xStream框架
xStream可以輕易的將Java對象和xml文檔相互轉(zhuǎn)換，而且可以修改某個(gè)特定的屬性和節(jié)點(diǎn)名稱，而且也支持json的轉(zhuǎn)換； 它們都完美支持JSON，但是對xml的支持還不是很好。一定程度上限制了對Java對象的描述，不能讓xml完全體現(xiàn)到對Java對象的描述。這里將會介紹xStream對JSON、XML的完美支持。xStream不僅對XML的轉(zhuǎn)換非常友好，而且提供annotation注解，可以在JavaBean中完成對xml節(jié)點(diǎn)、屬性的描述。以及對JSON也支持，只需要提供相關(guān)的JSONDriver就可以完成轉(zhuǎn)換。
一、準(zhǔn)備工作
1、 下載jar包、及官方資源
xStream的jar下載地址：
https://nexus.codehaus.org/content/repositories/releases/com/thoughtworks/xstream/xstream-distribution/1.3.1/xstream-distribution-1.3.1-bin.zip
官方的示例很全，官方參考示例：http://xstream.codehaus.org/tutorial.html
添加xstream-1.3.1.jar文件到工程中，就可以開始下面的工作；需要的jar如下：
2、 測試用例代碼
package com.hoo.test;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.StringReader;
import java.io.Writer;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;
import org.codehaus.jettison.json.JSONException;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import com.hoo.entity.Birthday;
import com.hoo.entity.Classes;
import com.hoo.entity.ListBean;
import com.hoo.entity.Student;
import com.thoughtworks.xstream.XStream;
import com.thoughtworks.xstream.io.HierarchicalStreamWriter;
import com.thoughtworks.xstream.io.json.JettisonMappedXmlDriver;
import com.thoughtworks.xstream.io.json.JsonHierarchicalStreamDriver;
import com.thoughtworks.xstream.io.json.JsonWriter;
/**
* <b>function:</b>Java對象和XML字符串的相互轉(zhuǎn)換
* jar-lib-version: xstream-1.3.1
* @author hoojo
* @createDate Nov 27, 2010 12:15:15 PM
* @file XStreamTest.java
* @package com.hoo.test
* @project WebHttpUtils
* @blog http://blog.csdn.net/IBM_hoojo
* @email hoojo_@126.com
* @version 1.0
*/
@SuppressWarnings("unchecked")public class XStreamTest {private XStream xstream = null;
private ObjectOutputStream out = null;
private ObjectInputStream in = null;
private Student bean = null;
/**
* <b>function:</b>初始化資源準(zhǔn)備
* @author hoojo
* @createDate Nov 27, 2010 12:16:28 PM
*/
@Before
public void init() { try {xstream = new XStream();
//xstream = new XStream(new DomDriver()); // 需要xpp3 jar
} catch (Exception e) {e.printStackTrace();
}
bean = new Student();
bean.setAddress("china"); bean.setEmail("jack@email.com");bean.setId(1);
bean.setName("jack");Birthday day = new Birthday();
day.setBirthday("2010-11-22");bean.setBirthday(day);
}
/**
* <b>function:</b>釋放對象資源
* @author hoojo
* @createDate Nov 27, 2010 12:16:38 PM
*/
@After
public void destory() {xstream = null;
bean = null;
try { if (out != null) {out.flush();
out.close();
}
if (in != null) {in.close();
}
} catch (IOException e) {e.printStackTrace();
}
System.gc();
}
public final void fail(String string) {System.out.println(string);
}
public final void failRed(String string) {System.err.println(string);
}
}
通過XStream對象的toXML方法就可以完成Java對象到XML的轉(zhuǎn)換，toXML方法還有2個(gè)相同簽名的方法，需要傳遞一個(gè)流。然后通過流來完成xml信息的輸出。
3、 需要的JavaBean
package com.hoo.entity;
public class Student {private int id;
private String name;
private String email;
private String address;
private Birthday birthday;
//getter、setter
