1.类型转换器

  1.     在日常的企业开发需求中，我们输入文本框的内容全部都是字符串类型，但是在后端处理的时候我们可以用其他基本类型来接受数据，也可以使用实体类来接受参数，这个是怎么完成的呢？就是通过SpringMVC提供的类型转换器，SpringMVC内部提供了非常丰富的类型转换器的支持，但是有些情况下有可能难以满足我们的需求，因此需要我们自己实现，如下：<br />![image.png](https://cdn.nlark.com/yuque/0/2021/png/23066524/1637063726704-a49bf789-af70-454e-8735-a369db2c2cf1.png#clientId=u28569ed8-9554-4&from=paste&height=623&id=uea3811e9&margin=%5Bobject%20Object%5D&name=image.png&originHeight=1246&originWidth=914&originalType=binary&ratio=1&size=369710&status=done&style=none&taskId=u6b2cc037-94b9-448f-b596-bf12d9250e4&width=457)
ConversionService converters =
    @org.springframework.format.annotation.DateTimeFormat java.lang.Long -> java.lang.String: org.springframework.format.datetime.DateTimeFormatAnnotationFormatterFactory@4ec4ca46,@org.springframework.format.annotation.NumberFormat java.lang.Long -> java.lang.String: org.springframework.format.number.NumberFormatAnnotationFormatterFactory@1628f3df
    @org.springframework.format.annotation.DateTimeFormat java.time.LocalDate -> java.lang.String: org.springframework.format.datetime.standard.Jsr310DateTimeFormatAnnotationFormatterFactory@4a98f52f,java.time.LocalDate -> java.lang.String : org.springframework.format.datetime.standard.TemporalAccessorPrinter@6b2739e8
    @org.springframework.format.annotation.DateTimeFormat java.time.LocalDateTime -> java.lang.String: org.springframework.format.datetime.standard.Jsr310DateTimeFormatAnnotationFormatterFactory@4a98f52f,java.time.LocalDateTime -> java.lang.String : org.springframework.format.datetime.standard.TemporalAccessorPrinter@515e3e2b
    @org.springframework.format.annotation.DateTimeFormat java.time.LocalTime -> java.lang.String: org.springframework.format.datetime.standard.Jsr310DateTimeFormatAnnotationFormatterFactory@4a98f52f,java.time.LocalTime -> java.lang.String : org.springframework.format.datetime.standard.TemporalAccessorPrinter@e5802af
    @org.springframework.format.annotation.DateTimeFormat java.time.OffsetDateTime -> java.lang.String: org.springframework.format.datetime.standard.Jsr310DateTimeFormatAnnotationFormatterFactory@4a98f52f,java.time.OffsetDateTime -> java.lang.String : org.springframework.format.datetime.standard.TemporalAccessorPrinter@8547711
    @org.springframework.format.annotation.DateTimeFormat java.time.OffsetTime -> java.lang.String: org.springframework.format.datetime.standard.Jsr310DateTimeFormatAnnotationFormatterFactory@4a98f52f,java.time.OffsetTime -> java.lang.String : org.springframework.format.datetime.standard.TemporalAccessorPrinter@5f7ef1af
    @org.springframework.format.annotation.DateTimeFormat java.time.ZonedDateTime -> java.lang.String: org.springframework.format.datetime.standard.Jsr310DateTimeFormatAnnotationFormatterFactory@4a98f52f,java.time.ZonedDateTime -> java.lang.String : org.springframework.format.datetime.standard.TemporalAccessorPrinter@e673fc2
    @org.springframework.format.annotation.DateTimeFormat java.util.Calendar -> java.lang.String: org.springframework.format.datetime.DateTimeFormatAnnotationFormatterFactory@4ec4ca46
    @org.springframework.format.annotation.DateTimeFormat java.util.Date -> java.lang.String: org.springframework.format.datetime.DateTimeFormatAnnotationFormatterFactory@4ec4ca46
    @org.springframework.format.annotation.NumberFormat java.lang.Byte -> java.lang.String: org.springframework.format.number.NumberFormatAnnotationFormatterFactory@1628f3df
    @org.springframework.format.annotation.NumberFormat java.lang.Double -> java.lang.String: org.springframework.format.number.NumberFormatAnnotationFormatterFactory@1628f3df
    @org.springframework.format.annotation.NumberFormat java.lang.Float -> java.lang.String: org.springframework.format.number.NumberFormatAnnotationFormatterFactory@1628f3df
    @org.springframework.format.annotation.NumberFormat java.lang.Integer -> java.lang.String: org.springframework.format.number.NumberFormatAnnotationFormatterFactory@1628f3df
