spring-boot前端参数单位转换

Posted 2021-01-30 沧海一滴

 

前端时间单位用的是unix时间戳，单位秒，而java后端用的是Date类型。
在request请求时，如何把前端的时间戳类型优雅的转换为后端的Date类型呢。

如果你想在response时，把后端的Date类型转换到前端的时间戳类型
可以看这篇文章java中JsonSerializer用法,前后端单位转换必备

这里我使用的是SpringBoot框架。

Controller代码

    @RequestMapping(value = "/add", method = RequestMethod.POST)
    public Result add(@Valid OrderForm form,
                      BindingResult bindingResult) {
        if (bindingResult.hasErrors()) {
        
        }

OrderForm对象

@Data
public class OrderForm {

    private String id;

    private String userName;
    
    private Date addTime;
}

这时，如果直接传addTime=1488264066是会报错的，提示类型不正确。
但如果你把addTime类型改成Long就可以

@Data
public class OrderForm {

    private String id;

    private String userName;
    
    private Long addTime;
}

说明spring已经帮我们做了String到Long的转换，但是没有做转换到Date类型。
我们来扩展即可。

在src/java/下建一个名字为bind的包。
下面放这3个java文件

/**
* 扩展类型转换
*/
public class CustomDateEditor extends PropertyEditorSupport {

    /**
     * @see java.beans.PropertyEditorSupport#setAsText(java.lang.String)
     */
    @Override
    public void setAsText(String text) throws IllegalArgumentException {
        setValue(new Date(Long.decode(text)));
    }

    /**
     * @see java.beans.PropertyEditorSupport#getAsText()
     */
    @Override
    public String getAsText() {
        Date value = (Date) getValue();
        return (value != null ? String.valueOf(TimeUnit.MILLISECONDS.toSeconds(value.getTime())) : "");
    }

}

/**
* 扩展web初始化的配置
*/
public class CustomDateWebBindingInitializer implements WebBindingInitializer {

    /**
     * @see org.springframework.web.bind.support.WebBindingInitializer#initBinder(org.springframework.web.bind.WebDataBinder,
     *      org.springframework.web.context.request.WebRequest)
     */
    @Override
    public void initBinder(WebDataBinder binder, WebRequest request) {
        binder.registerCustomEditor(Date.class, new CustomDateEditor());
    }

}

/**
* 让配置在request请求时生效
*/
@Configuration
public class CustomDateEditorConfiguration {

    @Autowired
    public void setWebBindingInitializer(RequestMappingHandlerAdapter requestMappingHandlerAdapter) {
        requestMappingHandlerAdapter.setWebBindingInitializer(new CustomDateWebBindingInitializer());
    }
}

配置好后，就可以接收到Date类型的内容了，全局生效。

作者：nul1
链接：https://www.jianshu.com/p/3a5fc2564501
來源：简书
简书著作权归作者所有，任何形式的转载都请联系作者获得授权并注明出处。

Java中

    //-----------------------------------------------------------------------
    /**
     * The ISO date-time formatter that formats or parses a date-time with an
     * offset, such as ‘2011-12-03T10:15:30+01:00‘.
     * <p>
     * This returns an immutable formatter capable of formatting and parsing
     * the ISO-8601 extended offset date-time format.
     * The format consists of:
     * <ul>
     * <li>The {@link #ISO_LOCAL_DATE_TIME}
     * <li>The {@link ZoneOffset#getId() offset ID}. If the offset has seconds then
     *  they will be handled even though this is not part of the ISO-8601 standard.
     *  Parsing is case insensitive.
     * </ul>
     * <p>
     * The returned formatter has a chronology of ISO set to ensure dates in
     * other calendar systems are correctly converted.
     * It has no override zone and uses the {@link ResolverStyle#STRICT STRICT} resolver style.
     */
    public static final DateTimeFormatter ISO_OFFSET_DATE_TIME;
    static {
        ISO_OFFSET_DATE_TIME = new DateTimeFormatterBuilder()
                .parseCaseInsensitive()
                .append(ISO_LOCAL_DATE_TIME)
                .appendOffsetId()
                .toFormatter(ResolverStyle.STRICT, IsoChronology.INSTANCE);
    }