public String toString() {return this.name + "#" + this.id + "#" + this.address + "#" + this.birthday + "#" + this.email;
}
}
二、Java轉(zhuǎn)換成XML
1、 JavaBean轉(zhuǎn)換XM
/**
* <b>function:</b>Java對象轉(zhuǎn)換成XML字符串
* @author hoojo
* @createDate Nov 27, 2010 12:19:01 PM
*/
@Test
public void writeBean2XML() { try { fail("------------Bean->XML------------");fail(xstream.toXML(bean));
fail("重命名后的XML");//類重命名
//xstream.alias("account", Student.class); //xstream.alias("生日", Birthday.class); //xstream.aliasField("生日", Student.class, "birthday"); //xstream.aliasField("生日", Birthday.class, "birthday");//fail(xstream.toXML(bean));
//屬性重命名
xstream.aliasField("郵件", Student.class, "email");//包重命名
xstream.aliasPackage("hoo", "com.hoo.entity");fail(xstream.toXML(bean));
} catch (Exception e) {e.printStackTrace();
}
}
看結(jié)果中的第一份xml內(nèi)容，是沒有經(jīng)過然后修改或重命名的文檔，按照原樣輸出。文檔中的第二份文檔的package經(jīng)過重命名，email屬性也經(jīng)過重命名以及類名也可以進(jìn)行重命名的。
運(yùn)行后結(jié)果如下：
------------Bean->XML------------
<com.hoo.entity.Student>
<id>1</id>
<name>jack</name>
<email>jack@email.com</email>
<address>china</address>
<birthday>
<birthday>2010-11-22</birthday>
</birthday>
</com.hoo.entity.Student>
重命名后的XML
<hoo.Student>
<id>1</id>
<name>jack</name>
<郵件>jack@email.com</郵件>
<address>china</address>
<birthday>
<birthday>2010-11-22</birthday>
</birthday>
</hoo.Student>
2、 將List集合轉(zhuǎn)換成xml文檔
/**
* <b>function:</b>將Java的List集合轉(zhuǎn)換成XML對象
* @author hoojo
* @createDate Nov 27, 2010 12:20:07 PM
*/
@Test
public void writeList2XML() { try {//修改元素名稱
xstream.alias("beans", ListBean.class); xstream.alias("student", Student.class); fail("----------List-->XML----------");ListBean listBean = new ListBean();
listBean.setName("this is a List Collection");List<Object> list = new ArrayList<Object>();
list.add(bean);
list.add(bean);//引用bean
//list.add(listBean);//引用listBean，父元素
bean = new Student();
bean.setAddress("china"); bean.setEmail("tom@125.com");bean.setId(2);
bean.setName("tom"); Birthday day = new Birthday("2010-11-22");bean.setBirthday(day);
list.add(bean);
listBean.setList(list);
//將ListBean中的集合設(shè)置空元素，即不顯示集合元素標(biāo)簽
//xstream.addImplicitCollection(ListBean.class, "list");
//設(shè)置reference模型
//xstream.setMode(XStream.NO_REFERENCES);//不引用
xstream.setMode(XStream.ID_REFERENCES);//id引用
//xstream.setMode(XStream.XPATH_ABSOLUTE_REFERENCES);//絕對路徑引用
//將name設(shè)置為父類（Student）的元素的屬性
xstream.useAttributeFor(Student.class, "name");
xstream.useAttributeFor(Birthday.class, "birthday");
//修改屬性的name
xstream.aliasAttribute("姓名", "name"); xstream.aliasField("生日", Birthday.class, "birthday");fail(xstream.toXML(listBean));
} catch (Exception e) {e.printStackTrace();
}
}
上面的代碼運(yùn)行后，結(jié)果如下：
----------List-->XML----------
<beans id="1">
<name>this is a List Collection</name>
<list id="2">
<student id="3" 姓名="jack">
<id>1</id>
<email>jack@email.com</email>
<address>china</address>
<birthday id="4" 生日="2010-11-22"/>
</student>
<student reference="3"/>
<student id="5" 姓名="tom">
<id>2</id>
