试图完成一个java代码程序

我正在为学校编写一个java代码，我已经花了好几天的时间在上面，我只是觉得我的方向不对。以下是有关该项目的信息：

对于有安全意识的专业人士来说，只有合适的人才能访问计算机系统中的数据，这一点很重要。这称为身份验证。一旦用户进入，他们只看到与他们在计算机系统中的角色相关的数据也很重要。这称为授权。对于zoo，您将开发一个身份验证系统来管理身份验证和授权。您已获得一个凭据文件，其中包含授权用户的凭据信息。您还获得了三个文件，每个角色一个：动物园管理员、兽医和管理员。每个角色文件描述特定角色应有权访问的数据。创建执行以下所有操作的身份验证系统：  要求用户输入用户名  要求用户输入密码  使用消息摘要五（MD5）哈希转换密码

不需要从头开始编写MD5。使用本文档中的代码并按照其中的注释执行此操作。  根据凭据文件中提供的有效凭据检查凭据

使用第二列中的哈希密码；第三列包含用于测试的实际密码，第四行包含 每个用户的角色。  在通知用户并退出程序之前，将失败的尝试限制为三次  在成功进行身份验证后，为经过身份验证的用户提供对正确角色文件的访问权限

应显示存储在角色文件中的系统信息。例如，如果zookeeper的凭据已成功通过身份验证，则将显示zookeeper文件中的内容。如果管理员的凭据已成功通过身份验证，则将显示管理员文件中的内容。  允许用户注销  停留在凭证屏幕上，直到尝试成功、尝试三次失败或用户选择退出

以下是我收到的五个文本文件：

admin.txt

你好，系统管理员

作为管理员，您可以访问动物园的主计算机系统。
这允许您监视系统中的用户及其角色

credentials.txt

/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package authentication;

import java.security.MessageDigest;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.Scanner;

/**
 *
 * @author JoeP
 */
public class ValidateCredentials {

    private boolean isValid;
    private String filePath;
    private String credentialsFileName;

    public ValidateCredentials() {
        isValid = false;
        //filePath = "C:\\Users\\joep\\Documents\\NetBeansProjects\\ Authentication\\";
        filePath = "";
        credentialsFileName = "credentials";
    }

    public boolean isCredentialsValid(String userName, String passWord) throws Exception {
        String original = passWord;
        MessageDigest md = MessageDigest.getInstance("MD5");
        md.update(original.getBytes());
        byte[] digest = md.digest();
        StringBuffer sb = new StringBuffer();
        for (byte b : digest) {
            sb.append(String.format("%02x", b & 0xff));
        }

        System.out.println("");
        System.out.println("original:" + original);
        System.out.println("digested:" + sb.toString()); //sb.toString() is what you'll need to compare password strings

        isValid = readDataFiles(userName, sb.toString());

        return isValid;
    }

    public boolean readDataFiles(String userName, String passWord) throws IOException {
        FileInputStream fileByteStream1 = null; // File input stream
        FileInputStream fileByteStream2 = null; // File input stream

        Scanner inFS1 = null;                   // Scanner object
        Scanner inFS2 = null;                   // Scanner object

        String textLine = null;
        boolean foundCredentials = false;

        // Try to open file
        System.out.println("");
        System.out.println("Opening file " + credentialsFileName + ".txt");
        fileByteStream1 = new FileInputStream(filePath + "credentials.txt");
        inFS1 = new Scanner(fileByteStream1);

        System.out.println("");
        System.out.println("Reading lines of text.");

        while (inFS1.hasNextLine()) {
            textLine = inFS1.nextLine();
            System.out.println(textLine);

            if (textLine.contains(userName) && textLine.contains(passWord)) {
                foundCredentials = true;
                break;
            }
        }

        // Done with file, so try to close it
        System.out.println("");
        System.out.println("Closing file " + credentialsFileName + ".txt");

        if (textLine != null) {
            fileByteStream1.close(); // close() may throw IOException if fails
        }

        if (foundCredentials == true) {
            // Try to open file
            System.out.println("");
            System.out.println("Opening file " + userName + ".txt");
            fileByteStream2 = new FileInputStream(filePath + userName + ".txt");
            inFS2 = new Scanner(fileByteStream2);

            System.out.println("");

             while (inFS2.hasNextLine()) {
                textLine = inFS2.nextLine();
                System.out.println(textLine);
            }