    //-----------------------------------------------------------------------
    /**
     * The ISO date-time formatter that formats or parses a date-time with an
     * offset, such as ‘2011-12-03T10:15:30+01:00‘.
     * <p>
     * This returns an immutable formatter capable of formatting and parsing
     * the ISO-8601 extended offset date-time format.
     * The format consists of:
     * <ul>
     * <li>The {@link #ISO_LOCAL_DATE_TIME}
     * <li>The {@link ZoneOffset#getId() offset ID}. If the offset has seconds then
     *  they will be handled even though this is not part of the ISO-8601 standard.
     *  Parsing is case insensitive.
     * </ul>
     * <p>
     * The returned formatter has a chronology of ISO set to ensure dates in
     * other calendar systems are correctly converted.
     * It has no override zone and uses the {@link ResolverStyle#STRICT STRICT} resolver style.
     */
    public static final DateTimeFormatter ISO_OFFSET_DATE_TIME;
    static {
        ISO_OFFSET_DATE_TIME = new DateTimeFormatterBuilder()
                .parseCaseInsensitive()
                .append(ISO_LOCAL_DATE_TIME)
                .appendOffsetId()
                .toFormatter(ResolverStyle.STRICT, IsoChronology.INSTANCE);
    }

 

    //-----------------------------------------------------------------------
    /**
     * The ISO instant formatter that formats or parses an instant in UTC,
     * such as ‘2011-12-03T10:15:30Z‘.
     * <p>
     * This returns an immutable formatter capable of formatting and parsing
     * the ISO-8601 instant format.
     * When formatting, the second-of-minute is always output.
     * The nano-of-second outputs zero, three, six or nine digits digits as necessary.
     * When parsing, time to at least the seconds field is required.
     * Fractional seconds from zero to nine are parsed.
     * The localized decimal style is not used.
     * <p>
     * This is a special case formatter intended to allow a human readable form
     * of an {@link java.time.Instant}. The {@code Instant} class is designed to
     * only represent a point in time and internally stores a value in nanoseconds
     * from a fixed epoch of 1970-01-01Z. As such, an {@code Instant} cannot be
     * formatted as a date or time without providing some form of time-zone.
     * This formatter allows the {@code Instant} to be formatted, by providing
     * a suitable conversion using {@code ZoneOffset.UTC}.
     * <p>
     * The format consists of:
     * <ul>
     * <li>The {@link #ISO_OFFSET_DATE_TIME} where the instant is converted from
     *  {@link ChronoField#INSTANT_SECONDS} and {@link ChronoField#NANO_OF_SECOND}
     *  using the {@code UTC} offset. Parsing is case insensitive.
     * </ul>
     * <p>
     * The returned formatter has no override chronology or zone.
     * It uses the {@link ResolverStyle#STRICT STRICT} resolver style.
     */
    public static final DateTimeFormatter ISO_INSTANT;
    static {
        ISO_INSTANT = new DateTimeFormatterBuilder()
                .parseCaseInsensitive()
                .appendInstant()
                .toFormatter(ResolverStyle.STRICT, null);
    }

java.time.format.DateTimeFormatter#ISO_INSTANT

 

 

Customizing Formats

---

Version note: This Date and Time section uses the date and time APIs in the java.util package. The java.time APIs, available in the JDK 8 release, provides a comprehensive date and time model that offers significant improvements over the java.util classes. The java.time APIs are described in the Date Time trail. The Legacy Date-Time Code page might be of particular interest.

---

The previous section, Using Predefined Formats, described the formatting styles provided by the DateFormat class. In most cases these predefined formats are adequate. However, if you want to create your own customized formats, you can use the SimpleDateFormat class.

