Question

我目前正在尝试从Unix服务器检索JSON文件。

我使用JSch进行连接，效果很好。现在我的挑战是向服务器发送命令（或多或少几个cd和ls，这是一个非常简单的命令）。

问题是我收到了错误，而且我被困住了。

以下是servlet的代码：

import java.io.IOException;
import java.io.PrintWriter;

import static java.lang.System.*;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.jcraft.jsch.ChannelSftp;
import com.jcraft.jsch.JSch;
import com.jcraft.jsch.Session;

import java.io.*;
import java.util.*;
import javax.servlet.*;
import javax.servlet.http.*;

import java.lang.Runtime;

@WebServlet("/ConnexionRecette")
public class ConnexionRecette extends HttpServlet {

    protected void processRequest(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {

        String user = "xxxx";
        String password = "xxxxxx!";
        String host = "xxxxxx";
        int port = 22;

        // String remoteFile = "xxxxxxxxxx";

        PrintWriter out = response.getWriter();
        response.setContentType("text/html");
        out.println("<html>");
        out.println("<head><title>Connect to serv test</title></head>");
        out.println("<body>");
        out.println("<br>print avant try");

        try {
            JSch jsch = new JSch();
            Session session = jsch.getSession(user, host, port);
            session.setPassword(password);
            session.setConfig("StrictHostKeyChecking", "no");
            out.println("<br>Establishing Connection...");
            session.connect();
            out.println("<br>Connection established.");
            out.println("<br>Crating SFTP Channel.");
            ChannelSftp sftpChannel = (ChannelSftp) session.openChannel("sftp");
            sftpChannel.connect();
            out.println("<br>SFTP Channel created.");
            out.println("<br> ********** Ok on serv, end of connection code, end of try. **********");


            Runtime runtime = Runtime.getRuntime();
            String[] args = { "cd .."};
            final Process process = runtime.exec(args);
        BufferedReader output = getOutput(process);
        BufferedReader error = getError(process);
        String line = "";


        while((line = output.readLine()) != null) {
            out.println(line);
        }

        while((line = error.readLine()) != null) {
            out.println(line);
        }
        process.waitFor();

    } catch (IOException e) {
        out.println("<br>Print in catch IO");
        out.println("<br>*********************<br>");
        e.printStackTrace();
        out.println("<br>*********************<br>");

    } catch (InterruptedException e) {
        out.println("<br>Print in catch Interrupted");
        out.println("<br>*********************<br>");
        out.println("<br>*********************<br>");
        e.printStackTrace();

    }
        out.println("<br>print après le try catch");
        out.println("</body>");
        out.println("</html>");
    }

    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {

        doGet(request, response);
    }

}

调用servlet时出错：

无法运行程序“ssh”：CreateProcess error = 2，Lefichierspécifiéestintrouvable

java.io.IOException: Cannot run program "cd ..": CreateProcess error=2, Le fichier spécifié est introuvable
at java.lang.ProcessBuilder.start(Unknown Source)
at java.lang.Runtime.exec(Unknown Source)
at java.lang.Runtime.exec(Unknown Source)
at ConnexionRecette.doGet(ConnexionRecette.java:92)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:622)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:292)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:212)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:141)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:616)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:528)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1100)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:687)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1520)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1476)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Unknown Source)

引起：java.io.IOException：CreateProcess error = 2，Lefichierspécifiéestintrouvable at java.lang.ProcessImpl.create（Native Method）在java.lang.ProcessImpl。（未知来源）在java.lang.ProcessImpl.start（未知来源）

提前致谢！

Answer 1

java.io.IOException：无法运行程序“cd ..”：CreateProcess error = 2，Lefichierspécifiéestintrouvable

cd不是一个程序。它是一个内部命令，用于更改正在运行的shell的当前目录。

每个正在运行的进程都有一个当前目录。启动外部程序无法更改。如果要更改代码的当前目录，则应使用由您使用的语言提供的库函数。我不了解Java，但是如果您搜索文档中的chdir或changeDirectory，我确信您找到了正确的方法。

另一方面，如果要更改刚刚打开的远程连接上的当前目录，则应该通过sftpChannel对象发出命令，或者更可能的是，使用其中一种方法来更改远程目录。（同样，这只是编程常识，我对Java或sftpChannel）一无所知。

无法运行程序“ssh”：CreateProcess error = 2，系统找不到指定的文件

1 个答案: