Remove Spring Core dependency from PDP engine

pdp-engine-oss-functional-benchmark/src/test/java/org/ow2/authzforce/core/pdp/benchmark/test/ComparativePdpTest.java

@@ -49,7 +49,7 @@
 import org.ow2.authzforce.xacml.Xacml3JaxbHelper;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
-import org.springframework.util.ResourceUtils;
+import org.ow2.authzforce.core.pdp.impl.ResourceLocationResolver;
 import org.wso2.balana.ConfigurationStore;
 import org.wso2.balana.PDP;
 import org.wso2.balana.PDPConfig;
@@ -358,7 +358,7 @@ public static Collection<Object[]> params() throws URISyntaxException, IOExcepti
 		/*
 		 * Each sub-directory of the root directory is data for a specific test. So we configure a test for each directory
 		 */
-		final URL testRootDir = ResourceUtils.getURL(TEST_RESOURCES_ROOT_DIRECTORY_LOCATION);
+		final URL testRootDir = ResourceLocationResolver.getUrl(TEST_RESOURCES_ROOT_DIRECTORY_LOCATION);
 		final Path testRootPath = Paths.get(testRootDir.toURI());
 
 		final PdpEngineInvoker authzforcePdpEngineInvoker = new AuthzForcePdpEngineInvoker(testRootPath.resolve(AUTHZFORCE_CE_PDP_CONF_DIRNAME));

pdp-engine/pom.xml

@@ -21,20 +21,10 @@
     <!-- distributionManagement defined in parent POM already -->
     <dependencies>
         <!-- Third-party dependencies -->
-        <dependency>
-            <!-- For redirecting Spring logs to slf4j -->
-            <groupId>org.slf4j</groupId>
-            <artifactId>jcl-over-slf4j</artifactId>
-        </dependency>
         <dependency>
             <groupId>org.eclipse.angus</groupId>
             <artifactId>jakarta.mail</artifactId>
         </dependency>
-        <dependency>
-            <!-- Needed for org.springframework.util.ResourceUtils,SystemPropertyUtils,FileCopyUtils, etc. -->
-            <groupId>org.springframework</groupId>
-            <artifactId>spring-core</artifactId>
-        </dependency>
         <dependency>
             <!-- For loading XML schemas with OASIS catalog (CatalogManager) -->
             <groupId>xml-resolver</groupId>

pdp-engine/src/main/java/org/ow2/authzforce/core/pdp/impl/DefaultEnvironmentProperties.java

@@ -19,7 +19,6 @@
 
 import org.ow2.authzforce.core.pdp.api.EnvironmentProperties;
 import org.ow2.authzforce.core.pdp.api.EnvironmentPropertyName;
-import org.springframework.util.PropertyPlaceholderHelper;
 
 import java.util.Map;
 import java.util.Map.Entry;
@@ -33,16 +32,11 @@
 public final class DefaultEnvironmentProperties implements EnvironmentProperties
 {
 
-	private static final String PROPERTY_PLACEHOLDER_PREFIX = "${";
-	private static final String PROPERTY_PLACEHOLDER_SUFFIX = "}";
 	/*
 	 * We cannot use ':' as default value separator because not valid in XML anyURI
 	 */
 	private static final String PROPERTY_PLACEHOLDER_DEFAULT_VALUE_SEPARATOR = "!";
 
-	private static final PropertyPlaceholderHelper PROPERTY_PLACEHOLDER_HELPER = new PropertyPlaceholderHelper(PROPERTY_PLACEHOLDER_PREFIX, PROPERTY_PLACEHOLDER_SUFFIX,
-	        PROPERTY_PLACEHOLDER_DEFAULT_VALUE_SEPARATOR, null, false);
-
 	private final Properties props = new Properties();
 
 	/**
@@ -85,7 +79,7 @@ public String replacePlaceholders(final String input)
 			return null;
 		}
 
-		return PROPERTY_PLACEHOLDER_HELPER.replacePlaceholders(input, placeholderName -> {
+		return PlaceholderResolver.replace(input, PROPERTY_PLACEHOLDER_DEFAULT_VALUE_SEPARATOR, placeholderName -> {
 
 			final String userDefinedPropVal = props.getProperty(placeholderName);
 			if (userDefinedPropVal != null)

pdp-engine/src/main/java/org/ow2/authzforce/core/pdp/impl/PdpBean.java

@@ -21,7 +21,6 @@
 import org.ow2.authzforce.core.pdp.api.policy.PrimaryPolicyMetadata;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
-import org.springframework.util.SystemPropertyUtils;
 