    @org.springframework.format.annotation.NumberFormat java.lang.Short -> java.lang.String: org.springframework.format.number.NumberFormatAnnotationFormatterFactory@1628f3df
    @org.springframework.format.annotation.NumberFormat java.math.BigDecimal -> java.lang.String: org.springframework.format.number.NumberFormatAnnotationFormatterFactory@1628f3df
    @org.springframework.format.annotation.NumberFormat java.math.BigInteger -> java.lang.String: org.springframework.format.number.NumberFormatAnnotationFormatterFactory@1628f3df
    java.lang.Boolean -> java.lang.String : org.springframework.core.convert.support.ObjectToStringConverter@430fd9a0
    java.lang.Character -> java.lang.Number : org.springframework.core.convert.support.CharacterToNumberFactory@39560299
    java.lang.Character -> java.lang.String : org.springframework.core.convert.support.ObjectToStringConverter@7ffc5a86
    java.lang.Enum -> java.lang.Integer : org.springframework.core.convert.support.EnumToIntegerConverter@7f642c95
    java.lang.Enum -> java.lang.String : org.springframework.core.convert.support.EnumToStringConverter@48af5069
    java.lang.Integer -> java.lang.Enum : org.springframework.core.convert.support.IntegerToEnumConverterFactory@421b3faf
    java.lang.Long -> java.time.Instant : org.springframework.format.datetime.standard.DateTimeConverters$LongToInstantConverter@7676b8a0
    java.lang.Long -> java.util.Calendar : org.springframework.format.datetime.DateFormatterRegistrar$LongToCalendarConverter@41b2ab4c,java.lang.Long -> java.util.Calendar : org.springframework.format.datetime.DateFormatterRegistrar$LongToCalendarConverter@51c90511
    java.lang.Long -> java.util.Date : org.springframework.format.datetime.DateFormatterRegistrar$LongToDateConverter@16ccf62,java.lang.Long -> java.util.Date : org.springframework.format.datetime.DateFormatterRegistrar$LongToDateConverter@601fac14
    java.lang.Number -> java.lang.Character : org.springframework.core.convert.support.NumberToCharacterConverter@4668902f
    java.lang.Number -> java.lang.Number : org.springframework.core.convert.support.NumberToNumberConverterFactory@6ca039f6
    java.lang.Number -> java.lang.String : org.springframework.core.convert.support.ObjectToStringConverter@3d185b20
    java.lang.String -> @org.springframework.format.annotation.DateTimeFormat java.lang.Long: org.springframework.format.datetime.DateTimeFormatAnnotationFormatterFactory@4ec4ca46,java.lang.String -> @org.springframework.format.annotation.NumberFormat java.lang.Long: org.springframework.format.number.NumberFormatAnnotationFormatterFactory@1628f3df
    java.lang.String -> @org.springframework.format.annotation.DateTimeFormat java.time.LocalDate: org.springframework.format.datetime.standard.Jsr310DateTimeFormatAnnotationFormatterFactory@4a98f52f,java.lang.String -> java.time.LocalDate: org.springframework.format.datetime.standard.TemporalAccessorParser@28573f94
    java.lang.String -> @org.springframework.format.annotation.DateTimeFormat java.time.LocalDateTime: org.springframework.format.datetime.standard.Jsr310DateTimeFormatAnnotationFormatterFactory@4a98f52f,java.lang.String -> java.time.LocalDateTime: org.springframework.format.datetime.standard.TemporalAccessorParser@40e4100b
    java.lang.String -> @org.springframework.format.annotation.DateTimeFormat java.time.LocalTime: org.springframework.format.datetime.standard.Jsr310DateTimeFormatAnnotationFormatterFactory@4a98f52f,java.lang.String -> java.time.LocalTime: org.springframework.format.datetime.standard.TemporalAccessorParser@3e4bfc6
    java.lang.String -> @org.springframework.format.annotation.DateTimeFormat java.time.OffsetDateTime: org.springframework.format.datetime.standard.Jsr310DateTimeFormatAnnotationFormatterFactory@4a98f52f,java.lang.String -> java.time.OffsetDateTime: org.springframework.format.datetime.standard.TemporalAccessorParser@68d04a58
