ExpressionTreeTest

java.lang.Object
- ExpressionTreeTest

```
public class ExpressionTreeTest
extends java.lang.Object
```
A test file created for ExpressionTree. The file takes in an input file, either the one with the default input file name, or, if that is not available the one provided in the command-line arguments. Otherwise, the program will request an input file name from the user. The test file will then process the file, which should have an expression on each line. For each expression, the program will build an ExpressionTree and print the result of the expression using the tree, the expression in prefix, infix and postfix, and the evaluation of the expression using a stack.

Author:

AnneMarie Caballero (annemariecabs)

Field Summary

Fields
Modifier and Type	Field	Description
`private static java.lang.String`	`DEFAULT_FILE_NAME`	The default name for the input file
`private static java.lang.String`	`EMPTY`	An empty String
`private static int`	`ERROR_CODE`	The code passed as a parameter to System.exit() when something has gone wrong
`private static java.lang.String`	`EXIT`	The word exit
`private static java.lang.String`	`INVALID_FILE_MESSAGE`	The message shown if the file holding the postfix expressions is not found
`private static java.lang.String`	`IOEXCEPTION_MESSAGE`	The message shown if the program encounters an IOException when reading the file with the expressions
`private static java.util.Scanner`	`keyboard`	The Scanner used to read user input on the keyboard
`private static java.lang.String`	`NEW_LINE`	A newline
`private static java.io.PrintWriter`	`output`	The PrintWriter to print to the output file with name OUTPUT_FILE_NAME
`private static java.lang.String`	`OUTPUT_FILE_NAME`	The name of the designated output file
`private static java.lang.String`	`PRINTWRITER_ERROR_MESSAGE`	The error message used if a PrintWriter throws a FileNotFoundException
`private static java.lang.String`	`SPACE`	A space

Constructor Summary

Constructors
Constructor Description

ExpressionTreeTest()

Constructors
Constructor	Description
`ExpressionTreeTest()`

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method	Description
`static void`	`main(java.lang.String[] args)`
`static void`	`printTest(ExpressionTree tree, java.lang.String[] expressions)`	Prints out the various tests this program is required to run.
`static java.lang.String[]`	`readFileWithPostfixExpressions(java.io.File file)`	Reads a file with postfixExpressions in it and returns the expressions as a String array with each index holding a singular expression.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - DEFAULT_FILE_NAME
```
private static final java.lang.String DEFAULT_FILE_NAME
```
    The default name for the input file
    
    See Also:
    
    Constant Field Values
  - OUTPUT_FILE_NAME
```
private static final java.lang.String OUTPUT_FILE_NAME
```
    The name of the designated output file
    
    See Also:
    
    Constant Field Values
  - IOEXCEPTION_MESSAGE
```
private static final java.lang.String IOEXCEPTION_MESSAGE
```
    The message shown if the program encounters an IOException when reading the file with the expressions
    
    See Also:
    
    Constant Field Values
  - INVALID_FILE_MESSAGE
```
private static final java.lang.String INVALID_FILE_MESSAGE
```
    The message shown if the file holding the postfix expressions is not found
    
    See Also:
    
    Constant Field Values
  - PRINTWRITER_ERROR_MESSAGE
```
private static final java.lang.String PRINTWRITER_ERROR_MESSAGE
```
    The error message used if a PrintWriter throws a FileNotFoundException
    
    See Also:
    
    Constant Field Values
  - EXIT
```
private static final java.lang.String EXIT
```
    The word exit
    
    See Also:
    
    Constant Field Values
  - SPACE
```
private static final java.lang.String SPACE
```
    A space
    
    See Also:
    
    Constant Field Values
  - EMPTY
```
private static final java.lang.String EMPTY
```
    An empty String
    
    See Also:
    
    Constant Field Values
  - NEW_LINE
```
private static final java.lang.String NEW_LINE
```
    A newline
    
    See Also:
    
    Constant Field Values
  - ERROR_CODE
```
private static final int ERROR_CODE
```
    The code passed as a parameter to System.exit() when something has gone wrong
    
    See Also:
    
    Constant Field Values
  - keyboard
```
private static java.util.Scanner keyboard
```
    The Scanner used to read user input on the keyboard
  - output
```
private static java.io.PrintWriter output
```
    The PrintWriter to print to the output file with name OUTPUT_FILE_NAME
- Constructor Detail
  - ExpressionTreeTest
```
public ExpressionTreeTest()
```
- Method Detail
  - main
```
public static void main(java.lang.String[] args)
```
  - readFileWithPostfixExpressions
```
public static java.lang.String[] readFileWithPostfixExpressions(java.io.File file)
                                                         throws java.io.IOException
```
    Reads a file with postfixExpressions in it and returns the expressions as a String array with each index holding a singular expression.
    
    Parameters:
    
    file - the name of the file to read
    
    Returns:
    
    a String[] with the expressions stored in it; an empty String[] if the file has no lines
    
    Throws:
    
    java.io.IOException - if an error has occurred in reading the file
  - printTest
```
public static void printTest(ExpressionTree tree,
                             java.lang.String[] expressions)
```
    Prints out the various tests this program is required to run. The scanner output needs to be a field that has already been initialized and closed after this method.
    
    Parameters:
    
    tree - an ExpressionTree to perform various operations on
    
    expressions - the list of expressions the ExpressionTree holds

Class ExpressionTreeTest

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

DEFAULT_FILE_NAME

OUTPUT_FILE_NAME

IOEXCEPTION_MESSAGE

INVALID_FILE_MESSAGE

PRINTWRITER_ERROR_MESSAGE

EXIT

SPACE

EMPTY

NEW_LINE

ERROR_CODE

keyboard

output

Constructor Detail

ExpressionTreeTest

Method Detail

main

readFileWithPostfixExpressions

printTest