<email>tom@125.com</email>
<address>china</address>
<birthday id="6" 生日="2010-11-22"/>
</student>
</list>
</beans>
如果不加xstream.addImplicitCollection(ListBean.class, "list");
這個(gè)設(shè)置的話，會出現(xiàn)一個(gè)List節(jié)點(diǎn)包裹著Student節(jié)點(diǎn)元素。添加addImplicitCollection可以忽略這個(gè)list節(jié)點(diǎn)元素。那么上面的list節(jié)點(diǎn)就不存在，只會在beans元素中出現(xiàn)name、student這2個(gè)xml元素標(biāo)簽；
setMode是設(shè)置相同的對象的引用方式，如果設(shè)置XStream.NO_REFERENCES就是不引用，會輸出2分相同的Student元素。如果是XStream.ID_REFERENCES會引用相同的那個(gè)對象的id屬性，如果是XStream.XPATH_ABSOLUTE_REFERENCES引用，那么它將顯示xpath路徑。上面采用的id引用，<student reference="3"/>這個(gè)引用了id=3的那個(gè)student標(biāo)簽元素；
useAttributeFor是設(shè)置某個(gè)節(jié)點(diǎn)顯示到父節(jié)點(diǎn)的屬性中，也就是將指定class中的指定屬性，在這個(gè)class元素節(jié)點(diǎn)的屬性中顯示。
如：<student><name>hoojo</name></student>
設(shè)置好后就是這樣的結(jié)果：<student name=”hoojo”></student>
aliasAttribute是修改屬性名稱。
3、 在JavaBean中添加Annotation注解進(jìn)行重命名設(shè)置
先看看JavaBean的代碼
package com.hoo.entity;
import java.util.Arrays;
import java.util.Calendar;
import java.util.GregorianCalendar;
import java.util.List;
import com.thoughtworks.xstream.annotations.XStreamAlias;
import com.thoughtworks.xstream.annotations.XStreamAsAttribute;
import com.thoughtworks.xstream.annotations.XStreamConverter;
import com.thoughtworks.xstream.annotations.XStreamImplicit;
import com.thoughtworks.xstream.annotations.XStreamOmitField;
@XStreamAlias("class")public class Classes {/*
* 設(shè)置屬性顯示
*/
@XStreamAsAttribute
@XStreamAlias("名稱")private String name;
/*
* 忽略
*/
@XStreamOmitField
private int number;
@XStreamImplicit(itemFieldName = "Students")
private List<Student> students;
@SuppressWarnings("unused")@XStreamConverter(SingleValueCalendarConverter.class)
private Calendar created = new GregorianCalendar();
public Classes(){} public Classes(String name, Student... stu) {this.name = name;
this.students = Arrays.asList(stu);
}
//getter、setter
}
SingleValueCalendarConverter.java這個(gè)是一個(gè)類型轉(zhuǎn)換器
package com.hoo.entity;
import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;
import com.thoughtworks.xstream.converters.Converter;
import com.thoughtworks.xstream.converters.MarshallingContext;
import com.thoughtworks.xstream.converters.UnmarshallingContext;
import com.thoughtworks.xstream.io.HierarchicalStreamReader;
import com.thoughtworks.xstream.io.HierarchicalStreamWriter;
public class SingleValueCalendarConverter implements Converter {public void marshal(Object source, HierarchicalStreamWriter writer,
MarshallingContext context) {Calendar calendar = (Calendar) source;
writer.setValue(String.valueOf(calendar.getTime().getTime()));
}
public Object unmarshal(HierarchicalStreamReader reader,
UnmarshallingContext context) {GregorianCalendar calendar = new GregorianCalendar();
calendar.setTime(new Date(Long.parseLong(reader.getValue())));
return calendar;
}
@SuppressWarnings("unchecked") public boolean canConvert(Class type) {return type.equals(GregorianCalendar.class);
}
}
再看看測試用例代碼
@Test
