scg/ch09/TextFileByWord

001 packagepackage is used to name the directory or folder a class is in scg.ch09;
002 
003 importimport means to make the classes and/or packages available in this program java.io.File;
004 importimport means to make the classes and/or packages available in this program java.io.FileNotFoundException;
005 importimport means to make the classes and/or packages available in this program java.util.ArrayList;
006 importimport means to make the classes and/or packages available in this program java.util.Scanner;
007 
008 /**
009  * Non-FANG program: A TextFileByWord object reads a file into a list.
010  * The listLoadFromFile(fname) method reads the contents of the file
011  * word by word, storing the results in the strings ArrayList.
012  *
013  * @authorthis is the Javadoc tag for documenting who created the source code  blad
014  */
015 publicpublic is used to indicate unrestricted access (any other class can have access) classclass is a group of fields and methods used for making objects TextFileByWord {open braces start code blocks and must be matched with a close brace
016   /**
017    * collection containing all of the strings (words) read from the file
018    */
019   ArrayList<String> strings;
020 
021   /**
022    * Construct a TextFileByWord object; initialize the strings list.
023    */
024   publicpublic is used to indicate unrestricted access (any other class can have access) TextFileByWord() {open braces start code blocks and must be matched with a close brace
025     strings =this assignment operator makes the left side equal to the right side newnew is used to create objects by calling the constructor ArrayList<String>();
026   }close braces end code blocks and must match an earlier open brace
027 
028   /**
029    * Create a newnew is used to create objects by calling the constructor strings list and fill it from the file. If there are
030    * any problems, the contents of strings is left unchanged.
031    *
032    * @paramthis is the Javadoc tag for documenting the purpose of parameters  fname
033    */
034   publicpublic is used to indicate unrestricted access (any other class can have access) voidvoid means the method does not return a value listLoadFromFile(String fname) {open braces start code blocks and must be matched with a close brace
035     File file =this assignment operator makes the left side equal to the right side newnew is used to create objects by calling the constructor File(fname);
036     ifif executes the next statement only if the condition in parenthesis evaluates to true (file.exists() &this performs a bit-wise and (not the same as boolean and which is &&)&this performs a bit-wise and (not the same as boolean and which is &&) file.canRead()) {open braces start code blocks and must be matched with a close brace
037       trytry is for executing a code block that may experience exceptions (errors) {open braces start code blocks and must be matched with a close brace
038         ArrayList<String> localStrings =this assignment operator makes the left side equal to the right side newnew is used to create objects by calling the constructor ArrayList<String>();
039         Scanner scanner =this assignment operator makes the left side equal to the right side newnew is used to create objects by calling the constructor Scanner(file);
040         String word;
041         whilewhile is a looping structure for executing code repeatedly (scanner.hasNext()) {open braces start code blocks and must be matched with a close brace
042           word =this assignment operator makes the left side equal to the right side scanner.next();
043           localStrings.add(word);
044         }close braces end code blocks and must match an earlier open brace
045         strings =this assignment operator makes the left side equal to the right side localStrings;
046         scanner.close();
047       }close braces end code blocks and must match an earlier open brace catchcatch means to handle an exception that may occur (FileNotFoundException e) {open braces start code blocks and must be matched with a close brace
048         System.out.println("PANIC: This should never happen!");
049         e.printStackTrace();
050       }close braces end code blocks and must match an earlier open brace
051     }close braces end code blocks and must match an earlier open brace elseelse is what happens when the if condition is false {open braces start code blocks and must be matched with a close brace
052       System.out.println("Unable to open \"" +adds two numbers together or concatenates Strings together fname +adds two numbers together or concatenates Strings together "\" for input");
053     }close braces end code blocks and must match an earlier open brace
054   }close braces end code blocks and must match an earlier open brace
055 
056   /**
057    * Print out the contents of the strings list, one entry per line.
058    */
059   publicpublic is used to indicate unrestricted access (any other class can have access) voidvoid means the method does not return a value listPrint() {open braces start code blocks and must be matched with a close brace
060     forfor is a looping structure for repeatedly executing a block of code (intint is the type for whole numbers and it is short for integer i =this assignment operator makes the left side equal to the right side 0; i !=this is the not equals operator which evaluates to true if both sides are different strings.size(); ++this is the increment operator, which increases the variable by 1i) {open braces start code blocks and must be matched with a close brace
061       System.out.println(strings.get(i));
062     }close braces end code blocks and must match an earlier open brace
063   }close braces end code blocks and must match an earlier open brace
064 
065   /**
066    * Get the number of words stored.
067    *
068    * @returnnull  the number of words in strings
069    */
070   publicpublic is used to indicate unrestricted access (any other class can have access) intint is the type for whole numbers and it is short for integer listSize() {open braces start code blocks and must be matched with a close brace
071     returnreturn means to provide the result of the method and/or cease execution of the method immediately strings.size();
072   }close braces end code blocks and must match an earlier open brace
073 
074   /**
075    * The argument list should consist of exactly one file name. Thus the
076    * length is checked and ifif executes the next statement only if the condition in parenthesis evaluates to true it is right then a TextFileByWord object
077    * is created and used to read and print out information about the
078    * contents of the named file.
079    *
080    * @paramthis is the Javadoc tag for documenting the purpose of parameters  args  the command-line arguments; should have one file name
081    */
082   publicpublic is used to indicate unrestricted access (any other class can have access) staticstatic means that an instance is not required for access (class level access) voidvoid means the method does not return a value mainThe main method is the place where applications begin executing.(String[brackets are typically used to declare, initialize and index (indicate which element of) arrays]brackets are typically used to declare, initialize and index (indicate which element of) arrays args) {open braces start code blocks and must be matched with a close brace
083     ifif executes the next statement only if the condition in parenthesis evaluates to true (args.length ==this is the comparison operator which evaluates to true if both sides are the same 1) {open braces start code blocks and must be matched with a close brace
084       String fname =this assignment operator makes the left side equal to the right side args[brackets are typically used to declare, initialize and index (indicate which element of) arrays0]brackets are typically used to declare, initialize and index (indicate which element of) arrays;
085       TextFileByWord byWord =this assignment operator makes the left side equal to the right side newnew is used to create objects by calling the constructor TextFileByWord();
086       byWord.listLoadFromFile(fname);
087       System.out.println("----- listPrint -----");
088       byWord.listPrint();
089       System.out.println("----- listPrint -----");
090       System.out.println("There were " +adds two numbers together or concatenates Strings together byWord.listSize() +adds two numbers together or concatenates Strings together
091         " words in " +adds two numbers together or concatenates Strings together fname);
092     }close braces end code blocks and must match an earlier open brace elseelse is what happens when the if condition is false {open braces start code blocks and must be matched with a close brace
093       System.out.println(
094         "Usage: provide exactly one (1) file name on command-line.");
095       System.out.println("Program Terminating");
096     }close braces end code blocks and must match an earlier open brace
097   }close braces end code blocks and must match an earlier open brace
098 }close braces end code blocks and must match an earlier open brace
099 
100 //Uploaded on Mon Mar 29 21:41:21 EDT 2010