Xstream之常用方式与常用注解

参考资料

1 xStream框架完美实现Java对象和xml文档JSON、XML相互转换

/article/4791848.html

2 xStream完美转换XML、JSON

http://archive.cnblogs.com/a/2025197/

官网:http://xstream.codehaus.org/download.html

相关jar包可在:

XStream之初识

/article/3885740.html下载

示例代码

Java代码








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

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

打印结果为:

Java代码








<xtream.Blog>
<writer>
<name>Guilherme Silveira</name>
</writer>
<entries>
<xtream.Entry>
<title>first</title>
<description>My first blog entry.</description>
</xtream.Entry>
<xtream.Entry>
<title>tutorial</title>
<description>Today we have developed a nice alias tutorial. Tell your friends! NOW!</description>
</xtream.Entry>
</entries>
</xtream.Blog>

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<xtream.Blog>
<writer>
<name>Guilherme Silveira</name>
</writer>
<entries>
<xtream.Entry>
<title>first</title>
<description>My first blog entry.</description>
</xtream.Entry>
<xtream.Entry>
<title>tutorial</title>
<description>Today we have developed a nice alias tutorial. Tell your friends! NOW!</description>
</xtream.Entry>
</entries>
</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

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

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








<blog>
<writer>
<name>Guilherme Silveira</name>
</writer>
<entries>
<entry>
<title>first</title>
<description>My first blog entry.</description>
</entry>
<entry>
<title>tutorial</title>
<description>Today we have developed a nice alias tutorial. Tell your friends! NOW!</description>
</entry>
</entries>
</blog>

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<blog>
<writer>
<name>Guilherme Silveira</name>
</writer>
<entries>
<entry>
<title>first</title>
<description>My first blog entry.</description>
</entry>
<entry>
<title>tutorial</title>
<description>Today we have developed a nice alias tutorial. Tell your friends! NOW!</description>
</entry>
</entries>
</blog>

修改子节点属性名称

将writer属性名称修改为:autor

Java代码








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

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

输出如下:

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<blog>
<author>
<name>Guilherme Silveira</name>
</author>
<entries>
<entry>
<title>first</title>
<description>My first blog entry.</description>
</entry>
<entry>
<title>tutorial</title>
<description>Today we have developed a nice alias tutorial. Tell your friends! NOW!</description>
</entry>
</entries>
</blog>

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<blog>
<author>
<name>Guilherme Silveira</name>
</author>
<entries>
<entry>
<title>first</title>
<description>My first blog entry.</description>
</entry>
<entry>
<title>tutorial</title>
<description>Today we have developed a nice alias tutorial. Tell your friends! NOW!</description>
</entry>
</entries>
</blog>

删除集合节点名称的设置

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

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

输出如下:

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<blog>
<author>
<name>Guilherme Silveira</name>
</author>
<entry>
<title>first</title>
<description>My first blog entry.</description>
</entry>
<entry>
<title>tutorial</title>
<description>Today we have developed a nice alias tutorial. Tell your friends! NOW!</description>
</entry>
</blog>

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<blog>
<author>
<name>Guilherme Silveira</name>
</author>
<entry>
<title>first</title>
<description>My first blog entry.</description>
</entry>
<entry>
<title>tutorial</title>
<description>Today we have developed a nice alias tutorial. Tell your friends! NOW!</description>
</entry>
</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

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

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

//重新命名

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

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

//注册转换器

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xstream.registerConverter(new AuthorConverter());

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xstream.registerConverter(new AuthorConverter());

转换器:

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import com.thoughtworks.xstream.converters.SingleValueConverter;
class AuthorConverter implements SingleValueConverter {
//显示节点属性值
public String toString(Object obj) {
return ((Author) obj).getName();
}

public Object fromString(String name) {
return new Author(name);
}

public boolean canConvert(Class type) {
return type.equals(Author.class);
}
}

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import com.thoughtworks.xstream.converters.SingleValueConverter;
class AuthorConverter implements SingleValueConverter {
//显示节点属性值
public String toString(Object obj) {
return ((Author) obj).getName();
}

public Object fromString(String name) {
return new Author(name);
}

public boolean canConvert(Class type) {
return type.equals(Author.class);
}
}

显示结果:

Java代码








<blog author="Guilherme Silveira">
<entry>
<title>first</title>
<description>My first blog entry.</description>
</entry>
<entry>
<title>tutorial</title>
<description>Today we have developed a nice alias tutorial. Tell your friends! NOW!</description>
</entry>
</blog>

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<blog author="Guilherme Silveira">
<entry>
<title>first</title>
<description>My first blog entry.</description>
</entry>
<entry>
<title>tutorial</title>
<description>Today we have developed a nice alias tutorial. Tell your friends! NOW!</description>
</entry>
</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








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

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XStream xstream = new XStream();
xstream.processAnnotations(Blog.class);
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);

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@XStreamAlias("blog")
public class Blog {

@XStreamAlias("author")
private Author writer;

.....
}

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@XStreamAlias("blog")
public class Blog {

@XStreamAlias("author")
private Author writer;

.....
}

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








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

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xstream.useAttributeFor(Blog.class, "writer");
//重新命名
xstream.aliasField("author", Blog.class, "writer");
//注册转换器
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

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public AuthorConverter() {

}

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public AuthorConverter() {

}

b 类声明必须为:public

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public class AuthorConverter implements SingleValueConverter {
...
}

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public class AuthorConverter implements SingleValueConverter {
...
}

不用注解这二点都可以不强制要求!

完整代码如下:

Java代码








import com.thoughtworks.xstream.XStream;
import com.thoughtworks.xstream.annotations.XStreamAlias;
import com.thoughtworks.xstream.annotations.XStreamAsAttribute;
import com.thoughtworks.xstream.annotations.XStreamConverter;
import com.thoughtworks.xstream.annotations.XStreamImplicit;
@XStreamAlias("blog")
public class Blog {

@XStreamAsAttribute
@XStreamAlias("author")
@XStreamConverter(AuthorConverter.class)
private Author writer;

@XStreamImplicit
private List entries = new ArrayList();

public Blog(Author writer) {
this.writer = writer;
}

public void add(Entry entry) {
entries.add(entry);
}

public List getContent() {
return entries;
}

public static void main(String[] args) {

Blog teamBlog = new Blog(new Author("Guilherme Silveira"));
teamBlog.add(new Entry("first", "My first blog entry."));
teamBlog
.add(new Entry("tutorial",
"Today we have developed a nice alias tutorial. Tell your friends! NOW!"));
XStream xstream = new XStream();
xstream.processAnnotations(Blog.class);
xstream.processAnnotations(Entry.class);
// 重新命名节点名
// xstream.aliasPackage("", "xtream");
/*
* xstream.alias("blog", Blog.class); xstream.alias("entry",
* Entry.class); //重新命名属性名 // xstream.aliasField("author", Blog.class,
* "writer"); //去节点 xstream.addImplicitCollection(Blog.class,
* "entries"); // xstream.useAttributeFor(Blog.class, "writer"); //
* xstream.aliasField("author", Blog.class, "writer"); //
* xstream.addImplicitCollection(Blog.class, "entries");
* //使用这个属性名作为节点上的元素 xstream.useAttributeFor(Blog.class, "writer");
* //重新命名 xstream.aliasField("author", Blog.class, "writer"); //注册转换器
* xstream.registerConverter(new AuthorConverter());
*/
System.out.println(xstream.toXML(teamBlog));
}

}