org.springframework.boot.SpringBootVersion Maven / Gradle / Ivy
/*
* Copyright 2012-2019 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;
import java.io.File;
import java.io.IOException;
import java.net.JarURLConnection;
import java.net.URL;
import java.net.URLConnection;
import java.security.CodeSource;
import java.util.jar.Attributes;
import java.util.jar.Attributes.Name;
import java.util.jar.JarFile;
/**
* Class that exposes the Spring Boot version. Fetches the
* {@link Name#IMPLEMENTATION_VERSION Implementation-Version} manifest attribute from the
* jar file via {@link Package#getImplementationVersion()}, falling back to locating the
* jar file that contains this class and reading the {@code Implementation-Version}
* attribute from its manifest.
*
* This class might not be able to determine the Spring Boot version in all environments.
* Consider using a reflection-based check instead: For example, checking for the presence
* of a specific Spring Boot method that you intend to call.
*
* @author Drummond Dawson
* @author Hendrig Sellik
* @author Andy Wilkinson
* @since 1.3.0
*/
public final class SpringBootVersion {
private SpringBootVersion() {
}
/**
* Return the full version string of the present Spring Boot codebase, or {@code null}
* if it cannot be determined.
* @return the version of Spring Boot or {@code null}
* @see Package#getImplementationVersion()
*/
public static String getVersion() {
return determineSpringBootVersion();
}
private static String determineSpringBootVersion() {
String implementationVersion = SpringBootVersion.class.getPackage().getImplementationVersion();
if (implementationVersion != null) {
return implementationVersion;
}
CodeSource codeSource = SpringBootVersion.class.getProtectionDomain().getCodeSource();
if (codeSource == null) {
return null;
}
URL codeSourceLocation = codeSource.getLocation();
try {
URLConnection connection = codeSourceLocation.openConnection();
if (connection instanceof JarURLConnection) {
return getImplementationVersion(((JarURLConnection) connection).getJarFile());
}
try (JarFile jarFile = new JarFile(new File(codeSourceLocation.toURI()))) {
return getImplementationVersion(jarFile);
}
}
catch (Exception ex) {
return null;
}
}
private static String getImplementationVersion(JarFile jarFile) throws IOException {
return jarFile.getManifest().getMainAttributes().getValue(Attributes.Name.IMPLEMENTATION_VERSION);
}
}