Java version Util
/**
*Copyright [2009-2010] [dennis zhuang(killme2008@gmail.com)]
*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
*/
/**
*Copyright [2009-2010] [dennis zhuang(killme2008@gmail.com)]
*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.google.code.yanf4j.util;
import java.io.IOException;
import java.lang.reflect.Method;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.nio.channels.Selector;
import java.nio.channels.spi.SelectorProvider;
/**
* System utils
*
* @author dennis
*
*/
public final class SystemUtils {
private SystemUtils() {
}
public static final String OS_NAME = System.getProperty("os.name");
private static boolean isLinuxPlatform = false;
static {
if (OS_NAME != null && OS_NAME.toLowerCase().indexOf("linux") >= 0) {
isLinuxPlatform = true;
}
}
public static final String JAVA_VERSION = System
.getProperty("java.version");
private static boolean isAfterJava6u4Version = false;
static {
if (JAVA_VERSION != null) {
// java4 or java5
if (JAVA_VERSION.indexOf("1.4.") >= 0
|| JAVA_VERSION.indexOf("1.5.") >= 0) {
isAfterJava6u4Version = false;
} else if (JAVA_VERSION.indexOf("1.6.") >= 0) {
int index = JAVA_VERSION.indexOf("_");
if (index > 0) {
String subVersionStr = JAVA_VERSION.substring(index + 1);
if (subVersionStr != null && subVersionStr.length() > 0) {
try {
int subVersion = Integer.parseInt(subVersionStr);
if (subVersion >= 4) {
isAfterJava6u4Version = true;
}
} catch (NumberFormatException e) {
}
}
}
// after java6
} else {
isAfterJava6u4Version = true;
}
}
}
public static final boolean isLinuxPlatform() {
return isLinuxPlatform;
}
public static final boolean isAfterJava6u4Version() {
return isAfterJava6u4Version;
}
public static void main(String[] args) {
System.out.println(isAfterJava6u4Version());
}
public static final int getSystemThreadCount() {
return getCpuProcessorCount();
}
public static final int getCpuProcessorCount() {
return Runtime.getRuntime().availableProcessors();
}
public static final Selector openSelector() throws IOException {
Selector result = null;
// check if it is linux os
if (SystemUtils.isLinuxPlatform()) {
try {
Class<?> providerClazz = Class
.forName("sun.nio.ch.EPollSelectorProvider");
if (providerClazz != null) {
try {
Method method = providerClazz.getMethod("provider");
if (method != null) {
SelectorProvider selectorProvider = (SelectorProvider) method
.invoke(null);
if (selectorProvider != null) {
result = selectorProvider.openSelector();
}
}
} catch (Exception e) {
// ignore
}
}
} catch (Exception e) {
// ignore
}
}
if (result == null) {
result = Selector.open();
}
return result;
}
public static final String getRawAddress(InetSocketAddress inetSocketAddress) {
InetAddress address = inetSocketAddress.getAddress();
return address != null ? address.getHostAddress() : inetSocketAddress
.getHostName();
}
}
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