Polishing.

Refine Javadoc. Move LdapEncoder lookup into LdapParameters. Eagerly instantiate LdapEncoder. Refine method naming.

Add NameEncoder and LikeEncoder for simplified usage.

See #509
Original pull request: #518

Author: mp911de

src/main/java/org/springframework/data/ldap/repository/LdapEncode.java

@@ -24,26 +24,42 @@
 import org.springframework.core.annotation.AliasFor;
 
 /**
- * Allows passing of custom {@link LdapEncoder}.
+ * Annotation which indicates that a method parameter should be encoded using a specific {@link LdapEncoder} for a
+ * repository query method invocation.
+ * <p>
+ * If no {@link LdapEncoder} is configured, bound method parameters are encoded using
+ * {@link org.springframework.ldap.support.LdapEncoder#filterEncode(String)}. The default encoder considers chars such
+ * as {@code *} (asterisk) to be encoded which might interfere with the intent of running a Like query. Since Spring
+ * Data LDAP doesn't parse queries it is up to you to decide which encoder to use.
+ * <p>
+ * {@link LdapEncoder} implementations must declare a no-args constructor so they can be instantiated during repository
+ * initialization.
+ * <p>
+ * Note that parameter encoding applies only to parameters that are directly bound to a query. Parameters used in Value
+ * Expressions (SpEL, Configuration Properties) are not considered for encoding and must be encoded properly by using
+ * SpEL Method invocations or a SpEL Extension.
  *
  * @author Marcin Grzejszczak
- * @since 3.5.0
+ * @author Mark Paluch
+ * @since 3.5
+ * @see LdapEncoder.LikeEncoder
+ * @see LdapEncoder.NameEncoder
  */
-@Target(ElementType.PARAMETER)
+@Target({ ElementType.PARAMETER, ElementType.ANNOTATION_TYPE })
 @Retention(RetentionPolicy.RUNTIME)
 @Documented
 public @interface LdapEncode {
 
 	/**
-	 * {@link LdapEncoder} to instantiate to encode query parameters.
+	 * {@link LdapEncoder} to encode query parameters.
 	 *
 	 * @return {@link LdapEncoder} class
 	 */
 	@AliasFor("encoder")
 	Class<? extends LdapEncoder> value();
 
 	/**
-	 * {@link LdapEncoder} to instantiate to encode query parameters.
+	 * {@link LdapEncoder} to encode query parameters.
 	 *
 	 * @return {@link LdapEncoder} class
 	 */

src/main/java/org/springframework/data/ldap/repository/LdapEncoder.java

@@ -15,18 +15,70 @@
  */
 package org.springframework.data.ldap.repository;
 
+import org.springframework.util.ObjectUtils;
+
 /**
- * Allows plugging in custom encoding for {@link LdapEncode}.
+ * Strategy interface to escape values for use in LDAP filters.
+ * <p>
+ * Accepts an LDAP filter value to be encoded (escaped) for String-based LDAP query usage as LDAP queries do not feature
+ * an out-of-band parameter binding mechanism.
+ * <p>
+ * Make sure that your implementation escapes special characters in the value adequately to prevent injection attacks.
  *
  * @author Marcin Grzejszczak
- * @since 3.5.0
+ * @author Mark Paluch
+ * @since 3.5
  */
 public interface LdapEncoder {
 
 	/**
-	 * Escape a value for use in a filter.
-	 * @param value the value to escape.
-	 * @return a properly escaped representation of the supplied value.
+	 * Encode a value for use in a filter.
+	 *
+	 * @param value the value to encode.
+	 * @return a properly encoded representation of the supplied value.
+	 */
+	String encode(String value);
+
+	/**
+	 * {@link LdapEncoder} using {@link org.springframework.ldap.support.LdapEncoder#nameEncode(String)}. Encodes a value
+	 * for use with a DN. Escapes for LDAP, not JNDI!
+	 */
+	class NameEncoder implements LdapEncoder {
+
+		@Override
+		public String encode(String value) {
+			return org.springframework.ldap.support.LdapEncoder.nameEncode(value);
+		}
+	}
+
+	/**
+	 * Escape a value for use in a filter retaining asterisks ({@code *}) for like/contains searches.
 	 */
-	String filterEncode(String value);
+	class LikeEncoder implements LdapEncoder {
+
+		@Override
+		public String encode(String value) {
+
+			if (ObjectUtils.isEmpty(value)) {
+				return value;
+			}
+
+			String[] substrings = value.split("\\*", -2);
+
+			if (substrings.length == 1) {
+				return org.springframework.ldap.support.LdapEncoder.filterEncode(substrings[0]);
+			}
+
+			StringBuilder buff = new StringBuilder();
+			for (int i = 0; i < substrings.length; i++) {
+				buff.append(org.springframework.ldap.support.LdapEncoder.filterEncode(substrings[i]));
+				if (i < substrings.length - 1) {
+					buff.append("*");
+				}
+			}
+
+			return buff.toString();
+		}
+	}
+
 }

src/main/java/org/springframework/data/ldap/repository/query/LdapParameters.java

@@ -18,18 +18,22 @@
 import java.lang.reflect.Method;
 import java.util.List;
 
