SpringBoot--LocalDateTime--全局格式转换/前后端/前端入参/响应给前端

阳光穿透心脏的1/2处 2022-09-11 12:30 733阅读 0赞

原文网址：[SpringBoot--LocalDateTime--全局格式转换/前后端/前端入参/响应给前端\_IT利刃出鞘的博客-CSDN博客][SpringBoot--LocalDateTime--_IT_-CSDN]

# 简介 #

**说明**

项目我们经常会有前后端时间转换的场景，比如：创建时间、更新时间等。一般情况下，前后端使用时间戳或者年月日的格式进行传递。

如果后端收到了前端的参数每次都手动转化为想要的格式，后端每次将数据传给前端时都手动处理为想要的格式实在是太麻烦了。

基于如上原因，本文介绍可以方便地进行格式自动转化的配置方案，后端用的是SpringBoot，时间类型用的是LocalDateTime。

**其他**

有人说，可以这样配置：

spring:  
jackson:  
date-format: yyyy-MM-dd HH:mm:ss  
time-zone: GMT+8  
serialization:  
write-dates-as-timestamps: false

但是，这种配置只适用于Date这种，不适用于LocalDateTime等。 Date序列化/反序列化时都是用的这种格式："2020-08-19T16:30:18.823+00:00"。

# 响应给前端 #

## 时间戳格式 ##

### 法1：自定义序列化器 ###

**简介**

本法只能用于将数据转为时间吹响应给前端，无法自动解析前端传进来的时间戳（无论是直接接收还是通过实体类接收都不行）。

此方法不仅仅可以用于返给前端数据，也可以用于后端的转换：使用jackson的ObjectMapper().writeValueAsString方法将对象转为json字符串。而下边的全局配置就不可以。

**配置类**

package com.example.config;
    
    import com.fasterxml.jackson.core.JsonGenerator;
    import com.fasterxml.jackson.core.JsonParser;
    import com.fasterxml.jackson.databind.DeserializationContext;
    import com.fasterxml.jackson.databind.JsonDeserializer;
    import com.fasterxml.jackson.databind.JsonSerializer;
    import com.fasterxml.jackson.databind.SerializerProvider;
    
    import java.io.IOException;
    import java.time.Instant;
    import java.time.LocalDateTime;
    import java.time.ZoneId;
    
    public class LocalDateTimeConfig {
        // 序列化实现
        public static class LocalDateTimeSerializer extends JsonSerializer<LocalDateTime> {
            @Override
            public void serialize(LocalDateTime value, JsonGenerator gen, SerializerProvider serializers)
                    throws IOException {
                if (value != null) {
                    long timestamp = value.atZone(ZoneId.systemDefault()).toInstant().toEpochMilli();
                    gen.writeNumber(timestamp);
                }
            }
        }
    
        // 反序列化实现
        public static class LocalDateTimeDeserializer extends JsonDeserializer<LocalDateTime> {
            @Override
            public LocalDateTime deserialize(JsonParser p, DeserializationContext deserializationContext)
                    throws IOException {
                long timestamp = p.getValueAsLong();
                if (timestamp > 0) {
                    return LocalDateTime.ofInstant(Instant.ofEpochMilli(timestamp), ZoneId.systemDefault());
                } else {
                    return null;
                }
            }
        }
    }

**Entity**

package com.example.business.entity;
    
    import com.example.config.LocalDateTimeConfig;
    import com.fasterxml.jackson.databind.annotation.JsonSerialize;
    import lombok.AllArgsConstructor;
    import lombok.Data;
    
    import java.time.LocalDateTime;
    
    @Data
    @AllArgsConstructor
    public class User {
        private Long id;
    
        private String userName;
    
        @JsonSerialize(using = LocalDateTimeConfig.LocalDateTimeSerializer.class)
        private LocalDateTime createTime;
    }

**Controller**

package com.example.business.controller;
    
    import com.example.business.entity.User;
    import org.springframework.web.bind.annotation.GetMapping;
    import org.springframework.web.bind.annotation.PostMapping;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RestController;
    
    import java.time.LocalDateTime;
    
    @RestController
    @RequestMapping("user")
    public class UserController {
        @GetMapping("getUser")
        public User getUser() {
            return new User(null, "Tony", LocalDateTime.now());
        }
    }

**测试**

postman访问：[http://localhost:8080/user/getUser][http_localhost_8080_user_getUser]

postman结果：

![watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBASVTliKnliIPlh7rpnpg_size_19_color_FFFFFF_t_70_g_se_x_16][]

**注意**：本法只能用于将数据转为时间吹响应给前端，无法自动解析前端传进来的时间戳。示例如下：

**代码**

package com.example.business.entity;
    
    import com.example.config.LocalDateTimeConfig;
    import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
    import com.fasterxml.jackson.databind.annotation.JsonSerialize;
    import lombok.AllArgsConstructor;
    import lombok.Data;
    
    import java.time.LocalDateTime;
    
    @Data
    @AllArgsConstructor
    public class User {
        private Long id;
    
        private String userName;
    
        @JsonSerialize(using = LocalDateTimeConfig.LocalDateTimeSerializer.class)
        @JsonDeserialize(using = LocalDateTimeConfig.LocalDateTimeDeserializer.class)
        private LocalDateTime createTime;
    }

package com.example.business.controller;
    
    import com.example.business.entity.User;
    import org.springframework.web.bind.annotation.GetMapping;
    import org.springframework.web.bind.annotation.PostMapping;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RestController;
    
    import java.time.LocalDateTime;
    
    @RestController
    @RequestMapping("user")
    public class UserController {
        @PostMapping("save")
        public User save(User user) {
            System.out.println("保存用户：" + user);
            return user;
        }
    }

**测试**

postman访问：[http://localhost:8080/user/save?userName=Tony&createTime=1631790000][http_localhost_8080_user_save_userName_Tony_createTime_1631790000]

postman结果：

![watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBASVTliKnliIPlh7rpnpg_size_20_color_FFFFFF_t_70_g_se_x_16][]

后端结果：

2021-09-16 19:41:26.855  WARN 93488 --- [nio-8080-exec-1] .w.s.m.s.DefaultHandlerExceptionResolver : Resolved [org.springframework.validation.BindException: org.springframework.validation.BeanPropertyBindingResult: 1 errors
    Field error in object 'user' on field 'createTime': rejected value [1631790000]; codes [typeMismatch.user.createTime,typeMismatch.createTime,typeMismatch.java.time.LocalDateTime,typeMismatch]; arguments [org.springframework.context.support.DefaultMessageSourceResolvable: codes [user.createTime,createTime]; arguments []; default message [createTime]]; default message [Failed to convert value of type 'java.lang.String[]' to required type 'java.time.LocalDateTime'; nested exception is org.springframework.core.convert.ConversionFailedException: Failed to convert from type [java.lang.String] to type [@com.fasterxml.jackson.databind.annotation.JsonSerialize @com.fasterxml.jackson.databind.annotation.JsonDeserialize java.time.LocalDateTime] for value '1631790000'; nested exception is java.lang.IllegalArgumentException: Parse attempt failed for value [1631790000]]]

### 法2：**ObjectMapper+自定义序列化** ###

**简介**

所有Controller的JSON数据返回，只要是LocalDateTime类型都会被转成时间戳。

本法只能用于将数据转为时间吹响应给前端，无法自动解析前端传进来的时间戳（无论是直接接收还是通过实体类接收都不行）。

若继承了WebMvcConfigurationSupport对mvc进行配置，则本处配置失效。例如：  
public class WebMvcConfig extends WebMvcConfigurationSupport\{\}

**配置类**

package com.example.config;
     
    import com.fasterxml.jackson.core.JsonGenerator;
    import com.fasterxml.jackson.core.JsonParser;
    import com.fasterxml.jackson.databind.*;
    import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;
    import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.Configuration;
    import org.springframework.context.annotation.Primary;
     
    import java.io.IOException;
    import java.time.Instant;
    import java.time.LocalDateTime;
    import java.time.ZoneId;
     