            // Done with file, so try to close it
            System.out.println("");
            System.out.println("Closing file " + userName + ".txt");

            if (textLine != null) {
                fileByteStream2.close(); // close() may throw IOException if fails
            }
        }

        return foundCredentials;
    }

}

格里芬·凯斯108DE81C31BF9C622F768766B74E9285F“字母汤”动物园管理员 rosario.dawson 3E34BAA4 EE2FF767AF8C120A496742B5“动物医生”管理员 伯尼大猩猩a584efafa8f9ea7fe5cf18442f32b07b“秘密密码”兽医 donald.monkey 17B1B7D8A7066966ED220BC414F729AD3“M0nk3y业务”动物园管理员 jerome.grizzlybear 3ADE92111E6307F8F2AAE4721E77900“灰熊1234”兽医 bruce.grizzlybear 0d107d09f5bbe40cade3de5c71e9e9b7“letmein”管理员

validateCredentials.txt

/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package authentication;

import java.security.MessageDigest;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.Scanner;

/**
 *
 * @author JoeP
 */
public class ValidateCredentials {

    private boolean isValid;
    private String filePath;
    private String credentialsFileName;

    public ValidateCredentials() {
        isValid = false;
        //filePath = "C:\\Users\\joep\\Documents\\NetBeansProjects\\ Authentication\\";
        filePath = "";
        credentialsFileName = "credentials";
    }

    public boolean isCredentialsValid(String userName, String passWord) throws Exception {
        String original = passWord;
        MessageDigest md = MessageDigest.getInstance("MD5");
        md.update(original.getBytes());
        byte[] digest = md.digest();
        StringBuffer sb = new StringBuffer();
        for (byte b : digest) {
            sb.append(String.format("%02x", b & 0xff));
        }

        System.out.println("");
        System.out.println("original:" + original);
        System.out.println("digested:" + sb.toString()); //sb.toString() is what you'll need to compare password strings

        isValid = readDataFiles(userName, sb.toString());

        return isValid;
    }

    public boolean readDataFiles(String userName, String passWord) throws IOException {
        FileInputStream fileByteStream1 = null; // File input stream
        FileInputStream fileByteStream2 = null; // File input stream

        Scanner inFS1 = null;                   // Scanner object
        Scanner inFS2 = null;                   // Scanner object

        String textLine = null;
        boolean foundCredentials = false;

        // Try to open file
        System.out.println("");
        System.out.println("Opening file " + credentialsFileName + ".txt");
        fileByteStream1 = new FileInputStream(filePath + "credentials.txt");
        inFS1 = new Scanner(fileByteStream1);

        System.out.println("");
        System.out.println("Reading lines of text.");

        while (inFS1.hasNextLine()) {
            textLine = inFS1.nextLine();
            System.out.println(textLine);

            if (textLine.contains(userName) && textLine.contains(passWord)) {
                foundCredentials = true;
                break;
            }
        }

        // Done with file, so try to close it
        System.out.println("");
        System.out.println("Closing file " + credentialsFileName + ".txt");

        if (textLine != null) {
            fileByteStream1.close(); // close() may throw IOException if fails
        }

        if (foundCredentials == true) {
            // Try to open file
            System.out.println("");
            System.out.println("Opening file " + userName + ".txt");
            fileByteStream2 = new FileInputStream(filePath + userName + ".txt");
            inFS2 = new Scanner(fileByteStream2);

            System.out.println("");

             while (inFS2.hasNextLine()) {
                textLine = inFS2.nextLine();
                System.out.println(textLine);
            }

            // Done with file, so try to close it
            System.out.println("");
            System.out.println("Closing file " + userName + ".txt");

            if (textLine != null) {
                fileByteStream2.close(); // close() may throw IOException if fails
            }
        }

        return foundCredentials;
    }

}

兽医.txt

你好，兽医

作为兽医，你可以查阅所有动物的健康记录。这允许您查看每只动物的病史、当前治疗/疾病（如果有），并维护疫苗接种日志

zookeeper.txt

喂，动物园管理员

作为动物园管理员，您可以访问所有动物信息及其日常监测日志。这可以让你追踪它们的食性、栖息地条件和一般福利

最后，这是到目前为止我所拥有的代码，但当我尝试在Netbeans中运行它时，它就无法工作

import java.io.File;
import java.nio.charset.Charset;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.security.MessageDigest;
import java.util.List;
import java.util.Scanner;

public class Authentication {

    public static void main(String args[]) {

        try {
            Scanner scan = null;
            scan = new Scanner(new File("credentials.txt"));
            String credentials[][] = new String[100][4];
            int count = 0;
            while (scan.hasNextLine()) {
//read name and hased pass
                credentials[count][0] = scan.next();
                credentials[count][1] = scan.next();

