org.springframework.boot.loader.ExecutableArchiveLauncher Maven / Gradle / Ivy
/*
* Copyright 2012-2017 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
*
* https://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.boot.loader;
import java.util.ArrayList;
import java.util.List;
import java.util.jar.JarEntry;
import java.util.jar.Manifest;
import org.springframework.boot.loader.archive.Archive;
/**
* Base class for executable archive {@link Launcher}s.
*
* @author Phillip Webb
* @author Andy Wilkinson
*/
public abstract class ExecutableArchiveLauncher extends Launcher {
private final Archive archive;
public ExecutableArchiveLauncher() {
try {
this.archive = createArchive();
}
catch (Exception ex) {
throw new IllegalStateException(ex);
}
}
protected ExecutableArchiveLauncher(Archive archive) {
this.archive = archive;
}
protected final Archive getArchive() {
return this.archive;
}
@Override
protected String getMainClass() throws Exception {
Manifest manifest = this.archive.getManifest();
String mainClass = null;
if (manifest != null) {
mainClass = manifest.getMainAttributes().getValue("Start-Class");
}
if (mainClass == null) {
throw new IllegalStateException(
"No 'Start-Class' manifest entry specified in " + this);
}
return mainClass;
}
@Override
protected List getClassPathArchives() throws Exception {
List archives = new ArrayList<>(
this.archive.getNestedArchives(this::isNestedArchive));
postProcessClassPathArchives(archives);
return archives;
}
/**
* Determine if the specified {@link JarEntry} is a nested item that should be added
* to the classpath. The method is called once for each entry.
* @param entry the jar entry
* @return {@code true} if the entry is a nested item (jar or folder)
*/
protected abstract boolean isNestedArchive(Archive.Entry entry);
/**
* Called to post-process archive entries before they are used. Implementations can
* add and remove entries.
* @param archives the archives
* @throws Exception if the post processing fails
*/
protected void postProcessClassPathArchives(List archives) throws Exception {
}
}