Java 配 Shell 等于美酒加咖啡

Runtime runtime = Runtime.getRuntime();runtime.addShutdownHook(new Thread() {    @Override    public void run() {        System.out.println("打扫战场，释放资源，完成优雅停服");    }});System.out.println("服务启动完成");

服务启动完成打扫战场，释放资源，完成优雅停服

Runtime runtime = Runtime.getRuntime();System.out.println(String.format("JVM可用本机CPU内核数 %d", runtime.availableProcessors()));//默认为系统的1/4System.out.println(String.format("最大可用内存空间 %d M", runtime.maxMemory() / 1024 / 1024));//默认为系统的1/64System.out.println(String.format("可用内存空间 %d M", runtime.totalMemory() / 1024 / 1024));System.out.println(String.format("空闲内存空间 %d M", runtime.freeMemory() / 1024 / 1024));

df [选项]... [FILE]...

public class Foo {
    public static void main(String[] args) throws Exception {        //df命令用于查看磁盘的分区，磁盘已使用的空间，剩余的空间        //df -h以合适的单位来显示信息        System.out.println(exec("df -h"));    }
    private static String exec(String command) throws Exception {        String[] cmd = {"/bin/sh", "-c", command};        StringBuilder out = new StringBuilder();        BufferedReader reader = null;        InputStream in = null;        try {            Process process = Runtime.getRuntime().exec(cmd);            in = process.getInputStream();            reader = new BufferedReader(new InputStreamReader(in));            String line;            while ((line = reader.readLine()) != null) {                out.append(line + "\n");            }            process.waitFor();        } finally {            if (reader != null) {                reader.close();            }        }        return out.toString();    }}