    @Configuration
    public class LocalDateTimeConfig {
     
        // 序列化LocalDateTime
        @Bean
        @Primary
        public ObjectMapper serializingObjectMapper() {
            ObjectMapper objectMapper = new ObjectMapper();
            JavaTimeModule javaTimeModule = new JavaTimeModule();
            javaTimeModule.addSerializer(LocalDateTime.class, new LocalDateTimeSerializer());
            javaTimeModule.addDeserializer(LocalDateTime.class, new LocalDateTimeDeserializer());
            objectMapper.registerModule(javaTimeModule);
            return objectMapper;
        }
     
        // 序列化实现
        public static class LocalDateTimeSerializer extends JsonSerializer<LocalDateTime> {
            @Override
            public void serialize(LocalDateTime value, JsonGenerator gen, SerializerProvider serializers)
                    throws IOException {
                if (value != null){
                    long timestamp = value.atZone(ZoneId.systemDefault()).toInstant().toEpochMilli();
                    gen.writeNumber(timestamp);
                }
            }
        }
     
        // 反序列化实现
        public static class LocalDateTimeDeserializer extends JsonDeserializer<LocalDateTime> {
            @Override
            public LocalDateTime deserialize(JsonParser p, DeserializationContext deserializationContext)
                    throws IOException {
                long timestamp = p.getValueAsLong();
                if (timestamp > 0){
                    return LocalDateTime.ofInstant(Instant.ofEpochMilli(timestamp),ZoneId.systemDefault());
                }else{
                    return null;
                }
            }
        }
    }

**Entity**

package com.example.business.entity;
    
    import lombok.AllArgsConstructor;
    import lombok.Data;
    
    import java.time.LocalDateTime;
    
    @Data
    @AllArgsConstructor
    public class User {
        private Long id;
    
        private String userName;
    
        private LocalDateTime createTime;
    }

**Controller**

package com.example.business.controller;
    
    import com.example.business.entity.User;
    import org.springframework.web.bind.annotation.GetMapping;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RestController;
    
    import java.time.LocalDateTime;
    
    @RestController
    @RequestMapping("user")
    public class UserController {
        @GetMapping("getUser")
        public User getUser() {
            return new User(null, "Tony", LocalDateTime.now());
        }
    }

**测试**

postman访问：[http://localhost:8080/user/getUser][http_localhost_8080_user_getUser]

postman结果：

![watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBASVTliKnliIPlh7rpnpg_size_17_color_FFFFFF_t_70_g_se_x_16][]

### **法3：Jackson2ObjectMapperBuilderCustomizer** ###

**简介**

所有Controller的JSON数据返回，只要是LocalDateTime类型都会被转成时间戳。

本法只能用于将数据转为时间吹响应给前端，无法自动解析前端传进来的时间戳（无论是直接接收还是通过实体类接收都不行）。

若继承了WebMvcConfigurationSupport对mvc进行配置，则本处配置失效。例如：  
public class WebMvcConfig extends WebMvcConfigurationSupport\{\}

**配置类**

package com.example.config;
    
    import com.fasterxml.jackson.core.JsonGenerator;
    import com.fasterxml.jackson.core.JsonParser;
    import com.fasterxml.jackson.databind.DeserializationContext;
    import com.fasterxml.jackson.databind.JsonDeserializer;
    import com.fasterxml.jackson.databind.JsonSerializer;
    import com.fasterxml.jackson.databind.SerializerProvider;
    import org.springframework.boot.autoconfigure.jackson.Jackson2ObjectMapperBuilderCustomizer;
    import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.Configuration;
    
    import java.io.IOException;
    import java.time.Instant;
    import java.time.LocalDateTime;
    import java.time.ZoneId;
     
    @Configuration
    public class LocalDateTimeConfig {
     
        @Bean
        public Jackson2ObjectMapperBuilderCustomizer jackson2ObjectMapperBuilderCustomizer() {
            return builder -> {
                builder.serializerByType(LocalDateTime.class, new LocalDateTimeSerializer());
                builder.deserializerByType(LocalDateTime.class,new LocalDateTimeDeserializer());
            };
        }
     
