1、操作系统判断
boolean isWindows = System.getProperty("os.name")
.toLowerCase().startsWith("windows");2、读取调用命令的输出
输出(Output)必须被读取，否则我们的进程将挂起，不能成功返回。
通过StreamGobbler类来读取InputStream:
private static class StreamGobbler implements Runnable {
private InputStream inputStream;
private Consumer<String> consumer;
public StreamGobbler(InputStream inputStream, Consumer<String> consumer) {
this.inputStream = inputStream;
this.consumer = consumer;
}
@Override
public void run() {
new BufferedReader(new InputStreamReader(inputStream)).lines()
.forEach(consumer);
}
}3、使用Runtime.exec()调用cmd命令和shell命令并将结果输出到控制台
String homeDirectory = System.getProperty("user.home");
Process process;
if (isWindows) {
process = Runtime.getRuntime()
.exec(String.format("cmd.exe /c dir %s", homeDirectory));
} else {
process = Runtime.getRuntime()
.exec(String.format("sh -c ls %s", homeDirectory));
}
StreamGobbler streamGobbler =
new StreamGobbler(process.getInputStream(), System.out::println);
Executors.newSingleThreadExecutor().submit(streamGobbler);
int exitCode = process.waitFor();
assert exitCode == 0;4、使用ProcessBuilder调用cmd命令和shell命令并将结果输出到控制台
对于有些复杂的处理，可以使用ProcessBuilder，使用它可以：
- 使用
builder.directory()更改我们的shell命令正在运行的工作目录 - 使用
builder.environment()将自定义键值映射设置为环境变量 - 将输入和输出流重定向到自定义替换
- 使用
builder.inheritIO()将它们都继承到当前JVM进程的流
ProcessBuilder builder = new ProcessBuilder();
if (isWindows) {
builder.command("cmd.exe", "/c", "dir");
} else {
builder.command("sh", "-c", "ls");
}
builder.directory(new File(System.getProperty("user.home")));
Process process = builder.start();
StreamGobbler streamGobbler =
new StreamGobbler(process.getInputStream(), System.out::println);
Executors.newSingleThreadExecutor().submit(streamGobbler);
int exitCode = process.waitFor();
assert exitCode == 0;