错误

Question

我需要在远程计算机上运行shell脚本。我正在使用JSch连接到远程计算机并使用ChannelExec执行shell脚本。 如果在执行命令时出现任何错误，我需要知道如何知道。

以下是我的代码

ChannelExec channel = (ChannelExec) session.openChannel("exec");

BufferedReader in = new BufferedReader(new InputStreamReader(channel.getInputStream()));    
String command = scriptName;
if(parameter != null && !parameter.isEmpty()){
    command += " " + parameter;
}

LOGGER.debug("Command To be Executed: " + command);             

channel.setCommand(command);
channel.connect();

//capture output
String msg;

StringBuffer output = new StringBuffer();
while ((msg = in.readLine()) != null)
{
    //output = output + msg;
    output.append(msg);
}

LOGGER.debug("Output Message = " + output.toString());

LOGGER.debug("ERROR STATUS --" + channel.getExitStatus());

channel.disconnect();
session.disconnect();

Answer 1

从“exec”频道的官方示例开始，不要重新发明轮子：
http://www.jcraft.com/jsch/examples/Exec.java.html

要阅读错误，请使用ChannelExec.getErrStream读取错误流。

或者将输出和错误流合并为一个：
How to get one stream from error stream and input stream when calling a script using JSCH

Answer 2

如果您已经知道会发生哪种异常，我们可以使用以下方式。

您可以通过获取Input Stream来检查在远程主机中执行的命令的响应，然后根据您的成功条件解析该流。

        ChannelExec execChannel = (ChannelExec) session.openChannel("exec");
        List<String> executionResult = new ArrayList<>();
        execChannel.setErrStream(System.err);
        InputStream consoleInputStream = execChannel.getInputStream();
        String command = "./executeScript.sh"
        execChannel.setCommand(command);
        execChannel.connect();
        BufferedReader consoleReader = new BufferedReader(new 
        InputStreamReader(consoleInputStream));
        String consoleData;
        while ((consoleData = consoleReader.readLine()) != null) {
            executionResult.add(consoleData);
        }

        for (String resultLine : executionResult) {
            Pattern errorPattern = Pattern.compile(("(?i)\\Exception\\b"));
            Matcher errorMatcher = errorPattern.matcher(resultLine); 
            if (errorMatcher.find())
      logs.writeLog(Level.SEVERE, "Error occurred while executing command");
        }