        /**
         * 序列化
         */
        public static class LocalDateTimeSerializer extends JsonSerializer<LocalDateTime> {
            @Override
            public void serialize(LocalDateTime value, JsonGenerator gen, SerializerProvider serializers)
                    throws IOException {
                if (value != null){
                    long timestamp = value.atZone(ZoneId.systemDefault()).toInstant().toEpochMilli();
                    gen.writeNumber(timestamp);
                }
            }
        }
     
        /**
         * 反序列化
         */
        public static class LocalDateTimeDeserializer extends JsonDeserializer<LocalDateTime> {
            @Override
            public LocalDateTime deserialize(JsonParser p, DeserializationContext deserializationContext)
                    throws IOException {
                long timestamp = p.getValueAsLong();
                if (timestamp > 0){
                    return LocalDateTime.ofInstant(Instant.ofEpochMilli(timestamp),ZoneId.systemDefault());
                }else{
                    return null;
                }
            }
        }
    }

**Entity**

**Controller**

package com.example.business.controller;
    
    import com.example.business.entity.User;
    import org.springframework.web.bind.annotation.GetMapping;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RestController;
    
    import java.time.LocalDateTime;
    
    @RestController
    @RequestMapping("user")
    public class UserController {
        @GetMapping("getUser")
        public User getUser() {
            return new User(null, "Tony", LocalDateTime.now());
        }
    }

**测试**

postman访问：[http://localhost:8080/user/getUser][http_localhost_8080_user_getUser]

postman结果：

![watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBASVTliKnliIPlh7rpnpg_size_19_color_FFFFFF_t_70_g_se_x_16 1][]

### **法4：实现WebMvcConfigurer** ###

**简介**

实现WebMvcConfigurer接口是官方推荐的，下边两种不推荐。

1.  实现WebMvcConfigurerAdapter：Spring5.0之后是废弃的。
2.  继承WebMvcConfigurationSupport：会导致yml的配置失效。原因：WebMvcAutoConfiguration有个条件注解： @ConditionalOnMissingBean(WebMvcConfigurationSupport.class)

本法我自己未测试通过，先贴出代码，后边再看

package com.example.config;
     
    import com.fasterxml.jackson.core.JsonGenerator;
    import com.fasterxml.jackson.core.JsonParser;
    import com.fasterxml.jackson.databind.*;
    import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;
    import org.springframework.context.annotation.Configuration;
    import org.springframework.http.converter.HttpMessageConverter;
    import org.springframework.http.converter.json.MappingJackson2HttpMessageConverter;
    import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
     
    import java.io.IOException;
    import java.time.Instant;
    import java.time.LocalDateTime;
    import java.time.ZoneId;
    import java.util.List;
     
    @Configuration
    public class LocalDateTimeConfig implements WebMvcConfigurer {
        @Override
        public void extendMessageConverters(List<HttpMessageConverter<?>> converters) {
            MappingJackson2HttpMessageConverter converter = new MappingJackson2HttpMessageConverter();
            ObjectMapper objectMapper = converter.getObjectMapper();
            JavaTimeModule javaTimeModule = new JavaTimeModule();
            //这里可以多次addSerializer与addDeserializer
            javaTimeModule.addSerializer(LocalDateTime.class, new LocalDateTimeSerializer());
            javaTimeModule.addDeserializer(LocalDateTime.class, new LocalDateTimeDeserializer());
            objectMapper.registerModule(javaTimeModule);
            converter.setObjectMapper(objectMapper);
            converters.add(0, converter);
        }
     
        // 序列化实现
        public static class LocalDateTimeSerializer extends JsonSerializer<LocalDateTime> {
            @Override
            public void serialize(LocalDateTime localDateTime, JsonGenerator gen, SerializerProvider serializers)
                    throws IOException {
                if (localDateTime != null){
                    long timestamp = localDateTime.atZone(ZoneId.systemDefault()).toInstant().toEpochMilli();
                    gen.writeNumber(timestamp);
                }
            }
        }
     