+import org.springframework.beans.BeanUtils;
 import org.springframework.core.MethodParameter;
 import org.springframework.data.geo.Distance;
+import org.springframework.data.ldap.repository.LdapEncode;
+import org.springframework.data.ldap.repository.LdapEncoder;
 import org.springframework.data.repository.query.Parameter;
 import org.springframework.data.repository.query.Parameters;
 import org.springframework.data.repository.query.ParametersSource;
 import org.springframework.data.util.TypeInformation;
+import org.springframework.lang.Nullable;
 
 /**
  * Custom extension of {@link Parameters} discovering additional
  *
  * @author Marcin Grzejszczak
- * @since 3.5.0
+ * @since 3.5
  */
 public class LdapParameters extends Parameters<LdapParameters, LdapParameters.LdapParameter> {
 
@@ -65,9 +69,10 @@ protected LdapParameters createFrom(List<LdapParameter> parameters) {
 	 *
 	 * @author Marcin Grzejszczak
 	 */
-	static class LdapParameter extends Parameter {
+	protected static class LdapParameter extends Parameter {
 
-		final MethodParameter parameter;
+		private final @Nullable LdapEncoder ldapEncoder;
+		private final MethodParameter parameter;
 
 		/**
 		 * Creates a new {@link LdapParameter}.
@@ -76,8 +81,29 @@ static class LdapParameter extends Parameter {
 		 * @param domainType must not be {@literal null}.
 		 */
 		LdapParameter(MethodParameter parameter, TypeInformation<?> domainType) {
+
 			super(parameter, domainType);
 			this.parameter = parameter;
+
+			LdapEncode encode = parameter.getParameterAnnotation(LdapEncode.class);
+
+			if (encode != null) {
+				this.ldapEncoder = BeanUtils.instantiateClass(encode.value());
+			} else {
+				this.ldapEncoder = null;
+			}
+		}
+
+		public boolean hasLdapEncoder() {
+			return ldapEncoder != null;
+		}
+
+		public LdapEncoder getLdapEncoder() {
+
+			if (ldapEncoder == null) {
+				throw new IllegalStateException("No LdapEncoder found for parameter " + parameter);
+			}
+			return ldapEncoder;
 		}
 	}
 

src/main/java/org/springframework/data/ldap/repository/query/StringBasedQuery.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2016-2024 the original author or authors.
+ * Copyright 2024 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,6 +15,8 @@
  */
 package org.springframework.data.ldap.repository.query;
 
+import static org.springframework.data.ldap.repository.query.StringBasedQuery.BindingContext.*;
+
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
@@ -25,10 +27,8 @@
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
-import org.springframework.beans.BeanUtils;
 import org.springframework.data.expression.ValueExpression;
 import org.springframework.data.expression.ValueExpressionParser;
-import org.springframework.data.ldap.repository.LdapEncode;
 import org.springframework.data.repository.query.Parameter;
 import org.springframework.data.repository.query.ParameterAccessor;
 import org.springframework.data.repository.query.Parameters;
@@ -39,12 +39,11 @@
 import org.springframework.util.Assert;
 import org.springframework.util.StringUtils;
 
-import static org.springframework.data.ldap.repository.query.StringBasedQuery.BindingContext.ParameterBinding;
-
 /**
  * String-based Query abstracting a query with parameter bindings.
  *
  * @author Marcin Grzejszczak
+ * @author Mark Paluch
  * @since 3.5
  */
 class StringBasedQuery {
@@ -79,8 +78,7 @@ private ExpressionDependencies createExpressionDependencies() {
 
 		for (ParameterBinding binding : queryParameterBindings) {
 			if (binding.isExpression()) {
-				dependencies
-						.add(binding.getRequiredExpression().getExpressionDependencies());
+				dependencies.add(binding.getRequiredExpression().getExpressionDependencies());
 			}
 		}
 
@@ -256,7 +254,6 @@ private static Matcher findNextBindingOrExpression(String input, int startPositi
 	 */
 	static class ParameterBinder {
 
-
 		private static final String ARGUMENT_PLACEHOLDER = "?_param_?";
 		private static final Pattern ARGUMENT_PLACEHOLDER_PATTERN = Pattern.compile(Pattern.quote(ARGUMENT_PLACEHOLDER));
 
