xStream框架
xStream可以轻易的将Java对象和xml文档相互转换,而且可以修改某个特定的属性和节点名称,而且也支持json的转换;
前面有介绍过json-lib这个框架
以及Jackson这个框架
它们都完美支持JSON,但是对xml的支持还不是很好。一定程度上限制了对Java对象的描述,不能让xml完全体现到对Java对象的描述。这里将会介绍xStream对JSON、XML的完美支持。xStream不仅对XML的转换非常友好,而且提供annotation注解,可以在JavaBean中完成对xml节点、属性的描述。以及对JSON也支持,只需要提供相关的JSONDriver就可以完成转换。
一、准备工作
1、 下载jar包、及官方资源
xStream的jar下载地址:
官方的示例很全,官方参考示例:http://xstream.codehaus.org/tutorial.html
添加xstream-1.3.1.jar文件到工程中,就可以开始下面的工作;需要的jar如下:
2、 测试用例代码
package com.hoo.test; <!--CRLF-->
<!--CRLF-->
import java.io.IOException; <!--CRLF-->
import java.io.ObjectInputStream; <!--CRLF-->
import java.io.ObjectOutputStream; <!--CRLF-->
import java.io.StringReader; <!--CRLF-->
import java.io.Writer; <!--CRLF-->
import java.util.ArrayList; <!--CRLF-->
import java.util.HashMap; <!--CRLF-->
import java.util.Iterator; <!--CRLF-->
import java.util.List; <!--CRLF-->
import java.util.Map; <!--CRLF-->
import java.util.Set; <!--CRLF-->
import org.codehaus.jettison.json.JSONException; <!--CRLF-->
import org.junit.After; <!--CRLF-->
import org.junit.Before; <!--CRLF-->
import org.junit.Test; <!--CRLF-->
import com.hoo.entity.Birthday; <!--CRLF-->
import com.hoo.entity.Classes; <!--CRLF-->
import com.hoo.entity.ListBean; <!--CRLF-->
import com.hoo.entity.Student; <!--CRLF-->
import com.thoughtworks.xstream.XStream; <!--CRLF-->
import com.thoughtworks.xstream.io.HierarchicalStreamWriter; <!--CRLF-->
import com.thoughtworks.xstream.io.json.JettisonMappedXmlDriver; <!--CRLF-->
import com.thoughtworks.xstream.io.json.JsonHierarchicalStreamDriver; <!--CRLF-->
import com.thoughtworks.xstream.io.json.JsonWriter; <!--CRLF-->
<!--CRLF-->
/** <!--CRLF-->
* <b>function:</b>Java对象和XML字符串的相互转换 <!--CRLF-->
* jar-lib-version: xstream-1.3.1 <!--CRLF-->
* @author hoojo <!--CRLF-->
* @createDate Nov 27, 2010 12:15:15 PM <!--CRLF-->
* @file XStreamTest.java <!--CRLF-->
* @package com.hoo.test <!--CRLF-->
* @project WebHttpUtils <!--CRLF-->
* @blog <!--CRLF-->
* @email [email protected] <!--CRLF-->
* @version 1.0 <!--CRLF-->
*/ <!--CRLF-->
@SuppressWarnings("unchecked") <!--CRLF-->
public class XStreamTest { <!--CRLF-->
<!--CRLF-->
private XStream xstream = null; <!--CRLF-->
private ObjectOutputStream out = null; <!--CRLF-->
private ObjectInputStream in = null; <!--CRLF-->
<!--CRLF-->
private Student bean = null; <!--CRLF-->
<!--CRLF-->
/** <!--CRLF-->
* <b>function:</b>初始化资源准备 <!--CRLF-->
* @author hoojo <!--CRLF-->
* @createDate Nov 27, 2010 12:16:28 PM <!--CRLF-->
*/ <!--CRLF-->
@Before
<!--CRLF-->
public void init() { <!--CRLF-->
try { <!--CRLF-->
xstream = new XStream(); <!--CRLF-->
//xstream = new XStream(new DomDriver()); // 需要xpp3 jar <!--CRLF-->
} catch (Exception e) { <!--CRLF-->
e.printStackTrace();
<!--CRLF-->
}
<!--CRLF-->
bean = new Student(); <!--CRLF-->
bean.setAddress("china"); <!--CRLF-->
bean.setEmail("[email protected]"); <!--CRLF-->
bean.setId(1);
<!--CRLF-->
bean.setName("jack"); <!--CRLF-->
Birthday day = new Birthday(); <!--CRLF-->
day.setBirthday("2010-11-22"); <!--CRLF-->
bean.setBirthday(day);
<!--CRLF-->
}
<!--CRLF-->
<!--CRLF-->
/** <!--CRLF-->
* <b>function:</b>释放对象资源 <!--CRLF-->
* @author hoojo <!--CRLF-->
* @createDate Nov 27, 2010 12:16:38 PM <!--CRLF-->
*/ <!--CRLF-->
@After
<!--CRLF-->
public void destory() { <!--CRLF-->
xstream = null;
<!--CRLF-->
bean = null;
<!--CRLF-->
try { <!--CRLF-->
if (out != null) { <!--CRLF-->
out.flush();
<!--CRLF-->
out.close();
<!--CRLF-->
}
<!--CRLF-->
if (in != null) { <!--CRLF-->
in.close();
<!--CRLF-->
}
<!--CRLF-->
} catch (IOException e) { <!--CRLF-->
e.printStackTrace();
<!--CRLF-->
}
<!--CRLF-->
System.gc();
<!--CRLF-->
}
<!--CRLF-->
<!--CRLF-->
public final void fail(String string) { <!--CRLF-->
System.out.println(string);
<!--CRLF-->
}
<!--CRLF-->
<!--CRLF-->
public final void failRed(String string) { <!--CRLF-->
System.err.println(string);
<!--CRLF-->
}
<!--CRLF-->
}
通过XStream对象的toXML方法就可以完成Java对象到XML的转换,toXML方法还有2个相同签名的方法,需要传递一个流。然后通过流来完成xml信息的输出。
3、 需要的JavaBean
package com.hoo.entity; <!--CRLF-->
<!--CRLF-->
public class Student { <!--CRLF-->
private int id; <!--CRLF-->
private String name; <!--CRLF-->
private String email; <!--CRLF-->
