XML操作类库XStream使用详解
1.Xstream介绍
(1)Xstream介绍
Xstream是一种OXMapping 技术,是用来处理XML文件序列化的框架,在将JavaBean序列化,或将XML文件反序列化的时候,不需要其它辅助类和映射文件,使得XML序列化不再繁索。Xstream也可以将JavaBean序列化成Json或反序列化,使用非常方便。
(2)Xstream的简单例子
class Person//JavaBean实体类 { private String name; private int age; public Person(String name,int age) { this.name=name; this.age=age; } @Override public String toString() { return "Person [name=" + name + ", age=" + age + "]"; } } public class Test { public static void main(String[] args) { Person bean=new Person("张三",19); XStream xstream = new XStream(); //XML序列化 String xml = xstream.toXML(bean); System.out.println(xml); //XML反序列化 bean=(Person)xstream.fromXML(xml); System.out.println(bean); xstream = new XStream(new JettisonMappedXmlDriver()); xstream.setMode(XStream.NO_REFERENCES); //Json序列化 String json=xstream.toXML(bean); System.out.println(json); //Json反序列 bean=(Person)xstream.fromXML(json); System.out.println(bean); } }
注意: Xstream序列化XML时需要引用的jar包:xstream-[version].jar、xpp3-[version].jar、xmlpull-[version].jar。Xstream序列化Json需要引用的jar包:jettison-[version].jar。
使用Xstream序列化时,对JavaBean没有任何限制。JavaBean的字段可以是私有的,也可以没有getter或setter方法,还可以没有默认的构造函数。
2.Xstream的基本使用
(1)Xstream序列化XML
Xstream序列化XML时可以允许用户使用不同的XML解析器,用户可以使用一个标准的JAXP DOM解析器或自Java6集成StAX解析器。这样用户就不需要依赖xpp3-[version].jar。
Xstream序列化XML时,也可以对XML节点重命名。
public class Test { public static void main(String[] args) { Person bean=new Person("张三",19); //XStream xstream = new XStream();//需要XPP3库 //XStream xstream = new XStream(new DomDriver());//不需要XPP3库 XStream xstream = new XStream(new StaxDriver());//不需要XPP3库开始使用Java6 xstream.alias("人",Person.class);//为类名节点重命名 //XML序列化 String xml = xstream.toXML(bean); System.out.println(xml); //XML反序列化 bean=(Person)xstream.fromXML(xml); System.out.println(bean); } }
(2)Xstream序列化Json
Xstream序列化Json与序列化XML类似,例如:
public class Test { public static void main(String[] args) { Person bean=new Person("张三",19); XStream xstream = new XStream(new JettisonMappedXmlDriver());//设置Json解析器 xstream.setMode(XStream.NO_REFERENCES);//设置reference模型,不引用 xstream.alias("人",Person.class);//为类名节点重命名 //Json序列化 String xml = xstream.toXML(bean); System.out.println(xml); //Json反序列化 bean=(Person)xstream.fromXML(xml); System.out.println(bean); } }
3.Xstream序列化重命名
(1)为包重命名:Xstream.aliasPackage()
方法
public class Test { public static void main(String[] args) { Person bean=new Person("张三",19); XStream xstream = new XStream(); xstream.aliasPackage("com.lzw", "test");//为包名称重命名 //序列化 String xml = xstream.toXML(bean); System.out.println(xml); //反序列化 bean=(Person)xstream.fromXML(xml); System.out.println(bean); } }
(2)为类重命名:Xstream.alias()
方法
public class Test { public static void main(String[] args) { Person bean=new Person("张三",19); XStream xstream = new XStream(); xstream.alias("人", Person.class);//为类名节点重命名 //序列化 String xml = xstream.toXML(bean); System.out.println(xml); //反序列化 bean=(Person)xstream.fromXML(xml); System.out.println(bean); } }
(3)为字段重命名:Xstream.aliasField()
方法
public class Test { public static void main(String[] args) { Person bean=new Person("张三",19); XStream xstream = new XStream(); xstream.aliasField("姓名", Person.class,"name");//为类的字段节点重命名 xstream.aliasField("年龄", Person.class,"age");//为类的字段节点重命名 //序列化 String xml = xstream.toXML(bean); System.out.println(xml); //反序列化 bean=(Person)xstream.fromXML(xml); System.out.println(bean); } }
(4)省略集合根节点:Xstream.addImplicitCollection()
方法
class Person { private String name; private int age; private List friends; public Person(String name, int age, String... friends) { this.name = name; this.age = age; this.friends = Arrays.asList(friends); } @Override public String toString() { return "Person [name=" + name + ", age=" + age + ", friends=" + friends + "]"; } } public class Test { public static void main(String[] args) { Person bean =new Person("张三",19,"李四","王五","赵六"); XStream xstream = new XStream(); xstream.addImplicitCollection(Person.class, "friends");//省略集合根节点 //序列化 String xml = xstream.toXML(bean); System.out.println(xml); //反序列化 bean=(Person)xstream.fromXML(xml); System.out.println(bean); } }
(5)把字段节点设置成属性:Xstream.useAttributeFor()
方法
public class Test { public static void main(String[] args) { Person bean =new Person("张三",19,"李四","王五","赵六"); XStream xstream = new XStream(); xstream.useAttributeFor(Person.class, "name");//把字段节点设置成属性 //序列化 String xml = xstream.toXML(bean); System.out.println(xml); //反序列化 bean=(Person)xstream.fromXML(xml); System.out.println(bean); } }
