com.alibaba.nacos.common.utils.ResourceUtils Maven / Gradle / Ivy
/*
* Copyright 1999-2018 Alibaba Group Holding Ltd.
*
* 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 com.alibaba.nacos.common.utils;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.Properties;
/**
* resource util.
*
* @author boyan
*/
public class ResourceUtils {
private ResourceUtils() {
}
private static final String CLASSPATH_PREFIX = "classpath:";
/**
* Returns the URL of the resource on the classpath.
*
* @param resource The resource to find
* @return The resource
* @throws IOException If the resource cannot be found or read
*/
public static URL getResourceUrl(String resource) throws IOException {
if (resource.startsWith(CLASSPATH_PREFIX)) {
String path = resource.substring(CLASSPATH_PREFIX.length());
ClassLoader classLoader = ResourceUtils.class.getClassLoader();
URL url = (classLoader != null ? classLoader.getResource(path) : ClassLoader.getSystemResource(path));
if (url == null) {
throw new FileNotFoundException("Resource [" + resource + "] does not exist");
}
return url;
}
try {
return new URL(resource);
} catch (MalformedURLException ex) {
return new File(resource).toURI().toURL();
}
}
/**
* Returns the URL of the resource on the classpath.
*
* @param loader The classloader used to load the resource
* @param resource The resource to find
* @return The resource
* @throws IOException If the resource cannot be found or read
*/
public static URL getResourceUrl(ClassLoader loader, String resource) throws IOException {
URL url = null;
if (loader != null) {
url = loader.getResource(resource);
}
if (url == null) {
url = ClassLoader.getSystemResource(resource);
}
if (url == null) {
throw new IOException("Could not find resource " + resource);
}
return url;
}
/**
* Returns a resource on the classpath as a Stream object.
*
* @param resource The resource to find
* @return The resource
* @throws IOException If the resource cannot be found or read
*/
public static InputStream getResourceAsStream(String resource) throws IOException {
ClassLoader loader = ResourceUtils.class.getClassLoader();
return getResourceAsStream(loader, resource);
}
/**
* Returns a resource on the classpath as a Stream object.
*
* @param loader The classloader used to load the resource
* @param resource The resource to find
* @return The resource
* @throws IOException If the resource cannot be found or read
*/
public static InputStream getResourceAsStream(ClassLoader loader, String resource) throws IOException {
InputStream in = null;
if (loader != null) {
in = loader.getResourceAsStream(resource);
}
if (in == null) {
in = ClassLoader.getSystemResourceAsStream(resource);
}
if (in == null) {
throw new IOException("Could not find resource " + resource);
}
return in;
}
/**
* Returns a resource on the classpath as a Properties object.
*
* @param resource The resource to find
* @return The resource
* @throws IOException If the resource cannot be found or read
*/
public static Properties getResourceAsProperties(String resource) throws IOException {
ClassLoader loader = ResourceUtils.class.getClassLoader();
return getResourceAsProperties(loader, resource);
}
/**
* Returns a resource on the classpath as a Properties object.
*
* @param loader The classloader used to load the resource
* @param resource The resource to find
* @return The resource
* @throws IOException If the resource cannot be found or read
*/
public static Properties getResourceAsProperties(ClassLoader loader, String resource) throws IOException {
Properties props = new Properties();
InputStream in = getResourceAsStream(loader, resource);
props.load(in);
IoUtils.closeQuietly(in);
return props;
}
/**
* Returns a resource on the classpath as a Reader object.
*
* @param resource The resource to find
* @return The resource
* @throws IOException If the resource cannot be found or read
*/
public static InputStreamReader getResourceAsReader(String resource, String charsetName) throws IOException {
return new InputStreamReader(getResourceAsStream(resource), charsetName);
}
/**
* Returns a resource on the classpath as a Reader object.
*
* @param loader The classloader used to load the resource
* @param resource The resource to find
* @return The resource
* @throws IOException If the resource cannot be found or read
*/
public static Reader getResourceAsReader(ClassLoader loader, String resource, String charsetName)
throws IOException {
return new InputStreamReader(getResourceAsStream(loader, resource), charsetName);
}
/**
* Returns a resource on the classpath as a File object.
*
* @param resource The resource to find
* @return The resource
* @throws IOException If the resource cannot be found or read
*/
public static File getResourceAsFile(String resource) throws IOException {
return new File(getResourceUrl(resource).getFile());
}
/**
* Returns a resource on the classpath as a File object.
*
* @param url The resource url to find
* @return The resource
*/
public static File getResourceAsFile(URL url) {
return new File(url.getFile());
}
/**
* Returns a resource on the classpath as a File object.
*
* @param loader The classloader used to load the resource
* @param resource The resource to find
* @return The resource
* @throws IOException If the resource cannot be found or read
*/
public static File getResourceAsFile(ClassLoader loader, String resource) throws IOException {
return new File(getResourceUrl(loader, resource).getFile());
}
}