Such an opportunity will be offered during lab today (Practical Makeup).

The FINAL EXAM is in class today (3:30-5:15pm).

(Half of these ALMOST PASSED the previous test, so the chances look good.)

Many thanks to Lebogang Molefi for coming to our office hour last night.

A summary of what we discussed is included below:

class StringTokenizer {
  String line;
  StringTokenizer (String line) {
    this.line = line.trim();
  }
  boolean hasMoreTokens() {
    return line.length() != 0;
  }
  String nextToken() {
    if (this.hasMoreTokens()) {
      String token = "";
      int i = 0;
      while (i < line.length() && line.charAt(i) != ' ') {
        token = token + line.charAt(i);
        i = i + 1;
      }
      if (i >= line.length()) line = "";
      else line = line.substring(i);
      line = line.trim();
      return token;
    } else {
      return null;
    }
  }
}

So it's a good exercise.

Many thanks to Lebo Molefi and Charles Calligan for coming last night (Sat night).

We discussed these problems:

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

class OmitLongWords {
  public static void main(String[] args) throws Exception {
    process(args[0], Integer.parseInt(args[1])); 
  } 
  public static void process(String fileName, int len) throws Exception { 
    BufferedReader b = new BufferedReader(new FileReader(fileName)); 
    String line = b.readLine(); 
    while (line != null) {
      StringTokenizer st = new StringTokenizer(line); 
      while (st.hasMoreTokens()) {
        String token = st.nextToken(); 
        if (token.length() <= len) 
          System.out.println(token); 
      } 
      line = b.readLine(); 
    }
  } 
} 

class EveryNthLine throws Exception {
  public static void main(String[] args) {
    generateData(args[0], 1000); 
    extractLines(args[0], Integer.parseInt(args[1])); 
  } 
  public static void generateData(String fileName, int numOfLines) /* throws Exception */ {
    FileWriter outStream = new FileWriter(fileName); 
    for (int i = 0; i < numOfLines; i++) {
      outStream.write("Line no. " + i + " of the file " + fileName + "\n"); 
    } 
    outStream.close(); 
  } 
  public static void extractLines(String fileName, int period) throws Exception {
    BufferedReader b = new BufferedReader(new FileReader(fileName)); 
    String line = b.readLine(); 
    int count = 1; 
    while (line != null) {
      if (count % period == 0) {
        System.out.println(line); 
      } 
      line = b.readLine(); 
      count += 1; 
    }
  } 
} 

Questions were like these:

1. How do you print the chars in a String, one per line?
   Answer: using a for loop seems to be the most natural solution.
   Exercise: do it using a while loop instead.

2. How do you count the number of lines in a file?
   Answer: using a while loop seems to be the most natural solution.
   Exercise: do it using a for loop instead.

3. How do you print the tokens in a sentence, one per line?
   Answer: using a while loop seems to be the most natural solution.
   Exercise: do it using a for loop instead.

4. How do you calculate the square root of n using successive approximations?
   Answer: using a while loop seems to be the most natural approach.
   Exercise: do it using a for loop instead.

5. Same questions for finding the max in a two-dimensional array of ints.

6. Same questions for bubble sort.

7. Same questions for selection sort.

8. Same question for calculating the standard deviation of a sequence of numbers stored in a double[].

Many thanks to Lebo Molefi and Charles Calligan for coming last night (Fri night).

We discussed this problem:

public class Exam {
  public static void main(String[] args) {
    Room[][] a = new Room[2][3];
    for (int i = 0; i < a.length; i++)
      for (int j = 0; j < a[i].length; j++)
        a[i][j] = new Room("F" + i + ", #" + j,
                           Math.random() * 6 + 2, Math.random() * 8 + 2);
    show(a);
    System.out.println("So the largest room is: " + largestRoom(a).getName());
  }
  public static void show(Room[][] m) {
    for (int i = 0; i < m.length; i++)
      for (int j = 0; j  largest.getArea())
          largest = mansion[i][j];
    return largest;
  }
}

class Room {
  double width;
  double length;
  String name;
  Room(String n, double w, double l) {
    length = l; width = w; name = n;
  }
  double getWidth() { return width;}
  double getLength() { return length;}
  double getArea() { return length * width;}
  String getName() { return name;}
  void report() {
    System.out.println(name + " " + getArea());
  }
}