private String address; <!--CRLF-->
private Birthday birthday; <!--CRLF-->
//getter、setter <!--CRLF-->
public String toString() { <!--CRLF-->
return this.name + "#" + this.id + "#" + this.address + "#" + this.birthday + "#" + this.email; <!--CRLF-->
}
<!--CRLF-->
}
二、Java转换成XML
1、 JavaBean转换XM
/** <!--CRLF-->
* <b>function:</b>Java对象转换成XML字符串 <!--CRLF-->
* @author hoojo <!--CRLF-->
* @createDate Nov 27, 2010 12:19:01 PM <!--CRLF-->
*/ <!--CRLF-->
@Test
<!--CRLF-->
public void writeBean2XML() { <!--CRLF-->
try { <!--CRLF-->
fail("------------Bean->XML------------"); <!--CRLF-->
fail(xstream.toXML(bean));
<!--CRLF-->
fail("重命名后的XML"); <!--CRLF-->
//类重命名 <!--CRLF-->
//xstream.alias("account", Student.class); <!--CRLF-->
//xstream.alias("生日", Birthday.class); <!--CRLF-->
//xstream.aliasField("生日", Student.class, "birthday"); <!--CRLF-->
//xstream.aliasField("生日", Birthday.class, "birthday"); <!--CRLF-->
//fail(xstream.toXML(bean)); <!--CRLF-->
//属性重命名 <!--CRLF-->
xstream.aliasField("邮件", Student.class, "email"); <!--CRLF-->
//包重命名 <!--CRLF-->
xstream.aliasPackage("hoo", "com.hoo.entity"); <!--CRLF-->
fail(xstream.toXML(bean));
<!--CRLF-->
} catch (Exception e) { <!--CRLF-->
e.printStackTrace();
<!--CRLF-->
}
<!--CRLF-->
}
看结果中的第一份xml内容,是没有经过然后修改或重命名的文档,按照原样输出。文档中的第二份文档的package经过重命名,email属性也经过重命名以及类名也可以进行重命名的。
运行后结果如下:
------------Bean->XML------------ <!--CRLF-->
<com.hoo.entity.Student> <!--CRLF-->
<id>1</id> <!--CRLF-->
<name>jack</name> <!--CRLF-->
<email>[email protected]</email> <!--CRLF-->
<address>china</address> <!--CRLF-->
<birthday> <!--CRLF-->
<birthday>2010-11-22</birthday> <!--CRLF-->
</birthday> <!--CRLF-->
</com.hoo.entity.Student> <!--CRLF-->
重命名后的XML
<!--CRLF-->
<hoo.Student> <!--CRLF-->
<id>1</id> <!--CRLF-->
<name>jack</name> <!--CRLF-->
<邮件>[email protected]</邮件> <!--CRLF-->
<address>china</address> <!--CRLF-->
<birthday> <!--CRLF-->
<birthday>2010-11-22</birthday> <!--CRLF-->
</birthday> <!--CRLF-->
</hoo.Student>
2、 将List集合转换成xml文档
/** <!--CRLF-->
* <b>function:</b>将Java的List集合转换成XML对象 <!--CRLF-->
* @author hoojo <!--CRLF-->
* @createDate Nov 27, 2010 12:20:07 PM <!--CRLF-->
*/ <!--CRLF-->
@Test
<!--CRLF-->
public void writeList2XML() { <!--CRLF-->
try { <!--CRLF-->
//修改元素名称 <!--CRLF-->
xstream.alias("beans", ListBean.class); <!--CRLF-->
xstream.alias("student", Student.class); <!--CRLF-->
fail("----------List-->XML----------"); <!--CRLF-->
ListBean listBean = new ListBean(); <!--CRLF-->
listBean.setName("this is a List Collection"); <!--CRLF-->
<!--CRLF-->
List<Object> list = new ArrayList<Object>(); <!--CRLF-->
list.add(bean);
<!--CRLF-->
list.add(bean);//引用bean <!--CRLF-->
//list.add(listBean);//引用listBean,父元素 <!--CRLF-->
<!--CRLF-->
bean = new Student(); <!--CRLF-->
bean.setAddress("china"); <!--CRLF-->
bean.setEmail("[email protected]"); <!--CRLF-->
bean.setId(2);
<!--CRLF-->
bean.setName("tom"); <!--CRLF-->
Birthday day = new Birthday("2010-11-22"); <!--CRLF-->
bean.setBirthday(day);
<!--CRLF-->
<!--CRLF-->
list.add(bean);
<!--CRLF-->
listBean.setList(list);
<!--CRLF-->
<!--CRLF-->
//将ListBean中的集合设置空元素,即不显示集合元素标签 <!--CRLF-->
//xstream.addImplicitCollection(ListBean.class, "list"); <!--CRLF-->
<!--CRLF-->
//设置reference模型 <!--CRLF-->
//xstream.setMode(XStream.NO_REFERENCES);//不引用 <!--CRLF-->
xstream.setMode(XStream.ID_REFERENCES);//id引用 <!--CRLF-->
//xstream.setMode(XStream.XPATH_ABSOLUTE_REFERENCES);//绝对路径引用 <!--CRLF-->
<!--CRLF-->
//将name设置为父类(Student)的元素的属性 <!--CRLF-->
xstream.useAttributeFor(Student.class, "name"); <!--CRLF-->
xstream.useAttributeFor(Birthday.class, "birthday"); <!--CRLF-->
//修改属性的name <!--CRLF-->
xstream.aliasAttribute("姓名", "name"); <!--CRLF-->
xstream.aliasField("生日", Birthday.class, "birthday"); <!--CRLF-->
<!--CRLF-->
fail(xstream.toXML(listBean));
<!--CRLF-->
} catch (Exception e) { <!--CRLF-->
e.printStackTrace();
<!--CRLF-->
}
<!--CRLF-->
}
上面的代码运行后,结果如下:
----------List-->XML---------- <!--CRLF-->
<beans id="1"> <!--CRLF-->
<name>this is a List Collection</name> <!--CRLF-->
<list id="2"> <!--CRLF-->
<student id="3" 姓名="jack"> <!--CRLF-->
<id>1</id> <!--CRLF-->
<email>[email protected]</email> <!--CRLF-->
<address>china</address> <!--CRLF-->
