org.flywaydb.core.internal.util.scanner.classpath.JarFileClassPathLocationScanner Maven / Gradle / Ivy
/**
* Copyright 2010-2016 Boxfuse GmbH
*
* 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.flywaydb.core.internal.util.scanner.classpath;
import java.io.IOException;
import java.net.JarURLConnection;
import java.net.URISyntaxException;
import java.net.URL;
import java.net.URLConnection;
import java.util.Enumeration;
import java.util.Set;
import java.util.TreeSet;
import java.util.jar.JarEntry;
import java.util.jar.JarFile;
/**
* ClassPathLocationScanner for jar files.
*/
public class JarFileClassPathLocationScanner implements ClassPathLocationScanner {
public Set findResourceNames(String location, URL locationUrl) throws IOException {
JarFile jarFile = getJarFromUrl(locationUrl);
try {
// For Tomcat and non-expanded WARs.
String prefix = jarFile.getName().toLowerCase().endsWith(".war") ? "WEB-INF/classes/" : "";
return findResourceNamesFromJarFile(jarFile, prefix, location);
} finally {
jarFile.close();
}
}
/**
* Retrieves the Jar file represented by this URL.
*
* @param locationUrl The URL of the jar.
* @return The jar file.
* @throws IOException when the jar could not be resolved.
*/
private JarFile getJarFromUrl(URL locationUrl) throws IOException {
URLConnection con = locationUrl.openConnection();
if (con instanceof JarURLConnection) {
// Should usually be the case for traditional JAR files.
JarURLConnection jarCon = (JarURLConnection) con;
jarCon.setUseCaches(false);
return jarCon.getJarFile();
}
// No JarURLConnection -> need to resort to URL file parsing.
// We'll assume URLs of the format "jar:path!/entry", with the protocol
// being arbitrary as long as following the entry format.
// We'll also handle paths with and without leading "file:" prefix.
String urlFile = locationUrl.getFile();
int separatorIndex = urlFile.indexOf("!/");
if (separatorIndex != -1) {
String jarFileUrl = urlFile.substring(0, separatorIndex);
if (jarFileUrl.startsWith("file:")) {
try {
return new JarFile(new URL(jarFileUrl).toURI().getSchemeSpecificPart());
} catch (URISyntaxException ex) {
// Fallback for URLs that are not valid URIs (should hardly ever happen).
return new JarFile(jarFileUrl.substring("file:".length()));
}
}
return new JarFile(jarFileUrl);
}
return new JarFile(urlFile);
}
/**
* Finds all the resource names contained in this directory within this jar file.
*
* @param jarFile The jar file.
* @param prefix The prefix to ignore within the jar file.
* @param location The location to look under.
* @return The resource names.
* @throws java.io.IOException when reading the jar file failed.
*/
private Set findResourceNamesFromJarFile(JarFile jarFile, String prefix, String location) throws IOException {
String toScan = prefix + location + (location.endsWith("/") ? "" : "/");
Set resourceNames = new TreeSet();
Enumeration entries = jarFile.entries();
while (entries.hasMoreElements()) {
String entryName = entries.nextElement().getName();
if (entryName.startsWith(toScan)) {
resourceNames.add(entryName.substring(prefix.length()));
}
}
return resourceNames;
}
}