SpringMVC日期格式化

一、关于SpringMVC日期的格式化大概可分为四点

1.@ResponseBody方式返回json的日期格式化

2.ajax方式返回json的日期格式化

3.数据保存时String转Date

4.页面展示时，Date转固定格式的String

二、配置实现日期格式化

无配置的json数据，日期显示为timestamp

{"id":8,"loginName":"chensan","loginPwd":"123456","userName":"陈三","mnemonic":null,"sex":2,"birthday":631123200000,"status":1,"createBy":1,"createDatetime":1527955762000,"updateBy":1,"updateDatetime":1528040703000,"delFlag":null,"remark":"xsdssds说到底发生的bbbbb","roleIds":null}

1.@ResponseBody方式返回json的日期格式化

在com.fasterxml.jackson.databind.ObjectMapper设置相应属性

SerializationFeature.WRITE_DATES_AS_TIMESTAMPS默认为true，日期显示为时间戳；

修改为false

{"id":8,"loginName":"chensan","loginPwd":"123456","userName":"陈三","mnemonic":null,"sex":2,"birthday":"1989-12-31T16:00:00.000+0000","status":1,"createBy":1,"createDatetime":"2018-06-02T16:09:22.000+0000","updateBy":1,"updateDatetime":"2018-06-03T15:45:03.000+0000","delFlag":null,"remark":"xsdssds说到底发生的bbbbb","roleIds":null}

时区默认0时区，设置东八区timezone="GMT+8"

{"id":8,"loginName":"chensan","loginPwd":"123456","userName":"陈三","mnemonic":null,"sex":2,"birthday":"1990-01-01T00:00:00.000+0800","status":1,"createBy":1,"createDatetime":"2018-06-03T00:09:22.000+0800","updateBy":1,"updateDatetime":"2018-06-03T23:45:03.000+0800","delFlag":null,"remark":"xsdssds说到底发生的bbbbb","roleIds":null}

日期格式化DateFormat设置为"yyyy-MM-dd HH:mm:ss"格式

{"id":8,"loginName":"chensan","loginPwd":"123456","userName":"陈三","mnemonic":null,"sex":2,"birthday":"1990-01-01 00:00:00","status":1,"createBy":1,"createDatetime":"2018-06-03 00:09:22","updateBy":1,"updateDatetime":"2018-06-03 23:45:03","delFlag":null,"remark":"xsdssds说到底发生的bbbbb","roleIds":null}

无时分秒的日期，时分秒以0补齐，如：birthday，需要在字段上设置@JsonFormat(pattern=”yyyy-MM-dd”)；用以覆盖ObjectMapper中的配置 ；

也可以不配置ObjectMapper中相应的配置，只须在日期字段设置@JsonFormat(pattern="yyyy-MM-dd HH:mm:ss", timezone="GMT+8")配置日期格式和时区，根据实际情况设置日期格式和时区；

{"id":8,"loginName":"chensan","loginPwd":"123456","userName":"陈三","mnemonic":null,"sex":2,"birthday":"1990-01-01","status":1,"createBy":1,"createDatetime":"2018-06-03 00:09:22","updateBy":1,"updateDatetime":1528040703000,"delFlag":null,"remark":"xsdssds说到底发生的bbbbb","roleIds":null}

这个返回的json去掉了jackson的ObjectMapper配置，配置了 @JsonFormat的字段也不会以时间戳显示；

当然，建议统一设置jackson配置；

public class CustomObjectMapper extends ObjectMapper {
	private static final long serialVersionUID = 1L;
	
	public CustomObjectMapper() {
		//禁止使用时间戳
		this.configure(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS, false);
		//设置为中国上海时区
		this.setTimeZone(TimeZone.getTimeZone("GMT+8"));
		//设置日期格式
		this.setDateFormat(new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"));
		
		//反序列化时，属性不存在的兼容处理  
		//this.getDeserializationConfig().withoutFeatures(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES);  
		//如果是空对象的时候,不抛异常
		//this.configure(SerializationFeature.FAIL_ON_EMPTY_BEANS, false);
		//反序列化的时候如果多了其他属性,不抛出异常
        //this.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);  
        //单引号处理  
        //this.configure(com.fasterxml.jackson.core.JsonParser.Feature.ALLOW_SINGLE_QUOTES, true); 
	}

}

springmvc配置文件

<mvc:annotation-driven>
  <mvc:message-converters>
    <bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
	  <property name="objectMapper" ref="jacksonObjectMapper" />
    </bean>
  </mvc:message-converters>
</mvc:annotation-driven>

<bean id="jacksonObjectMapper" class="com.chensan.config.CustomObjectMapper" />

参考：https://www.cnblogs.com/lcngu/p/5785805.html

https://www.cnblogs.com/coder6/p/6738781.html

Spring3.x和Spring4.x的配置有区别，参考：https://blog.csdn.net/m0_38016299/article/details/78338048

2.ajax方式返回json的日期格式化

非@ResponseBody的日期格式化

BaseController

public class BaseController {
	protected static final Logger loger = LoggerFactory.getLogger(BaseController.class);
	
	protected static SerializeConfig mapping = new SerializeConfig();
	protected static String dateFormat;  
	static {
	    dateFormat = "yyyy-MM-dd HH:mm:ss";
	    mapping.put(Date.class, new SimpleDateFormatSerializer(dateFormat));
	}
	
	/**
	 * 向客户端输出html字符串
	 * @param response HttpServletResponse响应
	 * @param content 要输出到客户端的字符串
	 */
	public void writeResponse(HttpServletResponse response, String content) {
		response.setCharacterEncoding("utf-8");
		response.setContentType("text/html; charset=UTF-8");
		PrintWriter writer;
		try {
			writer = response.getWriter();
			writer.write(content);
			writer.flush();
		} catch (IOException e) {
			loger.error("向客户端写入数据失败", e);
		}
	}
	
