feat (core): Java ☕ static Thing API

.bazelproject

@@ -13,6 +13,4 @@ derive_targets_from_directories: true
 workspace_type: java
 
 additional_languages:
-  go
   kotlin
-  typescript

java/dev/enola/common/Builder.java

@@ -17,7 +17,7 @@
  */
 package dev.enola.common;
 
-public interface Builder<T> {
+public interface Builder<B> {
 
-    T build();
+    B build();
 }

java/dev/enola/common/convert/ObjectToStringBiConverter.java

@@ -17,10 +17,13 @@
  */
 package dev.enola.common.convert;
 
+import com.google.errorprone.annotations.Immutable;
+
 import java.io.IOException;
 import java.util.Optional;
 
 /** Converts objects of type T to & from String, if it can. */
+@Immutable
 public interface ObjectToStringBiConverter<T>
         extends BiConverter<T, String>, ConverterIntoAppendable<T>, ObjectClassConverter {
 

java/dev/enola/common/convert/ObjectToStringBiConverterWithFormat.java

@@ -24,6 +24,7 @@
 
 public class ObjectToStringBiConverterWithFormat implements ObjectToStringBiConverter<Object> {
 
+    @SuppressWarnings("Immutable")
     private final Format format;
 
     public ObjectToStringBiConverterWithFormat(Format format) {

java/dev/enola/common/convert/ObjectToStringBiConverters.java

@@ -18,6 +18,7 @@
 package dev.enola.common.convert;
 
 import java.net.URISyntaxException;
+import java.time.Instant;
 import java.time.LocalDate;
 
 public final class ObjectToStringBiConverters {
@@ -29,6 +30,10 @@ public final class ObjectToStringBiConverters {
             new ObjectToStringWithToStringBiConverter<>(
                     Boolean.class, input -> Boolean.valueOf(input));
 
+    public static final ObjectToStringBiConverter<Integer> INT =
+            new ObjectToStringWithToStringBiConverter<>(
+                    Integer.class, input -> Integer.valueOf(input));
+
     public static final ObjectToStringBiConverter<java.net.URI> URI =
             new ObjectToStringWithToStringBiConverter<>(
                     java.net.URI.class,
@@ -44,5 +49,9 @@ public final class ObjectToStringBiConverters {
             new ObjectToStringWithToStringBiConverter<>(
                     LocalDate.class, input -> LocalDate.parse(input));
 
+    public static final ObjectToStringBiConverter<Instant> INSTANT =
+            new ObjectToStringWithToStringBiConverter<>(
+                    Instant.class, input -> Instant.parse(input));
+
     private ObjectToStringBiConverters() {}
 }

java/dev/enola/common/convert/ObjectToStringWithToStringBiConverter.java

@@ -34,6 +34,8 @@
 public class ObjectToStringWithToStringBiConverter<T> implements ObjectToStringBiConverter<T> {
 
     private final Class<T> from;
+
+    @SuppressWarnings("Immutable")
     private final Function<String, T> converter;
 
     public ObjectToStringWithToStringBiConverter(Class<T> clazz, Function<String, T> function) {

java/dev/enola/datatype/Datatype.java

@@ -17,13 +17,17 @@
  */
 package dev.enola.datatype;
 
+import com.google.errorprone.annotations.Immutable;
+
 import dev.enola.common.convert.ObjectToStringBiConverter;
 
 import java.lang.reflect.Type;
 import java.util.Optional;
 import java.util.regex.Pattern;
 
-public interface Datatype<T> /* TODO extends Thing */ {
+@Immutable
+public interface Datatype<T> {
+    // NB: NOT extends Thing; there's a DatatypeThing for that!
 
     /** IRI of this datatype. Always present, never null or empty. */
     String iri();

java/dev/enola/datatype/Datatypes.java

@@ -28,6 +28,8 @@
 // https://docs.enola.dev/models/datatypes and have a working HTTP redirector.
 public final class Datatypes {
 
+    // TODO Move dev.enola.datatype.Datatypes to dev.enola.model.xsd.Datatypes!
+
     // Nota Bene: There's no NULL here - the absence of a value is not a Datatype!
 