public void writeList2XML4Annotation() { try { failRed("---------annotation Bean --> XML---------");Student stu = new Student();
stu.setName("jack"); Classes c = new Classes("一班", bean, stu);c.setNumber(2);
//對指定的類使用Annotation
//xstream.processAnnotations(Classes.class);
//啟用Annotation
//xstream.autodetectAnnotations(true);
xstream.alias("student", Student.class);fail(xstream.toXML(c));
} catch (Exception e) {e.printStackTrace();
}
}
當(dāng)啟用annotation或是對某個(gè)特定的類啟用annotation時(shí)，上面的classes這個(gè)類才有效果。如果不啟用annotation，運(yùn)行后結(jié)果如下：
---------annotation Bean --> XML---------
<com.hoo.entity.Classes>
<name>一班</name>
<number>2</number>
<students class="java.util.Arrays$ArrayList">
<a class="student-array">
<student>
<id>1</id>
<name>jack</name>
<email>jack@email.com</email>
<address>china</address>
<birthday>
<birthday>2010-11-22</birthday>
</birthday>
</student>
<student>
<id>0</id>
<name>jack</name>
</student>
</a>
</students>
<created>
<time>1303292056718</time>
<timezone>Asia/Shanghai</timezone>
</created>
</com.hoo.entity.Classes>
當(dāng)啟用annotation后xstream.processAnnotations(Classes.class)，結(jié)果如下：
---------annotation Bean --> XML---------
<class 名稱="一班">
<Students>
<id>1</id>
<name>jack</name>
<email>jack@email.com</email>
<address>china</address>
<birthday>
<birthday>2010-11-22</birthday>
</birthday>
</Students>
<Students>
<id>0</id>
<name>jack</name>
</Students>
<created>1303292242937</created>
</class>
4、 Map集合轉(zhuǎn)換xml文檔
/**
* <b>function:</b>Java Map集合轉(zhuǎn)XML
* @author hoojo
* @createDate Nov 27, 2010 1:13:26 PM
*/
@Test
public void writeMap2XML() { try { failRed("---------Map --> XML---------");Map<String, Student> map = new HashMap<String, Student>();
map.put("No.1", bean);//putbean = new Student();
bean.setAddress("china"); bean.setEmail("tom@125.com");bean.setId(2);
bean.setName("tom"); Birthday day = new Birthday("2010-11-22");bean.setBirthday(day);
map.put("No.2", bean);//putbean = new Student();
bean.setName("jack"); map.put("No.3", bean);//put xstream.alias("student", Student.class); xstream.alias("key", String.class);xstream.useAttributeFor(Student.class, "id");
xstream.useAttributeFor("birthday", String.class);fail(xstream.toXML(map));
} catch (Exception e) {e.printStackTrace();
}
}
運(yùn)行后結(jié)果如下：
---------Map --> XML---------
<map>
<entry>
<key>No.3</key>
<student id="0">
<name>jack</name>
</student>
</entry>
<entry>
<key>No.1</key>
<student id="1">
<name>jack</name>
<email>jack@email.com</email>
<address>china</address>
<birthday birthday="2010-11-22"/>
</student>
</entry>
<entry>
<key>No.2</key>
<student id="2">
<name>tom</name>
<email>tom@125.com</email>
<address>china</address>
<birthday birthday="2010-11-22"/>
</student>
</entry>
</map>
5、 用OutStream輸出流寫XML
/**
* <b>function:</b>用OutStream輸出流寫XML
* @author hoojo
* @createDate Nov 27, 2010 1:13:48 PM
*/
@Test
public void writeXML4OutStream() { try {out = xstream.createObjectOutputStream(System.out);
Student stu = new Student();
stu.setName("jack"); Classes c = new Classes("一班", bean, stu);c.setNumber(2);