<birthday id="4" 生日="2010-11-22"/> <!--CRLF-->
</student> <!--CRLF-->
<student reference="3"/> <!--CRLF-->
<student id="5" 姓名="tom"> <!--CRLF-->
<id>2</id> <!--CRLF-->
<email>[email protected]</email> <!--CRLF-->
<address>china</address> <!--CRLF-->
<birthday id="6" 生日="2010-11-22"/> <!--CRLF-->
</student> <!--CRLF-->
</list> <!--CRLF-->
</beans>
如果不加xstream.addImplicitCollection(ListBean.class, "list");
这个设置的话,会出现一个List节点包裹着Student节点元素。添加addImplicitCollection可以忽略这个list节点元素。那么上面的list节点就不存在,只会在beans元素中出现name、student这2个xml元素标签;
setMode是设置相同的对象的引用方式,如果设置XStream.NO_REFERENCES就是不引用,会输出2分相同的Student元素。如果是XStream.ID_REFERENCES会引用相同的那个对象的id属性,如果是XStream.XPATH_ABSOLUTE_REFERENCES引用,那么它将显示xpath路径。上面采用的id引用,<student reference="3"/>这个引用了id=3的那个student标签元素;
useAttributeFor是设置某个节点显示到父节点的属性中,也就是将指定class中的指定属性,在这个class元素节点的属性中显示。
如:<student><name>hoojo</name></student>
设置好后就是这样的结果:<student name=”hoojo”></student>
aliasAttribute是修改属性名称。
3、 在JavaBean中添加Annotation注解进行重命名设置
先看看JavaBean的代码
package com.hoo.entity; <!--CRLF-->
<!--CRLF-->
import java.util.Arrays; <!--CRLF-->
import java.util.Calendar; <!--CRLF-->
import java.util.GregorianCalendar; <!--CRLF-->
import java.util.List; <!--CRLF-->
import com.thoughtworks.xstream.annotations.XStreamAlias; <!--CRLF-->
import com.thoughtworks.xstream.annotations.XStreamAsAttribute; <!--CRLF-->
import com.thoughtworks.xstream.annotations.XStreamConverter; <!--CRLF-->
import com.thoughtworks.xstream.annotations.XStreamImplicit; <!--CRLF-->
import com.thoughtworks.xstream.annotations.XStreamOmitField; <!--CRLF-->
<!--CRLF-->
@XStreamAlias("class") <!--CRLF-->
public class Classes { <!--CRLF-->
<!--CRLF-->
/* <!--CRLF-->
* 设置属性显示 <!--CRLF-->
*/ <!--CRLF-->
@XStreamAsAttribute
<!--CRLF-->
@XStreamAlias("名称") <!--CRLF-->
private String name; <!--CRLF-->
<!--CRLF-->
/* <!--CRLF-->
* 忽略 <!--CRLF-->
*/ <!--CRLF-->
@XStreamOmitField
<!--CRLF-->
private int number; <!--CRLF-->
<!--CRLF-->
@XStreamImplicit(itemFieldName = "Students") <!--CRLF-->
private List<Student> students; <!--CRLF-->
<!--CRLF-->
@SuppressWarnings("unused") <!--CRLF-->
@XStreamConverter(SingleValueCalendarConverter.class) <!--CRLF-->
private Calendar created = new GregorianCalendar(); <!--CRLF-->
<!--CRLF-->
<!--CRLF-->
public Classes(){} <!--CRLF-->
public Classes(String name, Student... stu) { <!--CRLF-->
this.name = name; <!--CRLF-->
this.students = Arrays.asList(stu); <!--CRLF-->
}
<!--CRLF-->
//getter、setter <!--CRLF-->
}
SingleValueCalendarConverter.java这个是一个类型转换器
package com.hoo.entity; <!--CRLF-->
<!--CRLF-->
import java.util.Calendar; <!--CRLF-->
import java.util.Date; <!--CRLF-->
import java.util.GregorianCalendar; <!--CRLF-->
import com.thoughtworks.xstream.converters.Converter; <!--CRLF-->
import com.thoughtworks.xstream.converters.MarshallingContext; <!--CRLF-->
import com.thoughtworks.xstream.converters.UnmarshallingContext; <!--CRLF-->
import com.thoughtworks.xstream.io.HierarchicalStreamReader; <!--CRLF-->
import com.thoughtworks.xstream.io.HierarchicalStreamWriter; <!--CRLF-->
<!--CRLF-->
public class SingleValueCalendarConverter implements Converter { <!--CRLF-->
public void marshal(Object source, HierarchicalStreamWriter writer, <!--CRLF-->
MarshallingContext context) {
<!--CRLF-->
Calendar calendar = (Calendar) source;
<!--CRLF-->
writer.setValue(String.valueOf(calendar.getTime().getTime()));
<!--CRLF-->
}
<!--CRLF-->
<!--CRLF-->
public Object unmarshal(HierarchicalStreamReader reader, <!--CRLF-->
UnmarshallingContext context) {
<!--CRLF-->
GregorianCalendar calendar = new GregorianCalendar(); <!--CRLF-->
calendar.setTime(new Date(Long.parseLong(reader.getValue()))); <!--CRLF-->
return calendar; <!--CRLF-->
}
<!--CRLF-->
<!--CRLF-->
@SuppressWarnings("unchecked") <!--CRLF-->
public boolean canConvert(Class type) { <!--CRLF-->
return type.equals(GregorianCalendar.class); <!--CRLF-->
}
<!--CRLF-->
}
再看看测试用例代码
@Test
<!--CRLF-->
public void writeList2XML4Annotation() { <!--CRLF-->
try { <!--CRLF-->
failRed("---------annotation Bean --> XML---------"); <!--CRLF-->
Student stu = new Student(); <!--CRLF-->
stu.setName("jack"); <!--CRLF-->
Classes c = new Classes("一班", bean, stu); <!--CRLF-->
