public class JsonDateValueProcessor implements JsonValueProcessor {
    private String format ="yyyyMMdd";

    public JsonDateValueProcessor() {
        super();
    }

    public JsonDateValueProcessor(String format) {
        super();
        this.format = format;
    }

    @Override
    public Object processArrayValue(Object paramObject,
                                    JsonConfig paramJsonConfig) {
        return process(paramObject);
    }

    @Override
    public Object processObjectValue(String paramString, Object paramObject,
                                     JsonConfig paramJsonConfig) {
        return process(paramObject);
    }


    private Object process(Object value){
        if(value instanceof Date){
            SimpleDateFormat sdf = new SimpleDateFormat(format, Locale.CHINA);
            return sdf.format(value);
        }
        return value =http://www.mamicode.com/= null ?"" : value.toString();
    }
}

controller里这样写

List<T> list = service.queryFromWtxs();   //查询到要显示的实体类表
JsonConfig jsonConfig = new JsonConfig();
jsonConfig.registerJsonValueProcessor(Date.class, new JsonDateValueProcessor());
JSONArray jsonArray22=JSONArray.fromObject(list,jsonConfig);        //实体类表转成json；时间变转换器里的时间格式
sum = list.size();
mv.addObject("list",jsonArray22);        //在jsp使用“list”

时间格式的时间 转json的时候变成正常的string时间20170519