failRed("---------ObjectOutputStream # JavaObject--> XML---------");out.writeObject(stu);
out.writeObject(new Birthday("2010-05-33"));out.write(22);//byte
out.writeBoolean(true);
out.writeFloat(22.f);
out.writeUTF("hello"); } catch (Exception e) {e.printStackTrace();
}
}
使用輸出流后，可以通過流對象完成xml的構(gòu)建，即使沒有JavaBean對象，你可以用流來構(gòu)建一個(gè)復(fù)雜的xml文檔，運(yùn)行后結(jié)果如下：
---------ObjectOutputStream # JavaObject--> XML---------
<object-stream>
<com.hoo.entity.Student>
<id>0</id>
<name>jack</name>
</com.hoo.entity.Student>
<com.hoo.entity.Birthday>
<birthday>2010-05-33</birthday>
</com.hoo.entity.Birthday>
<byte>22</byte>
<boolean>true</boolean>
<float>22.0</float>
<string>hello</string>
</object-stream>
三、XML內(nèi)容轉(zhuǎn)換Java對象
1、 用InputStream將XML文檔轉(zhuǎn)換成java對象
/**
* <b>function:</b>用InputStream將XML文檔轉(zhuǎn)換成java對象
* 需要額外的jar xpp3-main.jar
* @author hoojo
* @createDate Nov 27, 2010 1:14:52 PM
*/
@Test
public void readXML4InputStream() { try {String s = "<object-stream><com.hoo.entity.Student><id>0</id><name>jack</name>" +
"</com.hoo.entity.Student><com.hoo.entity.Birthday><birthday>2010-05-33</birthday>" +
"</com.hoo.entity.Birthday><byte>22</byte><boolean>true</boolean><float>22.0</float>" +
"<string>hello</string></object-stream>";
failRed("---------ObjectInputStream## XML --> javaObject---------");StringReader reader = new StringReader(s);
in = xstream.createObjectInputStream(reader);
Student stu = (Student) in.readObject();
Birthday b = (Birthday) in.readObject();
byte i = in.readByte();
boolean bo = in.readBoolean();
float f = in.readFloat();
String str = in.readUTF();
System.out.println(stu);
System.out.println(b);
System.out.println(i);
System.out.println(bo);
System.out.println(f);
System.out.println(str);
} catch (Exception e) {e.printStackTrace();
}
}
讀取后，轉(zhuǎn)換的Java對象，結(jié)果如下：
---------ObjectInputStream## XML --> javaObject---------
jack#0#null#null#null
2010-05-33
22
true
22.0
hello
2、 將xml文檔轉(zhuǎn)換成Java對象
/**
* <b>function:</b>將XML字符串轉(zhuǎn)換成Java對象
* @author hoojo
* @createDate Nov 27, 2010 2:39:06 PM
*/
@Test
public void readXml2Object() { try { failRed("-----------Xml >>> Bean--------------");Student stu = (Student) xstream.fromXML(xstream.toXML(bean));
fail(stu.toString());
List<Student> list = new ArrayList<Student>();
list.add(bean);//add
Map<String, Student> map = new HashMap<String, Student>();
map.put("No.1", bean);//putbean = new Student();
bean.setAddress("china"); bean.setEmail("tom@125.com");bean.setId(2);
bean.setName("tom"); Birthday day = new Birthday("2010-11-22");bean.setBirthday(day);
list.add(bean);//add
map.put("No.2", bean);//putbean = new Student();
bean.setName("jack");list.add(bean);//add
map.put("No.3", bean);//put failRed("==========XML >>> List===========");List<Student> studetns = (List<Student>) xstream.fromXML(xstream.toXML(list));
fail("size:" + studetns.size());//3 for (Student s : studetns) {fail(s.toString());
}
