package com.bjs.acrosstime.utils;

import java.util.ArrayList;

import java.util.Date;

import java.util.List;

import java.util.Map;

import org.apache.log4j.Logger;

import org.codehaus.jackson.annotate.JsonIgnore;

import org.codehaus.jackson.map.ObjectMapper;

import org.codehaus.jackson.map.type.TypeFactory;

/**

* @author Peter

*/

public class JsonUtils {

private static Logger errLogger = Logger.getLogger("error");

private static Logger apiAccessLogger = Logger.getLogger("access");

private static final String PREFIX = "apiAccessAop";

//each thread has its own ObjectMapper instance

private static ThreadLocal<ObjectMapper> objMapperLocal = new ThreadLocal<ObjectMapper>(){

@Override

public ObjectMapper initialValue(){

return new ObjectMapper();

}

};

public static String toJSON(Object value) {

String result = null;

try {

result = objMapperLocal.get().writeValueAsString(value);

} catch (Exception e) {

e.printStackTrace();

}

// Fix null string

if ("null".equals(result)) {

result = null;

}

return result;

}

public static <T> T toT(String jsonString, Class<T> clazz) {

try {

return objMapperLocal.get().readValue(jsonString, clazz);

} catch (Exception e) {

errLogger.error("toT error: "+ jsonString,e);

}

return null;

}

public static <T> List<T> toTList(String jsonString, Class<T> clazz) {

try {

return objMapperLocal.get().readValue(jsonString, TypeFactory.collectionType(List.class, clazz));

} catch (Exception e) {

errLogger.error("toTList error: "+ jsonString,e);

}

return null;

}

@SuppressWarnings("unchecked")

public static Map<String, Object> toMap(String jsonString) {

return toT(jsonString, Map.class);

}

public static void main(String[] args) {

Message msg1 = new Message();

msg1.uid = "1";

msg1.opr_time = new Date();

msg1.content = "hello world---1";

Message msg2 = new Message();

msg2.uid = "2";

msg2.opr_time = new Date();

msg2.content = "hello world---2";

List<Message> list = new ArrayList<Message>();

list.add(msg1);

list.add(msg2);

final String json = toJSON(list);

System.out.println(json);

//String l = "[{\"opr_time\":\"2012-05-12 12:33:22\",\"uid\":\"akun\",\"content\":\"\u5927\u5730\u9707\u7684\u4eba\u4eec\u5b89\u606f\u5427\"},{\"opr_time\":\"2012-05-12 12:33:25\",\"uid\":\"requelqi\",\"content\":\"\u6211\u56de\u5bb6\u4e86\"},{\"opr_time\":\"2012-05-12 12:37:25\",\"uid\":\"stone\",\"content\":\"\u4eca\u5929\u4e0d\u65b9\u4fbf\u6e38\u620f\"}]";

final List<Message> newMsg = JsonUtils.toTList(json, Message.class);

System.out.println(newMsg);

System.out.println((newMsg.get(0).uid));

}

static class Message {

String uid;

Date opr_time;

@JsonIgnore

String content;

public String getUid() {

return uid;

}

public void setUid(String uid) {

this.uid = uid;

}

public Date getOpr_time() {

return opr_time;

}

public void setOpr_time(Date opr_time) {

this.opr_time = opr_time;

}

public String getContent() {

return content;

}

public void setContent(String content) {

this.content = content;

}

}

}