Question

Homework description::::: Write JAVA program with following description. Sample output with code will be helful...

A compiler must examine tokens in a program and decide whether they are reserved words in the Java language, or identifiers defined by the user. Design a program that reads a Java program and makes a list of all the identifiers along with the number of occurrences of each identifier in the source code.

To do this, you should make use of a dictionary. The dictionary will hold all the identifiers that you find in the Java program and the number of times the identifier appears in the program.

In addition, your program will need a data structure containing all the Java reserved words and operators. Write Java code that will create a balanced binary tree of the reserved words and operators in the Java language. A listing of reserved words and operators is to be read from the file, JavaKeywords.txt; the name of the program to be analyed is supplied as a command line argument.

Whenever your program encounters a token, it should search the binary search tree of reserved words. If the token is not a reserved word, then search the dictionary of identifiers. If the token is not in either dictionary, add it to the dictionary of identifiers. If the token appears in the identifiers dictionary, increment the frequency counter for that entry.

Use object-oriented program design for this project. Follow style and documenting examples given in class for earlier projects. Each file must begin with a comment block with your name, program name, course number, and due date. The block must also include the purpose, input, and output of the program.

Input Your program must be able to retrieve the names of the input files from the command line. The first file name is JavaKeywords.txt and the second is the name of the program to be parsed for identifiers.

Output Your program is to display an inorder traversal of the tree containing the Java reserved words and operators (one per line) along with labeled information regarding the height and number of nodes in the tree; followed by a list of the identifiers and the number of times each of them appears in the test program.

Answer 1

//Here we are importing files that we need for our program

import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.util.HashMap;
import java.util.Hashtable;
import java.util.Map;

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

// reading file here
BufferedReader reader = new BufferedReader(new FileReader(new File("javaKeywords.txt")));
String presentLine = null;
Map ReservedDictionary = new HashMap();
  
while((presentLine = reader.readLine()) != null) {reading each line and splitting and checking
// Split the input line.
String[] tokens = presentLine.split("\\s+");
  
// Ignore empty lines.
if(presentLine.equals(""))
continue;
String[] identifiers = {"char", "boolean", "byte", "short","int","long","float","double"};

for(String token: tokens) {
token = token.replace(".", "");
token = token.replace(",", "");
for(int z=0;z<identifiers.length;z++){
if(token==identifiers[z]){ // checking whether identifier or not
if(ReservedDictionary.containsKey(token)) { //checking token
Integer val = ReservedDictionary.get(token);
ReservedDictionary.put(token, val + 1); //otherwise we are pushing to reserved dictionary
}
}
}
}
}
  
// Printing all identifiers stored in the ReservedDictionary
for(String key: ReservedDictionary.keySet())
System.out.println(key + ": " + ReservedDictionary.get(key));
reader.close(); //closing the file
}
}

output

key : public 4

key :class 1

key: static 1