failRed("==========XML >>> Map===========");Map<String, Student> maps = (Map<String, Student>) xstream.fromXML(xstream.toXML(map));
fail("size:" + maps.size());//3Set<String> key = maps.keySet();
Iterator<String> iter = key.iterator();
while (iter.hasNext()) {String k = iter.next();
fail(k + ":" + map.get(k));
}
} catch (Exception e) {e.printStackTrace();
}
}
運(yùn)行后結(jié)果如下：
-----------Xml >>> Bean--------------
jack#1#china#2010-11-22#jack@email.com
==========XML >>> List===========
size:3
jack#1#china#2010-11-22#jack@email.com
tom#2#china#2010-11-22#tom@125.com
jack#0#null#null#null
==========XML >>> Map===========
size:3
No.3:jack#0#null#null#null
No.1:jack#1#china#2010-11-22#jack@email.com
No.2:tom#2#china#2010-11-22#tom@125.com
怎么樣，成功的完成XML到JavaBean、List、Map的轉(zhuǎn)換，更多對象轉(zhuǎn)換還需要大家一一嘗試。用法類似~這里就不一樣贅述。
四、XStream對JSON的支持
xStream對JSON也有非常好的支持，它提供了2個(gè)模型驅(qū)動(dòng)。用這2個(gè)驅(qū)動(dòng)可以完成Java對象到JSON的相互轉(zhuǎn)換。使用JettisonMappedXmlDriver驅(qū)動(dòng)，將Java對象轉(zhuǎn)換成json，需要添加jettison.jar
1、 用JettisonMappedXmlDriver完成Java對象到JSON的轉(zhuǎn)換
/**
* <b>function:</b>XStream結(jié)合JettisonMappedXmlDriver驅(qū)動(dòng)，轉(zhuǎn)換Java對象到JSON
* 需要添加jettison jar
* @author hoojo
* @createDate Nov 27, 2010 1:23:18 PM
*/
@Test
public void writeEntity2JETTSON() { failRed("=======JettisonMappedXmlDriver===JavaObject >>>> JaonString=========");xstream = new XStream(new JettisonMappedXmlDriver());
xstream.setMode(XStream.NO_REFERENCES);
xstream.alias("student", Student.class);fail(xstream.toXML(bean));
}
運(yùn)行后結(jié)果如下：
=======JettisonMappedXmlDriver===JavaObject >>>> JaonString=========
{"student":{"id":1,"name":"jack","email":"jack@email.com","address":"china","birthday":[{},"2010-11-22"]}}JSON的轉(zhuǎn)換和XML的轉(zhuǎn)換用法一樣，只是創(chuàng)建XStream需要傳遞一個(gè)參數(shù)，這個(gè)參數(shù)就是xml到JSON映射轉(zhuǎn)換的驅(qū)動(dòng)。這里會降到兩個(gè)驅(qū)動(dòng)，分別是JettisonMappedXmlDriver、JsonHierarchicalStreamDriver。
2、 JsonHierarchicalStreamDriver完成Java對象到JSON的轉(zhuǎn)換
/**
* <b>function:</b>用XStream結(jié)合JsonHierarchicalStreamDriver驅(qū)動(dòng)
* 轉(zhuǎn)換java對象為JSON字符串
* @author hoojo
* @createDate Nov 27, 2010 1:16:46 PM
*/
@Test
public void writeEntiry2JSON() { failRed("======JsonHierarchicalStreamDriver====JavaObject >>>> JaonString=========");xstream = new XStream(new JsonHierarchicalStreamDriver());
//xstream.setMode(XStream.NO_REFERENCES);
xstream.alias("student", Student.class); failRed("-------Object >>>> JSON---------");fail(xstream.toXML(bean));
//failRed("========JsonHierarchicalStreamDriver==刪除根節(jié)點(diǎn)=========");//刪除根節(jié)點(diǎn)
xstream = new XStream(new JsonHierarchicalStreamDriver() { public HierarchicalStreamWriter createWriter(Writer out) {return new JsonWriter(out, JsonWriter.DROP_ROOT_MODE);
}
});
//xstream.setMode(XStream.NO_REFERENCES);
xstream.alias("student", Student.class);fail(xstream.toXML(bean));
}
運(yùn)行后結(jié)果如下：
======JsonHierarchicalStreamDriver====JavaObject >>>> JaonString=========
-------Object >>>> JSON---------
{"student": {"id": 1,
"name": "jack",
"email": "jack@email.com",
"address": "china",