Here are solutions to TBS (III) administered last night:

class Exam {
  public static int countSpaces(String line) {
    for (int i = 0, sum = 0; i < line.length(); i++) 
      if (line.charAt(i) == ' ') 
        sum += 1; 
    return sum; 
  } 

  public static double calculate(String fileName) throws IOException {
    BufferedReader b = new BufferedReader(new FileReader(fileName)); 
    String line = b.readLine(); 
    double chars = 0, spaces = 0; 
    while (line != null) {
      chars += line.length(); 
      spaces += Exam.countSpaces(line); 
    } 
    return spaces/chars; 
  } 

  public static int find(int[] a, int value) {
    int i;  
    for (i = a.length - 1; i >= 0; i--)
      if (a[i] >= value) 
        return i; 
    return i; // notice we return -1 if search is unsuccessful
  } 
} 

Adrian's office hours during August 2-12:

• MTWRF (LH201D): 10:30-11:30am and 1-2pm or by appointment.

• MTWRF, Sat, and Sun: 7:30pm-8:30pm (in LH115) or by appointment.

Please come to get help, or make up exams and/or assignments.

Lab Assignment for today: implement the three problems and submit them.

TBS make-up (re-take) is scheduled for Wednesday during the lecture.

import javax.swing.*; 
import java.awt.*; 
import java.awt.event.*; 

public class Two extends JFrame implements ActionListener {
    public static void main(String[] args) {
	Two a = new Two(); 
    }
    JButton a, b; 
    public Two() {
	Container a = this.getContentPane();
	a.setLayout(new FlowLayout()); 
	a.add(this.a = new JButton("One"));
	a.add(this.b = new JButton("Two"));
	pack(); 
        setTitle("exam"); 
	setVisible(true); 
	setSize(400, 400); 
	this.a.addActionListener(this); 
        this.b.addActionListener(this); 
    }
    public void actionPerformed(ActionEvent e) {
	System.out.println("Ouch!..."); 
        if (e.getSource() == this.a) this.setSize(800, 800); 
	else this.setSize(200, 200); 
    }
}

Here's the problem we discussed in class on Thursday (that started with a question from Paul Touloukian).

You can use everything you want:

• bring the book
• on-line API
• on-line lecture/lab notes
• your own code
• Internet

just don't communicate with anyone except the course instructors.

Review the basic material in chapters 1-14 in the text.

Exercises on the test would be 6-8 in number, like the ones in OnCourse for the TBS.

• LH115 will be reserved
• between 7:30pm-8:30pm daily (MTWR)

for extra help (Adrian's office hour).

I remain available during the day 9-10am and 1-2pm or by appointment MTWR.

Fridays I am available 1pm-4pm or by appointment.

<?xml version="1.0" encoding="ISO-8859-1"?>

<!DOCTYPE web-app
    PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
    "http://java.sun.com/dtd/web-app_2_3.dtd">

<web-app>

    <servlet>
        <servlet-name>One</servlet-name>
        <servlet-class>One</servlet-class>
    </servlet>

    <servlet-mapping>
        <servlet-name>One</servlet-name>
        <url-pattern>/servlet/One</url-pattern>
    </servlet-mapping>

    <servlet>
        <servlet-name>Fv2_3</servlet-name>
        <servlet-class>Two</servlet-class>
    </servlet>

    <servlet-mapping>
        <servlet-name>Fv2_3</servlet-name>
        <url-pattern>/servlet/Fancy</url-pattern>
    </servlet-mapping>


</web-app>

The quiz will be: describe (succinctly) the steps necessary to install Tomcat.

The lab work for this week will be: have Tomcat installed.

Lecture Notes for July 20 indicate how you can install Tomcat 5.5.9 in your burrowww account.

Lecture Notes for July 21 contain the list of usernames and ports.

TBS in class today, Jeremy is proctoring, I am in Chicago, returning in the evening.

• GenericClient.java should be placed on the desktop, the server in your burrowww account.
• Use www.cs.indiana.edu, port 80, to test GenericClient.java
• I will post port numbers here by Monday for your servers.

Those who crave a semester project can and should try to rewrite this game in an object-oriented way.

This used to be an old A201 Lab as you can see.

