Question

Problem 1

1. In the src → edu.neiu.p2 directory, create a package named problem1.

2. Create a Java class named StringParser with the following:

• A public static method named findInteger that takes a String and two char variables as parameters (in that order) and does not return anything.

• The method should find and print the integer value that is located in between the two characters. You can assume that the second char parameter will always follow the first char parameter. However, you cannot assume that the parameters will be different from each other. Print out the result in this format (where XX represents the integer value): Integer: XX

• You may not use any loops, conditional statements, or regex (including switch statements and the tertiary operator).

• You cannot assume that only valid integers or nothing will appear in between the specified characters. If the value is not valid or there is nothing in between the specified characters, print out "Invalid characters" followed by printing out the result of calling the toString method on the exception object.

• Hint: Think about the methods that you can use to convert Strings to integers and whether they throw exceptions! Make sure to handle the most specific exception class (i.e. do NOT use the superclass Exception to catch the exception object).

3. Once you’ve created the method, run the StringParserTest class in the tests package to see if you’ve created the code correctly.

4. To help yourself debug and test your code, create a Java class named StringParserDemo that has the main method. In the main method include at least three examples. Note that for the examples below, the method call is provided, followed by the expected output.

StringParser.findInteger("rugtsbckgus! 32*", "l','*'); Expected Output: Integer: 32 StringParser. FindInteger("rujfbgl&Xfkslga", '&', '%'); Invalid integer java.lang.Number Format Exception: For input string: "" StringParser.findInteger("rusbdi#10384jjdksu", '',''); Integer: 1038

Problem 1: StringParserTest class

package neiu.edu.p2.tests.problem1;

// UNCOMMENT THIS IMPORT
//import neiu.edu.p2.problem1.StringParser;

import java.io.ByteArrayOutputStream;
import java.io.PrintStream;

public class StringParserTest {
    public static void main(String[] args) {
        // TESTS - UNCOMMENT THE TEST METHOD CALLS
        /*shouldTestIntegerSurroundedByDifferentCharacters();
        shouldTestIntegerSurroundedBySameCharacters();
        shouldTestNoValuesInBetweenCharacters();
        shouldTestForInvalidValuesInBetweenCharacters();*/
    }

    // UNCOMMENT ALL OF THESE TESTS
    /*private static void shouldTestIntegerSurroundedByDifferentCharacters() {
        System.out.println("Test Name: " + Thread.currentThread().getStackTrace()[1].getMethodName());
        System.out.print("Test Outcome: ");

        final ByteArrayOutputStream outContent = new ByteArrayOutputStream();
        final PrintStream originalOut = System.out;
        System.setOut(new PrintStream(outContent));

        try {
            StringParser.findInteger("rugtsbckgus!32*", '!', '*');
            String out = outContent.toString();
            System.setOut(originalOut);
            System.out.println("Integer: 32\n".equals(out) ? "PASSED" : "FAILED");
            System.out.println("Expected:\nInteger: 32");
            System.out.println("Actual:\n" + out);
        } catch (RuntimeException e) {
            System.out.println("FAILED. ERROR!!");
            e.printStackTrace();
        }
        System.out.println();
    }

    private static void shouldTestIntegerSurroundedBySameCharacters() {
        System.out.println("Test Name: " + Thread.currentThread().getStackTrace()[1].getMethodName());
        System.out.print("Test Outcome: ");

        final ByteArrayOutputStream outContent = new ByteArrayOutputStream();
        final PrintStream originalOut = System.out;
        System.setOut(new PrintStream(outContent));

        try {
            StringParser.findInteger("rusbdi#1038#jjdksu", '#', '#');
            String out = outContent.toString();
            System.setOut(originalOut);
            System.out.println("Integer: 1038\n".equals(out) ? "PASSED" : "FAILED");
            System.out.println("Expected:\nInteger: 1038");
            System.out.println("Actual:\n" + out);
        } catch (RuntimeException e) {
            System.out.println("FAILED. ERROR!!");
            e.printStackTrace();
        }
        System.out.println();
    }

