org.apache.tomcat.util.scan.JarFileUrlJar Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.apache.tomcat.util.scan;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.net.JarURLConnection;
import java.net.URISyntaxException;
import java.net.URL;
import java.util.Enumeration;
import java.util.HashSet;
import java.util.Set;
import java.util.jar.JarEntry;
import java.util.jar.JarFile;
import java.util.jar.Manifest;
import java.util.zip.ZipEntry;
import java.util.zip.ZipFile;
import org.apache.tomcat.Jar;
/**
* Implementation of {@link Jar} that is optimised for file based JAR URLs that
* refer directly to a JAR file (e.g URLs of the form jar:file: ... .jar!/ or
* file:... .jar).
*/
public class JarFileUrlJar implements Jar {
private final JarFile jarFile;
private final URL jarFileURL;
private final boolean multiRelease;
private Enumeration entries;
private Set entryNamesSeen;
private JarEntry entry = null;
public JarFileUrlJar(URL url, boolean startsWithJar) throws IOException {
if (startsWithJar) {
// jar:file:...
JarURLConnection jarConn = (JarURLConnection) url.openConnection();
jarConn.setUseCaches(false);
jarFile = jarConn.getJarFile();
jarFileURL = jarConn.getJarFileURL();
} else {
// file:...
File f;
try {
f = new File(url.toURI());
} catch (URISyntaxException e) {
throw new IOException(e);
}
jarFile = new JarFile(f, true, ZipFile.OPEN_READ, Runtime.version());
jarFileURL = url;
}
boolean multiReleaseValue = false;
try {
multiReleaseValue = jarFile.isMultiRelease();
} catch (IllegalStateException e) {
// ISE can be thrown if the JAR URL is bad, for example:
// https://github.com/spring-projects/spring-boot/issues/33633
// The Javadoc does not document that ISE and given what it does for a vanilla IOE,
// this looks like a Java bug, it should return false instead.
}
multiRelease = multiReleaseValue;
}
@Override
public URL getJarFileURL() {
return jarFileURL;
}
@Override
public InputStream getInputStream(String name) throws IOException {
// JarFile#getEntry() is multi-release aware
ZipEntry entry = jarFile.getEntry(name);
if (entry == null) {
return null;
} else {
return jarFile.getInputStream(entry);
}
}
@Override
public long getLastModified(String name) throws IOException {
// JarFile#getEntry() is multi-release aware
ZipEntry entry = jarFile.getEntry(name);
if (entry == null) {
return -1;
} else {
return entry.getTime();
}
}
@Override
public boolean exists(String name) throws IOException {
// JarFile#getEntry() is multi-release aware
ZipEntry entry = jarFile.getEntry(name);
return entry != null;
}
@Override
public String getURL(String entry) {
StringBuilder result = new StringBuilder("jar:");
result.append(getJarFileURL().toExternalForm());
result.append("!/");
result.append(entry);
return result.toString();
}
@Override
public void close() {
if (jarFile != null) {
try {
jarFile.close();
} catch (IOException e) {
// Ignore
}
}
}
@Override
public void nextEntry() {
// JarFile#entries() is NOT multi-release aware
if (entries == null) {
entries = jarFile.entries();
if (multiRelease) {
entryNamesSeen = new HashSet<>();
}
}
if (multiRelease) {
// Need to ensure that:
// - the one, correct entry is returned where multiple versions
// are available
// - that the order of entries in the JAR doesn't prevent the
// correct entries being returned
// - the case where an entry appears in the versions location
// but not in the the base location is handled correctly
// Enumerate the entries until one is reached that represents an
// entry that has not been seen before.
String name = null;
while (true) {
if (entries.hasMoreElements()) {
entry = entries.nextElement();
name = entry.getName();
// Get 'base' name
if (name.startsWith("META-INF/versions/")) {
int i = name.indexOf('/', 18);
if (i == -1) {
continue;
}
name = name.substring(i + 1);
}
if (name.length() == 0 || entryNamesSeen.contains(name)) {
continue;
}
entryNamesSeen.add(name);
// JarFile.getJarEntry is version aware so use it
entry = jarFile.getJarEntry(entry.getName());
break;
} else {
entry = null;
break;
}
}
} else {
if (entries.hasMoreElements()) {
entry = entries.nextElement();
} else {
entry = null;
}
}
}
@Override
public String getEntryName() {
if (entry == null) {
return null;
} else {
return entry.getName();
}
}
@Override
public InputStream getEntryInputStream() throws IOException {
if (entry == null) {
return null;
} else {
return jarFile.getInputStream(entry);
}
}
@Override
public Manifest getManifest() throws IOException {
return jarFile.getManifest();
}
@Override
public void reset() throws IOException {
entries = null;
entryNamesSeen = null;
entry = null;
}
}