c.setNumber(2);
<!--CRLF-->
//对指定的类使用Annotation <!--CRLF-->
//xstream.processAnnotations(Classes.class); <!--CRLF-->
//启用Annotation <!--CRLF-->
//xstream.autodetectAnnotations(true); <!--CRLF-->
xstream.alias("student", Student.class); <!--CRLF-->
fail(xstream.toXML(c));
<!--CRLF-->
} catch (Exception e) { <!--CRLF-->
e.printStackTrace();
<!--CRLF-->
}
<!--CRLF-->
}
当启用annotation或是对某个特定的类启用annotation时,上面的classes这个类才有效果。如果不启用annotation,运行后结果如下:
---------annotation Bean --> XML--------- <!--CRLF-->
<com.hoo.entity.Classes> <!--CRLF-->
<name>一班</name> <!--CRLF-->
<number>2</number> <!--CRLF-->
<students class="java.util.Arrays$ArrayList"> <!--CRLF-->
<a class="student-array"> <!--CRLF-->
<student> <!--CRLF-->
<id>1</id> <!--CRLF-->
<name>jack</name> <!--CRLF-->
<email>[email protected]</email> <!--CRLF-->
<address>china</address> <!--CRLF-->
<birthday> <!--CRLF-->
<birthday>2010-11-22</birthday> <!--CRLF-->
</birthday> <!--CRLF-->
</student> <!--CRLF-->
<student> <!--CRLF-->
<id>0</id> <!--CRLF-->
<name>jack</name> <!--CRLF-->
</student> <!--CRLF-->
</a> <!--CRLF-->
</students> <!--CRLF-->
<created> <!--CRLF-->
<time>1303292056718</time> <!--CRLF-->
<timezone>Asia/Shanghai</timezone> <!--CRLF-->
</created> <!--CRLF-->
</com.hoo.entity.Classes>
当启用annotation后xstream.processAnnotations(Classes.class),结果如下:
---------annotation Bean --> XML--------- <!--CRLF-->
<class 名称="一班"> <!--CRLF-->
<Students> <!--CRLF-->
<id>1</id> <!--CRLF-->
<name>jack</name> <!--CRLF-->
<email>[email protected]</email> <!--CRLF-->
<address>china</address> <!--CRLF-->
<birthday> <!--CRLF-->
<birthday>2010-11-22</birthday> <!--CRLF-->
</birthday> <!--CRLF-->
</Students> <!--CRLF-->
<Students> <!--CRLF-->
<id>0</id> <!--CRLF-->
<name>jack</name> <!--CRLF-->
</Students> <!--CRLF-->
<created>1303292242937</created> <!--CRLF-->
</class>
4、 Map集合转换xml文档
/** <!--CRLF-->
* <b>function:</b>Java Map集合转XML <!--CRLF-->
* @author hoojo <!--CRLF-->
* @createDate Nov 27, 2010 1:13:26 PM <!--CRLF-->
*/ <!--CRLF-->
@Test
<!--CRLF-->
public void writeMap2XML() { <!--CRLF-->
try { <!--CRLF-->
failRed("---------Map --> XML---------"); <!--CRLF-->
Map<String, Student> map = new HashMap<String, Student>(); <!--CRLF-->
map.put("No.1", bean);//put <!--CRLF-->
<!--CRLF-->
bean = new Student(); <!--CRLF-->
bean.setAddress("china"); <!--CRLF-->
bean.setEmail("[email protected]"); <!--CRLF-->
bean.setId(2);
<!--CRLF-->
bean.setName("tom"); <!--CRLF-->
Birthday day = new Birthday("2010-11-22"); <!--CRLF-->
bean.setBirthday(day);
<!--CRLF-->
map.put("No.2", bean);//put <!--CRLF-->
<!--CRLF-->
bean = new Student(); <!--CRLF-->
bean.setName("jack"); <!--CRLF-->
map.put("No.3", bean);//put <!--CRLF-->
<!--CRLF-->
xstream.alias("student", Student.class); <!--CRLF-->
xstream.alias("key", String.class); <!--CRLF-->
xstream.useAttributeFor(Student.class, "id"); <!--CRLF-->
xstream.useAttributeFor("birthday", String.class); <!--CRLF-->
fail(xstream.toXML(map));
<!--CRLF-->
} catch (Exception e) { <!--CRLF-->
e.printStackTrace();
<!--CRLF-->
}
<!--CRLF-->
}
运行后结果如下:
---------Map --> XML--------- <!--CRLF-->
<map> <!--CRLF-->
<entry> <!--CRLF-->
<key>No.3</key> <!--CRLF-->
<student id="0"> <!--CRLF-->
<name>jack</name> <!--CRLF-->
</student> <!--CRLF-->
</entry> <!--CRLF-->
<entry> <!--CRLF-->
<key>No.1</key> <!--CRLF-->
<student id="1"> <!--CRLF-->
<name>jack</name> <!--CRLF-->
<email>[email protected]</email> <!--CRLF-->
<address>china</address> <!--CRLF-->
<birthday birthday="2010-11-22"/> <!--CRLF-->
</student> <!--CRLF-->
</entry> <!--CRLF-->
<entry> <!--CRLF-->
<key>No.2</key> <!--CRLF-->
<student id="2"> <!--CRLF-->
<name>tom</name> <!--CRLF-->
<email>[email protected]</email> <!--CRLF-->
<address>china</address> <!--CRLF-->
<birthday birthday="2010-11-22"/> <!--CRLF-->
</student> <!--CRLF-->
</entry> <!--CRLF-->
</map>
5、 用OutStream输出流写XML
/** <!--CRLF-->
* <b>function:</b>用OutStream输出流写XML <!--CRLF-->
* @author hoojo <!--CRLF-->
* @createDate Nov 27, 2010 1:13:48 PM <!--CRLF-->
*/ <!--CRLF-->
@Test
<!--CRLF-->
public void writeXML4OutStream() { <!--CRLF-->
try { <!--CRLF-->
out = xstream.createObjectOutputStream(System.out);
<!--CRLF-->
