基础地址只差一个斜杠，为什么新路径换了位置？

import java.net.URI;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.ArrayList;
import java.util.List;
import java.util.Objects;

public class UriResolveBoundary {
    static final String HOST = "https://api.example.test";
    static final String ITEM_BASE = HOST + "/v1/orders";
    static final String CHILD_BASE = ITEM_BASE + "/";

    record Fixture(String name, String base, String reference, String expected,
                   boolean expectedAbsolute, boolean expectedAuthority) {}
    record Row(String name, String base, String reference, String resolved,
               boolean referenceAbsolute, boolean referenceAuthority,
               String scheme, String host, String rawPath, String query, String fragment,
               boolean sameBaseScheme, boolean sameBaseHost) {
        String json() {
            return "{\"case\":" + quote(name) + ",\"base\":" + quote(base)
                + ",\"reference\":" + quote(reference) + ",\"resolved\":" + quote(resolved)
                + ",\"reference_is_absolute\":" + referenceAbsolute
                + ",\"reference_has_authority\":" + referenceAuthority
                + ",\"result_scheme\":" + quote(scheme) + ",\"result_host\":" + quote(host)
                + ",\"result_raw_path\":" + quote(rawPath) + ",\"result_query\":" + quote(query)
                + ",\"result_fragment\":" + quote(fragment)
                + ",\"same_base_scheme\":" + sameBaseScheme
                + ",\"same_base_host\":" + sameBaseHost + "}";
        }
        String csv() {
            return String.join(",", List.of(name, base, reference, resolved,
                Boolean.toString(referenceAbsolute), Boolean.toString(referenceAuthority),
                scheme, host, rawPath, query == null ? "<null>" : query,
                fragment == null ? "<null>" : fragment,
                Boolean.toString(sameBaseScheme), Boolean.toString(sameBaseHost))
                .stream().map(UriResolveBoundary::csvCell).toList());
        }
    }

    static String quote(String value) {
        if (value == null) return "null";
        return "\"" + value.replace("\\", "\\\\").replace("\"", "\\\"")
            .replace("\r", "\\r").replace("\n", "\\n").replace("\t", "\\t") + "\"";
    }
    static String csvCell(String value) { return "\"" + value.replace("\"", "\"\"") + "\""; }
    static void require(boolean condition, String message) {
        if (!condition) throw new AssertionError(message);
    }

    public static void main(String[] args) throws Exception {
        Path output = args.length == 0 ? Path.of("uri-output") : Path.of(args[0]);
        List<Fixture> cases = List.of(
            new Fixture("base_without_slash", ITEM_BASE, "42", HOST + "/v1/42", false, false),
            new Fixture("base_with_slash", CHILD_BASE, "42", CHILD_BASE + "42", false, false),
            new Fixture("root_path", CHILD_BASE, "/42", HOST + "/42", false, false),
            new Fixture("dot_path", CHILD_BASE, "./42", CHILD_BASE + "42", false, false),
            new Fixture("parent_path", CHILD_BASE, "../42", HOST + "/v1/42", false, false),
            new Fixture("absolute_other_host", CHILD_BASE, "https://other.example.test/42",
                "https://other.example.test/42", true, true),
            new Fixture("network_path", CHILD_BASE, "//cdn.example.test/42",
                "https://cdn.example.test/42", false, true),
            new Fixture("fragment_only", ITEM_BASE + "?view=full", "#detail",
                ITEM_BASE + "?view=full#detail", false, false),
            new Fixture("absolute_other_scheme", CHILD_BASE, "http://api.example.test/42",
                "http://api.example.test/42", true, true)
        );
        List<Row> rows = new ArrayList<>();
        for (Fixture fixture : cases) {
            // URI parses syntax only. No URL, socket, HttpClient or DNS calls are made.
            URI base = URI.create(fixture.base);
            URI reference = URI.create(fixture.reference);
            URI result = base.resolve(reference);
            require(result.toString().equals(fixture.expected), fixture.name + ": " + result);
            require(reference.isAbsolute() == fixture.expectedAbsolute, fixture.name + ": absolute");
            require((reference.getRawAuthority() != null) == fixture.expectedAuthority,
                fixture.name + ": authority");
            require(base.toString().equals(fixture.base), "base URI unexpectedly changed");
            require(reference.toString().equals(fixture.reference), "reference unexpectedly changed");
            require(result.isAbsolute() && !result.isOpaque() && result.getHost() != null,
                fixture.name + ": unexpected fixture type");
            rows.add(new Row(fixture.name, fixture.base, fixture.reference, result.toString(),
                reference.isAbsolute(), reference.getRawAuthority() != null,
                result.getScheme(), result.getHost(), result.getRawPath(),
                result.getRawQuery(), result.getRawFragment(),
                Objects.equals(base.getScheme(), result.getScheme()),
                Objects.equals(base.getHost(), result.getHost())));
        }
        require(!rows.get(6).referenceAbsolute && !rows.get(6).sameBaseHost,
            "a relative network-path reference can replace authority");
        require(rows.get(8).sameBaseHost && !rows.get(8).sameBaseScheme,
            "same host alone does not preserve the scheme");
        require(rows.get(7).query.equals("view=full") && rows.get(7).fragment.equals("detail"),
            "fragment-only reference keeps fixture path/query");
        Files.createDirectories(output);
        String version = System.getProperty("java.version");
        String json = "{\n  \"java_version\":" + quote(version)
            + ",\n  \"scope\":\"JDK_URI_syntax_only_no_network_or_authorization\","
            + "\n  \"cases\":9,\n  \"rows\":[\n    "
            + String.join(",\n    ", rows.stream().map(Row::json).toList()) + "\n  ]\n}\n";
        String csv = "case,base,reference,resolved,reference_is_absolute,reference_has_authority,"
            + "result_scheme,result_host,result_raw_path,result_query,result_fragment,"
            + "same_base_scheme,same_base_host\n"
            + String.join("\n", rows.stream().map(Row::csv).toList()) + "\n";
        Files.writeString(output.resolve("report.json"), json, StandardCharsets.UTF_8);
        Files.writeString(output.resolve("matrix.csv"), csv, StandardCharsets.UTF_8);
        System.out.println("Java " + version + "; 9 cases; URI syntax only; no network requests");
        System.out.println("base tail: orders + 42 -> /v1/42; orders/ + 42 -> /v1/orders/42");
        System.out.println("//cdn reference: isAbsolute=false, host changes; same host can change scheme");
        System.out.println("PASS; " + output);
    }
}