    java.lang.String -> @org.springframework.format.annotation.DateTimeFormat java.time.OffsetTime: org.springframework.format.datetime.standard.Jsr310DateTimeFormatAnnotationFormatterFactory@4a98f52f,java.lang.String -> java.time.OffsetTime: org.springframework.format.datetime.standard.TemporalAccessorParser@2a8ae894
    java.lang.String -> @org.springframework.format.annotation.DateTimeFormat java.time.ZonedDateTime: org.springframework.format.datetime.standard.Jsr310DateTimeFormatAnnotationFormatterFactory@4a98f52f,java.lang.String -> java.time.ZonedDateTime: org.springframework.format.datetime.standard.TemporalAccessorParser@28dbab47
    java.lang.String -> @org.springframework.format.annotation.DateTimeFormat java.util.Calendar: org.springframework.format.datetime.DateTimeFormatAnnotationFormatterFactory@4ec4ca46
    java.lang.String -> @org.springframework.format.annotation.DateTimeFormat java.util.Date: org.springframework.format.datetime.DateTimeFormatAnnotationFormatterFactory@4ec4ca46
    java.lang.String -> @org.springframework.format.annotation.NumberFormat java.lang.Byte: org.springframework.format.number.NumberFormatAnnotationFormatterFactory@1628f3df
    java.lang.String -> @org.springframework.format.annotation.NumberFormat java.lang.Double: org.springframework.format.number.NumberFormatAnnotationFormatterFactory@1628f3df
    java.lang.String -> @org.springframework.format.annotation.NumberFormat java.lang.Float: org.springframework.format.number.NumberFormatAnnotationFormatterFactory@1628f3df
    java.lang.String -> @org.springframework.format.annotation.NumberFormat java.lang.Integer: org.springframework.format.number.NumberFormatAnnotationFormatterFactory@1628f3df
    java.lang.String -> @org.springframework.format.annotation.NumberFormat java.lang.Short: org.springframework.format.number.NumberFormatAnnotationFormatterFactory@1628f3df
    java.lang.String -> @org.springframework.format.annotation.NumberFormat java.math.BigDecimal: org.springframework.format.number.NumberFormatAnnotationFormatterFactory@1628f3df
    java.lang.String -> @org.springframework.format.annotation.NumberFormat java.math.BigInteger: org.springframework.format.number.NumberFormatAnnotationFormatterFactory@1628f3df
    java.lang.String -> java.lang.Boolean : org.springframework.core.convert.support.StringToBooleanConverter@5eba909b
    java.lang.String -> java.lang.Character : org.springframework.core.convert.support.StringToCharacterConverter@12febea6
    java.lang.String -> java.lang.Enum : org.springframework.core.convert.support.StringToEnumConverterFactory@41e4c006
    java.lang.String -> java.lang.Number : org.springframework.core.convert.support.StringToNumberConverterFactory@5d6c983e
    java.lang.String -> java.nio.charset.Charset : org.springframework.core.convert.support.StringToCharsetConverter@3184a445
    java.lang.String -> java.time.Duration: org.springframework.format.datetime.standard.DurationFormatter@437e9192
    java.lang.String -> java.time.Instant: org.springframework.format.datetime.standard.InstantFormatter@14dfe2b
    java.lang.String -> java.time.Month: org.springframework.format.datetime.standard.MonthFormatter@501f0275
    java.lang.String -> java.time.MonthDay: org.springframework.format.datetime.standard.MonthDayFormatter@230d0cca
    java.lang.String -> java.time.Period: org.springframework.format.datetime.standard.PeriodFormatter@6b25f6d0
    java.lang.String -> java.time.Year: org.springframework.format.datetime.standard.YearFormatter@3ecd1f21
    java.lang.String -> java.time.YearMonth: org.springframework.format.datetime.standard.YearMonthFormatter@1448edd0
    java.lang.String -> java.util.Currency : org.springframework.core.convert.support.StringToCurrencyConverter@4e203f5f
    java.lang.String -> java.util.Locale : org.springframework.core.convert.support.StringToLocaleConverter@1867278f
    java.lang.String -> java.util.Properties : org.springframework.core.convert.support.StringToPropertiesConverter@388ee7a7
    java.lang.String -> java.util.TimeZone : org.springframework.core.convert.support.StringToTimeZoneConverter@663f1943
