Java 执行 Linux 命令

一、本地执行 Linux 命令

1. 执行单条命令

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;

public class ShellUtil {

    public void execCmd(String cmd) throws IOException {
        Runtime run = Runtime.getRuntime();
        Process proc = null;
        BufferedReader br = null;
        InputStream in = null;

        try {
            proc = run.exec(cmd, null, null);
            in = proc.getInputStream();
            br = new BufferedReader(new InputStreamReader(in));

            String result;
            while ((result = br.readLine()) != null) {
                System.out.println("job result [" + result + "]");
            }

            proc.waitFor();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (proc != null)
                proc.destroy();
            if (in != null)
                in.close();
            if (br != null)
                br.close();
        }
    }
}

2. 执行含有管道符（|）的多级命令

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.List;

public class ShellUtil {

    public List execCmd(String cmd) throws IOException {
        List list = new ArrayList();
        Runtime run = Runtime.getRuntime();
        Process proc = null;
        BufferedReader br = null;
        InputStream in = null;

        try {
            proc = run.exec(new String[]{"/bin/sh", "-c", cmd});
            in = proc.getInputStream();
            br = new BufferedReader(new InputStreamReader(in));

            String result;
            while ((result = br.readLine()) != null) {
                System.out.println("job result [" + result + "]");
                list.add(result);
            }

            proc.waitFor();
            return list;
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (proc != null)
                proc.destroy();
            if (in != null)
                in.close();
            if (br != null)
                br.close();
        }
        return list;
    }
}

3. 执行多条命令

import java.io.*;
import java.util.ArrayList;
import java.util.List;

public class ShellUtil {

    /**
     * 命令集合
     */
    public static List getCommandList() {
        String path = "/root";
        List commands = new ArrayList();
        commands.add("cd " + path);
        commands.add("ls");
        return commands;
    }


    /**
     * 执行命令
     */
    public static List execCommands(List commands) throws IOException {
        List list = new ArrayList();
        Runtime run = Runtime.getRuntime();
        Process proc = null;
        BufferedReader in = null;
        PrintWriter out = null;

        try {
            proc = run.exec("/bin/bash", null, null);
            in = new BufferedReader(new InputStreamReader(proc.getInputStream()));
            out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(proc.getOutputStream())), true);

            // 写入执行命令
            for (String line : commands) {
                out.println(line);
            }
            // 这个命令必须执行，否则 in 流不结束
            out.println("exit");

            String line;
            while ((line = in.readLine()) != null) {
                System.out.println("readLine: " + line);
                list.add(line);
            }

            // 释放资源
            proc.waitFor();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (proc != null)
                proc.destroy();
            if (in != null)
                in.close();
            if (out != null)
                out.close();
        }
        return list;
    }
}

二、远程执行 Linux 命令

    ch.ethz.ganymed
    ganymed-ssh2
    262

import ch.ethz.ssh2.Connection;
import ch.ethz.ssh2.Session;
import ch.ethz.ssh2.StreamGobbler;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;

public class LinuxUtil {
    public static void main(String[] args) {

        String hostname = "127.0.0.1";
        String username = "root";
        String password = "123456";

        try {
            Connection conn = new Connection(hostname);
            conn.connect();
            boolean isAuthenticated = conn.authenticateWithPassword(username, password);
            if (!isAuthenticated) {
                throw new IOException("Authentication failed");
            }
            Session sess = conn.openSession();

            // 命令语句,必须使用绝对路径否则无效(环境变量也不可以)。如：java --version
            sess.execCommand("pwd");

            InputStream stdout = new StreamGobbler(sess.getStdout());
            BufferedReader br = new BufferedReader(new InputStreamReader(stdout));
            while (true) {
                String line = br.readLine();
                if (line == null) {
                    break;
                }
                
                // 输出命令执行结果
                System.out.println(line);
            }
            sess.close();
            conn.close();
        } catch (IOException e) {
            e.printStackTrace(System.err);
            System.exit(2);
        }
    }
}