RequestMapping: case insensitive path matching [SPR-13286]

[spring-projects-issues]

Yi EungJun opened SPR-13286 and commented

I want @RequestMapping annotations to match paths in case-insensitive manner so that @RequestMapping("/path/to/{name}") matches not only /path/to/me but also /path/To/me, /PATH/to/me, and so on.

There is a known workaround to do that as follows:

public class CaseInsensitivePathMatcher extends AntPathMatcher {
    @Override
    protected boolean doMatch(String pattern, String path, boolean fullMatch, Map<String, String> uriTemplateVariables) {
        return super.doMatch(pattern.toLowerCase(), path.toLowerCase(), fullMatch, uriTemplateVariables);
    }
}

But it makes the values of URI template variables lowercase. I want to keep the case information.

---

Referenced from: commits 291550a

[spring-projects-issues]

Yi EungJun commented

I'm trying to fix this myself. At the first glance, this issue can be solved by making AntPathMatcher matches patterns in case-insensitive manner as follows:

diff --git a/spring-core/src/main/java/org/springframework/util/AntPathMatcher.java b/spring-core/src/main/java/org/springframework/util/AntPathMatcher.java
index 3132b1c..5bee271 100644
--- a/spring-core/src/main/java/org/springframework/util/AntPathMatcher.java
+++ b/spring-core/src/main/java/org/springframework/util/AntPathMatcher.java
@@ -583,7 +583,7 @@ public class AntPathMatcher implements PathMatcher {
                                end = m.end();
                        }
                        patternBuilder.append(quote(pattern, end, pattern.length()));
-                       this.pattern = Pattern.compile(patternBuilder.toString());
+                       this.pattern = Pattern.compile(patternBuilder.toString(), Pattern.CASE_INSENSITIVE);
                }
 
                private String quote(String s, int start, int end) {

But I am afraid that it causes a lot of side-effects because RequestMapping is not the only client which uses AntPathMatcher. I guess the side effects may be avoided by adding a flag for case-insensitive matching to AntPathmathcer and RequestMapping.

Is there anything more should be considered?

[spring-projects-issues]

Juergen Hoeller commented

I've introduced a public setCaseInsensitive method on AntPathMatcher, allowing you to configure this externally. The default is still false, so there's no backwards compatibility issue. Would this make sense for your purposes?

Juergen

[spring-projects-issues]

Yi EungJun commented

It sounds great! I think it would make sense to me.

Is it possible to configure that AntPathMatcher matches in case-insensitive manner only for a specific controller? And can I try the your new AntPathMatcher?

[spring-projects-issues]

Juergen Hoeller commented

I've turned this around into a setCaseSensitive method, defaulting to true, which can be switched to false for case-insensitive matching. This will be available in the next 4.2.0.BUILD-SNAPSHOT in about an hour.

I'm afraid the only way to customize the PathMatcher is at the HandlerMapping level, e.g. through the <mvc:annotation-driven path-matcher="..."/> attribute.

Juergen

[spring-projects-issues]

Yi EungJun commented

I tested it and it works very well for me!

Thanks very much, Juergen.

Here is my configuration:

@Configuration
public class WebConfig extends WebMvcConfigurerAdapter {
    @Override
    public void configurePathMatch(PathMatchConfigurer configurer) {
        AntPathMatcher matcher = new AntPathMatcher();
        matcher.setCaseSensitive(false);
        configurer.setPathMatcher(matcher);
    }
}