xml="<apps>\n" +
" <app>\n" +
"  <id>1</id>\n" +
"  <name>burn</name>\n" +
"  <version>1.0</version>\n" +
"  <info>\n" +
"   <size>10.5</size>\n" +
"   <message>hhhhhhhh</message>\n" +
"  </info>\n" +
"  <info>\n" +
"   <size>10.5</size>\n" +
"   <message>hhhhhhhh</message>\n" +
"  </info>\n" +
" </app>\n" +
" <app>\n" +
"  <id>2</id>\n" +
"  <name>burn2</name>\n" +
"  <version>2.1</version>\n" +
"  <info>\n" +
"   <size>10.5</size>\n" +
"   <message>hhhhhhhh</message>\n" +
"  </info>\n" +
"  <info>\n" +
"   <size>10.5</size>\n" +
"   <message>hhhhhhhh</message>\n" +
"  </info>\n" +
" </app>\n" +
" <app>\n" +
"  <id>3</id>\n" +
"  <name>burn3</name>\n" +
"  <version>3.2</version>\n" +
"  <info>\n" +
"   <size>10.5</size>\n" +
"   <message>hhhhhhhh</message>\n" +
"  </info>\n" +
"  <info>\n" +
"   <size>10.5</size>\n" +
"   <message>hhhhhhhh</message>\n" +
"  </info>\n" +
" </app>\n" +
"</apps>";

/**
* 
xml数据对应的封装类(注意实体类和xml数据的对应关系，所有标签都得对应)
*/
@XStreamAlias("apps")//配置标签别名
public class AppBean {


@XStreamImplicit//忽略集合根节点
private List<App> app_list;


//必须有无参构造方法
public AppBean() {
}


public AppBean(List<App> app_list) {
this.app_list = app_list;
}


public List<App> getApp_list() {
return app_list;
}


public void setApp_list(List<App> app_list) {
this.app_list = app_list;
}


@XStreamAlias("app")
public static class App{


private long id;
private String name;
private String version;


@XStreamImplicit
private List<Infor> infor_list;


public App() {
}


public App(long id, List<Infor> infor_list, String name, String version) {
this.id = id;
this.infor_list = infor_list;
this.name = name;
this.version = version;
}


public long getId() {
return id;
}


public void setId(long id) {
this.id = id;
}


public List<Infor> getInfor_list() {
return infor_list;
}


public void setInfor_list(List<Infor> infor_list) {
this.infor_list = infor_list;
}


public String getName() {
return name;
}


public void setName(String name) {
this.name = name;
}


public String getVersion() {
return version;
}


public void setVersion(String version) {
this.version = version;
}


@XStreamAlias("info")
public static class Infor{


private String message;
private double size;


public Infor() {
}


public Infor(String message, double size) {
this.message = message;
this.size = size;
}


public String getMessage() {
return message;
}


public void setMessage(String message) {
this.message = message;
}


public double getSize() {
return size;
}


public void setSize(double size) {
this.size = size;
}
}
}
}

XStream xStream=new XStream();
xStream.processAnnotations(AppBean.class);//声明使用注解的类
AppBean ab2= (AppBean) xStream.fromXML(xml);//xml-->Bean，只能解析为对象，不能解析为集合
String xml=xStream.toXML(AppBean.class)//Bean-->xml