@@ -358,15 +355,20 @@ private Object getParameterValueForBinding(ParameterBinding binding) {
 			if (binding.isExpression()) {
 				return evaluator.apply(binding.getRequiredExpression());
 			}
-			Object value = binding.isNamed()
-					? parameterAccessor.getBindableValue(getParameterIndex(parameters, binding.getRequiredParameterName()))
-					: parameterAccessor.getBindableValue(binding.getParameterIndex());
+
+			int index = binding.isNamed() ? getParameterIndex(parameters, binding.getRequiredParameterName())
+					: binding.getParameterIndex();
+			Object value = parameterAccessor.getBindableValue(index);
 
 			if (value == null) {
 				return null;
 			}
 
-			return binding.getEncodedValue(parameters, value);
+			String toString = value.toString();
+			LdapParameters.LdapParameter parameter = parameters.getBindableParameter(index);
+
+			return parameter.hasLdapEncoder() ? parameter.getLdapEncoder().encode(toString)
+					: LdapEncoder.filterEncode(toString);
 		}
 
 		private int getParameterIndex(Parameters<?, ?> parameters, String parameterName) {
@@ -413,38 +415,6 @@ static ParameterBinding named(String name) {
 				return new ParameterBinding(-1, null, name);
 			}
 
-			Object getEncodedValue(LdapParameters ldapParameters, Object value) {
-				org.springframework.data.ldap.repository.LdapEncoder encoder = encoderForParameter(ldapParameters);
-				if (encoder == null) {
-					return LdapEncoder.filterEncode(value.toString());
-				}
-				return encoder.filterEncode(value.toString());
-			}
-
-
-			@Nullable
-			org.springframework.data.ldap.repository.LdapEncoder encoderForParameter(LdapParameters ldapParameters) {
-				for (LdapParameters.LdapParameter parameter : ldapParameters) {
-					if (isByName(parameter) || isByIndex(parameter)) {
-						LdapEncode ldapEncode = parameter.parameter.getParameterAnnotation(LdapEncode.class);
-						if (ldapEncode == null) {
-							return null;
-						}
-						Class<? extends org.springframework.data.ldap.repository.LdapEncoder> encoder = ldapEncode.value();
-						return BeanUtils.instantiateClass(encoder);
-					}
-				}
-				return null;
-			}
-
-			private boolean isByIndex(LdapParameters.LdapParameter parameter) {
-				return parameterIndex != -1 && parameter.getIndex() == parameterIndex;
-			}
-
-			private boolean isByName(LdapParameters.LdapParameter parameter) {
-				return parameterName != null && parameterName.equals(parameter.getName().orElse(null));
-			}
-
 			boolean isNamed() {
 				return (parameterName != null);
 			}

src/test/java/org/springframework/data/ldap/repository/LdapEncoderUnitTests.java

@@ -0,0 +1,44 @@
+/*
+ * Copyright 2024 the original author or 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 org.springframework.data.ldap.repository;
+
+import static org.assertj.core.api.Assertions.*;
+
+import org.junit.jupiter.api.Test;
+
+/**
+ * Unit tests for {@link LdapEncoder}.
+ *
+ * @author Mark Paluch
+ */
+class LdapEncoderUnitTests {
+
+	@Test // GH-509
+	void shouldEncodeName() {
+
+		String result = new LdapEncoder.NameEncoder().encode("# foo ,+\"\\<>; ");
+
+		assertThat(result).isEqualTo("\\# foo \\,\\+\\\"\\\\\\<\\>\\;\\ ");
+	}
+
+	@Test // GH-509
+	void shouldEncodeLikeFilter() {
+
+		String result = new LdapEncoder.LikeEncoder().encode("*hugo*ern(o)*");
+
+		assertThat(result).isEqualTo("*hugo*ern\\28o\\29*");
+	}
+}

src/test/java/org/springframework/data/ldap/repository/query/AnnotatedLdapRepositoryQueryUnitTests.java

@@ -15,14 +15,16 @@
  */
 package org.springframework.data.ldap.repository.query;
 
+import static org.assertj.core.api.Assertions.*;
+
 import java.util.List;
 
 import org.junit.jupiter.api.Test;
 import org.mockito.Mockito;
 
 import org.springframework.data.ldap.core.mapping.LdapMappingContext;
-import org.springframework.data.ldap.repository.LdapEncoder;
 import org.springframework.data.ldap.repository.LdapEncode;
+import org.springframework.data.ldap.repository.LdapEncoder;
 import org.springframework.data.ldap.repository.LdapRepository;
 import org.springframework.data.ldap.repository.Query;
 import org.springframework.data.mapping.model.EntityInstantiators;
@@ -32,8 +34,6 @@
 import org.springframework.ldap.core.LdapOperations;
 import org.springframework.ldap.query.LdapQuery;
 
-import static org.assertj.core.api.Assertions.assertThat;
-
 /**
  * Unit tests for {@link AnnotatedLdapRepositoryQuery}
  *
@@ -122,7 +122,7 @@ interface QueryRepository extends LdapRepository<SchemaEntry> {
 	static class MyEncoder implements LdapEncoder {
 
 		@Override
-		public String filterEncode(String value) {
+		public String encode(String value) {
 			return value + "bar";
 		}
 	}