问题描述
我想将 Console 中的输出重定向到 JavaFX TextArea,我在这里遵循一个建议:JavaFX: Redirect console output to TextArea that is created in SceneBuilder
我试图在 PrintStream() 中将字符集设置为 UTF-8,但是 it does not look so well。将字符集设置为 UTF-16 会有所改善,但 it is still illegible。
在 Eclipse IDE 中,控制台中假设的文本输出结果很好:
KHA khởi đầu phiên giao dịch sáng nay ở mức 23600 điểm,khối lượng giao dịch trong ngày đạt 765 cổ phiếu,tương đương khoảng 18054000 đồng.
Controller.java
public class Controller {
@FXML
private Button button;
public Button getButton() {
return button;
}
@FXML
private TextArea textArea;
public TextArea getTextArea() {
return textArea;
}
private PrintStream printStream;
public PrintStream getPrintStream() {
return printStream;
}
public void initialize() {
textArea.setWrapText(true);
printStream = new PrintStream(new UItextoutput(textArea),true,StandardCharsets.UTF_8);
} // Encoding set to UTF-8
public class UItextoutput extends OutputStream {
private TextArea text;
public UItextoutput(TextArea text) {
this.text = text;
}
public void appendText(String valueOf) {
Platform.runLater(() -> text.appendText(valueOf));
}
public void write(int b) throws IOException {
appendText(String.valueOf((char) b));
}
}
}
UI.java
public class UI extends Application {
@Override
public void start(Stage stage) {
try {
FXMLLoader loader = new FXMLLoader(getClass().getResource("Sample.fxml"));
Parent root = loader.load();
Controller control = loader.getController();
stage.setTitle("Title");
stage.setScene(new Scene(root));
stage.show();
control.getButton().setonAction(new EventHandler<ActionEvent>() {
public void handle(ActionEvent event) {
try {
System.setout(control.getPrintStream());
System.setErr(control.getPrintStream());
System.out.println(
"KHA khởi đầu phiên giao dịch sáng nay ở mức 23600 điểm,tương đương khoảng 18054000 đồng.");
} catch (Exception e) {
e.printstacktrace();
}
}
});
} catch (Exception e) {
e.printstacktrace();
}
}
public static void main(String[] args) {
launch(args);
}
}
示例.fxml
<?xml version="1.0" encoding="UTF-8"?>
<?import javafx.scene.control.Button?>
<?import javafx.scene.control.TextArea?>
<?import javafx.scene.layout.borderpane?>
<borderpane prefheight="339.0" prefWidth="468.0" xmlns:fx="http://javafx.com/fxml/1" xmlns="http://javafx.com/javafx/11.0.1" fx:controller="main.Controller">
<center>
<TextArea fx:id="textArea" prefheight="200.0" prefWidth="200.0" borderpane.alignment="CENTER" />
</center>
<right>
<Button fx:id="button" mnemonicParsing="false" onAction="#getButton" text="Button" borderpane.alignment="CENTER" />
</right>
</borderpane>
我还是 Java 新手,所以我不熟悉 PrintStream 或 OutputStream 的工作原理。请原谅我的无知。
感谢每一个建议。
解决方法
我相信您的问题是由以下代码引起的:
public void write(int b) throws IOException {
appendText(String.valueOf((char) b));
}
这是将每个单独的字节转换为一个字符。换句话说,它假设每个字符都由一个字节表示。这不一定是真的。某些编码 such as UTF-8 可能使用多个字节来表示单个字符。如果他们希望能够表示超过 256 个字符,就必须这样做。
您需要正确解码传入的字节。与其自己尝试这样做,不如找到一种使用 BufferedReader
之类的方法。幸运的是,PipedInputStream
和 PipedOutputStream
可以做到这一点。例如:
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.PipedInputStream;
import java.io.PipedOutputStream;
import java.io.PrintStream;
import java.io.UncheckedIOException;
import javafx.application.Application;
import javafx.application.Platform;
import javafx.scene.Scene;
import javafx.scene.control.TextArea;
import javafx.stage.Stage;
import static java.nio.charset.StandardCharsets.UTF_8;
public class Main extends Application {
@Override
public void start(Stage primaryStage) {
TextArea area = new TextArea();
area.setWrapText(true);
redirectStandardOut(area);
primaryStage.setScene(new Scene(area,800,600));
primaryStage.show();
System.out.println(
"KHA khởi đầu phiên giao dịch sáng nay ở mức 23600 điểm,khối lượng giao dịch trong ngày đạt 765 cổ phiếu,tương đương khoảng 18054000 đồng.");
}
private void redirectStandardOut(TextArea area) {
try {
PipedInputStream in = new PipedInputStream();
System.setOut(new PrintStream(new PipedOutputStream(in),true,UTF_8));
Thread thread = new Thread(new StreamReader(in,area));
thread.setDaemon(true);
thread.start();
} catch (IOException ex) {
throw new UncheckedIOException(ex);
}
}
private static class StreamReader implements Runnable {
private final StringBuilder buffer = new StringBuilder();
private boolean notify = true;
private final BufferedReader reader;
private final TextArea textArea;
StreamReader(InputStream input,TextArea textArea) {
this.reader = new BufferedReader(new InputStreamReader(input,UTF_8));
this.textArea = textArea;
}
@Override
public void run() {
try (reader) {
int charAsInt;
while ((charAsInt = reader.read()) != -1) {
synchronized (buffer) {
buffer.append((char) charAsInt);
if (notify) {
notify = false;
Platform.runLater(this::appendTextToTextArea);
}
}
}
} catch (IOException ex) {
throw new UncheckedIOException(ex);
}
}
private void appendTextToTextArea() {
synchronized (buffer) {
textArea.appendText(buffer.toString());
buffer.delete(0,buffer.length());
notify = true;
}
}
}
}
使用上面的 buffer
是为了避免 JavaFX 应用程序线程被任务淹没。
您需要考虑的其他一些事项:
- 由于您使用的是字符串文字,因此请确保使用 UTF-8 保存源文件并使用
-encoding UTF-8
编译代码。 - 确保您与
TextArea
一起使用的字体可以代表您想要的所有字符。 -
可能您还需要使用
-Dfile.encoding=UTF-8
运行应用程序,但我不确定。我没有,但它仍然对我有用。
尝试将您的默认 JVM 编码设置为 UTF-8。
java -Dfile.encoding=UTF-8 -jar YourJarfile.jar
有关更多详细信息,请查看此线程:Setting the default Java character encoding
如果您不想导出文件,请进入 Eclipse Preferences > General > Workspace 并将文本文件编码设置为 UTF-8(或您想要的编码) ).