内容发布更新时间 : 2024/5/4 13:38:43星期一 下面是文章的全部内容请认真阅读。

(bitString.charAt(6) - '0') * 2 + (bitString.charAt(7) - '0') * 1;

return result + toHexChar(value); }

/** Convert an integer to a single hex digit in a character */ public static char toHexChar(int hexValue) { if (hexValue <= 9 && hexValue >= 0) return (char)(hexValue + '0');

else // hexValue <= 15 && hexValue >= 10 return (char)(hexValue - 10 + 'A'); }

public static String getBits(int value) { String result = \;

int mask = 1;

for (int i = 7; i >= 0; i--) { int temp = value >> i; int bit = temp & mask; result = result + bit; }

return result; } }

17.20

import java.io.*;

import javafx.application.Application; import javafx.geometry.Pos; import javafx.scene.Scene;

import javafx.scene.control.Button; import javafx.scene.control.Label; import javafx.scene.control.ScrollPane; import javafx.scene.control.TextArea; import javafx.scene.control.TextField; import javafx.scene.layout.BorderPane; import javafx.stage.Stage;

public class Exercise17_20 extends Application { private TextField tfFilename = new TextField(); private Button btSave = new Button(\);

private TextArea taBits = new TextArea();

public void start(Stage primaryStage) { BorderPane pane1 = new BorderPane(); pane1.setLeft(new Label(\)); pane1.setCenter(tfFilename);

BorderPane pane = new BorderPane(); pane.setTop(pane1);

pane.setCenter(new ScrollPane(taBits)); pane.setBottom(btSave);

BorderPane.setAlignment(btSave, Pos.CENTER);

// Create a scene and place it in the stage Scene scene = new Scene(pane, 400, 120);

primaryStage.setTitle(\); // Set the stage title primaryStage.setScene(scene); // Place the scene in the stage primaryStage.show(); // Display the stage

taBits.setWrapText(true); tfFilename.setOnAction(e -> { try {

FileInputStream in = new

FileInputStream(tfFilename.getText().trim());

String s = \; int value;

while ((value = in.read()) != -1) { s += getBits(value); }

in.close(); taBits.setText(s); }

catch (IOException ex) { ex.printStackTrace(); } });

btSave.setOnAction(e -> { try {

BitOutputStream output = new BitOutputStream(new File(tfFilename.getText().trim()));

output.writeBit(taBits.getText().trim());

output.close(); }

catch (IOException ex) { ex.printStackTrace(); } }); }

public static String getBits(int value) { String result = \;

int mask = 1;

for (int i = 7; i >= 0; i--) { int temp = value >> i; int bit = temp & mask; result = result + bit; }

return result; }

public static class BitOutputStream { private FileOutputStream output; private int value; private int count = 0;

private int mask = 1; // The bits are all zeros except the last one

public BitOutputStream(File file) throws IOException { output = new FileOutputStream(file); }

public void writeBit(char bit) throws IOException { count++;

value = value << 1;

if (bit == '1') value = value | mask;

if (count == 8) { output.write(value); count = 0; } }

public void writeBit(String bitString) throws IOException {

for (int i = 0; i < bitString.length(); i++) writeBit(bitString.charAt(i)); }

/** Write the last byte and close the stream. If the last byte is not full, right-shfit with zeros */

public void close() throws IOException { if (count > 0) {

value = value << (8 - count); output.write(value); }

output.close(); } } /**

* The main method is only needed for the IDE with limited * JavaFX support. Not needed for running from the command line. */

public static void main(String[] args) { launch(args); } }

17.21

import java.io.*;

import javafx.application.Application; import javafx.geometry.Pos; import javafx.scene.Scene;

import javafx.scene.control.Button; import javafx.scene.control.Label; import javafx.scene.control.ScrollPane; import javafx.scene.control.TextArea; import javafx.scene.control.TextField; import javafx.scene.layout.BorderPane; import javafx.stage.Stage;

public class Exercise17_21 extends Application { private TextField tfFilename = new TextField(); private Button btSave = new Button(\); private TextArea taBits = new TextArea();

public void start(Stage primaryStage) { BorderPane pane1 = new BorderPane(); pane1.setLeft(new Label(\)); pane1.setCenter(tfFilename);

BorderPane pane = new BorderPane(); pane.setTop(pane1);

pane.setCenter(new ScrollPane(taBits)); pane.setBottom(btSave);

BorderPane.setAlignment(btSave, Pos.CENTER);

// Create a scene and place it in the stage Scene scene = new Scene(pane, 400, 120);

primaryStage.setTitle(\); // Set the stage title primaryStage.setScene(scene); // Place the scene in the stage primaryStage.show(); // Display the stage

taBits.setWrapText(true); tfFilename.setOnAction(e -> { try {

FileInputStream in = new

FileInputStream(tfFilename.getText().trim());

String s = \; int value;

while ((value = in.read()) != -1) { s += getHex(getBits(value)); }

in.close(); taBits.setText(s); }

catch (IOException ex) { ex.printStackTrace(); } });

btSave.setOnAction(e -> { try {

BitOutputStream output = new BitOutputStream(new File(tfFilename.getText().trim()));

output.writeBit(toBits(taBits.getText().trim())); output.close(); }