com.wl4g.component.common.lang.JavaVersion Maven / Gradle / Ivy
/*
* Copyright 2017 ~ 2025 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
*
* 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.wl4g.component.common.lang;
/**
* Java versions.
*/
public enum JavaVersion {
/**
* Java 1.9.
*/
NINE(9, "1.9", "java.security.cert.URICertStoreParameters"),
/**
* Java 1.8.
*/
EIGHT(8, "1.8", "java.util.function.Function"),
/**
* Java 1.7.
*/
SEVEN(7, "1.7", "java.nio.file.Files"),
/**
* Java 1.6.
*/
SIX(6, "1.6", "java.util.ServiceLoader");
private final int value;
private final String name;
private final boolean available;
private JavaVersion(int value, String name, String className) {
this.value = value;
this.name = name;
this.available = isPresent(className, getClass().getClassLoader());
}
public int getValue() {
return value;
}
@Override
public String toString() {
return this.name;
}
/**
* Returns the {@link JavaVersion} of the current runtime.
*
* @return the {@link JavaVersion}
*/
public static JavaVersion runtimeJavaVersion() {
for (JavaVersion candidate : JavaVersion.values()) {
if (candidate.available) {
return candidate;
}
}
return SIX;
}
/**
* Determine whether the {@link Class} identified by the supplied name is
* present and can be loaded. Will return {@code false} if either the class
* or one of its dependencies is not present or cannot be loaded.
*
* @param className
* the name of the class to check
* @param classLoader
* the class loader to use (may be {@code null} which indicates
* the default class loader)
* @return whether the specified class is present
*/
private static boolean isPresent(String className, ClassLoader classLoader) {
try {
Class.forName(className, false, classLoader);
return true;
} catch (Throwable ex) {
// Class or one of its dependencies is not present...
return false;
}
}
}