Student stu = new Student(); <!--CRLF-->
stu.setName("jack"); <!--CRLF-->
Classes c = new Classes("一班", bean, stu); <!--CRLF-->
c.setNumber(2);
<!--CRLF-->
failRed("---------ObjectOutputStream # JavaObject--> XML---------"); <!--CRLF-->
out.writeObject(stu);
<!--CRLF-->
out.writeObject(new Birthday("2010-05-33")); <!--CRLF-->
out.write(22);//byte <!--CRLF-->
out.writeBoolean(true);
<!--CRLF-->
out.writeFloat(22.f);
<!--CRLF-->
out.writeUTF("hello"); <!--CRLF-->
<!--CRLF-->
} catch (Exception e) { <!--CRLF-->
e.printStackTrace();
<!--CRLF-->
}
<!--CRLF-->
}
使用输出流后,可以通过流对象完成xml的构建,即使没有JavaBean对象,你可以用流来构建一个复杂的xml文档,运行后结果如下:
---------ObjectOutputStream # JavaObject--> XML--------- <!--CRLF-->
<object-stream> <!--CRLF-->
<com.hoo.entity.Student> <!--CRLF-->
<id>0</id> <!--CRLF-->
<name>jack</name> <!--CRLF-->
</com.hoo.entity.Student> <!--CRLF-->
<com.hoo.entity.Birthday> <!--CRLF-->
<birthday>2010-05-33</birthday> <!--CRLF-->
</com.hoo.entity.Birthday> <!--CRLF-->
<byte>22</byte> <!--CRLF-->
<boolean>true</boolean> <!--CRLF-->
<float>22.0</float> <!--CRLF-->
<string>hello</string> <!--CRLF-->
</object-stream>
三、XML内容转换Java对象
1、 用InputStream将XML文档转换成java对象
/** <!--CRLF-->
* <b>function:</b>用InputStream将XML文档转换成java对象 <!--CRLF-->
* 需要额外的jar xpp3-main.jar <!--CRLF-->
* @author hoojo <!--CRLF-->
* @createDate Nov 27, 2010 1:14:52 PM <!--CRLF-->
*/ <!--CRLF-->
@Test
<!--CRLF-->
public void readXML4InputStream() { <!--CRLF-->
try { <!--CRLF-->
String s = "<object-stream><com.hoo.entity.Student><id>0</id><name>jack</name>" + <!--CRLF-->
"</com.hoo.entity.Student><com.hoo.entity.Birthday><birthday>2010-05-33</birthday>" + <!--CRLF-->
"</com.hoo.entity.Birthday><byte>22</byte><boolean>true</boolean><float>22.0</float>" + <!--CRLF-->
"<string>hello</string></object-stream>"; <!--CRLF-->
failRed("---------ObjectInputStream## XML --> javaObject---------"); <!--CRLF-->
StringReader reader = new StringReader(s); <!--CRLF-->
in = xstream.createObjectInputStream(reader);
<!--CRLF-->
Student stu = (Student) in.readObject();
<!--CRLF-->
Birthday b = (Birthday) in.readObject();
<!--CRLF-->
byte i = in.readByte(); <!--CRLF-->
boolean bo = in.readBoolean(); <!--CRLF-->
float f = in.readFloat(); <!--CRLF-->
String str = in.readUTF();
<!--CRLF-->
System.out.println(stu);
<!--CRLF-->
System.out.println(b);
<!--CRLF-->
System.out.println(i);
<!--CRLF-->
System.out.println(bo);
<!--CRLF-->
System.out.println(f);
<!--CRLF-->
System.out.println(str);
<!--CRLF-->
} catch (Exception e) { <!--CRLF-->
e.printStackTrace();
<!--CRLF-->
}
<!--CRLF-->
}
读取后,转换的Java对象,结果如下:
---------ObjectInputStream## XML --> javaObject---------
<!--CRLF-->
jack#0#null#null#null
<!--CRLF-->
2010-05-33
<!--CRLF-->
22
<!--CRLF-->
true
<!--CRLF-->
22.0
<!--CRLF-->
hello
2、 将xml文档转换成Java对象
/** <!--CRLF-->
* <b>function:</b>将XML字符串转换成Java对象 <!--CRLF-->
* @author hoojo <!--CRLF-->
* @createDate Nov 27, 2010 2:39:06 PM <!--CRLF-->
*/ <!--CRLF-->
@Test
<!--CRLF-->
public void readXml2Object() { <!--CRLF-->
try { <!--CRLF-->
failRed("-----------Xml >>> Bean--------------"); <!--CRLF-->
Student stu = (Student) xstream.fromXML(xstream.toXML(bean));
<!--CRLF-->
fail(stu.toString());
<!--CRLF-->
<!--CRLF-->
List<Student> list = new ArrayList<Student>(); <!--CRLF-->
list.add(bean);//add <!--CRLF-->
<!--CRLF-->
Map<String, Student> map = new HashMap<String, Student>(); <!--CRLF-->
map.put("No.1", bean);//put <!--CRLF-->
<!--CRLF-->
bean = new Student(); <!--CRLF-->
bean.setAddress("china"); <!--CRLF-->
bean.setEmail("[email protected]"); <!--CRLF-->
bean.setId(2);
<!--CRLF-->
bean.setName("tom"); <!--CRLF-->
Birthday day = new Birthday("2010-11-22"); <!--CRLF-->
bean.setBirthday(day);
<!--CRLF-->
list.add(bean);//add <!--CRLF-->
map.put("No.2", bean);//put <!--CRLF-->
<!--CRLF-->
bean = new Student(); <!--CRLF-->
bean.setName("jack"); <!--CRLF-->
list.add(bean);//add <!--CRLF-->
map.put("No.3", bean);//put <!--CRLF-->
<!--CRLF-->
failRed("==========XML >>> List==========="); <!--CRLF-->
List<Student> studetns = (List<Student>) xstream.fromXML(xstream.toXML(list));
<!--CRLF-->
fail("size:" + studetns.size());//3 <!--CRLF-->
for (Student s : studetns) { <!--CRLF-->