    java.lang.String -> java.util.UUID : org.springframework.core.convert.support.StringToUUIDConverter@49cc9297
    java.nio.charset.Charset -> java.lang.String : org.springframework.core.convert.support.ObjectToStringConverter@6f5a2664
    java.time.Duration -> java.lang.String : org.springframework.format.datetime.standard.DurationFormatter@437e9192
    java.time.Instant -> java.lang.Long : org.springframework.format.datetime.standard.DateTimeConverters$InstantToLongConverter@6a401b0
    java.time.Instant -> java.lang.String : org.springframework.format.datetime.standard.InstantFormatter@14dfe2b
    java.time.LocalDateTime -> java.time.LocalDate : org.springframework.format.datetime.standard.DateTimeConverters$LocalDateTimeToLocalDateConverter@3639d795
    java.time.LocalDateTime -> java.time.LocalTime : org.springframework.format.datetime.standard.DateTimeConverters$LocalDateTimeToLocalTimeConverter@2bdba24a
    java.time.Month -> java.lang.String : org.springframework.format.datetime.standard.MonthFormatter@501f0275
    java.time.MonthDay -> java.lang.String : org.springframework.format.datetime.standard.MonthDayFormatter@230d0cca
    java.time.OffsetDateTime -> java.time.Instant : org.springframework.format.datetime.standard.DateTimeConverters$OffsetDateTimeToInstantConverter@676ac921
    java.time.OffsetDateTime -> java.time.LocalDate : org.springframework.format.datetime.standard.DateTimeConverters$OffsetDateTimeToLocalDateConverter@326421e8
    java.time.OffsetDateTime -> java.time.LocalDateTime : org.springframework.format.datetime.standard.DateTimeConverters$OffsetDateTimeToLocalDateTimeConverter@3d974458
    java.time.OffsetDateTime -> java.time.LocalTime : org.springframework.format.datetime.standard.DateTimeConverters$OffsetDateTimeToLocalTimeConverter@3c072322
    java.time.OffsetDateTime -> java.time.ZonedDateTime : org.springframework.format.datetime.standard.DateTimeConverters$OffsetDateTimeToZonedDateTimeConverter@7412cd2a
    java.time.Period -> java.lang.String : org.springframework.format.datetime.standard.PeriodFormatter@6b25f6d0
    java.time.Year -> java.lang.String : org.springframework.format.datetime.standard.YearFormatter@3ecd1f21
    java.time.YearMonth -> java.lang.String : org.springframework.format.datetime.standard.YearMonthFormatter@1448edd0
    java.time.ZoneId -> java.util.TimeZone : org.springframework.core.convert.support.ZoneIdToTimeZoneConverter@5c8ff106
    java.time.ZonedDateTime -> java.time.Instant : org.springframework.format.datetime.standard.DateTimeConverters$ZonedDateTimeToInstantConverter@2b5c4212
    java.time.ZonedDateTime -> java.time.LocalDate : org.springframework.format.datetime.standard.DateTimeConverters$ZonedDateTimeToLocalDateConverter@7fe794b6
    java.time.ZonedDateTime -> java.time.LocalDateTime : org.springframework.format.datetime.standard.DateTimeConverters$ZonedDateTimeToLocalDateTimeConverter@1ee211ef
    java.time.ZonedDateTime -> java.time.LocalTime : org.springframework.format.datetime.standard.DateTimeConverters$ZonedDateTimeToLocalTimeConverter@669ff7d6
    java.time.ZonedDateTime -> java.time.OffsetDateTime : org.springframework.format.datetime.standard.DateTimeConverters$ZonedDateTimeToOffsetDateTimeConverter@685d298b
    java.time.ZonedDateTime -> java.util.Calendar : org.springframework.core.convert.support.ZonedDateTimeToCalendarConverter@6138bd15
    java.util.Calendar -> java.lang.Long : org.springframework.format.datetime.DateFormatterRegistrar$CalendarToLongConverter@32b267dc,java.util.Calendar -> java.lang.Long : org.springframework.format.datetime.DateFormatterRegistrar$CalendarToLongConverter@3027d26
    java.util.Calendar -> java.time.Instant : org.springframework.format.datetime.standard.DateTimeConverters$CalendarToInstantConverter@208023cf
    java.util.Calendar -> java.time.LocalDate : org.springframework.format.datetime.standard.DateTimeConverters$CalendarToLocalDateConverter@75a3f40