"birthday": {"birthday": "2010-11-22"
}
}}
{"id": 1,
"name": "jack",
"email": "jack@email.com",
"address": "china",
"birthday": {"birthday": "2010-11-22"
}
}
使用JsonHierarchicalStreamDriver轉(zhuǎn)換默認(rèn)會給轉(zhuǎn)換后的對象添加一個(gè)根節(jié)點(diǎn)，但是在構(gòu)建JsonHierarchicalStreamDriver驅(qū)動(dòng)的時(shí)候，你可以重寫createWriter方法，刪掉根節(jié)點(diǎn)。
看上面的結(jié)果，一個(gè)是默認(rèn)帶根節(jié)點(diǎn)的JSON對象，它只是將類名作為一個(gè)屬性，將對象作為該屬性的一個(gè)值。而另一個(gè)沒有帶根屬性的JSON就是通過重寫createWriter方法完成的。
3、 將List集合轉(zhuǎn)換成JSON字符串
@Test
public void writeList2JSON() { failRed("======JsonHierarchicalStreamDriver====JavaObject >>>> JaonString=========");JsonHierarchicalStreamDriver driver = new JsonHierarchicalStreamDriver();
xstream = new XStream(driver);
//xstream = new XStream(new JettisonMappedXmlDriver());//轉(zhuǎn)換錯(cuò)誤
//xstream.setMode(XStream.NO_REFERENCES);
xstream.alias("student", Student.class);List<Student> list = new ArrayList<Student>();
list.add(bean);//add
bean = new Student();
bean.setAddress("china"); bean.setEmail("tom@125.com");bean.setId(2);
bean.setName("tom"); Birthday day = new Birthday("2010-11-22");bean.setBirthday(day);
list.add(bean);//add
bean = new Student();
bean.setName("jack");list.add(bean);//add
fail(xstream.toXML(list));
//failRed("========JsonHierarchicalStreamDriver==刪除根節(jié)點(diǎn)=========");//刪除根節(jié)點(diǎn)
xstream = new XStream(new JsonHierarchicalStreamDriver() { public HierarchicalStreamWriter createWriter(Writer out) {return new JsonWriter(out, JsonWriter.DROP_ROOT_MODE);
}
});
xstream.alias("student", Student.class);fail(xstream.toXML(list));
}
運(yùn)行后結(jié)果如下
======JsonHierarchicalStreamDriver====JavaObject >>>> JaonString=========
##{"list": [ {"id": 1,
"name": "jack",
"email": "jack@email.com",
"address": "china",
"birthday": {"birthday": "2010-11-22"
}
},
{"id": 2,
"name": "tom",
"email": "tom@125.com",
"address": "china",
"birthday": {"birthday": "2010-11-22"
}
},
{"id": 0,
"name": "jack"
}
]}
#[
{"id": 1,
"name": "jack",
"email": "jack@email.com",
"address": "china",
"birthday": {"birthday": "2010-11-22"
}
},
{"id": 2,
"name": "tom",
"email": "tom@125.com",
"address": "china",
"birthday": {"birthday": "2010-11-22"
}
},
{"id": 0,
"name": "jack"
}
]
上面的list1是使用JsonHierarchicalStreamDriver 轉(zhuǎn)換的，當(dāng)然你也可以使用JettisonMappedXmlDriver驅(qū)動(dòng)進(jìn)行轉(zhuǎn)換；用JettisonMappedXmlDriver轉(zhuǎn)換后，你會發(fā)現(xiàn)格式不同而且沒有根屬性。
4、 Map轉(zhuǎn)換json
@Test
public void writeMap2JSON() { failRed("======JsonHierarchicalStreamDriver==== Map >>>> JaonString=========");xstream = new XStream(new JsonHierarchicalStreamDriver());
//xstream = new XStream(new JettisonMappedXmlDriver());
xstream.alias("student", Student.class);Map<String, Student> map = new HashMap<String, Student>();
map.put("No.1", bean);//putbean = new Student();
bean.setAddress("china"); bean.setEmail("tom@125.com");bean.setId(2);
bean.setName("tom"); bean.setBirthday(new Birthday("2010-11-21")); map.put("No.2", bean);//putbean = new Student();