	/**
	 * 根据MIME类型输出响应内容。
	 * @param response HttpServletResponse响应
	 * @param content 要输出到客户端的字符串
	 * @param contentType 输出ContentType
	 */
	public void writeResponseByMIME(HttpServletResponse response, String content, String contentType) {
		response.setCharacterEncoding("utf-8");
		response.setContentType(contentType + "; charset=UTF-8");
		
		PrintWriter writer;
		try {
			writer = response.getWriter();
			writer.write(content);
			writer.flush();
		} catch (IOException e) {
			loger.error("向客户端写入数据失败", e);
		}
	}
}

Controller继承BaseController

/**
	 * 测试ajax方式（非@ResponseBody注解方式）获取json数据
	 * @param id
	 * @param response
	 * 可以看到非@ResponseBody注解（ajax）方式获取的json格式为时间戳格式， 故而在BaseController对日期格式化
	 * 这里用的json包围fastjson，所以设置SerializeConfig，字段上注解用@JSONField(format="yyyy-MM-dd HH:mm:ss")，具体格式根据需要自定义
	 * 
	 */
	@RequestMapping("/getJsonData2/{id}")
	public void ajaxGetJsonData(@PathVariable(value = "id") Integer id, HttpServletResponse response) {
		User entity = userService.queryById(id);
		JSONPObject jsonp = new JSONPObject();
		jsonp.addParameter(entity);
		String jsonResult = JSON.toJSONString(jsonp, BaseController.mapping, SerializerFeature.WriteMapNullValue);
		this.writeResponseByMIME(response, jsonResult, MimeTypeUtils.APPLICATION_JSON_VALUE);
	}
	
	/**
	 * fastjson过滤字段
	 * @param id
	 * @param response
	 */
	@RequestMapping("/getJsonData3/{id}")
	public void ajaxGetJsonData2(@PathVariable(value = "id") Integer id, HttpServletResponse response) {
		User entity = userService.queryById(id);
		JSONPObject jsonp = new JSONPObject();
		jsonp.addParameter(entity);
		SimplePropertyPreFilter filter = new SimplePropertyPreFilter(User.class, "id", "userName", "loginName", 
				"birthday", "sex", "status", "createDatetime", "updateDatetime");
		String jsonResult = JSON.toJSONString(jsonp, BaseController.mapping, filter, SerializerFeature.WriteMapNullValue);
		this.writeResponseByMIME(response, jsonResult, MimeTypeUtils.APPLICATION_JSON_VALUE);
	}

null({"birthday":"1990-01-01 00:00:00","createBy":1,"createDatetime":"2018-06-03 00:09:22","delFlag":null,"id":8,"loginName":"chensan","loginPwd":"123456","mnemonic":null,"remark":"xsdssds说到底发生的bbbbb","roleIds":null,"sex":2,"status":1,"updateBy":1,"updateDatetime":"2018-06-03 23:45:03","userName":"陈三"})

BaseController设置日期格式为"yyyy-MM-dd HH:mm:ss"，birthday只有年月日需要在字段自定义格式@JSONField (format="yyyy-MM-dd")

3.数据保存时String转Date

数据保存时，页面的String不转为Date，则字段类型无法匹配，数据不能保存。在Model设置注解@DateTimeFormat(pattern = "yyyy-MM-dd HH:mm:ss")，将字符串格式化，@DateTimeFormat能将String自动转为Date；至于ConversionServiceFactoryBean，实在没必要啊，我最初还以为是可以将页面展示的日期格式化为"yyyy-MM-dd HH:mm:ss"格式才试了试。

ConversionServiceFactoryBean配置，参考：https://www.cnblogs.com/ssslinppp/p/4600043.html

4.页面展示时，Date转固定格式的String

页面不格式化的日期，如：Sun Jun 03 00:09:22 CST 2018

1.模板用format标签就行了，所有模板引擎都有提供

2.用spring的标签<%@ taglib prefix="s" uri="http://www.springframework.org/tags" %>，

<s:eval expression="formModel.createDatetime"/>需要搭配@DateTimeFormat标签使用

参考：https://www.cnblogs.com/liukemng/p/3748137.html

3.还有就是在js调用格式化

/ 自定义日期格式化
    Date.prototype.Format = function (fmt) {
        var o = {
            "M+": this.getMonth() + 1, // 月份
            "d+": this.getDate(), // 日
            "h+": this.getHours(), // 小时
            "m+": this.getMinutes(), // 分
            "s+": this.getSeconds(), // 秒
            "q+": Math.floor((this.getMonth() + 3) / 3), // 季度
            "S": this.getMilliseconds() // 毫秒
        };
        if (/(y+)/.test(fmt)) fmt = fmt.replace(RegExp.$1, (this.getFullYear() + "").substr(4 - RegExp.$1.length));
        for (var k in o)
        if (new RegExp("(" + k + ")").test(fmt)) fmt = fmt.replace(RegExp.$1, (RegExp.$1.length == 1) ? (o[k]) : (("00" + o[k]).substr(("" + o[k]).length)));
        return fmt;
    }

或者用日期选择器插件，初始化日期

4.见过最邪门的是公司的SpringCloud项目，去掉了所有配置文件的日期格式化，去掉了硬编码的java类配置与日期格式化相关的类，字段也没调用js和用format标签，但是thyemeleaft模板就是将日期格式化了。（问了老大本人，他指出所有配置的地方，奈何我已全测试过不顶用才去问的；项目很久他忘了是怎么配置的。实在搞不定，只能等把整个项目完全消化掉再去看了）