    private static void shouldTestNoValuesInBetweenCharacters() {
        System.out.println("Test Name: " + Thread.currentThread().getStackTrace()[1].getMethodName());
        System.out.print("Test Outcome: ");

        final ByteArrayOutputStream outContent = new ByteArrayOutputStream();
        final PrintStream originalOut = System.out;
        System.setOut(new PrintStream(outContent));

        try {
            StringParser.findInteger("rujfbgl&%fkslga", '&', '%');
            String out = outContent.toString();
            System.setOut(originalOut);
            String expected = "Invalid integer\n" + "java.lang.NumberFormatException: For input string: \"\"\n";
            System.out.println(expected.equals(out) ? "PASSED" : "FAILED");
            System.out.println("Expected:\n" + expected);
            System.out.println("Actual:\n" + out);
        } catch (RuntimeException e) {
            System.out.println("FAILED. ERROR!!");
            e.printStackTrace();
        }
        System.out.println();
    }

    private static void shouldTestForInvalidValuesInBetweenCharacters() {
        System.out.println("Test Name: " + Thread.currentThread().getStackTrace()[1].getMethodName());
        System.out.print("Test Outcome: ");

        final ByteArrayOutputStream outContent = new ByteArrayOutputStream();
        final PrintStream originalOut = System.out;
        System.setOut(new PrintStream(outContent));

        try {
            StringParser.findInteger("rusbdi^10.38^jjdksu", '^', '^');
            String out = outContent.toString();
            System.setOut(originalOut);
            String expected = "Invalid integer\n" + "java.lang.NumberFormatException: For input string: \"10.38\"\n";
            System.out.println(expected.equals(out) ? "PASSED" : "FAILED");
            System.out.println("Expected:\n" + expected);
            System.out.println("Actual:\n" + out);
        } catch (RuntimeException e) {
            System.out.println("FAILED. ERROR!!");
            e.printStackTrace();
        }
        System.out.println();
    }*/
}

please help

Answer 1

Here is the completed code for this problem. Comments are included, go through it, learn how things work and let me know if you have any doubts or if you need anything to change. If you are satisfied with the solution, please rate the answer. If not, PLEASE let me know before you rate, I’ll help you fix whatever issues. Thanks

// StringParser.java

package neiu.edu.p2.problem1;

public class StringParser {

      // required method

      public static void findInteger(String text, char first, char second) {

            // putting the code inside a try catch block

            try {

                  // finding index of char first in text, assuming first and second

                  // exist on text

                  int index1 = text.indexOf(first);

                  // finding index of char second, starting from index1+1 index

                  int index2 = text.indexOf(second, index1 + 1);

                  // parsing integer value between index1+1 and index2-1 as integer

                  int i = Integer.parseInt(text.substring(index1 + 1, index2));

                  // if parsing is successful, displaying in format 'Integer: XX\n'

                  System.out.print("Integer: " + i + "\n");

            } catch (NumberFormatException nfe) {

                  // if any exception occurred, displaying 'Invalid integer\n'

                  // followed by exception message

                  System.out.print("Invalid integer\n");

                  System.out.print(nfe + "\n");

            }

      }

}

// StringParserTest.java

package neiu.edu.p2.tests.problem1;

import neiu.edu.p2.problem1.StringParser;

import java.io.ByteArrayOutputStream;

import java.io.PrintStream;

public class StringParserTest {

    public static void main(String[] args) {

        // TESTS - UNCOMMENT THE TEST METHOD CALLS

        shouldTestIntegerSurroundedByDifferentCharacters();

        shouldTestIntegerSurroundedBySameCharacters();

        shouldTestNoValuesInBetweenCharacters();

        shouldTestForInvalidValuesInBetweenCharacters();

    }

    // UNCOMMENT ALL OF THESE TESTS

    private static void shouldTestIntegerSurroundedByDifferentCharacters() {

        System.out.println("Test Name: " + Thread.currentThread().getStackTrace()[1].getMethodName());

        System.out.print("Test Outcome: ");

        final ByteArrayOutputStream outContent = new ByteArrayOutputStream();

        final PrintStream originalOut = System.out;

        System.setOut(new PrintStream(outContent));

        try {

            StringParser.findInteger("rugtsbckgus!32*", '!', '*');

