feat: Add custom operator to Criteria.

Author: Wuzhengyu97

spring-data-r2dbc/src/test/java/org/springframework/data/r2dbc/query/CriteriaUnitTests.java

@@ -19,6 +19,8 @@
 import static org.springframework.data.relational.core.query.Criteria.*;
 
 import java.util.Arrays;
+import java.util.List;
+import java.util.stream.Collectors;
 
 import org.assertj.core.api.SoftAssertions;
 import org.junit.jupiter.api.Test;
@@ -290,4 +292,17 @@ void shouldBuildIsFalseCriteria() {
 		assertThat(criteria.getColumn()).isEqualTo(SqlIdentifier.unquoted("foo"));
 		assertThat(criteria.getComparator()).isEqualTo(Comparator.IS_FALSE);
 	}
+
+	@Test
+	void shouldBuildCustomCriteria() {
+		List<String> values = List.of("bar", "baz", "qux");
+		Criteria criteria = where("foo").custom("CUSTOM",
+				value -> "ARRAY[" + values.stream().map(s -> "'" + s + "'").collect(Collectors.joining(",")) + "]",
+				List.of("bar", "baz", "qux"));
+
+		assertThat(criteria.getColumn()).isEqualTo(SqlIdentifier.unquoted("foo"));
+		assertThat(criteria.getComparator()).isEqualTo(Comparator.CUSTOM);
+		assertThat(criteria.toString()).isEqualTo("foo CUSTOM ARRAY['bar','baz','qux']");
+	}
+
 }

spring-data-relational/src/main/java/org/springframework/data/relational/core/query/Criteria.java

@@ -21,7 +21,8 @@
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
-import java.util.StringJoiner;
+import java.util.Objects;
+import java.util.function.Function;
 
 import org.springframework.dao.InvalidDataAccessApiUsageException;
 import org.springframework.data.relational.core.sql.IdentifierProcessing;
@@ -456,47 +457,8 @@ private void render(CriteriaDefinition criteria, StringBuilder stringBuilder) {
 		stringBuilder.append(criteria.getColumn().toSql(IdentifierProcessing.NONE)).append(' ')
 				.append(criteria.getComparator().getComparator());
 
-		switch (criteria.getComparator()) {
-			case BETWEEN:
-			case NOT_BETWEEN:
-				Pair<Object, Object> pair = (Pair<Object, Object>) criteria.getValue();
-				stringBuilder.append(' ').append(pair.getFirst()).append(" AND ").append(pair.getSecond());
-				break;
-
-			case IS_NULL:
-			case IS_NOT_NULL:
-			case IS_TRUE:
-			case IS_FALSE:
-				break;
-
-			case IN:
-			case NOT_IN:
-				stringBuilder.append(" (").append(renderValue(criteria.getValue())).append(')');
-				break;
-
-			default:
-				stringBuilder.append(' ').append(renderValue(criteria.getValue()));
-		}
-	}
-
-	private static String renderValue(@Nullable Object value) {
-
-		if (value instanceof Number) {
-			return value.toString();
-		}
-
-		if (value instanceof Collection) {
-
-			StringJoiner joiner = new StringJoiner(", ");
-			((Collection<?>) value).forEach(o -> joiner.add(renderValue(o)));
-			return joiner.toString();
-		}
-
-		if (value != null) {
-			return String.format("'%s'", value);
-		}
-
-		return "null";
+		String renderValue = criteria.getComparator().render(Objects.requireNonNull(criteria.getValue()));
+		stringBuilder.append(renderValue);
 	}
 
 	/**
@@ -630,6 +592,8 @@ public interface CriteriaStep {
 		 * @return a new {@link Criteria} object
 		 */
 		Criteria isFalse();
+
+		Criteria custom(String comparator, Function<Object, String> renderFunc, Object value);
 	}
 
 	/**
@@ -789,6 +753,11 @@ public Criteria isFalse() {
 			return createCriteria(Comparator.IS_FALSE, false);
 		}
 
+		@Override
+		public Criteria custom(String comparator, Function<Object, String> renderFunc, Object value) {
+			return createCriteria(Comparator.CUSTOM.setCustomComparator(comparator, renderFunc), value);
+		}
+
 		protected Criteria createCriteria(Comparator comparator, @Nullable Object value) {
 			return new Criteria(this.property, comparator, value);
 		}

spring-data-relational/src/main/java/org/springframework/data/relational/core/query/CriteriaDefinition.java