bean.setName("jack"); map.put("No.3", bean);//putfail(xstream.toXML(map));
//failRed("========JsonHierarchicalStreamDriver==刪除根節(jié)點(diǎn)=========");//刪除根節(jié)點(diǎn)
xstream = new XStream(new JsonHierarchicalStreamDriver() { public HierarchicalStreamWriter createWriter(Writer out) {return new JsonWriter(out, JsonWriter.DROP_ROOT_MODE);
}
});
xstream.alias("student", Student.class);fail(xstream.toXML(map));
}
運(yùn)行后結(jié)果如下：
======JsonHierarchicalStreamDriver==== Map >>>> JaonString=========
{"map": [[
"No.3",
{"id": 0,
"name": "jack"
}
],
[
"No.1",
{"id": 1,
"name": "jack",
"email": "jack@email.com",
"address": "china",
"birthday": {"birthday": "2010-11-22"
}
}
],
[
"No.2",
{"id": 2,
"name": "tom",
"email": "tom@125.com",
"address": "china",
"birthday": {"birthday": "2010-11-21"
}
}
]
]}
[
[
"No.3",
{"id": 0,
"name": "jack"
}
],
[
"No.1",
{"id": 1,
"name": "jack",
"email": "jack@email.com",
"address": "china",
"birthday": {"birthday": "2010-11-22"
}
}
],
[
"No.2",
{"id": 2,
"name": "tom",
"email": "tom@125.com",
"address": "china",
"birthday": {"birthday": "2010-11-21"
}
}
]
]
5、 將JSON轉(zhuǎn)換java對象
/**
* <b>function:</b>JsonHierarchicalStreamDriver可以將簡單的json字符串轉(zhuǎn)換成java對象，list、map轉(zhuǎn)換不成功；
* JsonHierarchicalStreamDriver讀取JSON字符串到j(luò)ava對象出錯(cuò)
* @author hoojo
* @createDate Nov 27, 2010 1:22:26 PM
* @throws JSONException
*/
@Test
public void readJSON2Object() throws JSONException { String json = "{\"student\": {" +"\"id\": 1," +
"\"name\": \"haha\"," +
"\"email\": \"email\"," +
"\"address\": \"address\"," +
"\"birthday\": {" +"\"birthday\": \"2010-11-22\"" +
"}" +
"}}";
//JsonHierarchicalStreamDriver讀取JSON字符串到j(luò)ava對象出錯(cuò)，但JettisonMappedXmlDriver可以
xstream = new XStream(new JettisonMappedXmlDriver());
xstream.alias("student", Student.class);fail(xstream.fromXML(json).toString());
//JettisonMappedXmlDriver轉(zhuǎn)換List集合出錯(cuò)，但JsonHierarchicalStreamDriver可以轉(zhuǎn)換正確
//JettisonMappedXmlDriver 轉(zhuǎn)換的字符串 {"list":{"student":[{"id":1,"name":"haha","email":"email","address":"address","birthday":[{},"2010-11-22"]}]},"student":{"id":2,"name":"tom","email":"tom@125.com","address":"china","birthday":[{},"2010-11-22"]}} json = "{\"list\": [{" +"\"id\": 1," +
"\"name\": \"haha\"," +
"\"email\": \"email\"," +
"\"address\": \"address\"," +
"\"birthday\": {" +"\"birthday\": \"2010-11-22\"" +
"}" +
"},{" +"\"id\": 2," +
"\"name\": \"tom\"," +
"\"email\": \"tom@125.com\"," +
"\"address\": \"china\"," +
"\"birthday\": {" +"\"birthday\": \"2010-11-22\"" +
"}" +
"}]}";
System.out.println(json);//用js轉(zhuǎn)換成功
List list = (List) xstream.fromXML(json);
System.out.println(list.size());//0好像轉(zhuǎn)換失敗
}
運(yùn)行后結(jié)果如下：
haha#1#address#2010-11-22#email
{"list": [{"id": 1,"name": "haha","email": "email","address": "address","birthday": {"birthday": "2010-11-22"}},{"id": 2,"name": "tom","email": "tom@125.com","address": "china","birthday": {"birthday": "2010-11-22"}}]}0
JSON到Java的轉(zhuǎn)換是fromXML方法。
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