在java文本文件中查找不同的标记

我正在做一个作业，你必须接收一个包含一些代码的文件，识别其中的令牌，并以特定的格式输出它们。到目前为止，我已经从文件中获取了字符，并将其添加到数组列表中。现在我很难找到在文件中查找特定标记的逻辑。我知道你首先要做一个循环来遍历数组列表。我在我的分析笔记的评论中有一个我的逻辑大纲。我不知道如何让它遍历并只附加每个类型一次，因为它在for循环的第一次迭代中检查，然后在第二次迭代中再次检查，所以我觉得会有重叠。我将如何解决这个问题

import java.util.ArrayList;
import java.util.Scanner;
import java.io.*;
import java.lang.Character;

public class Main {

    /*
        Constants for specific tokens that can be identified easily.
     */
    final Character LPAREN = '(';
    final Character RPAREN = ')';
    final Character ADD_OP[] = {'+', '-'};
    final String MULT_OP[] = {"*", "/", "//", "%"};
    final Character ASSIGN[] = {':', '='};
    final Character IDENTIFIERS[] ={'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'j', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z'};
    final int NUMBERS[] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9};

    public static void main(String[] args) throws IOException {

        Scanner input = new Scanner(System.in); //Scanner for taking input from the user

        String fileName;
        System.out.println("Enter the name of the file.");
        fileName = input.next();

        fileExists(fileName); // Checks to see if the file exists

        ArrayList<Character> arrayOfTokens = new ArrayList<Character>();
        readToArray(arrayOfTokens, fileName);

        for(int i = 0; i < arrayOfTokens.size(); i++) {
            System.out.print(arrayOfTokens.get(i) + ", ");
        }

    }

    /*
        readToArray goes through a file and adds all its elements in individual character form. It is stored into an arraylist and it is then returned
        @param storeChar: This is an arraylist of characters that the characters will be saved into and then returned.
        @param fileName: The filename that you want to take the data from.
     */
    private static ArrayList<Character> readToArray(ArrayList<Character> storeChar, String fileName) throws IOException {
        /*
            Block of code to setup the fileInput stream to take in data from the file. Reads character by character and stores into an arraylist.
            int atChar: the current character the reader is at. Returns in int format (Need to be converted to character later on)
            int currentIndex: to add a character to an index. Increments until no more characters are left
         */
        FileInputStream fileInput = new FileInputStream(fileName);
        int atChar;
        int currentIndex = 0;

        /*
            Loop to go through and add the converted character from an int to the arraylist.
            Loops until atChar returns -1 which means no more characters in file.
         */
        while((atChar = fileInput.read()) != -1) {
            storeChar.add(currentIndex, (char)(atChar));
            currentIndex++;
        }
        fileInput.close();
        return storeChar;
    }

    /*
        fileExists method makes sure the file the user enters exists in the system. If it doesn't then the program will terminate before any further code is executed.
        @param fileName: Takes in a string paramater of the file name that you want to if it exists.
     */
    private static void fileExists(String fileName) {

        boolean ifExists; //Boolean statement that will later be set to the value of whether the file exists or not

        File file = new File(fileName);
        ifExists = file.exists();

        if(ifExists == false) {
            System.out.println("Unable to find the file. Will now close the program.");
            System.exit(0);
        }
    }

    private static ArrayList<String> analyzeForTokens(ArrayList<Character> tokens, Character LPAREN, Character RPAREN, Character ADD_OP, String MULTI_OP, Character ASSIGN, Character IDENTIFIERS, int NUMBERS) {

        ArrayList<String> indentified = new ArrayList<String>();

        for(int i = 0; i < tokens.size(); i++) { //first for loop go through the whole array list 
            //if statement to check if CURRENT character is an identifier, number, lparam, rparam etc...
                //Another loop to go until you find a white space. Then concatinate all indexes from first index to white space into new string
                //if started with indentifer param then it will take the appended string then append < identifierType >, identifierType (As long as identifier longer than one character)
                //if string only consists of one string then it is an id append <id>, id
                //if number converts the character integer and compares and so on....
            //Once returned just printout the values of the arraylist since they should be appended int he correct format

        }

        return indentified;
    }
}

输出：

<read>, read
<id>, a
<read>, read
<id>, b
<id>, c
<assign>, :=
<id>, a
<add_op>, +
<id>, b
<add_op>, +
<number>, 3
<write>, write
<id>, c 

，请阅读
，a
，读
，b
，c
, :=
，a
, +
，b
, +
, 3
，写
，c

你知道有一门课，对吧？…还有一门更高级的课程

<read>, read
<id>, a
<read>, read
<id>, b
<id>, c
<assign>, :=
<id>, a
<add_op>, +
<id>, b
<add_op>, +
<number>, 3
<write>, write
<id>, c