        // 反序列化实现
        public static class LocalDateTimeDeserializer extends JsonDeserializer<LocalDateTime> {
            @Override
            public LocalDateTime deserialize(JsonParser p, DeserializationContext deserializationContext)
                    throws IOException {
                long timestamp = p.getValueAsLong();
                if (timestamp > 0){
                    return LocalDateTime.ofInstant(Instant.ofEpochMilli(timestamp),ZoneId.systemDefault());
                }else{
                    return null;
                }
            }
        }
    }

## 年月日格式 ##

### 法1：@JsonFormat ###

**Entity**

package com.example.business.entity;
    
    import com.fasterxml.jackson.annotation.JsonFormat;
    import lombok.AllArgsConstructor;
    import lombok.Data;
    
    import java.time.LocalDateTime;
    
    @Data
    @AllArgsConstructor
    public class User {
        private Long id;
    
        private String userName;
    
        @JsonFormat(pattern = "yyyy-MM-dd HH:mm:ss",timezone="GMT+8")
        private LocalDateTime createTime;
    }

**Controller**

package com.example.business.controller;
    
    import com.example.business.entity.User;
    import org.springframework.web.bind.annotation.GetMapping;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RestController;
    
    import java.time.LocalDateTime;
    
    @RestController
    @RequestMapping("user")
    public class UserController {
        @GetMapping("getUser")
        public User getUser() {
            return new User(null, "Tony", LocalDateTime.now());
        }
    }

**测试**

postman访问：[http://localhost:8080/user/getUser][http_localhost_8080_user_getUser]

postman结果：

![watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBASVTliKnliIPlh7rpnpg_size_18_color_FFFFFF_t_70_g_se_x_16][]

### 其他：同“时间戳格式” ###

上边“时间戳格式”的所有方法都可以用到自定义格式上。

# 前端传入 #

## 时间戳格式 ##

### 法1：@ControllerAdvice+@InitBinder ###

**配置类**

package com.example.config;
    
    import org.springframework.web.bind.WebDataBinder;
    import org.springframework.web.bind.annotation.ControllerAdvice;
    import org.springframework.web.bind.annotation.InitBinder;
    
    import java.beans.PropertyEditorSupport;
    import java.time.*;
    
    @ControllerAdvice
    public class LocalDateTimeAdvice {
        @InitBinder
        protected void initBinder(WebDataBinder binder) {
            binder.registerCustomEditor(LocalDateTime.class, new PropertyEditorSupport() {
                @Override
                public void setAsText(String text) throws IllegalArgumentException {
                    setValue(Instant.ofEpochMilli(Long.parseLong(text))
                            .atZone(ZoneOffset.ofHours(8)).toLocalDateTime());
                }
            });
    
            binder.registerCustomEditor(LocalDate.class, new PropertyEditorSupport() {
                @Override
                public void setAsText(String text) throws IllegalArgumentException {
                    setValue(Instant.ofEpochMilli(Long.parseLong(text))
                            .atZone(ZoneId.systemDefault()).toLocalDate());
                }
            });
    
            binder.registerCustomEditor(LocalTime.class, new PropertyEditorSupport() {
                @Override
                public void setAsText(String text) throws IllegalArgumentException {
                    setValue(Instant.ofEpochMilli(Long.parseLong(text))
                            .atZone(ZoneId.systemDefault()).toLocalTime());
                }
            });
        }
    }

**Entity**

**Controller**

package com.example.business.controller;
    
    import com.example.business.entity.User;
    import org.springframework.web.bind.annotation.PostMapping;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RestController;
    
    @RestController
    @RequestMapping("user")
    public class UserController {
        @PostMapping("save")
        public User save(User user) {
            System.out.println("保存用户：" + user);
            return user;
        }
    }

