springMVC requestBody gets json deserialization, date format problem

When developing springMVC to receive data and deserialize objects, I encountered the problem that the date format cannot be converted normally.

E.g:

public class Entity{

private Date date ;

//get set method omitted

}

Front-end json data format: {"date":"2016-11-11 10:52"}

Use @requestBody Entity entity method to receive data error.

Checked the official documentation (http://docs.spring.io/spring/docs/4.3.1.BUILD-SNAPSHOT/spring-framework-reference/htmlsingle/#rest-mapping-json-converter) and found the following text :

You convert the request body to the method argument by using an HttpMessageConverter. HttpMessageConverter is responsible for converting from the HTTP request message to an object and converting from an object to the HTTP response body. The RequestMappingHandlerAdapter supports the @RequestBodyannotation with the following default HttpMessageConverters:

The general idea is that springmvc matches the type through HttpMessageConverter and converts it.

Then I took a look at the Message Converters used by springMVC .

It is found that springMVC is used for requests in json format

MappingJackson2XmlHttpMessageConverter做处理。

那么了解JACKson原理就能帮我们解决问题。

这里有一篇文章讲述了如何使用反序列化来处理格式问题。http://jackyrong.iteye.com/blog/2005323

使用这种方式，对于每种不同的格式化数据，都得去写一个处理类，并且还要注解，显得很麻烦。

于是我想到了第二种方式。

接收数据的时候，我使用string类型接收，然后使用阿里的fastjson去转换数据。

例如：

@RequestBody String myEntity

Entity entity = JSONObject.parseObject(myEntity,Entity.class);

@JSONField(format="yyyy-MM-dd HH:mm")

private Date date ; //格式化

但是再使用这种方式转换的时候，发现日期格式“2016-11-11 10:52”，也不能正确转换。

查了相关文档发现阿里支持的反序列化日期格式为：

ISO-8601日期格式
yyyy-MM-dd
yyyy-MM-dd HH:mm:ss
yyyy-MM-dd HH:mm:ss.SSS
毫秒数字
毫秒数字字符串
.NET JSON日期格式
new Date(1982932381111)

显然，这些不能满足我的需求。

于是在github(https://github.com/alibaba/fastjson/releases)上下载fastJson源码修改后编译：

找到com\alibaba\fastjson\util\TypeUtils.java对下面一段代码编辑：

if (value instanceof String) {
            String strVal = (String) value;
            
            JSONScanner dateLexer = new JSONScanner(strVal);
            try {
                if (dateLexer.scanISO8601DateIfMatch(false)) {
                    Calendar calendar = dateLexer.getCalendar();
                    return calendar.getTime();
                }
            } finally {
                dateLexer.close();
            }
            
            if (strVal.startsWith("/Date(") && strVal.endsWith(")/")) {
                String dotnetDateStr = strVal.substring(6, strVal.length() - 2);
                strVal = dotnetDateStr;
            }

            if (strVal.indexOf('-') != -1) {
                String format;
                if (strVal.length() == JSON.DEFFAULT_DATE_FORMAT.length()) {
                    format = JSON.DEFFAULT_DATE_FORMAT;
                } else if (strVal.length() == 10) {
                    format = "yyyy-MM-dd";
                } else if (strVal.length() == "yyyy-MM-dd HH:mm:ss".length()) {
                    format = "yyyy-MM-dd HH:mm:ss";
                } else {
                    format = "yyyy-MM-dd HH:mm:ss.SSS";
                }

                SimpleDateFormat dateFormat = new SimpleDateFormat(format, JSON.defaultLocale);
                dateFormat.setTimeZone(JSON.defaultTimeZone);
                try {
                    return (Date) dateFormat.parse(strVal);
                } catch (ParseException e) {
                    throw new JSONException("can not cast to Date, value : " + strVal);
                }
            }

            if (strVal.length() == 0) {
                return null;
            }

            longValue = Long.parseLong(strVal);
        }

对这段代码进行扩展：

if (strVal.indexOf('-') != -1) {
                String format;
                if (strVal.length() == JSON.DEFFAULT_DATE_FORMAT.length()) {
                    format = JSON.DEFFAULT_DATE_FORMAT;
                } else if (strVal.length() == 10) {
                    format = "yyyy-MM-dd";
                } else if (strVal.length() == "yyyy-MM-dd HH:mm:ss".length()) {
                    format = "yyyy-MM-dd HH:mm:ss";
                } else {
                    format = "yyyy-MM-dd HH:mm:ss.SSS";

}

After compiling, put it into the project.

Summary: When you encounter a problem, looking for official documents can help you quickly locate the problem. As for how to solve the problem, the benevolent sees the benevolent and the wise sees the wisdom.

springMVC requestBody gets json deserialization, date format problem

MappingJackson2XmlHttpMessageConverter做处理。

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