    java.util.Calendar -> java.time.LocalDateTime : org.springframework.format.datetime.standard.DateTimeConverters$CalendarToLocalDateTimeConverter@5b92ec5f
    java.util.Calendar -> java.time.LocalTime : org.springframework.format.datetime.standard.DateTimeConverters$CalendarToLocalTimeConverter@3648cd4b
    java.util.Calendar -> java.time.OffsetDateTime : org.springframework.format.datetime.standard.DateTimeConverters$CalendarToOffsetDateTimeConverter@65c3d54f
    java.util.Calendar -> java.time.ZonedDateTime : org.springframework.format.datetime.standard.DateTimeConverters$CalendarToZonedDateTimeConverter@6271e8dd
    java.util.Calendar -> java.util.Date : org.springframework.format.datetime.DateFormatterRegistrar$CalendarToDateConverter@5e9b9eea,java.util.Calendar -> java.util.Date : org.springframework.format.datetime.DateFormatterRegistrar$CalendarToDateConverter@181f31ba
    java.util.Currency -> java.lang.String : org.springframework.core.convert.support.ObjectToStringConverter@2c3cd8e9
    java.util.Date -> java.lang.Long : org.springframework.format.datetime.DateFormatterRegistrar$DateToLongConverter@133715f3,java.util.Date -> java.lang.Long : org.springframework.format.datetime.DateFormatterRegistrar$DateToLongConverter@4cb15e75
    java.util.Date -> java.util.Calendar : org.springframework.format.datetime.DateFormatterRegistrar$DateToCalendarConverter@1d56ea37,java.util.Date -> java.util.Calendar : org.springframework.format.datetime.DateFormatterRegistrar$DateToCalendarConverter@75a88521
    java.util.Locale -> java.lang.String : org.springframework.core.convert.support.ObjectToStringConverter@2af910f2
    java.util.Properties -> java.lang.String : org.springframework.core.convert.support.PropertiesToStringConverter@6d99fd4
    java.util.UUID -> java.lang.String : org.springframework.core.convert.support.ObjectToStringConverter@37df0d7
    org.springframework.core.convert.support.ArrayToArrayConverter@2b19ffdb
    org.springframework.core.convert.support.ArrayToCollectionConverter@4c019cc0
    org.springframework.core.convert.support.ArrayToObjectConverter@343b143b
    org.springframework.core.convert.support.ArrayToStringConverter@654a7e11
    org.springframework.core.convert.support.ByteBufferConverter@209ae681
    org.springframework.core.convert.support.ByteBufferConverter@209ae681
    org.springframework.core.convert.support.ByteBufferConverter@209ae681
    org.springframework.core.convert.support.ByteBufferConverter@209ae681
    org.springframework.core.convert.support.CollectionToArrayConverter@66c9dab
    org.springframework.core.convert.support.CollectionToCollectionConverter@470e5927
    org.springframework.core.convert.support.CollectionToObjectConverter@6c6550c9
    org.springframework.core.convert.support.CollectionToStringConverter@4c04c66a
    org.springframework.core.convert.support.FallbackObjectToStringConverter@2b2ed015
    org.springframework.core.convert.support.IdToEntityConverter@1661f15d,org.springframework.core.convert.support.ObjectToObjectConverter@80a17d3
    org.springframework.core.convert.support.MapToMapConverter@7292a9a
    org.springframework.core.convert.support.ObjectToArrayConverter@7a8895dc
    org.springframework.core.convert.support.ObjectToCollectionConverter@52fd0eec
    org.springframework.core.convert.support.ObjectToOptionalConverter@f5a1070
    org.springframework.core.convert.support.ObjectToOptionalConverter@f5a1070
    org.springframework.core.convert.support.ObjectToOptionalConverter@f5a1070
    org.springframework.core.convert.support.StreamConverter@3820b54f
    org.springframework.core.convert.support.StreamConverter@3820b54f
    org.springframework.core.convert.support.StreamConverter@3820b54f
    org.springframework.core.convert.support.StreamConverter@3820b54f
    org.springframework.core.convert.support.StringToArrayConverter@1c9b244
    org.springframework.core.convert.support.StringToCollectionConverter@13163c