@@ -16,9 +16,13 @@
 package org.springframework.data.relational.core.query;
 
 import java.util.Arrays;
+import java.util.Collection;
 import java.util.List;
+import java.util.StringJoiner;
+import java.util.function.Function;
 
 import org.springframework.data.relational.core.sql.SqlIdentifier;
+import org.springframework.data.util.Pair;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 
@@ -139,17 +143,89 @@ enum Combinator {
 
 	enum Comparator {
 		INITIAL(""), EQ("="), NEQ("!="), BETWEEN("BETWEEN"), NOT_BETWEEN("NOT BETWEEN"), LT("<"), LTE("<="), GT(">"), GTE(
-				">="), IS_NULL("IS NULL"), IS_NOT_NULL("IS NOT NULL"), LIKE(
-						"LIKE"), NOT_LIKE("NOT LIKE"), NOT_IN("NOT IN"), IN("IN"), IS_TRUE("IS TRUE"), IS_FALSE("IS FALSE");
+				">="), IS_NULL("IS NULL"), IS_NOT_NULL("IS NOT NULL"), LIKE("LIKE"), NOT_LIKE(
+						"NOT LIKE"), NOT_IN("NOT IN"), IN("IN"), IS_TRUE("IS TRUE"), IS_FALSE("IS FALSE"), CUSTOM("CUSTOM");
 
 		private final String comparator;
+		private Function<Object, String> customRenderValueFunc = Object::toString;
+		private String customComparator = "";
 
 		Comparator(String comparator) {
 			this.comparator = comparator;
 		}
 
+		Comparator setCustomComparator(String customComparator, Function<Object, String> customRenderValueFunc) {
+			if (this == CUSTOM) {
+				this.customComparator = customComparator;
+				this.customRenderValueFunc = customRenderValueFunc;
+			} else {
+				throw new UnsupportedOperationException("Only CUSTOM comparator can be customized.");
+			}
+			return this;
+		}
+
 		public String getComparator() {
+			if (this == CUSTOM) {
+				if (customComparator.isEmpty()) {
+					throw new UnsupportedOperationException("CUSTOM comparator must be customized.");
+				}
+				return customComparator;
+			}
 			return comparator;
 		}
+
+		private static String renderValue(@Nullable Object value) {
+
+			if (value instanceof Number) {
+				return value.toString();
+			}
+
+			if (value instanceof Collection) {
+
+				StringJoiner joiner = new StringJoiner(", ");
+				((Collection<?>) value).forEach(o -> joiner.add(renderValue(o)));
+				return joiner.toString();
+			}
+
+			if (value != null) {
+				return String.format("'%s'", value);
+			}
+
+			return "null";
+		}
+
+		public String render(Object value) {
+			StringBuilder stringBuilder = new StringBuilder();
+			switch (this) {
+				case BETWEEN:
+				case NOT_BETWEEN:
+					if (value instanceof Pair<?, ?> pair) {
+						stringBuilder.append(pair.getFirst()).append(" AND ").append(pair.getSecond());
+					} else {
+						throw new IllegalArgumentException("Value must be a Pair");
+					}
+					break;
+
+				case IS_NULL:
+				case IS_NOT_NULL:
+				case IS_TRUE:
+				case IS_FALSE:
+					break;
+
+				case IN:
+				case NOT_IN:
+					stringBuilder.append(" (").append(renderValue(value)).append(')');
+					break;
+				case CUSTOM:
+					stringBuilder.append(' ').append(customRenderValueFunc.apply(value));
+					break;
+
+				default:
+					stringBuilder.append(' ').append(renderValue(value));
+			}
+			return stringBuilder.toString();
+		}
+
 	}
+
 }

spring-data-relational/src/test/java/org/springframework/data/relational/core/query/CriteriaUnitTests.java

@@ -20,6 +20,8 @@
 import static org.springframework.data.relational.core.query.Criteria.*;
 
 import java.util.Arrays;
+import java.util.List;
+import java.util.stream.Collectors;
 
 import org.junit.jupiter.api.Test;
 
@@ -297,4 +299,17 @@ void shouldBuildIsFalseCriteria() {
 		assertThat(criteria.getComparator()).isEqualTo(CriteriaDefinition.Comparator.IS_FALSE);
 		assertThat(criteria.getValue()).isEqualTo(false);
 	}
+
+	@Test
+	void shouldBuildCustomCriteria() {
+		List<String> values = List.of("bar", "baz", "qux");
+		Criteria criteria = where("foo").custom("CUSTOM",
+				value -> "ARRAY[" + values.stream().map(s -> "'" + s + "'").collect(Collectors.joining(",")) + "]",
+				List.of("bar", "baz", "qux"));
+
+		assertThat(criteria.getColumn()).isEqualTo(SqlIdentifier.unquoted("foo"));
+		assertThat(criteria.getComparator()).isEqualTo(Comparator.CUSTOM);
+		assertThat(criteria.toString()).isEqualTo("foo CUSTOM ARRAY['bar','baz','qux']");
+	}
+
 }