List of Chapters
Chapter 13: Looking Good When Things Take Unexpected Turns
In this chapter:
<![CDATA[
import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Scanner keyboard = new Scanner(System.in);
String[] words = new String[5];
int i = 0;
try {
do {
words[i] = keyboard.next();
} while (!words[i++].equals("Quit"));
} catch (ArrayIndexOutOfBoundsException e) {
System.out.println("You can enter at most five words");
}
for (int j = 0; j < 5; j++) {
try {
System.out.println(words[j].length());
} catch (NullPointerException e) {
System.out.println("You could have entered up to five words");
}
}
keyboard.close();
}
}
]]>
<![CDATA[
@SuppressWarnings("serial")
class OutOfRangeException extends Exception {
private String value;
public OutOfRangeException(String value) {
this.value = value;
}
public String getValue() {
return value;
}
}
@SuppressWarnings("serial")
class NumberTooLargeException extends OutOfRangeException {
private String value;
public NumberTooLargeException(String value) {
super(value);
this.value = value;
}
public String getValue() {
return value;
}
}
import static java.lang.System.out;
import java.util.Scanner;
import java.text.NumberFormat;
public class InventoryD {
public static void main(String args[]) {
Scanner keyboard = new Scanner(System.in);
NumberFormat currency =
NumberFormat.getCurrencyInstance();
try {
out.print("What's the price per box? ");
String boxPriceIn = keyboard.next();
double boxPrice = Double.parseDouble(boxPriceIn);
if (boxPrice <= 0.0) {
throw new OutOfRangeException(boxPriceIn);
}
out.print("What's the maximum number of boxes? ");
String maxBoxesIn = keyboard.next();
int maxBoxes = Integer.parseInt(maxBoxesIn);
if(maxBoxes <= 0) {
throw new OutOfRangeException(maxBoxesIn);
}
out.print("How many boxes do we have? ");
String numBoxesIn = keyboard.next();
int numBoxes = Integer.parseInt(numBoxesIn);
if (numBoxes < 0) {
throw new OutOfRangeException(numBoxesIn);
}
if (numBoxes > maxBoxes) {
throw new NumberTooLargeException(numBoxesIn);
}
out.print("The value is ");
out.println(currency.format(numBoxes * boxPrice));
}
catch (NumberFormatException e) {
out.print(e.getMessage());
out.println(" Cannot turn string into a number.");
}
catch (OutOfRangeException e) {
out.print(e.getValue());
out.println("? That's impossible!");
}
catch (Exception e) {
out.print("Something went wrong, ");
out.print("but I'm clueless about what ");
out.println("it actually was.");
}
out.println("That's that.");
keyboard.close();
}
}
]]>
<![CDATA[
import java.io.File;
import java.io.FileNotFoundException;
import java.util.InputMismatchException;
import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Scanner diskScanner = null;
try {
diskScanner = new Scanner(new File("numbers.txt"));
} catch (FileNotFoundException e) {
e.printStackTrace();
}
int[] numerators = new int[5];
int[] denominators = new int[5];
int i = 0;
while (diskScanner.hasNextInt()) {
try {
numerators[i] = diskScanner.nextInt();
denominators[i] = diskScanner.nextInt();
} catch (IndexOutOfBoundsException e) {
System.out.println("Array index " + i + " is out of bounds.");
} catch (InputMismatchException e) {
System.out.println
("Attempt to read a value that's not an integer");
}
i++;
}
for (int j = 0; j < numerators.length; j++) {
try {
System.out.println(numerators[j] / denominators[j]);
} catch (ArithmeticException e) {
System.out.println("Divide by zero on array index " + i);
}
}
diskScanner.close();
}
}
]]>
<![CDATA[
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.EOFException;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
public class Main {
public static void main(String[] args) {
File fileIn = new File("input");
FileInputStream fileInStrm = null;
try {
fileInStrm = new FileInputStream(fileIn);
} catch (FileNotFoundException e1) {
e1.printStackTrace();
}
DataInputStream dataInStrm = new DataInputStream(fileInStrm);
File fileOut = new File("output");
FileOutputStream fileOutStrm = null;
try {
fileOutStrm = new FileOutputStream(fileOut);
} catch (FileNotFoundException e1) {
e1.printStackTrace();
}
DataOutputStream dataOutStrm = new DataOutputStream(fileOutStrm);
int numFilesCopied = 0;
try {
while (true) {
dataOutStrm.writeByte(dataInStrm.readByte());
}
} catch (EOFException e) {
numFilesCopied = 1;
} catch (IOException e) {
e.printStackTrace();
} catch (NullPointerException e) {
e.printStackTrace();
}
System.out.println("Number of files copied: " + numFilesCopied);
}
}
]]>
<![CDATA[
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.EOFException;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
public class Main {
public static void main(String[] args) throws Exception {
int numFilesCopied = 0;
File fileIn = new File("input");
FileInputStream fileInStrm = new FileInputStream(fileIn);
File fileOut = new File("output");
FileOutputStream fileOutStrm = new FileOutputStream(fileOut);
DataInputStream dataInStrm = null;
DataOutputStream dataOutStrm = null;
try {
dataInStrm = new DataInputStream(fileInStrm);
dataOutStrm = new DataOutputStream(fileOutStrm);
try {
while (true) {
dataOutStrm.writeByte(dataInStrm.readByte());
}
} catch (EOFException e) {
numFilesCopied = 1;
}
} catch (IOException e) {
e.printStackTrace();
} finally {
dataInStrm.close();
dataOutStrm.close();
}
System.out.println("Number of files copied: " + numFilesCopied);
}
}
]]>
<![CDATA[
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.EOFException;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
public class Main3 {
public static void main(String[] args) throws Exception {
int numFilesCopied = 0;
File fileIn = new File("input");
FileInputStream fileInStrm = new FileInputStream(fileIn);
File fileOut = new File("output");
FileOutputStream fileOutStrm = new FileOutputStream(fileOut);
try (DataInputStream dataInStrm = new DataInputStream(fileInStrm);
DataOutputStream dataOutStrm = new DataOutputStream(fileOutStrm)) {
try {
while (true) {
dataOutStrm.writeByte(dataInStrm.readByte());
}
} catch (EOFException e) {
numFilesCopied = 1;
}
} catch (IOException e) {
e.printStackTrace();
}
System.out.println("Number of files copied: " + numFilesCopied);
}
}
]]>