2.自定义类型转换器

2.1 xml文件配置

image.png

2.2 自定义类型转换器

package com.xixi.converts;

import org.springframework.core.convert.converter.Converter;
import org.springframework.stereotype.Component;
import org.springframework.util.StringUtils;

import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;

/**
 * @author yangkang
 * @version 1.0
 * @description: TODO
 * @date 2021/11/16 20:04
 */
@Component
public class MyStringToDateConvert implements Converter<String, Date> {
    @Override
    public Date convert(String source) {
        if (!StringUtils.isEmpty(source)) {
            try {

                if (source.split("-").length == 3) {
                    DateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd");
                    return dateFormat.parse(source);

                } else if (source.split("/").length == 3) {
                    DateFormat dateFormat = new SimpleDateFormat("yyyy/MM/dd");
                    return dateFormat.parse(source);
                } else {
                    throw new RuntimeException("日期转换错误：" + source);
                }
            } catch (ParseException e) {
                e.printStackTrace();
            }
        }
        return null;
    }
}

3.数据格式

Spring 提供了两个可以用于格式化数字、日期和时间的注解@NumberFormat和@DateTimeFormat，这两个标签可以用于javabean的属性或方法参数上。@NumberFormat可以用来格式化任何的数字的基本类型（如int，long）或java.lang.Number的实例（如 BigDecimal, Integer)。@DateTimeFormat可以用来格式化java.util.Date、java.util.Calendar和 java.util.Long类型.
要指定数字或日期/时间类型的属性，只需要在其上添加 @NumberFormat或@DateTimeFormat注解接可以了。例如下面的代码：

