BeanUtils的populate方法之日期处理

BeanUtils.populate(Obj, Map);可以使map转对象，但是如果是Obj有个日期字段而Map中这个字段为空时候就会报错，无法赋值，这个时候就需要一个日期转换器！

首先写一个日期转换器

//日期转换器
public class DateTimeConverter implements Converter{
	 private static final String DATE      = "yyyy-MM-dd";
	 private static final String DATETIME  = "yyyy-MM-dd HH:mm:ss";
	 private static final String TIMESTAMP = "yyyy-MM-dd HH:mm:ss.SSS";

	@Override
	public Object convert(Class type, Object value) {
		// TODO Auto-generated method stub
		 return toDate(type, value);
	}

	public static Object toDate(Class type, Object value) {
        if (value == null || "".equals(value))
            return null;
        if (value instanceof String) {
            String dateValue = value.toString().trim();
            int length = dateValue.length();
            if (type.equals(java.util.Date.class)) {
                try {
                    DateFormat formatter = null;
                    if (length <= 10) {
                        formatter = new SimpleDateFormat(DATE, new DateFormatSymbols(Locale.CHINA));
                        return formatter.parse(dateValue);
                    }
                    if (length <= 19) {
                        formatter = new SimpleDateFormat(DATETIME, new DateFormatSymbols(Locale.CHINA));
                        return formatter.parse(dateValue);
                    }
                    if (length <= 23) {
                        formatter = new SimpleDateFormat(TIMESTAMP, new DateFormatSymbols(Locale.CHINA));
                        return formatter.parse(dateValue);
                    }
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        }
        return value;
    }
}

然后再写一个通用的调用方法

public static void transMap2Bean(Map map, Object obj) {  
		  
        try {  
        	DateTimeConverter dtConverter = new DateTimeConverter();
        	ConvertUtilsBean convertUtilsBean = new ConvertUtilsBean();
        	convertUtilsBean.deregister(Date.class);
        	convertUtilsBean.register(dtConverter, Date.class);
        	BeanUtilsBean beanUtilsBean = new BeanUtilsBean(convertUtilsBean,
        		new PropertyUtilsBean());
        	beanUtilsBean.populate(obj, map);
  
        } catch (Exception e) {  
           
        }  
  
        return;  
  
    }