标签：
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；
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
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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对象和XML字符串的相互转换 * 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>初始化资源准备 * @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>释放对象资源 * @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
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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转换成XML
1、 JavaBean转换XM
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/** * <b>function:</b>Java对象转换成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"); //类重命名 //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)); //属性重命名 xstream.aliasField("邮件", Student.class, "email"); //包重命名 xstream.aliasPackage("hoo", "com.hoo.entity"); fail(xstream.toXML(bean)); } catch (Exception e) { e.printStackTrace(); } } |
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：
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------------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> <邮件>jack@email.com</邮件> <address>china</address> <birthday> <birthday>2010-11-22</birthday> </birthday> </hoo.Student> |
2、 将List集合转换成xml文档
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/** * <b>function:</b>将Java的List集合转换成XML对象 * @author hoojo * @createDate Nov 27, 2010 12:20:07 PM */ @Test public void writeList2XML() { try { //修改元素名称 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);
//将ListBean中的集合设置空元素，即不显示集合元素标签 //xstream.addImplicitCollection(ListBean.class, "list");
//设置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);//绝对路径引用
//将name设置为父类（Student）的元素的属性 xstream.useAttributeFor(Student.class, "name"); xstream.useAttributeFor(Birthday.class, "birthday"); //修改属性的name xstream.aliasAttribute("姓名", "name"); xstream.aliasField("生日", Birthday.class, "birthday");
fail(xstream.toXML(listBean)); } catch (Exception e) { e.printStackTrace(); } } |
上面的代码运行后，结果如下：
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----------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");
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
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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 {
/* * 设置属性显示 */ @XStreamAsAttribute @XStreamAlias("名称") 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这个是一个类型转换器
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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); } } |
再看看测试用例代码
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@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); //对指定的类使用Annotation //xstream.processAnnotations(Classes.class); //启用Annotation //xstream.autodetectAnnotations(true); xstream.alias("student", Student.class); fail(xstream.toXML(c)); } catch (Exception e) { e.printStackTrace(); } } |
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：
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---------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> |
当启用annotation后xstream.processAnnotations(Classes.class)，结果如下：
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---------annotation Bean --> XML--------- <class 名称="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集合转换xml文档
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/** * <b>function:</b>Java Map集合转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);//put
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); map.put("No.2", bean);//put
bean = 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(); } } |
运行后结果如下：
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---------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输出流写XML
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/** * <b>function:</b>用OutStream输出流写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：
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---------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内容转换Java对象
1、 用InputStream将XML文档转换成java对象
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/** * <b>function:</b>用InputStream将XML文档转换成java对象 * 需要额外的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(); } } |
读取后，转换的Java对象，结果如下：
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---------ObjectInputStream## XML --> javaObject--------- jack#0#null#null#null 2010-05-33 22 true 22.0 hello |
2、 将xml文档转换成Java对象
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/** * <b>function:</b>将XML字符串转换成Java对象 * @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);//put
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 map.put("No.2", bean);//put
bean = 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());//3 Set<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(); } } |
运行后结果如下：
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-----------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
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/** * <b>function:</b>XStream结合JettisonMappedXmlDriver驱动，转换Java对象到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)); } |
运行后结果如下：
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=======JettisonMappedXmlDriver===JavaObject >>>> JaonString========= {"student":{"id":1,"name":"jack","email":"jack@email.com","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
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/** * <b>function:</b>用XStream结合JsonHierarchicalStreamDriver驱动 * 转换java对象为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==删除根节点========="); //删除根节点 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)); } |
运行后结果如下：
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======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
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@Test public void writeList2JSON() { failRed("======JsonHierarchicalStreamDriver====JavaObject >>>> JaonString========="); JsonHierarchicalStreamDriver driver = new JsonHierarchicalStreamDriver(); xstream = new XStream(driver); //xstream = new XStream(new JettisonMappedXmlDriver());//转换错误 //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==删除根节点========="); //删除根节点 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)); } |
运行后结果如下
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======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 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
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@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);//put
bean = 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);//put
bean = new Student(); bean.setName("jack"); map.put("No.3", bean);//put
fail(xstream.toXML(map));
//failRed("========JsonHierarchicalStreamDriver==删除根节点========="); //删除根节点 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)); } |
运行后结果如下：
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======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、 将JSON转换java对象
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/** * <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； * JsonHierarchicalStreamDriver读取JSON字符串到java对象出错 * @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读取JSON字符串到java对象出错，但JettisonMappedXmlDriver可以 xstream = new XStream(new JettisonMappedXmlDriver()); xstream.alias("student", Student.class); fail(xstream.fromXML(json).toString());
//JettisonMappedXmlDriver转换List集合出错，但JsonHierarchicalStreamDriver可以转换正确 //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":"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转换成功 List list = (List) xstream.fromXML(json); System.out.println(list.size());//0好像转换失败 } |
运行后结果如下：
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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的转换是fromXML方法。
具体出处忘记了，本文仅限于学习记录,不做其他用途
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原文地址：http://www.cnblogs.com/qicaiaqilin/p/4785645.html