import java.math.BigDecimal;
import java.util.Calendar;
import java.util.Date;
import org.joda.time.LocalTime;
import org.springframework.format.annotation.DateTimeFormat;
import org.springframework.format.annotation.NumberFormat;
import org.springframework.format.annotation.DateTimeFormat.ISO;
import org.springframework.format.annotation.NumberFormat.Style;
public class Employee {
private String name;
/**
* numeric fields using @NumberFormat annotation for formatting.
*/
@NumberFormat(style = Style.CURRENCY)
private double salary;
@NumberFormat(style = Style.PERCENT)
private double w4AdditionalWithdraw;
@NumberFormat
private int dependents;
@NumberFormat(pattern = "0.00")
private BigDecimal visualAcuity;
/**
* date and time fields using @DateTimeFormat annotation for formatting.
*/
@DateTimeFormat(style = "M-")
private Date birthDate;
@DateTimeFormat(pattern = "w:yyyy")
private Calendar hireDate;
@DateTimeFormat(style = "-S")
private LocalTime startTime;
@DateTimeFormat(iso = ISO.DATE_TIME)
private long lastTimeEntry;
/**
* initialization block to provide sample data for display
*/
{
this.name = "John Doe";
this.salary = 30100.50;
this.w4AdditionalWithdraw = 0.02;
this.dependents = 5;
this.visualAcuity = new BigDecimal(".1");
Calendar dob = Calendar.getInstance();
dob.set(1964, Calendar.AUGUST, 30);
this.birthDate = dob.getTime();
this.hireDate = Calendar.getInstance();
this.startTime = new LocalTime(8, 0);
this.lastTimeEntry = (new Date()).getTime() - 10000;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public double getSalary() {
return salary;
}
public void setSalary(double salary) {
this.salary = salary;
}
public double getW4AdditionalWithdraw() {
return w4AdditionalWithdraw;
}
public void setW4AdditionalWithdraw(double w4AdditionalWithdraw) {
this.w4AdditionalWithdraw = w4AdditionalWithdraw;
}
public int getDependents() {
return dependents;
}
public void setDependents(int dependents) {
this.dependents = dependents;
}
public BigDecimal getVisualAcuity() {
return visualAcuity;
}
public void setVisualAcuity(BigDecimal visualAcuity) {
this.visualAcuity = visualAcuity;
}
public Date getBirthDate() {
return birthDate;
}
public void setBirthDate(Date birthDate) {
this.birthDate = birthDate;
}
public LocalTime getStartTime() {
return startTime;
}
public void setStartTime(LocalTime startTime) {
this.startTime = startTime;
}
public Calendar getHireDate() {
return hireDate;
}
public void setHireDate(Calendar hireDate) {
this.hireDate = hireDate;
}
public long getLastTimeEntry() {
return lastTimeEntry;
}
public void setLastTimeEntry(long lastTimeEntry) {
this.lastTimeEntry = lastTimeEntry;
}
}

注解类型
DateTimeFormat,互斥属性：

  • iso。类型为DateTimeFormat.ISO
    • DateTimeFormat.ISO.DATE: 格式yyyy-MM-dd。
    • DateTimeFormat.ISO.DATE_TIME: 格式yyyy-MM-dd HH:mm:ss .SSSZ。
    • DateTimeFormat.ISO.TIME: 格式HH:mm:ss .SSSZ。
    • DateTimeFormat.ISO.NONE: 表示不使用ISO格式的时间。
  • pattern。类型为String，使用自定义的时间格式化字符串。
  • style。类型为String，通过样式指定日期时间的格式，由两位字符组成，第1位表示日期的样式，第2位表示时间的格式：
    • S: 短日期/时间的样式；
    • M: 中日期/时间的样式；
    • L: 长日期/时间的样式；
    • F: 完整日期/时间的样式；
    • -: 忽略日期/时间的样式；
      • NumberFormat
  • pattern。类型为String，使用自定义的数字格式化字符串，”##,###.##”。
  • style。类型为NumberFormat.Style，常用值：
    • Style.NUMBER正常数字类型
    • Style.PERCENT百分数类型
    • Style.CURRENCY 货币类型

3.数据验证

一般情况下我们会在前端页面实现数据的校验，但是大家需要注意的是前端校验会存在数据的不安全问题，因此一般情况下我们都会使用前端校验+后端校验的方式，这样的话既能够满足用户的体验度，同时也能保证数据的安全，下面来说一下在springmvc中如何进行后端数据校验。
JSR303是 Java 为 Bean 数据合法性校验提供的标准，它已经包含在 JavaEE 6.0 中 。JSR 303 (Java Specification Requests意思是Java 规范提案)通过在Bean属性上标注类似于 @NotNull、@Max 等标准的注解指定校验规则，并通 j过标准的验证接口对 Bean 进行验证。
Hibernate Validator 实现了JSR349验证注解规范的技术。

image.png
image.png
spring中拥有自己的数据校验框架，同时支持JSR303标准的校验框架，可以在通过添加注解的方式进行数据校验。在spring中本身没有提供JSR303的实现，需要导入依赖的包。
pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>cn.tulingxueyuan</groupId>
    <artifactId>springmvc_viewResolver</artifactId>
    <version>1.0-SNAPSHOT</version>

