Introduce ResourcePropertySource

Allows convenient creation of a Properties-based PropertySource from a
Spring Resource object or resource location string such as
"classpath:com/myco/app.properties" or "file:/path/to/file.properties"

Issue: SPR-8328

git-svn-id: https://src.springframework.org/svn/spring-framework/trunk@4288 50f2f4bb-b051-0410-bef5-90022cba6387

org.springframework.core/src/main/java/org/springframework/core/io/ResourcePropertySource.java

@@ -0,0 +1,123 @@
+/*
+ * Copyright 2002-2011 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
+ *
+ *      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.springframework.core.io;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.Properties;
+
+import org.springframework.core.env.PropertiesPropertySource;
+import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
+import org.springframework.util.ClassUtils;
+import org.springframework.util.StringUtils;
+
+/**
+ * Subclass of {@link PropertiesPropertySource} that loads a {@link Properties}
+ * object from a given {@link Resource} or resource location such as
+ * {@code "classpath:/com/myco/foo.properties"} or {@code "file:/path/to/file.properties"}.
+ *
+ * @author Chris Beams
+ * @since 3.1
+ */
+public class ResourcePropertySource extends PropertiesPropertySource {
+
+	/**
+	 * Create a PropertySource having the given name based on Properties
+	 * loaded from the given resource.
+	 */
+	public ResourcePropertySource(String name, Resource resource) throws IOException {
+		super(name, loadPropertiesForResource(resource));
+	}
+
+	/**
+	 * Create a PropertySource based on Properties loaded from the given resource.
+	 * The name of the PropertySource will be generated based on the
+	 * {@link Resource#getDescription() description} of the given resource.
+	 */
+	public ResourcePropertySource(Resource resource) throws IOException {
+		this(getNameForResource(resource), resource);
+	}
+
+	/**
+	 * Create a PropertySource having the given name based on Properties loaded from
+	 * the given resource location and using the given class loader to load the
+	 * resource (assuming it is prefixed with {@code classpath:}).
+	 */
+	public ResourcePropertySource(String name, String location, ClassLoader classLoader) throws IOException {
+		this(name, getResourceForLocation(location, classLoader));
+	}
+
+	/**
+	 * Create a PropertySource having the given name based on Properties loaded from
+	 * the given resource location. The default thread context class loader will be
+	 * used to load the resource (assuming the location string is prefixed with
+	 * {@code classpath:}.
+	 */
+	public ResourcePropertySource(String name, String location) throws IOException {
+		this(name, location, ClassUtils.getDefaultClassLoader());
+	}
+
+	/**
+	 * Create a PropertySource based on Properties loaded from the given resource
+	 * location and use the given class loader to load the resource, assuming it is
+	 * prefixed with {@code classpath:}. The name of the PropertySource will be
+	 * generated based on the {@link Resource#getDescription() description} of the
+	 * resource.
+	 */
+	public ResourcePropertySource(String location, ClassLoader classLoader) throws IOException {
+		this(getResourceForLocation(location, classLoader));
+	}
+
+	/**
+	 * Create a PropertySource based on Properties loaded from the given resource
+	 * location. The name of the PropertySource will be generated based on the
+	 * {@link Resource#getDescription() description} of the resource.
+	 */
+	public ResourcePropertySource(String location) throws IOException {
+		this(getResourceForLocation(location, ClassUtils.getDefaultClassLoader()));
+	}
+
+
+	private static Resource getResourceForLocation(String location, ClassLoader classLoader) {
+		return new PathMatchingResourcePatternResolver(classLoader).getResource(location);
+	}
+
+	private static Properties loadPropertiesForResource(Resource resource) throws IOException {
+		Properties props = new Properties();
+		InputStream is = resource.getInputStream();
+		props.load(is);
+		try {
+			is.close();
+		} catch (IOException ex) {
+			// ignore
+		}
+		return props;
+	}
+
+	/**
+	 * Returns the description string for the resource, and if empty returns
+	 * the class name of the resource plus its identity hash code.
+	 */
+	private static String getNameForResource(Resource resource) {
+		String name = resource.getDescription();
+		if (!StringUtils.hasText(name)) {
+			name = resource.getClass().getSimpleName() + "@" + System.identityHashCode(resource);
+		}
+		return name;
+	}
+
+}

org.springframework.core/src/test/java/org/springframework/core/io/ResourcePropertySourceTests.java