     // TODO MAP, LIST etc. from https://yaml.org/type/
@@ -56,10 +58,6 @@ public final class Datatypes {
                     URI.class, // TODO Make this URI.class!
                     IRI_PATTERN);
 
-    // TODO public static final Datatype NUMBER = new NumberDatatype();
-
-    // TODO TIMESTAMP
-
     // TODO BINARY ... multibase ... with https://github.com/multiformats/java-multibase, or
     // https://github.com/filip26/copper-multibase, for https://github.com/multiformats/multibase.
     // Replace use of Base64.getEncoder().encodeToString() in MessageToThingConverter#b64()

java/dev/enola/model/w3/rdfs/HasLabel.java

@@ -0,0 +1,27 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Copyright 2024 The Enola <https://enola.dev> Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package dev.enola.model.w3.rdfs;
+
+import dev.enola.thing.KIRI;
+import dev.enola.thing.java.IRI;
+
+public interface HasLabel {
+
+    @IRI(KIRI.RDFS.LABEL)
+    String getLabel();
+}

java/dev/enola/model/xsd/Datatypes.java

@@ -21,6 +21,7 @@
 import dev.enola.datatype.Datatype;
 import dev.enola.datatype.ImmutableDatatype;
 
+import java.time.Instant;
 import java.time.LocalDate;
 
 /** Datatypes for <a href="http://www.w3.org/TR/xmlschema-2/">XML Schema (XSD)</a>. */
@@ -37,5 +38,21 @@ public final class Datatypes {
                     // https://www.oreilly.com/library/view/regular-expressions-cookbook/9781449327453/ch04s07.html
                     "(?<year>[0-9]{4})-?(?<month>1[0-2]|0[1-9])-?(?<day>3[01]|0[1-9]|[12][0-9])");
 
+    public static final Datatype<Integer> INT =
+            new ImmutableDatatype<>(
+                    "http://www.w3.org/2001/XMLSchema#int",
+                    ObjectToStringBiConverters.INT,
+                    Integer.class,
+                    // TODO Test coverage for this INT RegExp...
+                    "-?0*(?:214748364[0-7]|21474836[0-3]\\d|2147483[0-5]\\d{2}|214748[0-2]\\d{3}|21474[0-7]\\d{4}|2147[0-3]\\d{5}|214[0-6]\\d{6}|21[0-3]\\d{7}|20\\d{8}|1\\d{9}|[1-9]\\d{1,8}|0)");
+
+    public static final Datatype<Instant> DATE_TIME =
+            new ImmutableDatatype<>(
+                    "http://www.w3.org/2001/XMLSchema#dateTime",
+                    ObjectToStringBiConverters.INSTANT,
+                    Instant.class,
+                    // TODO Test coverage for this INT RegExp...
+                    "(\\d{4})-(\\d{2})-(\\d{2})T([0-9:]+)(Z|([+-])(\\d{2})(:(\\d{2})?)?)?");
+
     private Datatypes() {}
 }

java/dev/enola/thing/BUILD

@@ -61,7 +61,10 @@ java_library(
     name = "thing_java",
     srcs = glob(
         ["**/*.java"],
-        exclude = ["**/*Test.java"],
+        exclude = [
+            "**/*Test.java",
+            "**/Test*.java",
+        ],
     ),
     plugins = ["//tools/bazel/java_plugin:autoservice"],
     visibility = ["//:__subpackages__"],
@@ -76,6 +79,7 @@ java_library(
         "//java/dev/enola/data",
         "//java/dev/enola/datatype",
         "@maven//:com_github_java_json_tools_uri_template",
+        "@maven//:com_github_spotbugs_spotbugs_annotations",
         "@maven//:com_google_auto_service_auto_service_annotations",
         "@maven//:com_google_errorprone_error_prone_annotations",
         "@maven//:com_google_errorprone_error_prone_type_annotations",
@@ -90,6 +94,10 @@ java_library(
 junit_tests(
     name = "tests",
     srcs = glob(["**/*Test.java"]),
+    srcs_utils = glob(
+        ["**/Test*.java"],
+        exclude = ["**/*Test.java"],
+    ),
     deps = [
         ":thing_java",
         ":thing_java_proto",
@@ -104,6 +112,8 @@ junit_tests(
         "//java/dev/enola/rdf",
         "//models",
         "//test",
+        "@maven//:com_github_spotbugs_spotbugs_annotations",
+        "@maven//:com_google_errorprone_error_prone_annotations",
         "@maven//:org_jspecify_jspecify",
     ],
 )

java/dev/enola/thing/IImmutablePredicatesObjects.java

@@ -18,6 +18,8 @@
 package dev.enola.thing;
 
 import com.google.errorprone.annotations.Immutable;
+import com.google.errorprone.annotations.ThreadSafe;
 