**测试**

postman访问：[http://localhost:8080/user/save?userName=Tony&createTime=1631798001000][http_localhost_8080_user_save_userName_Tony_createTime_1631798001000]

postman结果

![watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBASVTliKnliIPlh7rpnpg_size_20_color_FFFFFF_t_70_g_se_x_16 1][]

后端结果

![watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBASVTliKnliIPlh7rpnpg_size_20_color_FFFFFF_t_70_g_se_x_16 2][]

### 法2：自定义参数转换器（Converter） ###

实现 org.springframework.core.convert.converter.Converter，自定义参数转换器。

**配置类**

package com.example.config;
    
    import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.Configuration;
    import org.springframework.core.convert.converter.Converter;
    
    import java.time.Instant;
    import java.time.LocalDateTime;
    import java.time.ZoneOffset;
    
    @Configuration
    public class LocalDateTimeConfig {
    
        @Bean
        public Converter<String, LocalDateTime> localDateTimeConverter() {
            return new LocalDateTimeConverter();
        }
    
        public static class LocalDateTimeConverter implements Converter<String, LocalDateTime> {
            @Override
            public LocalDateTime convert(String s) {
                return Instant.ofEpochMilli(Long.parseLong(s))
                        .atZone(ZoneOffset.ofHours(8)).toLocalDateTime();
            }
        }
    }

**Entity**

**Controller**

**测试**

postman访问：[http://localhost:8080/user/save?userName=Tony&createTime=1631798001000][http_localhost_8080_user_save_userName_Tony_createTime_1631798001000]

postman结果：

![watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBASVTliKnliIPlh7rpnpg_size_20_color_FFFFFF_t_70_g_se_x_16 3][]

后端结果

![watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBASVTliKnliIPlh7rpnpg_size_20_color_FFFFFF_t_70_g_se_x_16 4][]

## 年月日格式 ##

### 法1：@ControllerAdvice+@InitBinder ###

**配置类**

package com.example.config;
    
    import org.springframework.web.bind.WebDataBinder;
    import org.springframework.web.bind.annotation.ControllerAdvice;
    import org.springframework.web.bind.annotation.InitBinder;
    
    import java.beans.PropertyEditorSupport;
    import java.time.LocalDate;
    import java.time.LocalDateTime;
    import java.time.LocalTime;
    import java.time.format.DateTimeFormatter;
    
    @ControllerAdvice
    public class LocalDateTimeAdvice {
        @InitBinder
        protected void initBinder(WebDataBinder binder) {
            binder.registerCustomEditor(LocalDateTime.class, new PropertyEditorSupport() {
                @Override
                public void setAsText(String text) throws IllegalArgumentException {
                    setValue(LocalDateTime.parse(text, DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss")));
                }
            });
    
            binder.registerCustomEditor(LocalDate.class, new PropertyEditorSupport() {
                @Override
                public void setAsText(String text) throws IllegalArgumentException {
                    setValue(LocalDate.parse(text, DateTimeFormatter.ofPattern("yyyy-MM-dd")));
                }
            });
    
            binder.registerCustomEditor(LocalTime.class, new PropertyEditorSupport() {
                @Override
                public void setAsText(String text) throws IllegalArgumentException {
                    setValue(LocalTime.parse(text, DateTimeFormatter.ofPattern("HH:mm:ss")));
                }
            });
        }
    }

**Entity**

**Controller**

**测试**

postman访问：http://localhost:8080/user/save?userName=Tony&createTime=2021-09-16 21:13:21

postman结果：

![watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBASVTliKnliIPlh7rpnpg_size_20_color_FFFFFF_t_70_g_se_x_16 5][]

后端结果：

![watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBASVTliKnliIPlh7rpnpg_size_20_color_FFFFFF_t_70_g_se_x_16 6][]

### 法2：自定义参数转换器（Converter） ###

实现 org.springframework.core.convert.converter.Converter，自定义参数转换器。

**配置类**

package com.example.config;
    
    import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.Configuration;
    import org.springframework.core.convert.converter.Converter;
    
    import java.time.LocalDateTime;
    import java.time.format.DateTimeFormatter;
    