(6)隐藏字段:xstream.omitField()
方
public class Test { public static void main(String[] args) { Person bean =new Person("张三",19,"李四","王五","赵六"); XStream xstream = new XStream(); xstream.omitField(Person.class, "friends");//把字段节点隐藏 //序列化 String xml = xstream.toXML(bean); System.out.println(xml); //反序列化 bean=(Person)xstream.fromXML(xml); System.out.println(bean); } }
4.Xstream注解的使用
(1)设置Xstream应用注解使用Xstream注解前需要对Xstream进行配置,可以使用两种方式:应用某个JavaBean类的注解或自动使用JavaBean类的注解。代码如下:
XStream xstream = new XStream(); xstream.processAnnotations(Person.class);//应用Person类的注解 xstream.autodetectAnnotations(true);//自动检测注解
(2)重命名注解:@XStreamAlias()
@XStreamAlias("人") class Person { @XStreamAlias("姓名") private String name; @XStreamAlias("年龄") private int age; @XStreamAlias("朋友") private List friends; public Person(String name, int age, String... friends) { this.name = name; this.age = age; this.friends = Arrays.asList(friends); } @Override public String toString() { return "Person [name=" + name + ", age=" + age + ", friends=" + friends + "]"; } }
(3)省略集合根节点:@XStreamImplicit
class Person { private String name; private int age; //@XStreamImplicit//只隐藏集合根节点 @XStreamImplicit(itemFieldName="朋友")//设置重复的节点名,可能会导致无法反序列化 private List<String> friends; public Person(String name, int age, String... friends) { this.name = name; this.age = age; this.friends = Arrays.asList(friends); } @Override public String toString() { return "Person [name=" + name + ", age=" + age + ", friends=" + friends + "]"; } }
(4)把字段节点设置成属性:@XStreamAsAttribute
class Person { @XStreamAsAttribute private String name; @XStreamAsAttribute private int age; private List<String> friends; public Person(String name, int age, String... friends) { this.name = name; this.age = age; this.friends = Arrays.asList(friends); } @Override public String toString() { return "Person [name=" + name + ", age=" + age + ", friends=" + friends + "]"; } }
(5)隐藏字段:@XStreamOmitField
class Person { private String name; private int age; @XStreamOmitField private List<String> friends; public Person(String name, int age, String... friends) { this.name = name; this.age = age; this.friends = Arrays.asList(friends); } @Override public String toString() { return "Person [name=" + name + ", age=" + age + ", friends=" + friends + "]"; } }
(6)设置转换器:@XStreamConverter()
class Person { private String name; private int age; @XStreamConverter(value=BooleanConverter.class,booleans={false},strings={"男","女"}) private boolean sex; public Person(String name, int age, boolean sex) { this.name = name; this.age = age; this.sex=sex; } @Override public String toString() { return "Person [name=" + name + ", age=" + age + ", sex=" + sex + "]"; } }
5.Xstream自定义的转换器
(1)Xstream自带的转换器
Xstream内部有许多转换器,用于JavaBean对象到XML或Json之间的转换。
这些转换器的详细信息网址:http://xstream.codehaus.org/converters.html
(2)使用自定义的转换器
class Person { private String name; private int age; public Person(String name, int age) { this.name = name; this.age = age; } public String getName() { return name; } public void setName(String name) { this.name = name; } public int getAge() { return age; } public void setAge(int age) { this.age = age; } @Override public String toString() { return "Person [name=" + name + ", age=" + age + "]"; } } public class PersonConverter implements Converter { @Override//定义转换器能转换的JavaBean类型 public boolean canConvert(Class type) { return type.equals(Person.class); } @Override//把对象序列化成XML或Json public void marshal(Object value, HierarchicalStreamWriter writer, MarshallingContext context) { Person person = (Person) value; writer.startNode("姓名"); writer.setValue(person.getName()); writer.endNode(); writer.startNode("年龄"); writer.setValue(person.getAge()+""); writer.endNode(); writer.startNode("转换器"); writer.setValue("自定义的转换器"); writer.endNode(); } @Override//把XML或Json反序列化成对象 public Object unmarshal(HierarchicalStreamReader reader, UnmarshallingContext context) { Person person = new Person("",-1); reader.moveDown(); person.setName(reader.getValue()); reader.moveUp(); reader.moveDown(); person.setAge(Integer.parseInt(reader.getValue())); reader.moveUp(); return person; } } public class Test { public static void main(String[] args) { Person bean =new Person("张三",19); XStream xstream = new XStream(); xstream.registerConverter(new PersonConverter());//注册转换器 //序列化 String xml = xstream.toXML(bean); System.out.println(xml); //反序列化 bean=(Person)xstream.fromXML(xml); System.out.println(bean); } } } }
