Spring: #PathVariable from multiple path elements like with jax-rs? - spring

Question

I'm migrating some routes from a jax-rs based application to SpringBoot. In jax-rs I can use #Path to define a regex that contains multiple URL path elements:
#Path("{id:[^/]+/y[\d]{4}/m[\d]{1,2}/d[\d]{1,2}/h[\d]{1,2}}/")
The id variable in the method body will then be the matching segment of the URL and I can go about my day.
With #RequestMapping in Spring this doesn't work. As soon as you put a forward slash into the regex you get a PatternParseException.
PathContainer pathContainingSlash = PathContainer.parsePath("/api/test/y1978/m07/d15");
PathPatternParser parser = new PathPatternParser();
assertThrows(PatternParseException.class, () ->
parser.parse("/api/test/{ticketId:y[\\d]{4}/m[\\d]{1,2}/d[\\d]{1,2}}"));
This same problem appears to happen with AntPathMatcher.
AntPathMatcher antPathMatcher = new AntPathMatcher();
assertThrows(IllegalStateException.class, () ->
antPathMatcher.extractUriTemplateVariables(
"/api/test/{ticketId:y[\\d]{4}/m[\\d]{1,2}/d[\\d]{1,2}}",
"/api/test/y1978/m07/d15"));
This is a problem because I have about 78 of these URL patterns. I'm going to have to define each pattern individually with each path element being a separate variable. Then I'm going to have to use String concatenation to combine them back together in the format of a path.
#GetMapping("/{year:y[\\d]{4}}/{month:m[\\d]1,2}/{day:d[\\d]{1,2}")
public ResponseEntity<Void> foo(#PathVariable String year,
#PathVariable String month,
#PathVariable String day) {
String date = year + "/" + month + "/" + day;
}
Other than using Jax-rs in my SpringBoot app, is there accomplish this? It's possible to write them all like this but it seems sub-optimal.
For clarity, I really want a way to extract multiple path elements from a URL into a #PathVariable. I would like something like this:
#GetMapping("/api/test/{date:y[\\d]{4}/m[\\d]{1,2}/d[\\d]{1,2}}")
public ResponseEntity<Void> foo(#PathVariable String date) {}
So that date is now equal to y1978/m07/d15
Also, this is just one example pattern. There are 78 unique patterns, that have a varying number of a path elements and contents of the elements. In Jax-RS using #Path I can OR these regexes together and create one route and the path variable is accessible inside the method.

Answer 1

how about adding spring-boot-starter-validation for validation
requires addition of following jar
org.springframework.boot:spring-boot-starter-validation
add #org.springframework.validation.annotation.Validated on top of controller class
add #javax.validation.constraints.Pattern with regex attribute to the #PathVariable method params
#GetMapping("{year}/{month}/{day}")
public ResponseEntity<Void> foo(
#PathVariable #Pattern(regexp = "[\\d]{4}", message = "year must be ..") String year,
#PathVariable #Pattern(regexp = "[\\d]{1,2}", message = "month must ..") String month,
#PathVariable #Pattern(regexp = "[\\d]{1,2}", message= "day must be ..") String day) {
String date = year + "/" + month + "/" + day;
to return http 400 status, add a method to handle the ConstraintViolationException
#ExceptionHandler(value = { ConstraintViolationException.class })
protected ResponseEntity<List<String>> handleConstraintViolations(ConstraintViolationException ex, WebRequest request) {
List<String> errorMessages = ex.getConstraintViolations().stream()
.map(violation -> violation.getMessage()).collect(Collectors.toList());
return new ResponseEntity<List<String>>(errorMessages, HttpStatus.BAD_REQUEST);
}
more validation examples here:
https://reflectoring.io/bean-validation-with-spring-boot/
more exception handling options here:
https://www.baeldung.com/exception-handling-for-rest-with-spring

Answer 2

a possible option using path rewrite from this thread
Spring MVC Getting PathVariables containing dots and slashes
add
<dependency>
<groupId>org.tuckey</groupId>
<artifactId>urlrewritefilter</artifactId>
<version>4.0.3</version>
</dependency>
add rewrite rules to src/main/webapp/WEB-INF/urlrewrite.xml
<urlrewrite>
<rule>
<from>^/api/test/(y[\d]{4})/(m[\d]{2})/(d[\d]{2})$</from>
<to>/api/test?date=$1/$2/$3</to>
</rule>
</urlrewrite>
create controller methods matching the to path of the rewrite rule with query params
#GetMapping("/api/test")
public ResponseEntity<Void> foo(#RequestParam String date) {
System.out.println(date);
return new ResponseEntity<Void>(HttpStatus.OK);
}
add configuration class to register the rewrite filter with urlPatterns to filter
#Configuration
public class FiltersConfig {
#Bean
public FilterRegistrationBean<Filter> someFilterRegistration() {
FilterRegistrationBean<Filter> registration = new FilterRegistrationBean<Filter>();
registration.setFilter(rewriteFilter());
// add paths to filter
registration.addUrlPatterns("/api/*");
registration.setName("urlRewriteFilter");
registration.setOrder(1);
return registration;
}
public Filter rewriteFilter() {
return new UrlRewriteFilter();
}
}