Issue
I use Spring Boot and included jackson-datatype-jsr310 with Maven:
<dependency>
<groupId>com.fasterxml.jackson.datatype</groupId>
<artifactId>jackson-datatype-jsr310</artifactId>
<version>2.7.3</version>
</dependency>
When I try to use a RequestParam with a Java 8 Date/Time type,
@GetMapping("/test")
public Page<User> get(
@RequestParam(value = "start", required = false)
@DateTimeFormat(iso = DateTimeFormat.ISO.DATE_TIME) LocalDateTime start) {
//...
}
and test it with this URL:
/test?start=2016-10-8T00:00
I get the following error:
{
"timestamp": 1477528408379,
"status": 400,
"error": "Bad Request",
"exception": "org.springframework.web.method.annotation.MethodArgumentTypeMismatchException",
"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 [@org.springframework.web.bind.annotation.RequestParam @org.springframework.format.annotation.DateTimeFormat java.time.LocalDateTime] for value '2016-10-8T00:00'; nested exception is java.lang.IllegalArgumentException: Parse attempt failed for value [2016-10-8T00:00]",
"path": "/test"
}
Solution
TL;DR - you can capture it as a string with just @RequestParam, or you can have Spring additionally parse the string into a java date / time class via @DateTimeFormat on the parameter as well.
the @RequestParam is enough to grab the date you supply after the = sign, however, it comes into the method as a String. That is why it is throwing the cast exception.
There are a few ways to achieve this:
- parse the date yourself, grabbing the value as a string.
@GetMapping("/test")
public Page<User> get(@RequestParam(value="start", required = false) String start){
//Create a DateTimeFormatter with your required format:
DateTimeFormatter dateTimeFormat =
new DateTimeFormatter(DateTimeFormatter.BASIC_ISO_DATE);
//Next parse the date from the @RequestParam, specifying the TO type as
a TemporalQuery:
LocalDateTime date = dateTimeFormat.parse(start, LocalDateTime::from);
//Do the rest of your code...
}
- Leverage Spring's ability to automatically parse and expect date formats:
@GetMapping("/test")
public void processDateTime(@RequestParam("start")
@DateTimeFormat(iso = DateTimeFormat.ISO.DATE_TIME)
LocalDateTime date) {
// The rest of your code (Spring already parsed the date).
}
Answered By - Bwvolleyball
Answer Checked By - Marilyn (JavaFixing Volunteer)
