XML parsing entity tool class

import com.alibaba.fastjson.JSON;
import com.thoughtworks.xstream.XStream;
import com.thoughtworks.xstream.annotations.XStreamAlias;
import com.thoughtworks.xstream.converters.basic.DateConverter;
import com.thoughtworks.xstream.io.xml.DomDriver;
import com.thoughtworks.xstream.io.xml.XmlFriendlyNameCoder;
import com.thoughtworks.xstream.mapper.MapperWrapper;
import org.apache.commons.lang.StringUtils;

import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import java.util.TimeZone;

/**
 *  Must be  annotation driven
 *
 * @author
 */
public class XmlUtils {

    private static Map<Class<?>, XStream> xStreamMap = Collections.synchronizedMap(new HashMap<Class<?>, XStream>());

    /**
     * xml to obj
     */
    public static <T> T deserializeXml(String xml, Class<T> t) {
        if (StringUtils.isEmpty(xml)) {
            return null;
        }

        XStream xstream = getXStreamInstance(t);
        return (T)xstream.fromXML(xml);
    }

    /**
     * obj to xml
     */
    public static String toXml(Object obj) {
        if (obj == null) {
            return StringUtils.EMPTY;
        }
        XStream xstream = getXStreamInstance(obj.getClass());
        return xstream.toXML(obj);
    }

    /**
     * thread-safe
     *
     * @param clazz
     * @return
     * @auth zhuzhou
     */
    private static XStream getXStreamInstance(Class<?> clazz) {
        if (xStreamMap.containsKey(clazz)) {
            return xStreamMap.get(clazz);
        }
        synchronized (clazz) {
            if (xStreamMap.containsKey(clazz)) {
                return xStreamMap.get(clazz);
            }
            XStream xstream = new XStream(new DomDriver("utf-8", new XmlFriendlyNameCoder("_-", "_"))) {
                @Override
                protected MapperWrapper wrapMapper(MapperWrapper next) {
                    return new MapperWrapper(next) {
                        @Override
                        public boolean shouldSerializeMember(Class definedIn, String fieldName) {
                            if (definedIn == Object.class) {
                                //This is not compatible with implicit collections where item name is not defined
                                return false;
                            } else {
                                return super.shouldSerializeMember(definedIn, fieldName);
                            }
                        }
                    };
                }
            };

            xstream.processAnnotations(clazz);
            xstream.autodetectAnnotations(true);
            xstream.ignoreUnknownElements();
            xstream.registerConverter(new DateConverter(TimeZone.getDefault()));
            Class[] classes = new Class[]{clazz};
            xstream.allowTypes(classes);
            xStreamMap.put(clazz, xstream);
            return xstream;
        }
    }

    public static void main(String[] args) {
        for (int i = 1;i<20;i++) {
            new Thread(new Runnable() {
                @Override
                public void run() {
                    System.out.println(JSON.toJSONString(XmlUtils.deserializeXml(XmlUtils.toXml(
                        new RESPONSE("9999",
                            "Xml1111 Push failed thread11111111")),RESPONSE.class)));
                }
            }).start();
            new Thread(new Runnable() {
                @Override
                public void run() {

                    System.out.println(JSON.toJSONString(XmlUtils.deserializeXml(XmlUtils.toXml(
                        new RESPONSE1("9999",
                            "Xml2222 Push failed thread22222222")), RESPONSE1.class)));
                }
            }).start();
        }
    }


}

@XStreamAlias("RESPONSE1")
class RESPONSE1 {
    @XStreamAlias("RSCODE")
    private String rsCode;


    @XStreamAlias("RSMSG")
    private String rsMsg;


    public String getRsCode() {
        return rsCode;
    }

    public void setRsCode(String rsCode) {
        this.rsCode = rsCode;
    }

    public String getRsMsg() {
        return rsMsg;
    }

    public void setRsMsg(String rsMsg) {
        this.rsMsg = rsMsg;
    }


    public RESPONSE1(String rsCode, String rsMsg) {
        this.rsCode = rsCode;
        this.rsMsg = rsMsg;
    }
}


@XStreamAlias("RESPONSE")
class RESPONSE {
    @XStreamAlias("RSCODE")
    private String rsCode;


    @XStreamAlias("RSMSG")
    private String rsMsg;


    public String getRsCode() {
        return rsCode;
    }

    public void setRsCode(String rsCode) {
        this.rsCode = rsCode;
    }

    public String getRsMsg() {
        return rsMsg;
    }

    public void setRsMsg(String rsMsg) {
        this.rsMsg = rsMsg;
    }


    public RESPONSE(String rsCode, String rsMsg) {
        this.rsCode = rsCode;
        this.rsMsg = rsMsg;
    }
}

        <!-- https://mvnrepository.com/artifact/com.thoughtworks.xstream/xstream -->
        <dependency>
            <groupId>com.thoughtworks.xstream</groupId>
            <artifactId>xstream</artifactId>
            <version>1.4.18</version>
        </dependency>

        <!-- https://mvnrepository.com/artifact/com.alibaba/fastjson -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.79</version>
        </dependency>

        <!-- https://mvnrepository.com/artifact/commons-lang/commons-lang -->
        <dependency>
            <groupId>commons-lang</groupId>
            <artifactId>commons-lang</artifactId>
            <version>2.6</version>
        </dependency>