 @Immutable
+@ThreadSafe
 public interface IImmutablePredicatesObjects extends PredicatesObjects {}

java/dev/enola/thing/ImmutablePredicatesObjects.java

@@ -20,33 +20,38 @@
 import com.google.common.base.MoreObjects;
 import com.google.common.collect.ImmutableMap;
 import com.google.errorprone.annotations.Immutable;
+import com.google.errorprone.annotations.ThreadSafe;
+
+import org.jspecify.annotations.Nullable;
 
 import java.util.Collection;
 import java.util.Objects;
 
 @Immutable
+@ThreadSafe
 public class ImmutablePredicatesObjects implements IImmutablePredicatesObjects {
 
     // Suppressed because of @ImmutableTypeParameter T in PredicatesObjects.Builder#set:
     @SuppressWarnings("Immutable")
-    private final ImmutableMap<String, Object> properties;
-
-    private final ImmutableMap<String, String> datatypes;
+    protected final ImmutableMap<String, Object> properties;
 
-    public static PredicatesObjects.Builder builder() {
-        return new ImmutablePredicatesObjects.Builder();
-    }
-
-    public static PredicatesObjects.Builder builderWithExpectedSize(int expectedSize) {
-        return new ImmutablePredicatesObjects.Builder(expectedSize);
-    }
+    protected final ImmutableMap<String, String> datatypes;
 
     protected ImmutablePredicatesObjects(
             ImmutableMap<String, Object> properties, ImmutableMap<String, String> datatypes) {
         this.properties = properties;
         this.datatypes = datatypes;
     }
 
+    public static PredicatesObjects.Builder<? extends ImmutablePredicatesObjects> builder() {
+        return new ImmutablePredicatesObjects.Builder<>();
+    }
+
+    public static PredicatesObjects.Builder<? extends ImmutablePredicatesObjects>
+            builderWithExpectedSize(int expectedSize) {
+        return new ImmutablePredicatesObjects.Builder<>(expectedSize);
+    }
+
     @Override
     public ImmutableMap<String, Object> properties() {
         return properties;
@@ -59,7 +64,7 @@ public Collection<String> predicateIRIs() {
 
     @Override
     @SuppressWarnings("unchecked")
-    public <T> T get(String predicateIRI) {
+    public <T> @Nullable T get(String predicateIRI) {
         return (T) properties.get(predicateIRI);
     }
 
@@ -68,7 +73,7 @@ public ImmutableMap<String, String> datatypes() {
     }
 
     @Override
-    public String datatype(String predicateIRI) {
+    public @Nullable String datatype(String predicateIRI) {
         return datatypes.get(predicateIRI);
     }
 
@@ -77,8 +82,7 @@ public boolean equals(Object obj) {
         if (obj == this) return true;
         // NO NEED: if (obj == null) return false;
         // NOT:     if (getClass() != obj.getClass()) return false;
-        if (!(obj instanceof ImmutablePredicatesObjects)) return false;
-        final ImmutablePredicatesObjects other = (ImmutablePredicatesObjects) obj;
+        if (!(obj instanceof ImmutablePredicatesObjects other)) return false;
         return Objects.equals(this.properties, other.properties)
                 && Objects.equals(this.datatypes, other.datatypes);
     }
@@ -97,11 +101,12 @@ public String toString() {
     }
 
     @Override
-    public PredicatesObjects.Builder copy() {
-        return new ImmutablePredicatesObjects.Builder(properties(), datatypes());
+    public PredicatesObjects.Builder<? extends ImmutablePredicatesObjects> copy() {
+        return new Builder<>(properties(), datatypes());
     }
 
-    private static final class Builder implements PredicatesObjects.Builder {
+    private static final class Builder<B extends PredicatesObjects>
+            implements PredicatesObjects.Builder<B> {
 
         private final ImmutableMap.Builder<String, Object> properties;
         private final ImmutableMap.Builder<String, String> datatypes;
@@ -144,8 +149,9 @@ public PredicatesObjects.Builder set(
         }
 
         @Override
-        public PredicatesObjects build() {
-            return new ImmutablePredicatesObjects(properties.build(), datatypes.build());
+        public B build() {
+            // TODO Remove (B) type cast
+            return (B) new ImmutablePredicatesObjects(properties.build(), datatypes.build());
         }
     }
 }