/*
* Copyright 2002-2016 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.support;
import java.io.IOException;
import java.io.InputStream;
import java.io.Reader;
import java.net.URL;
import java.net.URLConnection;
import java.util.Enumeration;
import java.util.Properties;
import org.springframework.core.io.Resource;
import org.springframework.util.Assert;
import org.springframework.util.ClassUtils;
import org.springframework.util.DefaultPropertiesPersister;
import org.springframework.util.PropertiesPersister;
import org.springframework.util.ResourceUtils;
/**
* Convenient utility methods for loading of {@code java.util.Properties},
* performing standard handling of input streams.
*
* <p>For more configurable properties loading, including the option of a
* customized encoding, consider using the PropertiesLoaderSupport class.
*
* @author Juergen Hoeller
* @author Rob Harrop
* @since 2.0
* @see PropertiesLoaderSupport
*/
public abstract class PropertiesLoaderUtils {
private static final String XML_FILE_EXTENSION = ".xml";
/**
* Load properties from the given EncodedResource,
* potentially defining a specific encoding for the properties file.
* @see #fillProperties(java.util.Properties, EncodedResource)
*/
public static Properties loadProperties(EncodedResource resource) throws IOException {
Properties props = new Properties();
fillProperties(props, resource);
return props;
}
/**
* Fill the given properties from the given EncodedResource,
* potentially defining a specific encoding for the properties file.
* @param props the Properties instance to load into
* @param resource the resource to load from
* @throws IOException in case of I/O errors
*/
public static void fillProperties(Properties props, EncodedResource resource)
throws IOException {
fillProperties(props, resource, new DefaultPropertiesPersister());
}
/**
* Actually load properties from the given EncodedResource into the given Properties instance.
* @param props the Properties instance to load into
* @param resource the resource to load from
* @param persister the PropertiesPersister to use
* @throws IOException in case of I/O errors
*/
static void fillProperties(Properties props, EncodedResource resource, PropertiesPersister persister)
throws IOException {
InputStream stream = null;
Reader reader = null;
try {
String filename = resource.getResource().getFilename();
if (filename != null && filename.endsWith(XML_FILE_EXTENSION)) {
stream = resource.getInputStream();
persister.loadFromXml(props, stream);
}
else if (resource.requiresReader()) {
reader = resource.getReader();
persister.load(props, reader);
}
else {
stream = resource.getInputStream();
persister.load(props, stream);
}
}
finally {
if (stream != null) {
stream.close();
}
if (reader != null) {
reader.close();
}
}
}
/**
* Load properties from the given resource (in ISO-8859-1 encoding).
* @param resource the resource to load from
* @return the populated Properties instance
* @throws IOException if loading failed
* @see #fillProperties(java.util.Properties, Resource)
*/
public static Properties loadProperties(Resource resource) throws IOException {
Properties props = new Properties();
fillProperties(props, resource);
return props;
}
/**
* Fill the given properties from the given resource (in ISO-8859-1 encoding).
* @param props the Properties instance to fill
* @param resource the resource to load from
* @throws IOException if loading failed
*/
public static void fillProperties(Properties props, Resource resource) throws IOException {
InputStream is = resource.getInputStream();
try {
String filename = resource.getFilename();
if (filename != null && filename.endsWith(XML_FILE_EXTENSION)) {
props.loadFromXML(is);
}
else {
props.load(is);
}
}
finally {
is.close();
}
}
/**
* Load all properties from the specified class path resource
* (in ISO-8859-1 encoding), using the default class loader.
* <p>Merges properties if more than one resource of the same name
* found in the class path.
* @param resourceName the name of the class path resource
* @return the populated Properties instance
* @throws IOException if loading failed
*/
public static Properties loadAllProperties(String resourceName) throws IOException {
return loadAllProperties(resourceName, null);
}
/**
* Load all properties from the specified class path resource
* (in ISO-8859-1 encoding), using the given class loader.
* <p>Merges properties if more than one resource of the same name
* found in the class path.
* @param resourceName the name of the class path resource
* @param classLoader the ClassLoader to use for loading
* (or {@code null} to use the default class loader)
* @return the populated Properties instance
* @throws IOException if loading failed
*/
public static Properties loadAllProperties(String resourceName, ClassLoader classLoader) throws IOException {
Assert.notNull(resourceName, "Resource name must not be null");
ClassLoader classLoaderToUse = classLoader;
if (classLoaderToUse == null) {
classLoaderToUse = ClassUtils.getDefaultClassLoader();
}
Enumeration<URL> urls = (classLoaderToUse != null ? classLoaderToUse.getResources(resourceName) :
ClassLoader.getSystemResources(resourceName));
Properties props = new Properties();
while (urls.hasMoreElements()) {
URL url = urls.nextElement();
URLConnection con = url.openConnection();
ResourceUtils.useCachesIfNecessary(con);
InputStream is = con.getInputStream();
try {
if (resourceName.endsWith(XML_FILE_EXTENSION)) {
props.loadFromXML(is);
}
else {
props.load(is);
}
}
finally {
is.close();
}
}
return props;
}
}