(3)常用的转换器接口与抽象类
SingleValueConverter
:单值转换接口AbstractSingleValueConverter
:单值转换抽象类Converter
:常规转换器接口
6.Xstream对象流的使用
(1)Xstream对象输出流
class Person { private String name; private int age; public Person(String name, int age) { this.name = name; this.age = age; } } public class Test { public static void main(String[] args) throws IOException { XStream xstream = new XStream(); ObjectOutputStream out = xstream.createObjectOutputStream(System.out); out.writeObject(new Person("张三",12)); out.writeObject(new Person("李四",19)); out.writeObject("Hello"); out.writeInt(12345); out.close(); } }
注意: XStream对象流是通过标准java.io.ObjectOutputStream
和java.io.ObjectInputStream
对象。 因为XML文档只能有一个根节点,必须包装在一个序列化的所有元素 额外的根节点。 这个根节点默认 < object-stream >
上面的例子所示。
(2)Xstream对象输出流
class Person { private String name; private int age; public Person(String name, int age) { this.name = name; this.age = age; } @Override public String toString() { return "Person [name=" + name + ", age=" + age + "]"; } } public class Test { public static void main(String[] args) throws IOException, ClassNotFoundException { String s="<object-stream><test.Person><name>张三</name><age>12</age></test.Person><int>12345</int></object-stream>"; StringReader reader = new StringReader(s); XStream xstream = new XStream(); ObjectInputStream in = xstream.createObjectInputStream(reader); System.out.println((Person) in.readObject()); System.out.println(in.readInt()); } } }
7.Xstream持久化API
(1)保存JavaBean对象
class Person { private String name; private int age; public Person(String name, int age) { this.name = name; this.age = age; } @Override public String toString() { return "Person [name=" + name + ", age=" + age + "]"; } } public class Test { public static void main(String[] args) throws IOException, ClassNotFoundException { PersistenceStrategy strategy = new FilePersistenceStrategy(new File("D:\\tmp")); List list = new XmlArrayList(strategy); list.add(new Person("张三",13));//保存数据 list.add(new Person("李四",21)); list.add(new Person("王五",17)); } }
程序运行结果: 如果我们检查D:\tmp目录,有三个文件:int@0.xml、int@1.xml、int@2.xml;每个对象都被序列化到XML文件里。
(2)读取并删除JavaBean对象
public class Test { public static void main(String[] args) throws IOException, ClassNotFoundException { PersistenceStrategy strategy = new FilePersistenceStrategy(new File("D:\\tmp")); List list = new XmlArrayList(strategy); for (Iterator it = list.iterator(); it.hasNext();) { System.out.println((Person) it.next()); it.remove();//删除对象序列化文件 } } }
8.Xstream操作Json
(1)Xstream序列化Json的重命名
@XStreamAlias("人") class Person { @XStreamAlias("姓名") private String name; @XStreamAlias("年龄") private int age; public Person(String name, int age) { this.name = name; this.age = age; } @Override public String toString() { return "Person [name=" + name + ", age=" + age + "]"; } } public class Test { public static void main(String[] args) { Person bean=new Person("张三",19); XStream xstream = new XStream(new JettisonMappedXmlDriver());//设置Json解析器 xstream.autodetectAnnotations(true); //Json序列化 String xml = xstream.toXML(bean); System.out.println(xml); //Json反序列化 bean=(Person)xstream.fromXML(xml); System.out.println(bean); } }
注意: Xstream序列化Json的重命名的方式与其序列化成XML的方式一样!
(2)去掉序列化Json的根节点
class Person { private String name; private int age; public Person(String name, int age) { this.name = name; this.age = age; } @Override public String toString() { return "Person [name=" + name + ", age=" + age + "]"; } } public class Test00 { public static void main(String[] args) { Person bean=new Person("张三",19); XStream xstream = new XStream(new JsonHierarchicalStreamDriver() { public HierarchicalStreamWriter createWriter(Writer writer) { return new JsonWriter(writer, JsonWriter.DROP_ROOT_MODE); } }); //Json序列化 String xml = xstream.toXML(bean); System.out.println(xml); } } }
注意: 去掉根节点后的Json串是不能反序列化的,因为XStream 不知道它的类型。
(3)Json的解析器区别
前面两个例子使用了不同的Json解析器,这里说明他们的不同之处:
JettisonMappedXmlDriver
:是支持序列化和反序列化Json的。JsonHierarchicalStreamDriver
:只支持序列化,不支持反序列化。
总结
到此这篇关于XML操作类库XStream使用详解的文章就介绍到这了,更多相关XStream使用详解内容请搜索脚本之家以前的文章或继续浏览下面的相关文章希望大家以后多多支持脚本之家!
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