            String out = outContent.toString();

            System.setOut(originalOut);

            System.out.println("Integer: 32\n".equals(out) ? "PASSED" : "FAILED");

            System.out.println("Expected:\nInteger: 32");

            System.out.println("Actual:\n" + out);

        } catch (RuntimeException e) {

            System.out.println("FAILED. ERROR!!");

            e.printStackTrace();

        }

        System.out.println();

    }

    private static void shouldTestIntegerSurroundedBySameCharacters() {

        System.out.println("Test Name: " + Thread.currentThread().getStackTrace()[1].getMethodName());

        System.out.print("Test Outcome: ");

        final ByteArrayOutputStream outContent = new ByteArrayOutputStream();

        final PrintStream originalOut = System.out;

        System.setOut(new PrintStream(outContent));

        try {

            StringParser.findInteger("rusbdi#1038#jjdksu", '#', '#');

            String out = outContent.toString();

            System.setOut(originalOut);

            System.out.println("Integer: 1038\n".equals(out) ? "PASSED" : "FAILED");

            System.out.println("Expected:\nInteger: 1038");

            System.out.println("Actual:\n" + out);

        } catch (RuntimeException e) {

            System.out.println("FAILED. ERROR!!");

            e.printStackTrace();

        }

        System.out.println();

    }

    private static void shouldTestNoValuesInBetweenCharacters() {

        System.out.println("Test Name: " + Thread.currentThread().getStackTrace()[1].getMethodName());

        System.out.print("Test Outcome: ");

        final ByteArrayOutputStream outContent = new ByteArrayOutputStream();

        final PrintStream originalOut = System.out;

        System.setOut(new PrintStream(outContent));

        try {

            StringParser.findInteger("rujfbgl&%fkslga", '&', '%');

            String out = outContent.toString();

            System.setOut(originalOut);

            String expected = "Invalid integer\n" + "java.lang.NumberFormatException: For input string: \"\"\n";

            System.out.println(expected.equals(out) ? "PASSED" : "FAILED");

            System.out.println("Expected:\n" + expected);

            System.out.println("Actual:\n" + out);

        } catch (RuntimeException e) {

            System.out.println("FAILED. ERROR!!");

            e.printStackTrace();

        }

        System.out.println();

    }

    private static void shouldTestForInvalidValuesInBetweenCharacters() {

        System.out.println("Test Name: " + Thread.currentThread().getStackTrace()[1].getMethodName());

        System.out.print("Test Outcome: ");

        final ByteArrayOutputStream outContent = new ByteArrayOutputStream();

        final PrintStream originalOut = System.out;

        System.setOut(new PrintStream(outContent));

        try {

            StringParser.findInteger("rusbdi^10.38^jjdksu", '^', '^');

            String out = outContent.toString();

            System.setOut(originalOut);

            String expected = "Invalid integer\n" + "java.lang.NumberFormatException: For input string: \"10.38\"\n";

            System.out.println(expected.equals(out) ? "PASSED" : "FAILED");

            System.out.println("Expected:\n" + expected);

            System.out.println("Actual:\n" + out);

        } catch (RuntimeException e) {

            System.out.println("FAILED. ERROR!!");

            e.printStackTrace();

        }

        System.out.println();

    }

}

/*OUTPUT*/

Test Name: shouldTestIntegerSurroundedByDifferentCharacters

Test Outcome: PASSED

Expected:

Integer: 32

Actual:

Integer: 32

Test Name: shouldTestIntegerSurroundedBySameCharacters

Test Outcome: PASSED

Expected:

Integer: 1038

Actual:

Integer: 1038

Test Name: shouldTestNoValuesInBetweenCharacters

Test Outcome: PASSED

Expected:

Invalid integer

java.lang.NumberFormatException: For input string: ""

Actual:

Invalid integer

java.lang.NumberFormatException: For input string: ""

Test Name: shouldTestForInvalidValuesInBetweenCharacters

Test Outcome: PASSED

Expected:

Invalid integer

java.lang.NumberFormatException: For input string: "10.38"

Actual:

Invalid integer

java.lang.NumberFormatException: For input string: "10.38"