执行问题

Question

我已经调试了我的 java 代码。它似乎没有任何语法或逻辑错误。但是当我执行代码时，它并没有终止，也没有抛出任何错误。谁能帮我用另一种方法来解决这个问题？

这是我的 shell 脚本 -

echo "Name"
read name
if [ "$name" == "abcd" ]; then
 echo "correct name"
else
 echo "wrong name"
fi

echo "Password"
read password
if [ "$password" == "pwd" ]; then
 echo "Correct password"
else
 echo "Wrong password"
fi

echo "City"
read city
if [ "$city" == "bangalore" ]; then
 echo "correct city"
else
 echo "wrong city"
fi

---

这是我的 java 代码 -

package Pack;

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

import expectj.ExpectJ;
import expectj.Spawn;

public class Presentation extends Thread {

    public static StringBuffer execute(String cmd, List<Question> questions) {

        Utility u = new Utility();
        StringBuffer sb = new StringBuffer();
        ExpectJ exp = new ExpectJ();
        InputStreamReader isr = new InputStreamReader(System.in);
        BufferedReader br = new BufferedReader(isr);
        String answer = null;
        cmd = "sh /root/Desktop/details.sh";
        try {
            Spawn s = exp.spawn(cmd);
            Question q = null;
            int i = 0;
            while (i <= questions.size()) {
                System.out.println("iteration " + i);
                q = questions.get(i);
                try {
                    if (s.getCurrentStandardOutContents().contains(
                            q.getQuestion())) {
                        i++;
                    }
                    s.expect(q.getQuestion(), q.timeoutInSec);
                    if (q.isInteractive) {
                        System.out.println("Please provide your input: ");
                        answer = br.readLine();
                    } else {
                        if (q.isAnswerEncrypted) {
                            // TODO: decrypt the answer
                        } else {
                            answer = q.getAnswer();
                        }
                    }
                    s.send(answer + "\n");
                    i++;
                    try {
                        s.expectClose(3);
                        System.out.println("Script completed");
                        break;
                    } catch (Exception e) {

                    }
                } catch (Exception e) {
                    System.out.println("Timeout!!!Please answer "
                            + s.getCurrentStandardOutContents());
                    try {
                        answer = u.PromptUserForAnswerInCaseOfException();
                        s.send(answer + "\n");
                    } catch (IOException ioe) {
                        System.out.println("IO Exception..");
                    }
                }
            }
            s.expectClose();
        } catch (IOException ioe) {
            System.out.println("No more communication due to the lack of data");
        } catch (Exception e) {

        }
        return sb;
    }

    public static void main(String[] args) {

        String cmd = "sh /root/Desktop/details.sh";
        List<Question> questions = new ArrayList<Question>();

        Question question1 = new Question();
        question1.setQuestion("Name");
        question1.setIsInteractive(false);
        question1.setAnswer("abcd");
        question1.setIsAnswerEncrypted(false);

        Question question2 = new Question();
        question2.setQuestion("Password");
        question2.setIsInteractive(true);
        question2.timeoutInSec = 5;
        question2.setAnswer("pwd");
        question2.setIsAnswerEncrypted(false);

        Question question3 = new Question();
        question3.setQuestion("City");
        question3.setIsInteractive(false);
        question3.timeoutInSec = 5;
        question3.setAnswer("bangalore");
        question3.setIsAnswerEncrypted(false);

        questions.add(question2);
        questions.add(question1);
        questions.add(question3);

        System.out.println(questions.toString());
        try {
            execute(cmd, questions);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

Answer 1

编辑：关于您的程序：

while (i <= questions.size()) 敲响了警钟。当变量 i 等于 questions.size() 时，您已经到达列表的末尾。 questions.get(i) 将抛出异常，因为您正在尝试读取列表之外的内容。该子句应为while (i < questions.size()。

原始消息：这是关于如何调试似乎“陷入循环”的程序的建议：

如果您在 Eclipse 之类的 IDE 中运行，您可以“暂停”您当前正在调试的程序。然后通过查看调用堆栈，您可以看到当前执行点的位置。如果它在系统方法中，您可以“设置返回”，直到执行点到达您的代码。

Answer 2

如果您的循环中发生异常，它将永远不会结束，因为您没有break。也许您可以使用 for 循环。