转：Json与Bean互转，Timestamp类型的问题_JAVA_编程开发_程序员俱乐部

Json与Java Bean互相转换时,Bean中的Timestamp字段是无法直接处理的，需要实现两个转换器。

DateJsonValueProcessor的作用是Bean转换为Json时将Timepstamp转换为指定的时间格式。

class="java" name="code">
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;
import net.sf.json.JsonConfig;
import net.sf.json.processors.JsonValueProcessor;
/*** 将Bean中的Timestamp转换为json中的日期字符串*/
public class DateJsonValueProcessor implements JsonValueProcessor {
	public static final String Default_DATE_PATTERN ="yyyy-MM-dd";
	private DateFormat dateFormat ;
	public DateJsonValueProcessor(String datePattern){
		try{
			dateFormat  = new SimpleDateFormat(datePattern);}
		catch(Exception e ){
			dateFormat = new SimpleDateFormat(Default_DATE_PATTERN);
		}
	}
	public Object processArrayValue(Object value, JsonConfig jsonConfig) {
		return process(value);
	}
	public Object processObjectValue(String key, Object value,JsonConfig jsonConfig) {
		return process(value);
	}
	private Object process(Object value){
		return dateFormat.format((Date)value);
	}
}

TimestampMorpher的作用则与DateJsonValueProcessor相反，它是在Jsonl转换为Bean时，会把指定的时间格式转换为Timestamp

import java.sql.Timestamp;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import net.sf.ezmorph.MorphException;
import net.sf.ezmorph.object.AbstractObjectMorpher;
/*** 将json串中的日期字符串转换为bean中的Timestamp*/
public class TimestampMorpher extends AbstractObjectMorpher {
/*** 日期字符串格式*/
private String[] formats;
public TimestampMorpher(String[] formats) {
	this.formats = formats;
}
public Object morph(Object value) {
if( value == null){
	return null;
}
if( Timestamp.class.isAssignableFrom(value.getClass()) ){
	return (Timestamp) value;
}
if( !supports( value.getClass()) ){
	throw new MorphException( value.getClass() + " 是不支持的类型");
}
String strValue=(String) value;
SimpleDateFormat dateParser=null;
for( int i = 0; i < formats.length ; i++ ){
	if( null == dateParser ){
		dateParser=new SimpleDateFormat(formats[i]);
	}else{
		dateParser.applyPattern(formats[i]);
	}
	try{
		return new Timestamp( dateParser.parse( strValue.toLowerCase()).getTime() );}
	catch (ParseException e) {
		//e.printStackTrace();
	}
}
return null;
}
@Override
public Class morphsTo() {
	return Timestamp.class;
}
public boolean supports( Class clazz ){
	return String.class.isAssignableFrom( clazz );
}

}


public class JsonTest {
public static void main(String[] args) {
	String jsonStr="{\"id\":\"101\",\"name\":\"张三\",\"age\":\"20\",\"birthday\":\"1992-10-19 23:52:18\"}";
	Student s=new Student();
	Timestamp b=Timestamp.valueOf("1992-10-19 23:52:18");
	s.setId(123456);
	s.setName("李四");
	s.setAge(20);
	s.setBirthday(b);
	Student s1=jsonToBean(jsonStr);
	System.out.println(s1.getBirthday());
	System.out.println(beanToJson(s));
}
public static Student jsonToBean(String json){
	String[] formats={"yyyy-MM-dd HH:mm:ss","yyyy-MM-dd"};
	JSONUtils.getMorpherRegistry().registerMorpher(new TimestampMorpher(formats));
	JSONObject jsonObject=JSONObject.fromObject(json);
	return (Student)JSONObject.toBean(jsonObject,Student.class);
}

public static String beanToJson(Student s){
	JsonConfig config=new JsonConfig();
	config.registerJsonValueProcessor(Timestamp.class, new DateJsonValueProcessor("yyyy-MM-dd HH:mm:ss"));
	JSONObject json=JSONObject.fromObject(s,config);
	return json.toString();}
}