1  @XStreamAlias注解可在类与属性上使用设置名称,相当于: xstream.alias("blog", Blog.class); 

Java代码  

1. @XStreamAlias("blog")  
2. public class Blog {   
3.       
4.     @XStreamAlias("author")  
5.         private Author writer;  
6.   
7.     .....  
8. }  

当然Entry类也要设置同样的类属性:@XStreamAlias("entity") 
2 @XStreamImplicit去集合节点名:相当于 xstream.addImplicitCollection(Blog.class, "entries"); 
3 @XStreamConverter(AuthorConverter.class),参见以上的转换器类相当于: 

Java代码  

1. xstream.useAttributeFor(Blog.class, "writer");  
2. //重新命名  
3. xstream.aliasField("author", Blog.class, "writer");  
4. //注册转换器  
5. xstream.registerConverter(new AuthorConverter());  

要使用这个注解AuthorConverter必须符合二个条件 
a 必须要有个默认的无参构造函数 

Java代码  

1. public AuthorConverter() {  
2.           
3. }  

b 类声明必须为:public 

Java代码  

1. public class AuthorConverter implements SingleValueConverter {  
2.  ...  
3. }  

不用注解这二点都可以不强制要求! 
完整代码如下: 

Java代码  

1. import com.thoughtworks.xstream.XStream;  
2. import com.thoughtworks.xstream.annotations.XStreamAlias;  
3. import com.thoughtworks.xstream.annotations.XStreamAsAttribute;  
4. import com.thoughtworks.xstream.annotations.XStreamConverter;  
5. import com.thoughtworks.xstream.annotations.XStreamImplicit;  
6. @XStreamAlias("blog")  
7. public class Blog {  
8.   
9.     @XStreamAsAttribute  
10.     @XStreamAlias("author")  
11.     @XStreamConverter(AuthorConverter.class)  
12.     private Author writer;  
13.   
14.     @XStreamImplicit  
15.     private List entries = new ArrayList();  
16.   
17.     public Blog(Author writer) {  
18.         this.writer = writer;  
19.     }  
20.   
21.     public void add(Entry entry) {  
22.         entries.add(entry);  
23.     }  
24.   
25.     public List getContent() {  
26.         return entries;  
27.     }  
28.   
29.     public static void main(String[] args) {  
30.   
31.         Blog teamBlog = new Blog(new Author("Guilherme Silveira"));  
32.         teamBlog.add(new Entry("first", "My first blog entry."));  
33.         teamBlog  
34.                 .add(new Entry("tutorial",  
35.                         "Today we have developed a nice alias tutorial. Tell your friends! NOW!"));  
36.         XStream xstream = new XStream();  
37.         xstream.processAnnotations(Blog.class);  
38.         xstream.processAnnotations(Entry.class);  
39.         // 重新命名节点名  
40.         // xstream.aliasPackage("", "xtream");  
41.         /* 
42.          * xstream.alias("blog", Blog.class); xstream.alias("entry", 
43.          * Entry.class); //重新命名属性名 // xstream.aliasField("author", Blog.class, 
44.          * "writer"); //去节点 xstream.addImplicitCollection(Blog.class, 
45.          * "entries"); // xstream.useAttributeFor(Blog.class, "writer"); // 
46.          * xstream.aliasField("author", Blog.class, "writer"); // 
47.          * xstream.addImplicitCollection(Blog.class, "entries"); 
48.          * //使用这个属性名作为节点上的元素 xstream.useAttributeFor(Blog.class, "writer"); 
49.          * //重新命名 xstream.aliasField("author", Blog.class, "writer"); //注册转换器 
50.          * xstream.registerConverter(new AuthorConverter()); 
51.          */  
52.         System.out.println(xstream.toXML(teamBlog));  
53.     }  
54.   
55. }