Jeremy Martin

• SimpleTextEditor.java (the class we start from, with one minor addition)
• SimplePrintableJTextArea.java (the addition, basically a Unicorn)

Java code by David Ward (see original thread with details).

In class we also will go over the account creation process.

The quiz tomorrow in lab will be open-book, at least a page, up to two pages:

• a summary of the new operational knowledge (if any)
• that you gained in chapters 13 and 14.

Be specific. Be very specific!

For breaks we will use from now on:

They are still in the same location.

• contains only one problem, is due next Monday.

Homework Six posted,

• contains only one problem, is due the Monday after that.

The first Test of Basic Skills is

• next Monday in class (3:30-5:15pm, LH102).

The Practical Exam for this class

• is next Thursday, July 28, in lab(s).

Details on all of these to be posted tonight, along with all the grades thus far.

Use your IU network ID to log in, the messages will be automatically signed with your username.

TBS details will be announced on Monday (tomorrow).

So we won't be able to keep any office hours today.

Exam grades will be posted soon. Regular office hours resume on Monday morning.

I am available for appointments over the weekend, so e-mail me (dgerman@indiana.edu) if you need help.

MIDTERM EXAM 3:30-5:15pm in class today (Thursday, July 14).

Here's the quiz for the lab on Thursday (like 7.15/345 in Homework Two):

Design and implement a program that plays Time Bomb with the user.
Here's how the game works:

• the computer picks a secret word and then prints one asterisk for each letter in the word.
• The user guesses at the letters in the word.
• For every correct guess, an asterisk is replaced by a letter.
• For every incorrect guess the time bomb's fuse grows shorter.
• When the fuse disappears, after say, six incorrect guesses, the bomb explodes.

Here's a solution that would get all the points.
You are more than welcome to write a reasonably comparable (or equivalent) solution.

• the Midterm will be closed-book, written test.
• Three problems from the first three homework assignments will be on the test.
• There will be no GUI stuff on this test.

The OnCourse part of TBS materials is now complete. One more list will be posted tomorrow, and we'll be ready for it.

Thanks to

Yigang Huang

Here's a lesson we will be going over at some point (perhaps even today).

Thanks to

Melissa Troyer and Doug Ranger

void sort(Shape[] a) {
  boolean done = true; 
  do {
    for (int i = 0; i < a.length - 1; i++) {
      done = true && done || (i == 0);
      if (a[i].area() > a[i+1].area()) {
        Shape temp = a[i]; 
        a[i] = a[i+1]; 
        a[i+1] = temp; 
        done = false; 
      } 
    } 
  } while (! done); 
}

• Highlight to see how it could be fixed without moving lines around.

• Why does the fix work? And---does it?

There will be a larger document to be posted tonight that would complete the TBS Review.

Here are the notes used last summer and last spring with respect to file I/O and such.

Portions of Chapters 9 and 11 are useful in the lab today.

import java.io.*; 

class Channel {
  BufferedReader reader; 
  Channel() {
    reader = new BufferedReader(new InputStreamReader(System.in)); 
  } 
  String readLine() {
    String line = ""; 
    try {
      line = reader.readLine(); 
    } catch (Exception e) { }
    return line; 
  } 
  Channel(String file) {
    try { 
      reader = 
        new BufferedReader(
          new InputStreamReader(
            new FileInputStream(file))); 
    } catch (Exception e) { System.exit(0); } 
  } 
  public static void main(String[] args) {
    Channel c = new Channel(args[0]); 
    String line = c.readLine(); 
    while (line != null) { 
      System.out.println(line); 
      line = c.readLine(); 
    } 
    Channel b = new Channel(); 

    line = b.readLine(); 
    while (! line.equals("quit")) { 
      System.out.println(line); 
      line = b.readLine(); 
    } 

  } 
}

Slides one, two (and three) used in A201 might help.

A combination of chapter 8 and 9 will start our lecture on Tuesday.

Here's the problem: write a program that

• creates circles, triangles and rectangles and
• stores them in an array.
• It then goes through the array elements one by one,
• and it makes them print their area.

• Here's Heron's formula from MathWorld.
• You should know the formula for the area of a circle or that of a rectangle already.

The quiz next Monday will be on sorting (more details in class).

Also, from now on we will have a new section in the lecture entitled "Interview with a student."

The lab quiz for Thu July 7 is: one of the first three quizzes (randomly selected).

