Java - Input Mismatch Exception?

Question

I'm still learning java so excuse my lack of skill here, any help is appreciated! I've been working on this java I/O project for school all day at this point and now I'm getting this input mismatch error on line 73 qtr = inputFile.nextInt();. The value should be an int, so I'm not sure if maybe I'm pointing java in the wrong direction or something instead?

Here is my code

import java.util.Scanner;  // Access the Scanner class
import java.io.*;          // Access PrintWriter and related classes

public class FileInputOutputDemo {

   public static void main(String[] args) throws IOException {
   
      // Declare variables
      
    // Define the file names for this demo program
   
      final String INPUT_FILE  = ("C:\\Users\\Hilary\\Desktop\\CS 1050 Summer 2021\\Project 4\\1050 - Project 04 - Input.txt");
      final String OUTPUT_FILE = "Proj4OutputDemo_Output.txt";
      
      int numInputLines = 0;  // Number of lines in the input file
      int qtr = 0;     // Quarter
      String areaTitle = "";  // Area title
      String ownerTitle = ""; // Owner title
      double qtrlyWages = 0.0;     // Quarterly wages  
      int errorCounter = 0;
      int totalDollarQ1FED[];  
      int totalDollarQ1STATE[];    
      int totalDollarQ1LOC[];    
      int totalDollarQ1PRIV[];    
      int totalDollarQ2FED[];  
      int totalDollarQ2STATE[];    
      int totalDollarQ2LOC[];    
      int totalDollarQ2PRIV[];
      String line = "";    
        
    // Access the input/output files   
      File inputDataFile = new File(INPUT_FILE);
      Scanner inputFile  = new Scanner(inputDataFile);
      
      FileWriter outputDataFile = new FileWriter(OUTPUT_FILE);
      PrintWriter outputFile = new PrintWriter(outputDataFile);
      
      // Begin program execution
      
      line = "Reading  file " + INPUT_FILE + "\n" +
             "Creating file " + OUTPUT_FILE + "\n";
      writeInfo(outputFile, line, 3);
    
    // Read and echo the input file
    
      while (inputFile.hasNext()) {
         numInputLines++;
         qtr = inputFile.nextInt();
         areaTitle = inputFile.next();
         ownerTitle = inputFile.next();
         qtrlyWages = inputFile.nextDouble();

         line = numInputLines + ") " + qtr + ",  " + areaTitle + 
                ",  " + ownerTitle + ", " + qtrlyWages;
         writeInfo(outputFile, line,numInputLines);
      } // End while
      
      line = "\n# of input lines: " + numInputLines;
      writeInfo(outputFile, line, 0);
   
      // Without the close, no output is written to the output file!
      outputFile.close();
      inputFile.close();
        
   }

Here is a screenshot snippet of the beginning of my input file:

Thank you!!!

REVISED CODE 8/4

import java.io.*;          // Access PrintWriter and related classes

public class FileInputOutputDemo {

   public static void main(String[] args) throws IOException {
   
      // Declare variables
      
    // Define the file names for this demo program
   
      final String INPUT_FILE  = ("C:\\Users\\Hilary\\Desktop\\CS 1050 Summer 2021\\Project 4\\1050 - Project 04 - Input.txt");
      final String OUTPUT_FILE = "Proj4OutputDemo_Output.txt";
      
      int numInputLines = 0;  // Number of lines in the input file
      int qtr = 0;     // Quarter
      String areaTitle = "";  // Area title
      String ownerTitle = ""; // Owner title
      int qtrlyWages = 0;     // Quarterly wages  
      int errorCounter = 0;
      int totalDollarQ1FED[];  
      int totalDollarQ1STATE[];    
      int totalDollarQ1LOC[];    
      int totalDollarQ1PRIV[];    
      int totalDollarQ2FED[];  
      int totalDollarQ2STATE[];    
      int totalDollarQ2LOC[];    
      int totalDollarQ2PRIV[];
      String line = "";    
      int headerLines = 3;
        
    // Access the input/output files   
      File inputDataFile = new File(INPUT_FILE);
      Scanner inputFile  = new Scanner(inputDataFile);
 //     Scanner tabbed = new Scanner(inputDataFile);
      inputFile.useDelimiter("\t");
      
      FileWriter outputDataFile = new FileWriter(OUTPUT_FILE);
      PrintWriter outputFile = new PrintWriter(outputDataFile);
      
      // Begin program execution
      
      line = "Reading  file " + INPUT_FILE + "\n" +
             "Creating file " + OUTPUT_FILE + "\n";
      writeInfo(outputFile, line, 3);
    