 import java.io.IOException;
 import java.util.Collection;
@@ -56,44 +55,44 @@ public final class PdpBean implements PdpEngine
 	 * Configuration file. Only the 'defaultPDP' configuration will be loaded, i.e. 'pdp' element with 'name' matching the 'defaultPDP' attribute of the root 'config' element
 	 *
 	 * @param filePath
-	 *            configuration file path used as argument to {@link org.springframework.core.io.DefaultResourceLoader#getResource(String)} to resolve the resource; any placeholder ${...} in the path
+	 *            configuration file path (classpath resource, URL or file-system path); any placeholder ${...} in the path
 	 *            will be replaced with the corresponding system property value
 	 * @throws java.lang.IllegalArgumentException
 	 *             if there is an unresolvable placeholder in {@code filePath}
 	 */
 	public void setConfigFile(final String filePath) throws IllegalArgumentException
 	{
-		confLocation = SystemPropertyUtils.resolvePlaceholders(filePath);
+		confLocation = resolveSystemPropertyPlaceholders(filePath);
 		init();
 	}
 
 	/**
 	 * Configuration schema file. Used only for validating XML configurations (enclosed with 'xml' tag) of PDP extension modules in PDP configuration file set with {@link #setConfigFile(String)}
 	 *
 	 * @param filePath
-	 *            configuration file path used as argument to {@link org.springframework.core.io.DefaultResourceLoader#getResource(String)} to resolve the resource; any placeholder ${...} in the path
+	 *            configuration schema path (classpath resource, URL or file-system path); any placeholder ${...} in the path
 	 *            will be replaced with the corresponding system property value
 	 * @throws java.lang.IllegalArgumentException
 	 *             if there is an unresolvable placeholder in {@code filePath}
 	 */
 	public void setSchemaFile(final String filePath) throws IllegalArgumentException
 	{
-		extSchemaLocation = SystemPropertyUtils.resolvePlaceholders(filePath);
+		extSchemaLocation = resolveSystemPropertyPlaceholders(filePath);
 		init();
 	}
 
 	/**
 	 * Set XML catalog for resolving XML entities used in XML schema
 	 *
 	 * @param filePath
-	 *            configuration file path used as argument to {@link org.springframework.core.io.DefaultResourceLoader#getResource(String)} to resolve the resource; any placeholder ${...} in the path
+	 *            XML catalog path (classpath resource, URL or file-system path); any placeholder ${...} in the path
 	 *            will be replaced with the corresponding system property value
 	 * @throws java.lang.IllegalArgumentException
 	 *             if there is an unresolvable placeholder in {@code filePath}
 	 */
 	public void setCatalogFile(final String filePath) throws IllegalArgumentException
 	{
-		catalogLocation = SystemPropertyUtils.resolvePlaceholders(filePath);
+		catalogLocation = resolveSystemPropertyPlaceholders(filePath);
 		init();
 	}
 
@@ -117,6 +116,14 @@ private void init()
 
 	}
 
+	private static String resolveSystemPropertyPlaceholders(final String value)
+	{
+		return PlaceholderResolver.replace(value, ":", placeholderName -> {
+			final String systemProperty = System.getProperty(placeholderName);
+			return systemProperty == null ? System.getenv(placeholderName) : systemProperty;
+		});
+	}
+
 	@Override
 	public DecisionRequestBuilder<?> newRequestBuilder(final int expectedNumOfAttributeCategories, final int expectedTotalNumOfAttributes)
 	{

pdp-engine/src/main/java/org/ow2/authzforce/core/pdp/impl/PdpEngineConfiguration.java

@@ -48,7 +48,6 @@
 import org.ow2.authzforce.xmlns.pdp.ext.AbstractPolicyProvider;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
-import org.springframework.util.ResourceUtils;
 
 import javax.xml.transform.Source;
 import javax.xml.transform.stream.StreamSource;
@@ -274,7 +273,7 @@
 	private static <JAXB_CONF extends AbstractAttributeProvider> CloseableNamedAttributeProvider.DependencyAwareFactory newAttributeProviderProviderFactory(final JAXB_CONF jaxbConf,
 	        final EnvironmentProperties envProps)
 	{
 		final CloseableNamedAttributeProvider.FactoryBuilder<JAXB_CONF> attrProviderModBuilder = PdpExtensions.getAttributeProviderFactoryBuilder((Class<JAXB_CONF>) jaxbConf.getClass());
 		return attrProviderModBuilder.getInstance(jaxbConf, envProps);
 	}
 