//get original pass from file
                String l[] = scan.nextLine().split("\"[ ]+");
                l[0] = l[0].trim();
                l[0] = l[0].replace("\"", "");

                credentials[count][2] = l[0];
                credentials[count][3] = l[1].trim();
                count++;
            }

//ask for user input
            Scanner scanio = new Scanner(System.in);
            boolean RUN = true;
            int tries = 0;

            while (RUN) {
                System.out.println("**WELCOME**");
                System.out.println("1) Login");
                System.out.println("2) Exit");

                int ch = Integer.parseInt(scanio.nextLine().trim());

                if (ch == 1) {

//increment number of attempts
                    tries++;

//ask for user and pass
                    System.out.print("Input username:");
                    String username = scanio.nextLine();
                    System.out.print("Input password:");
                    String password = scanio.nextLine();

//generate hash
                    MessageDigest md;
                    md = MessageDigest.getInstance("MD5");
                    md.update(password.getBytes());
                    byte[] digest = md.digest();
                    StringBuilder sb = new StringBuilder();
                    for (byte b : digest) {
                        sb.append(String.format("%02x", b & 0xff));
                    }
                    String hPassword = sb.toString();

                    boolean badUser = true;
                    for (int i = 0; i < count; i++) {
                        if (username.contentEquals(credentials[i][0])) {
                            if (hPassword.contentEquals(credentials[i][1])) {
//everything looks good. login
                                List<String> data = null;

//check type of user and print
                                switch (credentials[i][3]) {
                                    case "zookeeper":
                                        data = Files.readAllLines(Paths.get("zookeeper.txt"), Charset.defaultCharset());
                                        break;
                                    case "admin":
                                        data = Files.readAllLines(Paths.get("admin.txt"), Charset.defaultCharset());
                                        break;
                                    case "veterinarian":
                                        data = Files.readAllLines(Paths.get("veterinarian.txt"), Charset.defaultCharset());
                                        break;
                                    default:
                                        break;
                                }

                                for (String s : data) {
                                    System.out.println(s);
                                }

//reset tries
                                tries = 0;

//now what to do?
                                System.out.println("\n1) Logout.");
                                System.out.println("2) Exit.");

                                ch = Integer.parseInt(scanio.nextLine().trim());
                                if (ch == 2) {
                                    RUN = false;
                                }

                                badUser = false;
                                break;
                            }
                        }
                    }

                    if (badUser) {
                        System.out.println("Invalid Username or password.");
                    }

                } else {
                    RUN = false;
                    break;
                }

//thief alert!!
                if (tries == 3) {
                    RUN = false;
                    System.out.println("Too many invlaid attempts.");
                }

            }

        } catch (Exception ex) {
            ex.printStackTrace();
        }

    }

}

导入java.io.File；
导入java.nio.charset.charset；
导入java.nio.file.Files；
导入java.nio.file.path；
导入java.security.MessageDigest；
导入java.util.List；
导入java.util.Scanner；
公共类身份验证{
公共静态void main（字符串参数[]）{
试一试{
扫描仪扫描=空；
扫描=新扫描仪（新文件（“credentials.txt”）；
字符串凭据[][]=新字符串[100][4]；
整数计数=0；
while（scan.hasNextLine（））{
//读名字并通过
凭据[count][0]=scan.next（）；
凭证[count][1]=扫描.next（）；
//从文件中获取原始通行证
字符串l[]=scan.nextLine（）.split（“\”[]+”）；
l[0]=l[0].trim（）；
l[0]=l[0]。替换（“\”，“）；
凭证[计数][2]=l[0]；
凭证[count][3]=l[1].trim（）；
计数++；
}
//请求用户输入
Scanner scanio=新扫描仪（System.in）；
布尔运行=真；
int=0；
while（运行）{
System.out.println（“**欢迎**”）；
System.out.println（“1）登录）；
系统输出打印（“2）退出”）；
int ch=Integer.parseInt（scanio.nextLine（）.trim（））；
如果（ch==1）{
//增加尝试次数
尝试++；
//询问用户和通行证
系统输出打印（“输入用户名：”）；
字符串username=scanio.nextLine（）；
系统输出打印（“输入密码：”）；
字符串密码=scanio.nextLine（）；
//生成散列
信息文摘md；
md=MessageDigest.getInstance（“MD5”）；
md.update（password.getBytes（））；
字节[]摘要=md.digest（）；
StringBuilder sb=新的StringBuilder（）；
for（字节b：摘要）{
sb.append（字符串格式（“%02x”，b&0xff））；
}
字符串hPassword=sb.toString（）；
布尔badUser=true；
for（int i=0；i