The code examples that follow demonstrate the methods of the SimpleDateFormat class. You can find the full source code for the examples in the file named SimpleDateFormatDemo.

About Patterns

When you create a SimpleDateFormat object, you specify a pattern String. The contents of the pattern String determine the format of the date and time. For a full description of the pattern‘s syntax, see the tables in Date Format Pattern Syntax.

The following code formats a date and time according to the pattern String passed to the SimpleDateFormat constructor. The String returned by the format method contains the formatted date and time that are to be displayed.

Date today;
String output;
SimpleDateFormat formatter;

formatter = new SimpleDateFormat(pattern, currentLocale);
today = new Date();
output = formatter.format(today);
System.out.println(pattern + " " + output);

The following table shows the output generated by the previous code example when the U.S. Locale is specified:

Customized Date and Time Formats

Pattern	Output
dd.MM.yy	30.06.09
yyyy.MM.dd G ‘at‘ hh:mm:ss z	2009.06.30 AD at 08:29:36 PDT
EEE, MMM d, ‘‘yy	Tue, Jun 30, ‘09
h:mm a	8:29 PM
H:mm	8:29
H:mm:ss:SSS	8:28:36:249
K:mm a,z	8:29 AM,PDT
yyyy.MMMMM.dd GGG hh:mm aaa	2009.June.30 AD 08:29 AM

Patterns and Locale

The SimpleDateFormat class is locale-sensitive. If you instantiate SimpleDateFormat without a Locale parameter, it will format the date and time according to the default Locale. Both the pattern and the Locale determine the format. For the same pattern, SimpleDateFormat may format a date and time differently if the Locale varies.

In the example code that follows, the pattern is hardcoded in the statement that creates the SimpleDateFormat object:

Date today;
String result;
SimpleDateFormat formatter;

formatter = new SimpleDateFormat("EEE d MMM yy", currentLocale);
today = new Date();
result = formatter.format(today);
System.out.println("Locale: " + currentLocale.toString());
System.out.println("Result: " + result);

When the currentLocale is set to different values, the preceding code example generates this output:

Locale: fr_FR
Result: mar. 30 juin 09
Locale: de_DE
Result: Di 30 Jun 09
Locale: en_US
Result: Tue 30 Jun 09

Date Format Pattern Syntax

You can design your own format patterns for dates and times from the list of symbols in the following table:

Symbol	Meaning	Presentation	Example
G	era designator	Text	AD
y	year	Number	2009
M	month in year	Text & Number	July & 07
d	day in month	Number	10
h	hour in am/pm (1-12)	Number	12
H	hour in day (0-23)	Number	0
m	minute in hour	Number	30
s	second in minute	Number	55
S	millisecond	Number	978
E	day in week	Text	Tuesday
D	day in year	Number	189
F	day of week in month	Number	2 (2nd Wed in July)
w	week in year	Number	27
W	week in month	Number	2
a	am/pm marker	Text	PM
k	hour in day (1-24)	Number	24
K	hour in am/pm (0-11)	Number	0
z	time zone	Text	Pacific Standard Time
‘	escape for text	Delimiter	(none)
‘	single quote	Literal	‘

Characters that are not letters are treated as quoted text. That is, they will appear in the formatted text even if they are not enclosed within single quotes.

The number of symbol letters you specify also determines the format. For example, if the "zz" pattern results in "PDT," then the "zzzz" pattern generates "Pacific Daylight Time." The following table summarizes these rules:

Presentation	Number of Symbols	Result
Text	1 - 3	abbreviated form, if one exists
Text	>= 4	full form
Number	minimum number of digits is required	shorter numbers are padded with zeros (for a year, if the count of ‘y‘ is 2, then the year is truncated to 2 digits)
Text & Number	1 - 2	number form
Text & Number	3	text form