@@ -282,14 +281,14 @@
 	        final int maxPolicySetRefDepth, final ExpressionFactory xacmlExprFactory, final CombiningAlgRegistry combiningAlgRegistry, final EnvironmentProperties envProps,
 	        final Optional<PolicyProvider<?>> otherHelpingPolicyProvider)
 	{
 		final CloseablePolicyProvider.Factory<JAXB_CONF> refPolicyProviderModFactory = PdpExtensions.getPolicyProviderFactory((Class<JAXB_CONF>) jaxbConf.getClass());
 		return refPolicyProviderModFactory.getInstance(jaxbConf, xacmlParserFactory, maxPolicySetRefDepth, xacmlExprFactory, combiningAlgRegistry, envProps, otherHelpingPolicyProvider);
 	}
 
 	private static <JAXB_CONF extends AbstractDecisionCache> DecisionCache newDecisionCache(final JAXB_CONF jaxbConf, final AttributeValueFactoryRegistry attValFactories,
 	        final EnvironmentProperties envProps)
 	{
 		final DecisionCache.Factory<JAXB_CONF> decisionCacheFactory = PdpExtensions.getDecisionCacheFactory((Class<JAXB_CONF>) jaxbConf.getClass());
 		return decisionCacheFactory.getInstance(jaxbConf, attValFactories, envProps);
 	}
 
@@ -434,7 +433,7 @@
 			final AttributeValueFactory<?> intValFactory = attValFactoryRegistry.getExtension(StandardDatatypes.INTEGER.getId());
 			assert intValFactory != null && intValFactory.getDatatype() == StandardDatatypes.INTEGER && intValFactory instanceof StringParseableValue.Factory;
 
 			final FunctionRegistry stdRegistry = StandardFunction.getRegistry(enableXPath, (StringParseableValue.Factory<IntegerValue>) intValFactory);
 			if (nonGenericFunctionExtensionIdentifiers.isEmpty())
 			{
 				functionRegistry = stdRegistry;
@@ -748,8 +747,7 @@
 	}
 
 	/**
-	 * Create PDP instance. Locations here can be any resource string supported by Spring ResourceLoader. More info: <a href="http://docs.spring.io/spring/docs/current/spring-framework-reference/html">Spring documentation</a>
-	 * /resources.html.
+	 * Create PDP instance. Locations may be classpath resources, URLs or file-system paths.
 	 * <p>
 	 * To allow using file paths relative to the parent folder of the configuration file (located at confLocation) anywhere in this configuration file (including in PDP extensions'), we define a
 	 * property 'PARENT_DIR', so that the placeholder ${PARENT_DIR} can be used as prefix for file paths in the configuration file. E.g. if confLocation = 'file:///path/to/configurationfile', then
@@ -775,7 +773,7 @@
 
 		try
 		{
-			final File confFile = ResourceUtils.getFile(confLocation);
+			final File confFile = ResourceLocationResolver.getFile(confLocation);
 			return getInstance(confFile, modelHandler);
 		}
 		catch (final FileNotFoundException e)
@@ -794,7 +792,7 @@
 		final URL confUrl;
 		try
 		{
-			confUrl = ResourceUtils.getURL(confLocation);
+			confUrl = ResourceLocationResolver.getUrl(confLocation);
 		}
 		catch (final FileNotFoundException e)
 		{
@@ -811,8 +809,7 @@
 
 	/**
 	 * <p>
-	 * Create PDP instance. Locations here can be any resource string supported by Spring ResourceLoader. More info: <a href="http://docs.spring.io/spring/docs/current/spring-framework-reference/html">Spring documentation</a>
-	 * /resources.html
+	 * Create PDP instance. Locations may be classpath resources, URLs or file-system paths.
 	 *</p>
 	 * <p>
 	 * For example: <code>classpath:com/myapp/aaa.xsd</code>, <code>file:///data/bbb.xsd</code>, <code>http://myserver/ccc.xsd</code>...
@@ -867,8 +864,7 @@
 
 	/**
 	 * <p>
-	 * Create PDP instance. Locations here may be any resource string supported by Spring ResourceLoader. More info: <a href="http://docs.spring.io/spring/docs/current/spring-framework-reference/html">Spring documentation</a>
-	 * /resources.html
+	 * Create PDP instance. Locations may be classpath resources, URLs or file-system paths.
 	 *</p>
 	 * <p>
 	 * For example: <code>classpath:com/myapp/aaa.xsd</code>, <code>file:///data/bbb.xsd</code>, <code>http://myserver/ccc.xsd</code>...
@@ -923,8 +919,8 @@
 	 * Create PDP instance.
 	 *
 	 * @param confLocation
-	 *            location of PDP configuration XML file, compliant with the PDP XML schema (pdp.xsd). This location may be any resource string supported by Spring ResourceLoader. For example:
-	 *            <code>classpath:com/myapp/aaa.xsd</code>, <code>file:///data/bbb.xsd</code>, <code>http://myserver/ccc.xsd</code>... More info: <a href="http://docs.spring.io/spring/docs/current/spring-framework-reference/html/resources.html">Spring documentation</a>
+	 *            location of PDP configuration XML file, compliant with the PDP XML schema (pdp.xsd). It may be a classpath resource, URL or file-system path. For example:
+	 *            <code>classpath:com/myapp/aaa.xsd</code>, <code>file:///data/bbb.xsd</code>, <code>http://myserver/ccc.xsd</code>.
 	 * @return PDP instance
 	 * @throws IOException
 	 *             I/O error reading from {@code confLocation}

