Question

Finish FormatJavaProgram.java that prompts the user for a file name and assumes that the file contains a Java program. Your program should read the file (e.g., InputFile.java) and output its contents properly indented to ProgramName_Formatted.java (e.g., InputFile_Formatted.java). (Note: It will be up to the user to change the name appropriately for compilation later.)

When you see a left-brace character ({) in the file, increase your indentation level by NUM_SPACES spaces. When you see a right-brace character (}), decrease your indentation level by NUM_SPACES spaces. You may assume that the file has only one opening or closing brace per line, that every block statement (such as if or for) uses braces rather than omitting them, and that every relevant occurrence of a { or } character in the file occurs at the end of a line.

Optional added challenges:

• Consider instance with opening and closing braces on same line (such as } else if(){).
• Make your program work correctly with input files that contain statements like System.out.println("} else if(){");

Code Below:

import java.io.*;
import java.util.*;

/**
* Program that takes an unformatted Java program and prints out the same Java
* program with proper indentation.
*
*
*/
public class FormatJavaProgram {

/** Constant representing number of spaces to indent */
public static final int NUM_SPACES = 4;

/**
* Starts the program
*
* @param args An array of command line arguments
*/
public static void main(String[] args) {
userInterface();
}

/**
* Program's user interface.
*/
public static void userInterface() {
// Create null objects as placeholders for scope
// We specifically want a File object since we are basing the
// output file's name on the input file's name
File file = null;
Scanner inputFile = null;

Scanner console = new Scanner(System.in);

// While we have not gotten a valid file that can make a Scanner
// we'll get an input file, and try to create a Scanner.
while (inputFile == null) {
file = getInputFile(console);
inputFile = getInputScanner(file);
}

// Create a PrintStream based on the valid file
// passed in by the user
PrintStream outputFile = getOutputPrintStream(file);

// If the PrintStream could be created, then process the
// Java file.
if (outputFile != null) {
processJavaFile(inputFile, outputFile);
} else {
System.out.println("Output file cannot be written");
}
}

/**
* Returns a File object from the file name entered by the user
*
* @param console Scanner for console
* @return a File representing the file on the OS entered by the user
*/
public static File getInputFile(Scanner console) {
File file = null;
// TODO: write method
return file;
}

/**
* Returns a Scanner for the specified file, or null if the file does not
* exist.
*
* @param file the File entered by the user
* @return a Scanner to read the file
*/
public static Scanner getInputScanner(File file) {
Scanner inputFile = null;
// TODO: write method that uses a try/catch. Catch should print error
// message, but NOT end program.
return inputFile;
}

/**
* Returns a PrintStream for the specified file, or null if the file cannot
* be created. PrintStream should be format of ProgramName_Formatted.java
* based on name of file.
*
* @param file the File entered by the user
* @return a PrintStream to print to the file.
*/
public static PrintStream getOutputPrintStream(File file) {
PrintStream outputFile = null;
// HINT: use File getName() to get name of file to use to set up name of
// formatted file.

// TODO: write method that uses a try/catch. Catch should print error
// message, but NOT end program.
return outputFile;
}

/**
* Processes a Java file and provides the proper indentation
*
* @param inputFile the Java file to process
* @param outputFile the file to write the formated code to
*/
public static void processJavaFile(Scanner inputFile, PrintStream outputFile) {
int indentLevels = 0;
while (inputFile.hasNextLine()) {
String line = inputFile.nextLine().trim(); // trim() cuts of leading
// and ending whitespace

//TODO: Along with updating the tests below, you will also need to consider how
// you will need to update indentLevels within each block of the if/else structure
  
// TODO: For added challenge, uncomment (remove /* and */) and add
// condition for opening and closing braces on same line
/*
if (true) { // If line contains both } and { like a catch line or else
// TODO: update test from "true"
  
outputFile.println(getFormattedLine(line, indentLevels));
  
} else
*/
if (true) { // If the line only contains a closing bracket
// TODO: update test from "true"

outputFile.println(getFormattedLine(line, indentLevels));

} else if (true) { // If the line only contains an opening bracket
// TODO: update test from "true"

outputFile.println(getFormattedLine(line, indentLevels));

} else { // All other lines

outputFile.println(getFormattedLine(line, indentLevels));