Note: the TBS review will be based entirely on your textbook.

Today in class we will look at this program:

import javax.swing.*; 
import java.awt.event.*; 
import java.awt.*; 

class Screen extends JPanel implements KeyListener {

    public void keyPressed(KeyEvent e) { 
	switch (e.getKeyCode()) {
	case 40:
	    System.out.println("down");
	    break;
	case 38:
	    System.out.println("up");
	    break;
	case 37:
	    System.out.println("left");
	    break;
	case 39:
	    System.out.println("right");
	    break;
	case KeyEvent.VK_KP_RIGHT:
	    System.out.println("right");
	    break;
	default:
	    System.out.println("some other key: " + e.getKeyCode());
	    break;
	}
    } 

    public void keyReleased(KeyEvent e) { 
	System.out.println("key released"); 
    } 

    public void keyTyped(KeyEvent e) { 
	System.out.println("key typed"); 	
    } 

    Screen() {
	setBackground(Color.white); 
        addKeyListener(this); 
    } 

}

class Example extends JFrame {
    public static void main(String[] args) {
	Example a = new Example(); 
    }
    Example() {
	getContentPane().setLayout(new BorderLayout()); 
        Screen a = new Screen(); 
	getContentPane().add("Center", a); 
	this.setSize(400, 400); 
	this.setVisible(true); 
	System.out.println(KeyEvent.VK_KP_RIGHT); 
	a.requestFocusInWindow(); 
    }
}

Code for today: One.java, Test.java and Screen.java.

• today's review (reading assignment) is chapter 6,
• tomorrow's: chapter 7.

Homework Two is posted, we need to start right away.

Note that if we replace One by Test (below):

public class Test extends JFrame {
    Test() {
        Container contentPane = this.getContentPane(); 
	contentPane.setLayout(new BorderLayout()); 
        contentPane.add("Center", new Screen()); 
	pack();
	setTitle("The other way around."); 
	setVisible(true); 
	setSize(400, 400); 
    }
    public static void main(String[] args) {
	new Test();       
    }
}

Recall the class diagram was:

Other than the replacement of Test for One everything else is still the same.

The lab test at the beginning of the lab on Monday is on class KeyboardReader (p. 157).

You will be asked to write the class and an example of its use (in a main method).

Here is the code developed in class on Thu (Jun 23).

Date: Fri, 24 Jun 2005 00:21:27 -0500 (EST)
From: Adrian German 
Subject: Office Hours for A202 Summer 2005  

Dear A202/A598 and I211 Friends,

Today, Friday June 24, we will be available as follows:

  1. Adrian 9am-4pm in LH201D (Lindley second floor)

  2. Russell 1pm-3:30pm also in LH201D (Lindley second floor, same office)

Please come if you need help.

Office hours in general:

  1. Adrian MTWRF 9-10am and 1-2pm LH201D (Lindley second floor)

  2. Russell M 1:15-3:15pm in LH201D (Lindley second floor)

  3. Jeremy T 9:30-11:30am in LH401A (Lindley fourth floor)

We want to make this semester the best ever, so please write to us if
anything is not quite working for you and we will be glad to help.

... Adrian

Here's today's lab assignment solution, posted so you can practice submitting it to OnCourse at the end of the lab.

Notice that OnCourse contains dropboxes for Lab Assignments 1, 2 and Homework Assignments 1 and 2 already.

• Lectures are MTWR 3:30-5:15pm
• Labs are MR 5:30-7:15pm

Sorry for any confusion I may have created during the first two days.

The lecture notes for yesterday have been updated with the code written in class.

More lecture notes for today and tomorrow are being posted now.

The lab test would be announced two days ahead of the lab always.

For Thursday the test (closed-book and written) asks you to:

• write a program (a class with a main)
• that accepts a sequence of integers on the command line
• sums them up and writes the sum back to the user

The solution to this problem will be worked out in class today.

Reading assignment for tomorrow: Chapters 2 and 3.

Notes for today's lecture have been posted.

Take a look at the KeyboardReader class developed on p. 157.

It's similar to what we developed at the end of A201 in Spring 2005.

First lecture in LH102 at 3:30pm.

Labs are MR 5:30-7:15pm in BH308/118.

Perhaps these slides will be useful today.

No class today, our schedule is MTWR.