我正在使用 JSch 连接到 SSH 并执行命令。其中一个命令给出了一个很大的输出。在终端中,如果执行命令,则必须按 Enter 键才能查看整个输出。使用 JSch 我无法检索整个输出。
当我使用交互式终端登录时,命令输出在填满屏幕后停止并等待 Enter。
代码取自 How to get jsch shell command output in String :
public class SshConnectionManager {
private static Session session;
private static ChannelShell channel;
private static String username = "";
private static String password = "";
private static String hostname = "";
private static Session getSession(){
if(session == null || !session.isConnected()){
session = connect(hostname,username,password);
}
return session;
}
private static Channel getChannel(){
if(channel == null || !channel.isConnected()){
try{
channel = (ChannelShell)getSession().openChannel("shell");
channel.connect();
}catch(Exception e){
System.out.println("Error while opening channel: "+ e);
}
}
return channel;
}
private static Session connect(String hostname, String username, String password){
JSch jSch = new JSch();
try {
session = jSch.getSession(username, hostname, 22);
Properties config = new Properties();
config.put("StrictHostKeyChecking", "no");
session.setConfig(config);
session.setPassword(password);
System.out.println("Connecting SSH to " + hostname + " - Please wait for few seconds... ");
session.connect();
System.out.println("Connected!");
}catch(Exception e){
System.out.println("An error occurred while connecting to "+hostname+": "+e);
}
return session;
}
private static void executeCommands(List<String> commands){
try{
Channel channel=getChannel();
System.out.println("Sending commands...");
sendCommands(channel, commands);
readChannelOutput(channel);
System.out.println("Finished sending commands!");
}catch(Exception e){
System.out.println("An error ocurred during executeCommands: "+e);
}
}
private static void sendCommands(Channel channel, List<String> commands){
try{
PrintStream out = new PrintStream(channel.getOutputStream());
out.println("#!/bin/bash");
for(String command : commands){
out.println(command);
}
out.println("exit");
out.flush();
}catch(Exception e){
System.out.println("Error while sending commands: "+ e);
}
}
private static void readChannelOutput(Channel channel){
byte[] buffer = new byte[1024];
try{
InputStream in = channel.getInputStream();
String line = "";
while (true){
while (in.available() > 0) {
int i = in.read(buffer, 0, 1024);
if (i < 0) {
break;
}
line = new String(buffer, 0, i);
System.out.println(line);
}
if(line.contains("logout")){
break;
}
if (channel.isClosed()){
break;
}
try {
Thread.sleep(1000);
} catch (Exception ee){}
}
}catch(Exception e){
System.out.println("Error while reading channel output: "+ e);
}
}
public static void close(){
channel.disconnect();
session.disconnect();
System.out.println("Disconnected channel and session");
}
public static void main(String[] args){
List<String> commands = new ArrayList<String>();
commands.add("ls -l");
executeCommands(commands);
close();
}
}
最佳答案
您通常不应使用“shell” channel 来自动执行命令。
“shell” channel 旨在实现交互式 shell session 。
因此它请求 PTY(伪终端),它具有对人类友好但对机器不友好的副作用,会破坏您的代码。
改用“exec” channel 。
参见Execute a list of commands from an ArrayList using JSch exec in Java
<小时/>如果您出于某种原因需要或想要使用“shell” channel (但不这样做,无论如何它都会咬您),请确保在 之前调用
:.setPty(false)
.connect
channel = (ChannelShell)getSession().openChannel("shell");
channel.setPty(false);
channel.connect();
<小时/>
旁注:
“#!/bin/bash”
纯粹是无稽之谈。 shell 会忽略所有以#
开头的命令(它是注释)。寄出去也没啥意义- 请勿使用
StrictHostKeyChecking=no
。请参阅JSch SFTP security with session.setConfig(“StrictHostKeyChecking”, “no”); .
关于java - JSch 问题 - 无法检索完整的命令输出,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/35502600/