@@ -0,0 +1,91 @@
+/*
+ * Copyright 2002-2011 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
+ *
+ *      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.springframework.core.io;
+
+import static org.hamcrest.CoreMatchers.is;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertThat;
+import static org.junit.Assert.assertTrue;
+
+import java.io.IOException;
+
+import org.easymock.internal.matchers.StartsWith;
+import org.junit.Test;
+import org.springframework.core.env.PropertySource;
+
+/**
+ * Unit tests for {@link ResourcePropertySource}.
+ *
+ * @author Chris Beams
+ * @since 3.1
+ */
+public class ResourcePropertySourceTests {
+
+	private static final String PROPERTIES_PATH = "org/springframework/core/io/example.properties";
+	private static final String PROPERTIES_LOCATION = "classpath:" + PROPERTIES_PATH;
+	private static final String PROPERTIES_RESOURCE_DESCRIPTION = "class path resource [" + PROPERTIES_PATH + "]";
+
+	@Test
+	public void withLocationAndGeneratedName() throws IOException {
+		PropertySource<?> ps = new ResourcePropertySource(PROPERTIES_LOCATION);
+		assertEquals(ps.getProperty("foo"), "bar");
+		assertThat(ps.getName(), is(PROPERTIES_RESOURCE_DESCRIPTION));
+	}
+
+	@Test
+	public void withLocationAndExplicitName() throws IOException {
+		PropertySource<?> ps = new ResourcePropertySource("ps1", PROPERTIES_LOCATION);
+		assertEquals(ps.getProperty("foo"), "bar");
+		assertThat(ps.getName(), is("ps1"));
+	}
+
+	@Test
+	public void withLocationAndExplicitNameAndExplicitClassLoader() throws IOException {
+		PropertySource<?> ps = new ResourcePropertySource("ps1", PROPERTIES_LOCATION, getClass().getClassLoader());
+		assertEquals(ps.getProperty("foo"), "bar");
+		assertThat(ps.getName(), is("ps1"));
+	}
+
+	@Test
+	public void withLocationAndGeneratedNameAndExplicitClassLoader() throws IOException {
+		PropertySource<?> ps = new ResourcePropertySource(PROPERTIES_LOCATION, getClass().getClassLoader());
+		assertEquals(ps.getProperty("foo"), "bar");
+		assertThat(ps.getName(), is(PROPERTIES_RESOURCE_DESCRIPTION));
+	}
+
+	@Test
+	public void withResourceAndGeneratedName() throws IOException {
+		PropertySource<?> ps = new ResourcePropertySource(new ClassPathResource(PROPERTIES_PATH));
+		assertEquals(ps.getProperty("foo"), "bar");
+		assertThat(ps.getName(), is(PROPERTIES_RESOURCE_DESCRIPTION));
+	}
+
+	@Test
+	public void withResourceAndExplicitName() throws IOException {
+		PropertySource<?> ps = new ResourcePropertySource("ps1", new ClassPathResource(PROPERTIES_PATH));
+		assertEquals(ps.getProperty("foo"), "bar");
+		assertThat(ps.getName(), is("ps1"));
+	}
+
+	@Test
+	public void withResourceHavingNoDescriptionAndGeneratedName() throws IOException {
+		PropertySource<?> ps = new ResourcePropertySource(new ByteArrayResource("foo=bar".getBytes(), ""));
+		assertEquals(ps.getProperty("foo"), "bar");
+		assertTrue(ps.getName().startsWith("ByteArrayResource@"));
+	}
+
+}

org.springframework.core/src/test/java/org/springframework/core/io/example.properties

@@ -0,0 +1 @@
+foo=bar