xml与java对象转换 -- XStreamAlias

@XStreamAlias使用

一、 特点:

简化的API; 
无映射文件; 
高性能,低内存占用; 
整洁的XML; 
不需要修改对象;支持内部私有字段,不需要setter/getter方法 
提供序列化接口; 
自定义转换类型策略; 

XStream的优点很多，但是也有一些小bug，比如在定义别名中的下划线“_”转换为xml后会变成“__”这个符号， 不过下划线问题可以用下面这个解决

 XStream xStream = new XStream(new XppDriver(new XmlFriendlyNameCoder("_-", "_")));

二、 使用场景

Transport转换 
Persistence 持久化对象 
Configuration 配置 
Unit Tests 单元测试

Interface服务之间XML消息的交互

案例代码：

@XStreamAlias("kfpt_dept") //注意这个，后面变成了<kfpt__dept>  下划线。。。。
class Dept {
    private String deptName;

    private List<Staff> staffs;

    public String getDeptName() {
        return deptName;
    }

    public void setDeptName(String deptName) {
        this.deptName = deptName;
    }

    public List<Staff> getStaffs() {
        return staffs;
    }

    public void setStaffs(List<Staff> staffs) {
        this.staffs = staffs;
    }

    @Override
    public String toString() {
        return ToStringBuilder.reflectionToString(this, ToStringStyle.MULTI_LINE_STYLE);
    }
}

@XStreamAlias("kfpt_staffs")
class Staff {
    private String name;
    private int age;

    public Staff() {
        super();
    }

    public Staff(String name, int age) {
        super();
        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 ToStringBuilder.reflectionToString(this, ToStringStyle.MULTI_LINE_STYLE);
    }

}

转换工具类：

public class XstreamUtil {
    
    /**
     * 将bean转换为xml
     * @param obj 转换的bean
     * @return bean转换为xml
     */
    public static String objectToXml(Object obj) {
      //  XStream xStream = new XStream();
 XStream xStream = new XStream(new XppDriver(new XmlFriendlyNameCoder("_-", "_")));//解决下划线问题
        //xstream使用注解转换
       xStream.processAnnotations(obj.getClass());
        return xStream.toXML(obj);
    }
 
    /**
     * 将xml转换为bean
     * @param <T> 泛型
     * @param xml 要转换为bean的xml
     * @param cls bean对应的Class
     * @return xml转换为bean
     */
    public static <T> T xmlToObject(String xml, Class<T> cls){
        XStream xstream = new XStream(new DomDriver());
        //xstream使用注解转换
        xstream.processAnnotations(cls);
        return (T) xstream.fromXML(xml);
    }
}

main方法测试

public static void main(String[] args) {
        //java bean 转 xml
        Dept d = new Dept();
        List<Staff> staffs = new ArrayList<>();
        Staff s1 = new Staff("wuyun", 20);
        Staff s2 = new Staff("lilei", 22);
        staffs.add(s1);
        staffs.add(s2);
        d.setDeptName("开放平台");
        d.setStaffs(staffs);
        System.out.println(objectToXml(d));
/*

 用这个方法 XStream xStream = new XStream(); 会有下划线问题

<kfpt__dept>
<deptName>开放平台</deptName>
<staffs>
<kfpt__staffs>
<name>wuyun</name>
<age>20</age>
</kfpt__staffs>
<kfpt__staffs>
<name>lilei</name>
<age>22</age>
</kfpt__staffs>
</staffs>
</kfpt__dept>

XStream xStream = new XStream(new XppDriver(new XmlFriendlyNameCoder("_-", "_")));//可以解决下划线问题

<kfpt_dept>
<deptName>开放平台</deptName>
<staffs>
<kfpt_staffs>
<name>wuyun</name>
<age>20</age>
</kfpt_staffs>
<kfpt_staffs>
<name>lilei</name>
<age>22</age>
</kfpt_staffs>
</staffs>
</kfpt_dept>

*/
        
        //xml 转 java bean 
        // String xml = "<kfpt__dept><deptName>开放平台</deptName><staffs><kfpt__staffs><name>wuyun</name><age>20</age></kfpt__staffs><kfpt__staffs><name>lilei</name><age>22</age></kfpt__staffs></staffs></kfpt__dept>";
        //        XStream xstream = new XStream(new DomDriver());
        //        //xstream使用注解转换
        //        xstream.processAnnotations(Dept.class);
        //        System.out.println(((Dept) xstream.fromXML(xml)).toString());

        //        System.out.println(xmlToObject(xml, Dept.class).toString());
/*

com.cmcc.open.ss.vo.req.Dept@5660d2d2[
deptName=开放平台
staffs=[com.cmcc.open.ss.vo.req.Staff@6eb1054b[
name=wuyun
age=20
], com.cmcc.open.ss.vo.req.Staff@27d2b7b3[
name=lilei
age=22
]]
]

*/



    }