    @Configuration
    public class LocalDateTimeConfig {
    
        @Bean
        public Converter<String, LocalDateTime> localDateTimeConverter() {
            return new LocalDateTimeConverter();
        }
    
        public static class LocalDateTimeConverter implements Converter<String, LocalDateTime> {
            @Override
            public LocalDateTime convert(String s) {
                return LocalDateTime.parse(s, DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss"));
            }
        }
    }

**Entity**

**Controller**

**测试**

postman访问：http://localhost:8080/user/save?userName=Tony&createTime=2021-09-16 21:13:21

postman结果：

![watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBASVTliKnliIPlh7rpnpg_size_20_color_FFFFFF_t_70_g_se_x_16 7][]

后端结果

![watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBASVTliKnliIPlh7rpnpg_size_20_color_FFFFFF_t_70_g_se_x_16 8][]

[SpringBoot--LocalDateTime--_IT_-CSDN]: https://knife.blog.csdn.net/article/details/120335612
[http_localhost_8080_user_getUser]: http://localhost:8080/user/getUser
[watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBASVTliKnliIPlh7rpnpg_size_19_color_FFFFFF_t_70_g_se_x_16]: /images/20220828/cb6144704bcd405aa0f3f6b8e6081f3d.png
[http_localhost_8080_user_save_userName_Tony_createTime_1631790000]: http://localhost:8080/user/save?userName=Tony&createTime=1631790000
[watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBASVTliKnliIPlh7rpnpg_size_20_color_FFFFFF_t_70_g_se_x_16]: /images/20220828/8b70dc3c26534dc8baf685446ff9edca.png
[watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBASVTliKnliIPlh7rpnpg_size_17_color_FFFFFF_t_70_g_se_x_16]: /images/20220828/e5ae0b0056834732b2f025478e4038f8.png
[watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBASVTliKnliIPlh7rpnpg_size_19_color_FFFFFF_t_70_g_se_x_16 1]: /images/20220828/aabab595c79f4562bdb543bec9f5a041.png
[watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBASVTliKnliIPlh7rpnpg_size_18_color_FFFFFF_t_70_g_se_x_16]: /images/20220828/434581c22a884ba3979f4a91d01f3502.png
[http_localhost_8080_user_save_userName_Tony_createTime_1631798001000]: http://localhost:8080/user/save?userName=Tony&createTime=1631798001000
[watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBASVTliKnliIPlh7rpnpg_size_20_color_FFFFFF_t_70_g_se_x_16 1]: /images/20220828/45b663fe0246461990f2859e32d71e68.png
[watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBASVTliKnliIPlh7rpnpg_size_20_color_FFFFFF_t_70_g_se_x_16 2]: /images/20220828/b20cc2be909048a98ec11c61417e5705.png
[watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBASVTliKnliIPlh7rpnpg_size_20_color_FFFFFF_t_70_g_se_x_16 3]: /images/20220828/523cab40d0194a70b3642d2b304671aa.png
[watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBASVTliKnliIPlh7rpnpg_size_20_color_FFFFFF_t_70_g_se_x_16 4]: /images/20220828/7f53e72760ab4a5db4b41494380094b8.png
[watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBASVTliKnliIPlh7rpnpg_size_20_color_FFFFFF_t_70_g_se_x_16 5]: /images/20220828/0c7257381f3a4959943d6d52a08c03a2.png
[watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBASVTliKnliIPlh7rpnpg_size_20_color_FFFFFF_t_70_g_se_x_16 6]: /images/20220828/9cb6c14a4428456ab754e98d04969a8f.png
[watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBASVTliKnliIPlh7rpnpg_size_20_color_FFFFFF_t_70_g_se_x_16 7]: /images/20220828/589bba7b7ed740c7a3b977b5271e5069.png
[watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBASVTliKnliIPlh7rpnpg_size_20_color_FFFFFF_t_70_g_se_x_16 8]: /images/20220828/d51b8345d0574d8f8a8042ee1149d11a.png