    // Read and echo the input file
      
      for (int i = 0; i < headerLines; i++) {
         inputFile.nextLine();
    //     numInputLines++;
      }
    
      while (inputFile.hasNext()) {
         numInputLines++;
         qtr = inputFile.nextInt();
         areaTitle = inputFile.next();
         ownerTitle = inputFile.next();
         qtrlyWages = inputFile.nextInt();

         line = numInputLines + ") " + qtr + ",  " + areaTitle + 
                ",  " + ownerTitle + ", " + qtrlyWages;
         writeInfo(outputFile, line,numInputLines);
      } // End while
      
      line = "\n# of input lines: " + numInputLines;
      writeInfo(outputFile, line, 0);
   
      // Without the close, no output is written to the output file!
      outputFile.close();
      inputFile.close();
        
   } // End main
   
   // ***********************************************************************
   
   /**
      writeInfo - Write info to the console and to an output file
      
      @param out - output file reference variable
      @param dataLine - a string with the line to output
      @param - numLines - if > 0, the output line # counter
      @return - none
      
      Note: if numLines > 0, this method inserts a blank line after
      SPACING lines
   */
   
   public static void writeInfo(PrintWriter out, String dataLine, int numLines)
   {
      final int SPACING = 5;     // Number of lines to introduce a blank line
      
      out.println(dataLine);
      System.out.println(dataLine);
      if (numLines % SPACING == 0  &&  numLines > 0)
      {
         out.println();
         System.out.println();
      }
   } // End writeInfo
} // End class```

@Dropout I just added a screenshot snippet of my input file! I didn't see where I could add an entire file. Any thoughts? — catherinemallory, Aug 03 '21 at 00:20
In the code it says you're using `1050 - Project 04 - Input.txt` and what you posted is obviously not a text file. — Dropout, Aug 03 '21 at 00:23
@Dropout Whoops! I've been staring at all of this for so long that I posted the wrong screenshot lol. Fixed! The text file screen shot is now up. — catherinemallory, Aug 03 '21 at 00:30
Is it tab separated? If so, you might want to change the delimiter character of your `Scanner`, with the `useDelimiter` method. I would actually recommend using two `Scanner` objects - one that reads the file a line at a time, then one that reads a line of the file, one field at a time. — Dawood ibn Kareem, Aug 03 '21 at 00:30
Yeah try what @DawoodibnKareem suggests, very good point, show us the output if it doesn't help. Also good night, be back in 8 hrs. — Dropout, Aug 03 '21 at 02:16
@Dropout @DawoodibnKareem Okay, here's my revised code. I made the delimiter \t (definitely helped!) But it's still giving me an input mismatch error, this time it's on line 84 ```qtrlyWages = inputFile.nextInt();``` . It's funny, I noticed that if I comment out line 84 momentarily-- it starts to print ```1) 1, Alabama -- Statewide, Federal Government, 0``` and then it's back to the same mismatch error in line 73... which confuses me because (based on the small printout) qtr seems to be correct? — catherinemallory, Aug 04 '21 at 19:05
Hi catherinemallory, and kudos for sticking with this. I think what might be happening now is that because you're only using one scanner, and that scanner doesn't consider newline to be a delimiter, the fourth field on one line and the first field on the next line are being treated as a single field. You probably want a delimiter expression that allows both tabs and newlines to be delimiters. I think something like `"\t|[\n\r]+"` might work. Alternatively, you could use my idea of having two scanners - one to read each line from the file, and one to read each field from the line. — Dawood ibn Kareem, Aug 04 '21 at 20:14

score 0 · Answer 1 · answered Aug 03 '21 at 03:41

0

The issue is that your input file data actually starts at line 4, the first 3 lines are just file and column headers. Since you aren't skipping these lines an InputMismatchException occurs.

To skip the file header, use Scanner.nextLine() as

int headerLines = 3;

for (int i = 0; i < headerLines; i++) {
    inputFile.nextLine();
    numInputLines++; // if you want to include the header into the count
}

while (inputFile.hasNext()) {
   // ...
}

answered Aug 03 '21 at 03:41

Ravi K Thapliyal

51,095
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Well that's one issue. Another problem is that `inputFile.next()` is only going to consume a single word, not the whole field; so when it's time to read the `79324` on the first line of data, you'll actually be reading the word `Statewide`. – Dawood ibn Kareem Aug 03 '21 at 04:04
@DawoodibnKareem Yes, you're correct. Personally, I would read the whole line and parse columns using a regex, but I don't want to spoon feed the complete solution. This post is just to get her past the exception, that's when she'll realize other problems with her code and see what a great advice using two scanners is. – Ravi K Thapliyal Aug 03 '21 at 05:44

Java - Input Mismatch Exception?

1 Answers1