fail(s.toString());
<!--CRLF-->
}
<!--CRLF-->
<!--CRLF-->
failRed("==========XML >>> Map==========="); <!--CRLF-->
Map<String, Student> maps = (Map<String, Student>) xstream.fromXML(xstream.toXML(map));
<!--CRLF-->
fail("size:" + maps.size());//3 <!--CRLF-->
Set<String> key = maps.keySet();
<!--CRLF-->
Iterator<String> iter = key.iterator();
<!--CRLF-->
while (iter.hasNext()) { <!--CRLF-->
String k = iter.next();
<!--CRLF-->
fail(k + ":" + map.get(k)); <!--CRLF-->
}
<!--CRLF-->
} catch (Exception e) { <!--CRLF-->
e.printStackTrace();
<!--CRLF-->
}
<!--CRLF-->
}
运行后结果如下:
-----------Xml >>> Bean--------------
<!--CRLF-->
jack#1#china#2010-11-22#[email protected]
<!--CRLF-->
==========XML >>> List===========
<!--CRLF-->
size:3
<!--CRLF-->
jack#1#china#2010-11-22#[email protected]
<!--CRLF-->
tom#2#china#2010-11-22#[email protected]
<!--CRLF-->
jack#0#null#null#null
<!--CRLF-->
==========XML >>> Map===========
<!--CRLF-->
size:3
<!--CRLF-->
No.3:jack#0#null#null#null
<!--CRLF-->
No.1:jack#1#china#2010-11-22#[email protected]
<!--CRLF-->
No.2:tom#2#china#2010-11-22#[email protected]
怎么样,成功的完成XML到JavaBean、List、Map的转换,更多对象转换还需要大家一一尝试。用法类似~这里就不一样赘述。
四、XStream对JSON的支持
xStream对JSON也有非常好的支持,它提供了2个模型驱动。用这2个驱动可以完成Java对象到JSON的相互转换。使用JettisonMappedXmlDriver驱动,将Java对象转换成json,需要添加jettison.jar
1、 用JettisonMappedXmlDriver完成Java对象到JSON的转换
/** <!--CRLF-->
* <b>function:</b>XStream结合JettisonMappedXmlDriver驱动,转换Java对象到JSON <!--CRLF-->
* 需要添加jettison jar <!--CRLF-->
* @author hoojo <!--CRLF-->
* @createDate Nov 27, 2010 1:23:18 PM <!--CRLF-->
*/ <!--CRLF-->
@Test
<!--CRLF-->
public void writeEntity2JETTSON() { <!--CRLF-->
failRed("=======JettisonMappedXmlDriver===JavaObject >>>> JaonString========="); <!--CRLF-->
xstream = new XStream(new JettisonMappedXmlDriver()); <!--CRLF-->
xstream.setMode(XStream.NO_REFERENCES);
<!--CRLF-->
xstream.alias("student", Student.class); <!--CRLF-->
fail(xstream.toXML(bean));
<!--CRLF-->
}
运行后结果如下:
=======JettisonMappedXmlDriver===JavaObject >>>> JaonString=========
<!--CRLF-->
{"student":{"id":1,"name":"jack","email":"[email protected]","address":"china","birthday":[{},"2010-11-22"]}}
JSON的转换和XML的转换用法一样,只是创建XStream需要传递一个参数,这个参数就是xml到JSON映射转换的驱动。这里会降到两个驱动,分别是JettisonMappedXmlDriver、JsonHierarchicalStreamDriver。
2、 JsonHierarchicalStreamDriver完成Java对象到JSON的转换
/** <!--CRLF-->
* <b>function:</b>用XStream结合JsonHierarchicalStreamDriver驱动 <!--CRLF-->
* 转换java对象为JSON字符串 <!--CRLF-->
* @author hoojo <!--CRLF-->
* @createDate Nov 27, 2010 1:16:46 PM <!--CRLF-->
*/ <!--CRLF-->
@Test
<!--CRLF-->
public void writeEntiry2JSON() { <!--CRLF-->
failRed("======JsonHierarchicalStreamDriver====JavaObject >>>> JaonString========="); <!--CRLF-->
xstream = new XStream(new JsonHierarchicalStreamDriver()); <!--CRLF-->
//xstream.setMode(XStream.NO_REFERENCES); <!--CRLF-->
xstream.alias("student", Student.class); <!--CRLF-->
failRed("-------Object >>>> JSON---------"); <!--CRLF-->
fail(xstream.toXML(bean));
<!--CRLF-->
<!--CRLF-->
//failRed("========JsonHierarchicalStreamDriver==删除根节点========="); <!--CRLF-->
//删除根节点 <!--CRLF-->
xstream = new XStream(new JsonHierarchicalStreamDriver() { <!--CRLF-->
public HierarchicalStreamWriter createWriter(Writer out) { <!--CRLF-->
return new JsonWriter(out, JsonWriter.DROP_ROOT_MODE); <!--CRLF-->
}
<!--CRLF-->
});
<!--CRLF-->
//xstream.setMode(XStream.NO_REFERENCES); <!--CRLF-->
xstream.alias("student", Student.class); <!--CRLF-->
fail(xstream.toXML(bean));
<!--CRLF-->
}
运行后结果如下:
======JsonHierarchicalStreamDriver====JavaObject >>>> JaonString=========
<!--CRLF-->
-------Object >>>> JSON---------
<!--CRLF-->
{"student": { <!--CRLF-->
"id": 1, <!--CRLF-->
"name": "jack", <!--CRLF-->
"email": "[email protected]", <!--CRLF-->
"address": "china", <!--CRLF-->
"birthday": { <!--CRLF-->
"birthday": "2010-11-22" <!--CRLF-->
}
<!--CRLF-->
}}
<!--CRLF-->
{
<!--CRLF-->
"id": 1, <!--CRLF-->
"name": "jack", <!--CRLF-->
"email": "[email protected]", <!--CRLF-->
"address": "china", <!--CRLF-->
"birthday": { <!--CRLF-->
"birthday": "2010-11-22" <!--CRLF-->
}
<!--CRLF-->
}
使用JsonHierarchicalStreamDriver转换默认会给转换后的对象添加一个根节点,但是在构建JsonHierarchicalStreamDriver驱动的时候,你可以重写createWriter方法,删掉根节点。