}
}
}

/**
* Returns a line of Java code formatted to the proper indentation
*
* @param line the line to format
* @param indentLevels the number of levels of indentation
* @return the formatted line
*/
public static String getFormattedLine(String line, int indentLevels) {
String formattedLine = "";

return formattedLine;
}

}

Answer 1

Please let me know if you have any doubts or you want me to modify the answer. And if you find this answer useful then don't forget to rate my answer as thumps up. Thank you! :)

import java.io.*;
import java.util.*;

public class FormatJavaProgram {

    public static final int NUM_SPACES = 4;

    public static void main(String[] args) {
        userInterface();
    }

    public static void userInterface() {
        Scanner console = new Scanner(System.in);

        Scanner fileReader = getInputScanner(console);

        PrintStream fileWriter = getOutputPrintStream(console);

        processJavaFile(fileReader, fileWriter);

        fileWriter.close();
        fileReader.close();
        console.close();
    }

    public static Scanner getInputScanner(Scanner console) {
        Scanner file = null;
        try {
            File f;
            do {
                System.out.print("Enter Java File to Format: ");
                String input = console.nextLine();
                f = new File(input);

            } while (!f.exists());
            file = new Scanner(f);

        } catch (FileNotFoundException ex) {
        }
        return file;
    }

    public static PrintStream getOutputPrintStream(Scanner console) {
        File f;
        PrintStream file = null;
        while (file == null) {
            try {
                System.out.print("Enter Output file: ");
                String input = console.nextLine();
                f = new File(input);
                file = new PrintStream(f);
            } catch (FileNotFoundException ex) {
            }
        }

        return file;

    }

  
    public static void processJavaFile(Scanner input, PrintStream output) {
        int indentLevels = 0;
        while (input.hasNextLine()) {
            String line = input.nextLine().trim();

            if (line.contains("}") && line.contains("{")) {
                output.println(getFormattedLine(line, indentLevels));

            } else if (line.contains("}")) {
                output.println(getFormattedLine(line, indentLevels));
                indentLevels--;

            } else if (line.contains("{")) {
                indentLevels++;
                if (line.contains("public class")) {
                    indentLevels--;
                }
                output.println(getFormattedLine(line, indentLevels));

            } else if (line.contains("import")) {
                output.println((getFormattedLine(line, indentLevels)));

            } else {
                indentLevels++;
                output.println((getFormattedLine(line, indentLevels)));
                indentLevels--;

            }
        }
    }

  
    public static String getFormattedLine(String line, int indentLevels) {
        String formattedLine = "";
        for (int i = 0; i < indentLevels; i++) {
            for (int j = 0; j < NUM_SPACES; j++) {
                formattedLine += " ";
            }
        }
        formattedLine += line;
        return formattedLine;
    }

}

FormatJavaProgram [/ldeaProjects/FormatJava Program] -/src/FormatJava Program.java [FormatJava Program] Format JavaProgram FormatJava Progra m src Main FormatJava Proo ram .Java Project vFormatJava Program import java.io. impo rt java.util. *; Idea Project s/FormatJavaPr idea out public class FormatJavaProgram sro GFormatJavaProgram FormatJavaProgram. iml ublic static final int NUM SPACES= 4: pub userInterfare (String [] args) { Scratches and Consoles 11 public static void userInterface() { Scanner console = new Scanner(System. in); 14 fileReader = getInputScanner (console) ; Scanner PrintStream fileWriter = getOutputPrintStream (console) ; processJavaFile(fileReader, fileWriter) ; 20 fileWriter. close(): fileReader.close (); 23 console.close(); 26 public static Scanner getInputScanne r ( Scanner console) { Scanner file = null: tr File f; do f Format: "): String innut Consale.pextLine(): =new File(input); while (!f.exists ( )); file new Scanner(f) ; 38 catch (FileNot Found Exception ex) ( FormatJavaProgram userinterface() Main / Library/Java/JavaVirtua lMachines/j dk-9.0.4.jdk/Contents/Home/bin/java "-javaagent :/Applications/Intellil IDEA CE.app/Contents/lib/idea_rt. jar=62720: /Applications/ Intelli] IDEA CE.app/Contents/bi Enter Java File to Format: Run O 2:28 LF: UTF-8: Compilation completed successfully in 13 s 799 ms (4 minutes ago)