XStream简介

用XStream可以很简单的将xml字符串和bean进行相互转换，具体代码如下。

先写一下XStreamFactory。用来对xml的字符进行处理。

public class XStreamFactory {

public static String PREFIX_CDATA = "<![CDATA[";

public static String SUFFIX_CDATA = "]]>";

/**

* 初始化XStream 可支持某一字段可以加入CDATA标签 如果需要某一字段使用原文

* 就需要在String类型的text的头加上"<![CDATA["和结尾处加上"]]>"标签， 以供XStream输出时进行识别

* @param isAddCDATA

* 是否支持CDATA标签

* @return

*/

public static XStream init(boolean isAddCDATA) {

XStream xstream = null;

if (isAddCDATA) {

xstream = new XStream(new XppDriver() {

public HierarchicalStreamWriter createWriter(Writer out) {

return new PrettyPrintWriter(out) {

protected void writeText(QuickWriter writer, String text) {

// 这里的意思就是如果xml串的每行标签里的内容有<![CDATA[和]]>，则将这两个去掉，而在需要组装返回给微信服务器的xml串时，如果每行标签里的内容没有<![CDATA[和]]>，则在前后加上这两个。

if (text.startsWith(PREFIX_CDATA)) {

text = text.replace(PREFIX_CDATA, "");

text = text.replace(SUFFIX_CDATA, "");

writer.write(text);

return;

}

if (!text.startsWith(PREFIX_CDATA)) {

text = PREFIX_CDATA + text + SUFFIX_CDATA;

}

writer.write(text);

}

};

};

});

} else {

xstream = new XStream();

}

return xstream;

}

}

如果需要对xml的字符进行处理，则需要在定义XStream里重写XppDriver的createWriter方法，就可以自定义xml的格式和处理字符内容。

微信服务器推送消息时发的xml串，每行的内容包括<![CDATA[开头和]]>结尾。上面的XStreamFactory就可以将每行内容里的<![CDATA[和]]>处理掉，同时返回到微信服务器的xml又可以加了<![CDATA[开头和]]>结尾。

下面介绍xml串和bean的简单互转。bean里面有对象属性

public class Address {

private String province;

private String city;

private String district;

public Address(String province, String city, String district) {

super();

this.province = province;

this.city = city;

this.district = district;

}

public String getProvince() {

return province;

}

public void setProvince(String province) {

this.province = province;

}

public String getCity() {

return city;

}

public void setCity(String city) {

this.city = city;

}

public String getDistrict() {

return district;

}

public void setDistrict(String district) {

this.district = district;

}

@Override

public String toString() {

return "province = " + province + " city = " + city + " district = " + district;

}

}

具体的对象

public class User {

private String username;

private String email;

private Address address;

public User(String username, String email, Address address) {

super();

this.username = username;

this.email = email;

this.address = address;

}

public String getUsername() {

return username;

}

public void setUsername(String username) {

this.username = username;

}

public String getEmail() {

return email;

}

public void setEmail(String email) {

this.email = email;

}

public Address getAddress() {

return address;

}

public void setAddress(Address address) {

this.address = address;

}

@Override

public String toString() {

return "username = " + username + " email = " + email;

}

}

测试类：

public class TestXStream {

public static void main(String[] args) {

Address address1 = new Address("广东省", "深圳市", "南山区");

User user = new User("koko", "[e-mail]", address1);

XStream xstream = XStreamFactory.init(false);

xstream.alias("user", User.class);

String xmlStr = xstream.toXML(user);

System.out.println(xmlStr);

System.out.println("-------------------------------------------");

User userBak = (User)xstream.fromXML(xmlStr);

System.out.println(userBak);

System.out.println(userBak.getAddress());

}

}

输出如下：

<user>

<username>koko</username>

<email>[e-mail]</email>

<address>

<province>广东省</province>

<city>深圳市</city>

<district>南山区</district>

</address>

</user>

-------------------------------------------

username = koko email = [e-mail]

province = 广东省 city = 深圳市 district = 南山区

 

如果bean里面是一个对象的集合，在转换成xml的时候加上xstream.alias("address", Address.class);其实这个xstream.alias();是加别名，只要转换时xml的标签里出现了的类的全路径,即需要加一个别名来控制。

public class User {

private String username;

private String email;

private List<Address> addressList;

public User(String username, String email, List<Address> addressList) {

super();

this.username = username;

this.email = email;

this.addressList = addressList;

}

public String getUsername() {

return username;

}

public void setUsername(String username) {

this.username = username;

}

public String getEmail() {

return email;

}

public void setEmail(String email) {

this.email = email;

}

public List<Address> getAddressList() {

return addressList;

}

public void setAddressList(List<Address> addressList) {

this.addressList = addressList;

}

@Override

public String toString() {

return "username = " + username + " email = " + email;

}

}

测试类：

public class TestXStream {

public static void main(String[] args) {

List<Address> lists = new ArrayList<>();

Address address1 = new Address("广东省", "深圳市", "南山区");

Address address2 = new Address("湖南省", "长沙市", "望城区");

lists.add(address1);

lists.add(address2);

User user = new User("koko", "[e-mail]", lists);

XStream xstream = XStreamFactory.init(false);

xstream.alias("user", User.class);

xstream.alias("address", Address.class);

String xmlStr = xstream.toXML(user);

System.out.println(xmlStr);

System.out.println("-------------------------------------------");

User userBak = (User)xstream.fromXML(xmlStr);

System.out.println(userBak);

for(Address address : userBak.getAddressList()) {

System.out.println(address);

}

}

}

 

输出结果：

<user>

<username>koko</username>

<email>[e-mail]</email>

<addressList>

<address>

<province>广东省</province>

<city>深圳市</city>

<district>南山区</district>

</address>

<address>

<province>湖南省</province>

<city>长沙市</city>

<district>望城区</district>

</address>

</addressList>

</user>

-------------------------------------------

username = koko email = [e-mail]

province = 广东省 city = 深圳市 district = 南山区

province = 湖南省 city = 长沙市 district = 望城区

以上即为XStream相互转换xml字符串和bean，简单易用。