看上面的结果,一个是默认带根节点的JSON对象,它只是将类名作为一个属性,将对象作为该属性的一个值。而另一个没有带根属性的JSON就是通过重写createWriter方法完成的。
3、 将List集合转换成JSON字符串
@Test
<!--CRLF-->
public void writeList2JSON() { <!--CRLF-->
failRed("======JsonHierarchicalStreamDriver====JavaObject >>>> JaonString========="); <!--CRLF-->
JsonHierarchicalStreamDriver driver = new JsonHierarchicalStreamDriver(); <!--CRLF-->
xstream = new XStream(driver); <!--CRLF-->
//xstream = new XStream(new JettisonMappedXmlDriver());//转换错误 <!--CRLF-->
//xstream.setMode(XStream.NO_REFERENCES); <!--CRLF-->
xstream.alias("student", Student.class); <!--CRLF-->
<!--CRLF-->
List<Student> list = new ArrayList<Student>(); <!--CRLF-->
list.add(bean);//add <!--CRLF-->
<!--CRLF-->
bean = new Student(); <!--CRLF-->
bean.setAddress("china"); <!--CRLF-->
bean.setEmail("[email protected]"); <!--CRLF-->
bean.setId(2);
<!--CRLF-->
bean.setName("tom"); <!--CRLF-->
Birthday day = new Birthday("2010-11-22"); <!--CRLF-->
bean.setBirthday(day);
<!--CRLF-->
list.add(bean);//add <!--CRLF-->
<!--CRLF-->
bean = new Student(); <!--CRLF-->
bean.setName("jack"); <!--CRLF-->
list.add(bean);//add <!--CRLF-->
<!--CRLF-->
fail(xstream.toXML(list));
<!--CRLF-->
<!--CRLF-->
//failRed("========JsonHierarchicalStreamDriver==删除根节点========="); <!--CRLF-->
//删除根节点 <!--CRLF-->
xstream = new XStream(new JsonHierarchicalStreamDriver() { <!--CRLF-->
public HierarchicalStreamWriter createWriter(Writer out) { <!--CRLF-->
return new JsonWriter(out, JsonWriter.DROP_ROOT_MODE); <!--CRLF-->
}
<!--CRLF-->
});
<!--CRLF-->
xstream.alias("student", Student.class); <!--CRLF-->
fail(xstream.toXML(list));
<!--CRLF-->
}
运行后结果如下
======JsonHierarchicalStreamDriver====JavaObject >>>> JaonString=========
<!--CRLF-->
##{"list": [ <!--CRLF-->
{
<!--CRLF-->
"id": 1, <!--CRLF-->
"name": "jack", <!--CRLF-->
"email": "[email protected]", <!--CRLF-->
"address": "china", <!--CRLF-->
"birthday": { <!--CRLF-->
"birthday": "2010-11-22" <!--CRLF-->
}
<!--CRLF-->
},
<!--CRLF-->
{
<!--CRLF-->
"id": 2, <!--CRLF-->
"name": "tom", <!--CRLF-->
"email": "[email protected]", <!--CRLF-->
"address": "china", <!--CRLF-->
"birthday": { <!--CRLF-->
"birthday": "2010-11-22" <!--CRLF-->
}
<!--CRLF-->
},
<!--CRLF-->
{
<!--CRLF-->
"id": 0, <!--CRLF-->
"name": "jack" <!--CRLF-->
}
<!--CRLF-->
]}
<!--CRLF-->
#[
<!--CRLF-->
{
<!--CRLF-->
"id": 1, <!--CRLF-->
"name": "jack", <!--CRLF-->
"email": "[email protected]", <!--CRLF-->
"address": "china", <!--CRLF-->
"birthday": { <!--CRLF-->
"birthday": "2010-11-22" <!--CRLF-->
}
<!--CRLF-->
},
<!--CRLF-->
{
<!--CRLF-->
"id": 2, <!--CRLF-->
"name": "tom", <!--CRLF-->
"email": "[email protected]", <!--CRLF-->
"address": "china", <!--CRLF-->
"birthday": { <!--CRLF-->
"birthday": "2010-11-22" <!--CRLF-->
}
<!--CRLF-->
},
<!--CRLF-->
{
<!--CRLF-->
"id": 0, <!--CRLF-->
"name": "jack" <!--CRLF-->
}
<!--CRLF-->
]
上面的list1是使用JsonHierarchicalStreamDriver 转换的,当然你也可以使用JettisonMappedXmlDriver驱动进行转换;用JettisonMappedXmlDriver转换后,你会发现格式不同而且没有根属性。
4、 Map转换json
@Test
<!--CRLF-->
public void writeMap2JSON() { <!--CRLF-->
failRed("======JsonHierarchicalStreamDriver==== Map >>>> JaonString========="); <!--CRLF-->
xstream = new XStream(new JsonHierarchicalStreamDriver()); <!--CRLF-->
//xstream = new XStream(new JettisonMappedXmlDriver()); <!--CRLF-->
xstream.alias("student", Student.class); <!--CRLF-->
<!--CRLF-->
Map<String, Student> map = new HashMap<String, Student>(); <!--CRLF-->
map.put("No.1", bean);//put <!--CRLF-->
<!--CRLF-->
bean = new Student(); <!--CRLF-->
bean.setAddress("china"); <!--CRLF-->
bean.setEmail("[email protected]"); <!--CRLF-->
bean.setId(2);
<!--CRLF-->
bean.setName("tom"); <!--CRLF-->
bean.setBirthday(new Birthday("2010-11-21")); <!--CRLF-->
map.put("No.2", bean);//put <!--CRLF-->
<!--CRLF-->
bean = new Student(); <!--CRLF-->
bean.setName("jack"); <!--CRLF-->
map.put("No.3", bean);//put <!--CRLF-->
<!--CRLF-->
fail(xstream.toXML(map));
<!--CRLF-->
<!--CRLF-->
//failRed("========JsonHierarchicalStreamDriver==删除根节点========="); <!--CRLF-->
//删除根节点 <!--CRLF-->
xstream = new XStream(new JsonHierarchicalStreamDriver() { <!--CRLF-->
public HierarchicalStreamWriter createWriter(Writer out) { <!--CRLF-->
