JSONObject转换JSON--将Date转换为指定格式

在将java.util.Date 类型字段转为json时，获取时取到的为[object object]，解决方法为：在讲对象转化为json格式是添加自定义的日期格式转化类，具体代码如下： 

public class DateJsonValueProcessor implements JsonValueProcessor {
    private String format = "yyyy-MM-dd";

    public DateJsonValueProcessor() {
    }

    public DateJsonValueProcessor(String format) {
        this.format = format;
    }

    public Object processArrayValue(Object value, JsonConfig jsonConfig) {
        String[] obj = {};
        if(value!=null)
        {
            if (value instanceof Date[]) {
                SimpleDateFormat sf = new SimpleDateFormat(format);
                Date[] dates = (Date[]) value;
                obj = new String[dates.length];
                for (int i = 0; i < dates.length; i++) {
                    obj[i] = sf.format(dates[i]);
                }
            }
        }
        return obj;
    }

    public Object processObjectValue(String key, Object value,
            JsonConfig jsonConfig) {
        if(value!=null)
        {
            if (value instanceof Date) {
                String str = new SimpleDateFormat(format).format((Date) value);
                return str;
            }
        }
        return value;
    }

    public String getFormat() {
        return format;
    }

    public void setFormat(String format) {
        this.format = format;
    }

}

使用方法： 

JsonConfig jsonConfig = new JsonConfig();
jsonConfig.registerJsonValueProcessor(java.util.Date.class, new DateJsonValueProcessor("yyyy-MM-dd"));

将json返回客户端 

HttpServletResponse response = this.getHttpResponse();
        response.setContentType("text/plain;charset=UTF-8");
        response.setHeader("Cache-Control","no-cache");
        JsonConfig jsonConfig = new JsonConfig();
        jsonConfig.registerJsonValueProcessor(Date.class, new DateJsonValueProcessor("yyyy-MM-dd"));
        try {
            response.getWriter().print(JSONObject.fromObject(conObj,jsonConfig));
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;

 参考：http://blessht.iteye.com/blog/2018901