将对象里面的时间类型属性 进行了格式的转换：

JSONObject result=new JSONObject();
JsonConfig jsonConfig=new JsonConfig();	
jsonConfig.registerJsonValueProcessor(java.util.Date.class, new DateJsonValueProcessor("yyyy-MM-dd"));
JSONArray jsonArray=JSONArray.fromObject(blogList, jsonConfig);
result.put("rows", jsonArray);

/**
 * json-lib 日期处理类
 * @author Administrator
 *
 */
public class DateJsonValueProcessor implements JsonValueProcessor{

	private String format;  
	
    public DateJsonValueProcessor(String format){  
        this.format = format;  
    }  
    
	public Object processArrayValue(Object value, JsonConfig jsonConfig) {
		// TODO Auto-generated method stub
		return null;
	}

	public Object processObjectValue(String key, Object value, JsonConfig jsonConfig) {
		if(value == null)  
        {  
            return "";  
        }  
        if(value instanceof java.sql.Timestamp)  
        {  
            String str = new SimpleDateFormat(format).format((java.sql.Timestamp)value);  
            return str;  
        }  
        if (value instanceof java.util.Date)  
        {  
            String str = new SimpleDateFormat(format).format((java.util.Date) value);  
            return str;  
        }  
          
        return value.toString(); 
	}

}