    <dependencies>

        <!-- https://mvnrepository.com/artifact/org.springframework/spring-webmvc -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>5.2.3.RELEASE</version>
        </dependency>

        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-validator</artifactId>
            <version>5.1.0.Final</version>
        </dependency>

    </dependencies>
</project>

JavaBean类：

package com.xixi.entity;

import org.hibernate.validator.constraints.Length;
import org.hibernate.validator.constraints.NotEmpty;
import org.hibernate.validator.constraints.Range;
import org.springframework.format.annotation.DateTimeFormat;
import org.springframework.format.annotation.NumberFormat;

import javax.validation.constraints.Min;
import javax.validation.constraints.NotNull;
import javax.validation.constraints.Past;
import java.util.Arrays;
import java.util.Date;

/**
 * @author yangkang
 * @version 1.0
 * @description: TODO
 * @date 2021/11/16 19:13
 */
public class User {


    @NotNull
    @Min(1)
    private Integer id;

    @NotEmpty(message = "姓名不能为空哦哦！！！")
    @Length(min = 2,max = 8)
    private String username;


    @Past
    @DateTimeFormat(pattern = "yyyy-MM-dd")
    private Date birthday;



    @NumberFormat(style = NumberFormat.Style.CURRENCY)
    private Double balance;

    private String[] hobbies;

    private Double salary;//工资

    @Range(min = 0,max = 100)
    private Double taskCount;//任务完成比




    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public Date getBirthday() {
        return birthday;
    }

    public void setBirthday(Date birthday) {
        this.birthday = birthday;
    }

    public Double getBalance() {
        return balance;
    }

    public void setBalance(Double balance) {
        this.balance = balance;
    }

    public String[] getHobbies() {
        return hobbies;
    }

    public void setHobbies(String[] hobbies) {
        this.hobbies = hobbies;
    }

    public Double getSalary() {
        return salary;
    }

    public void setSalary(Double salary) {
        this.salary = salary;
    }

    public Double getTaskCount() {
        return taskCount;
    }

    public void setTaskCount(Double taskCount) {
        this.taskCount = taskCount;
    }

    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", username='" + username + '\'' +
                ", birthday=" + birthday +
                ", balance=" + balance +
                ", hobbies=" + Arrays.toString(hobbies) +
                ", salary=" + salary +
                ", taskCount=" + taskCount +
                '}';
    }
}

Controller类：

package com.xixi.controller;


import com.xixi.entity.User;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.validation.BindingResult;
import org.springframework.validation.FieldError;
import org.springframework.web.bind.annotation.PostMapping;

import javax.validation.Valid;
import java.util.HashMap;
import java.util.List;
import java.util.Map;


/**
 * 实现数据验证的步骤：
 * 1.加入hibernate-validator的依赖
 * 2.一定要注意，要将新加入的jar包，加入到WEB-INF/lib中
 * 3.在需要验证的javabean加上注解
 * 4.在验证处理方法对应的javabean参数上加上@Valid
 * 5.在需要验证的处理方法参数加上BindingResult，代表自己处理错误，这样就不会显示错误页面
 *
 *
 * 基于原生form表单的实现方式：
 * 1。将错误信息循环通过map放入request域
 * 2。在jsp页面中通过${errors.id}获取对应的错误信息
 *
 */
@Controller
public class UserController {

    @PostMapping("/user")
    public String add(@Valid User user, BindingResult result, Model model) {
        //判断当前是否出现了错误
        if (result.hasErrors()) {
            //存放错误信息 key 错误信息的属性名 value 错误信息
            Map<String, String> errors = new HashMap<>();
            //获取所有的错误信息 包含错误的属性，错误信息
            List<FieldError> fieldErrors = result.getFieldErrors();
            for (FieldError fieldError : fieldErrors) {
                errors.put(fieldError.getField(), fieldError.getDefaultMessage());
            }
            model.addAttribute("errors", errors);
            return "user/add";
        }
        System.out.println(user);
        return "user/show";

    }
}