1. 檢測jdk版本

@SuppressWarnings("LoopStatementThatDoesntLoop")private static int javaVersion0() {int javaVersion;// Not really a loopfor (;;) {// Androidif (isAndroid()) {javaVersion = 6;break;}try {Class.forName("java.time.Clock", false, getClassLoader(Object.class));javaVersion = 8;break;} catch (Exception e) {// Ignore }try {Class.forName("java.util.concurrent.LinkedTransferQueue", false, getClassLoader(BlockingQueue.class));javaVersion = 7;break;} catch (Exception e) {// Ignore }javaVersion = 6;break;}if (logger.isDebugEnabled()) {logger.debug("Java version: {}", javaVersion);}return javaVersion;}

2. 檢測是否window

private static boolean isWindows0() {boolean windows = SystemPropertyUtil.get("os.name", "").toLowerCase(Locale.US).contains("win");if (windows) {logger.debug("Platform: Windows");}return windows;}

3. 檢測是否root權限

private static boolean isRoot0() {if (isWindows()) {return false;}String[] ID_COMMANDS = { "/usr/bin/id", "/bin/id", "/usr/xpg4/bin/id", "id"};Pattern UID_PATTERN = Pattern.compile("^(?:0|[1-9][0-9]*)$");for (String idCmd: ID_COMMANDS) {Process p = null;BufferedReader in = null;String uid = null;try {p = Runtime.getRuntime().exec(new String[] { idCmd, "-u" });in = new BufferedReader(new InputStreamReader(p.getInputStream(), CharsetUtil.US_ASCII));uid = in.readLine();in.close();for (;;) {try {int exitCode = p.waitFor();if (exitCode != 0) {uid = null;}break;} catch (InterruptedException e) {// Ignore }}} catch (Exception e) {// Failed to run the command.uid = null;} finally {if (in != null) {try {in.close();} catch (IOException e) {// Ignore }}if (p != null) {try {p.destroy();} catch (Exception e) {// Android sometimes triggers an ErrnoException. }}}if (uid != null && UID_PATTERN.matcher(uid).matches()) {logger.debug("UID: {}", uid);return "0".equals(uid);}}logger.debug("Could not determine the current UID using /usr/bin/id; attempting to bind at privileged ports.");Pattern PERMISSION_DENIED = Pattern.compile(".*(?:denied|not.*permitted).*");for (int i = 1023; i > 0; i --) {ServerSocket ss = null;try {ss = new ServerSocket();ss.setReuseAddress(true);ss.bind(new InetSocketAddress(i));if (logger.isDebugEnabled()) {logger.debug("UID: 0 (succeded to bind at port {})", i);}return true;} catch (Exception e) {// Failed to bind.// Check the error message so that we don't always need to bind 1023 times.String message = e.getMessage();if (message == null) {message = "";}message = message.toLowerCase();if (PERMISSION_DENIED.matcher(message).matches()) {break;}} finally {if (ss != null) {try {ss.close();} catch (Exception e) {// Ignore. }}}}logger.debug("UID: non-root (failed to bind at any privileged ports)");return false;}

4.檢測最大直接內存

private static long maxDirectMemory0() {long maxDirectMemory = 0;try {// Try to get from sun.misc.VM.maxDirectMemory() which should be most accurate.Class<?> vmClass = Class.forName("sun.misc.VM", true, getSystemClassLoader());Method m = vmClass.getDeclaredMethod("maxDirectMemory");maxDirectMemory = ((Number) m.invoke(null)).longValue();} catch (Throwable t) {// Ignore }if (maxDirectMemory > 0) {return maxDirectMemory;}try {// Now try to get the JVM option (-XX:MaxDirectMemorySize) and parse it.// Note that we are using reflection because Android doesn't have these classes.Class<?> mgmtFactoryClass = Class.forName("java.lang.management.ManagementFactory", true, getSystemClassLoader());Class<?> runtimeClass = Class.forName("java.lang.management.RuntimeMXBean", true, getSystemClassLoader());Object runtime = mgmtFactoryClass.getDeclaredMethod("getRuntimeMXBean").invoke(null);@SuppressWarnings("unchecked")List<String> vmArgs = (List<String>) runtimeClass.getDeclaredMethod("getInputArguments").invoke(runtime);for (int i = vmArgs.size() - 1; i >= 0; i --) {Matcher m = MAX_DIRECT_MEMORY_SIZE_ARG_PATTERN.matcher(vmArgs.get(i));if (!m.matches()) {continue;}maxDirectMemory = Long.parseLong(m.group(1));switch (m.group(2).charAt(0)) {case 'k': case 'K':maxDirectMemory *= 1024;break;case 'm': case 'M':maxDirectMemory *= 1024 * 1024;break;case 'g': case 'G':maxDirectMemory *= 1024 * 1024 * 1024;break;}break;}} catch (Throwable t) {// Ignore }if (maxDirectMemory <= 0) {maxDirectMemory = Runtime.getRuntime().maxMemory();logger.debug("maxDirectMemory: {} bytes (maybe)", maxDirectMemory);} else {logger.debug("maxDirectMemory: {} bytes", maxDirectMemory);}return maxDirectMemory;}

等等

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轉載于:https://www.cnblogs.com/davidwang456/p/5121956.html

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