return new JsonWriter(out, JsonWriter.DROP_ROOT_MODE); <!--CRLF-->
}
<!--CRLF-->
});
<!--CRLF-->
xstream.alias("student", Student.class); <!--CRLF-->
fail(xstream.toXML(map));
<!--CRLF-->
}
运行后结果如下:
======JsonHierarchicalStreamDriver==== Map >>>> JaonString=========
<!--CRLF-->
{"map": [ <!--CRLF-->
[
<!--CRLF-->
"No.3", <!--CRLF-->
{
<!--CRLF-->
"id": 0, <!--CRLF-->
"name": "jack" <!--CRLF-->
}
<!--CRLF-->
],
<!--CRLF-->
[
<!--CRLF-->
"No.1", <!--CRLF-->
{
<!--CRLF-->
"id": 1, <!--CRLF-->
"name": "jack", <!--CRLF-->
"email": "[email protected]", <!--CRLF-->
"address": "china", <!--CRLF-->
"birthday": { <!--CRLF-->
"birthday": "2010-11-22" <!--CRLF-->
}
<!--CRLF-->
}
<!--CRLF-->
],
<!--CRLF-->
[
<!--CRLF-->
"No.2", <!--CRLF-->
{
<!--CRLF-->
"id": 2, <!--CRLF-->
"name": "tom", <!--CRLF-->
"email": "[email protected]", <!--CRLF-->
"address": "china", <!--CRLF-->
"birthday": { <!--CRLF-->
"birthday": "2010-11-21" <!--CRLF-->
}
<!--CRLF-->
}
<!--CRLF-->
]
<!--CRLF-->
]}
<!--CRLF-->
[
<!--CRLF-->
[
<!--CRLF-->
"No.3", <!--CRLF-->
{
<!--CRLF-->
"id": 0, <!--CRLF-->
"name": "jack" <!--CRLF-->
}
<!--CRLF-->
],
<!--CRLF-->
[
<!--CRLF-->
"No.1", <!--CRLF-->
{
<!--CRLF-->
"id": 1, <!--CRLF-->
"name": "jack", <!--CRLF-->
"email": "[email protected]", <!--CRLF-->
"address": "china", <!--CRLF-->
"birthday": { <!--CRLF-->
"birthday": "2010-11-22" <!--CRLF-->
}
<!--CRLF-->
}
<!--CRLF-->
],
<!--CRLF-->
[
<!--CRLF-->
"No.2", <!--CRLF-->
{
<!--CRLF-->
"id": 2, <!--CRLF-->
"name": "tom", <!--CRLF-->
"email": "[email protected]", <!--CRLF-->
"address": "china", <!--CRLF-->
"birthday": { <!--CRLF-->
"birthday": "2010-11-21" <!--CRLF-->
}
<!--CRLF-->
}
<!--CRLF-->
]
<!--CRLF-->
]
5、 将JSON转换java对象
/** <!--CRLF-->
* <b>function:</b>JsonHierarchicalStreamDriver可以将简单的json字符串转换成java对象,list、map转换不成功; <!--CRLF-->
* JsonHierarchicalStreamDriver读取JSON字符串到java对象出错 <!--CRLF-->
* @author hoojo <!--CRLF-->
* @createDate Nov 27, 2010 1:22:26 PM <!--CRLF-->
* @throws JSONException <!--CRLF-->
*/ <!--CRLF-->
@Test
<!--CRLF-->
public void readJSON2Object() throws JSONException { <!--CRLF-->
String json = "{/"student/": {" + <!--CRLF-->
"/"id/": 1," + <!--CRLF-->
"/"name/": /"haha/"," + <!--CRLF-->
"/"email/": /"email/"," + <!--CRLF-->
"/"address/": /"address/"," + <!--CRLF-->
"/"birthday/": {" + <!--CRLF-->
"/"birthday/": /"2010-11-22/"" + <!--CRLF-->
"}" + <!--CRLF-->
"}}"; <!--CRLF-->
//JsonHierarchicalStreamDriver读取JSON字符串到java对象出错,但JettisonMappedXmlDriver可以 <!--CRLF-->
xstream = new XStream(new JettisonMappedXmlDriver()); <!--CRLF-->
xstream.alias("student", Student.class); <!--CRLF-->
fail(xstream.fromXML(json).toString());
<!--CRLF-->
<!--CRLF-->
//JettisonMappedXmlDriver转换List集合出错,但JsonHierarchicalStreamDriver可以转换正确 <!--CRLF-->
//JettisonMappedXmlDriver 转换的字符串 {"list":{"student":[{"id":1,"name":"haha","email":"email","address":"address","birthday":[{},"2010-11-22"]}]},"student":{"id":2,"name":"tom","email":"[email protected]","address":"china","birthday":[{},"2010-11-22"]}} <!--CRLF-->
json = "{/"list/": [{" + <!--CRLF-->
"/"id/": 1," + <!--CRLF-->
"/"name/": /"haha/"," + <!--CRLF-->
"/"email/": /"email/"," + <!--CRLF-->
"/"address/": /"address/"," + <!--CRLF-->
"/"birthday/": {" + <!--CRLF-->
"/"birthday/": /"2010-11-22/"" + <!--CRLF-->
"}" + <!--CRLF-->
"},{" + <!--CRLF-->
"/"id/": 2," + <!--CRLF-->
"/"name/": /"tom/"," + <!--CRLF-->
"/"email/": /"[email protected]/"," + <!--CRLF-->
"/"address/": /"china/"," + <!--CRLF-->
"/"birthday/": {" + <!--CRLF-->
"/"birthday/": /"2010-11-22/"" + <!--CRLF-->
"}" + <!--CRLF-->
"}]}"; <!--CRLF-->
System.out.println(json);//用js转换成功 <!--CRLF-->
List list = (List) xstream.fromXML(json);
<!--CRLF-->
System.out.println(list.size());//0好像转换失败 <!--CRLF-->
}
运行后结果如下:
haha#1#address#2010-11-22#email
<!--CRLF-->
{"list": [{"id": 1,"name": "haha","email": "email","address": "address","birthday": {"birthday": "2010-11-22"}}, <!--CRLF-->
{"id": 2,"name": "tom","email": "[email protected]","address": "china","birthday": {"birthday": "2010-11-22"}}]} <!--CRLF-->
0
JSON到Java的转换是fromXML方法。
标签:XML,bean,xstream,JSON,jack,new,xStream,com,2010 From: https://blog.51cto.com/u_16203469/7626985