pdp-engine/src/main/java/org/ow2/authzforce/core/pdp/impl/PdpModelHandler.java

@@ -62,8 +62,7 @@ public final class PdpModelHandler
 	private final JAXBContext confJaxbCtx;
 
 	/**
-	 * Load Configuration model handler. Parameters here are locations to XSD files. Locations can be any resource string supported by Spring ResourceLoader.
-	 * <a href="http://docs.spring.io/spring/docs/current/spring-framework-reference/html/resources.html">More info</a>.
+	 * Load Configuration model handler. Parameters here are locations to XSD files. Locations may be classpath resources, URLs or file-system paths.
 	 * <p>
 	 * For example: <code>classpath:com/myapp/aaa.xsd</code>, <code>file:///data/bbb.xsd</code>, <code>http://myserver/ccc.xsd</code>...
 	 *

pdp-engine/src/main/java/org/ow2/authzforce/core/pdp/impl/PlaceholderResolver.java

@@ -0,0 +1,108 @@
+/*
+ * Copyright 2012-2026 THALES.
+ *
+ * This file is part of AuthzForce CE.
+ *
+ * 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
+ *
+ *     http://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.ow2.authzforce.core.pdp.impl;
+
+import java.util.HashSet;
+import java.util.Set;
+import java.util.function.Function;
+
+/** Internal placeholder expansion support. */
+final class PlaceholderResolver
+{
+	private static final String PREFIX = "${";
+	private static final char SUFFIX = '}';
+
+	private PlaceholderResolver()
+	{
+		// Utility class.
+	}
+
+	static String replace(final String input, final String defaultValueSeparator, final Function<String, String> valueResolver)
+	{
+		return replace(input, defaultValueSeparator, valueResolver, new HashSet<>());
+	}
+
+	private static String replace(final String input, final String defaultValueSeparator, final Function<String, String> valueResolver, final Set<String> activePlaceholders)
+	{
+		final StringBuilder output = new StringBuilder(input);
+		int startIndex = output.indexOf(PREFIX);
+		while (startIndex >= 0)
+		{
+			final int endIndex = findEndIndex(output, startIndex + PREFIX.length());
+			if (endIndex < 0)
+			{
+				break;
+			}
+
+			final String originalPlaceholder = output.substring(startIndex + PREFIX.length(), endIndex);
+			if (!activePlaceholders.add(originalPlaceholder))
+			{
+				throw new IllegalArgumentException("Circular placeholder reference '" + originalPlaceholder + "'");
+			}
+
+			final String placeholder = replace(originalPlaceholder, defaultValueSeparator, valueResolver, activePlaceholders);
+			String value = valueResolver.apply(placeholder);
+			if (value == null && defaultValueSeparator != null)
+			{
+				final int separatorIndex = placeholder.indexOf(defaultValueSeparator);
+				if (separatorIndex >= 0)
+				{
+					value = valueResolver.apply(placeholder.substring(0, separatorIndex));
+					if (value == null)
+					{
+						value = placeholder.substring(separatorIndex + defaultValueSeparator.length());
+					}
+				}
+			}
+
+			if (value == null)
+			{
+				throw new IllegalArgumentException("Could not resolve placeholder '" + placeholder + "'");
+			}
+
+			value = replace(value, defaultValueSeparator, valueResolver, activePlaceholders);
+			output.replace(startIndex, endIndex + 1, value);
+			activePlaceholders.remove(originalPlaceholder);
+			startIndex = output.indexOf(PREFIX, startIndex + value.length());
+		}
+
+		return output.toString();
+	}
+
+	private static int findEndIndex(final CharSequence input, final int contentStartIndex)
+	{
+		int nested = 0;
+		for (int index = contentStartIndex; index < input.length(); index++)
+		{
+			if (index + 1 < input.length() && input.charAt(index) == '$' && input.charAt(index + 1) == '{')
+			{
+				nested++;
+				index++;
+			}
+			else if (input.charAt(index) == SUFFIX)
+			{
+				if (nested == 0)
+				{
+					return index;
+				}
+				nested--;
+			}
+		}
+		return -1;
+	}
+}