java将输出打印到多个textarea

你可以使用以下方法将Java的输出打印到多个textarea上：

1. 创建一个PrintStream对象来捕获System.out输出：

PrintStream printStream = new PrintStream(new OutputStream() {
    @Override
    public void write(int b) throws IOException {
        // do nothing
    }
});

2. 为每个textarea创建一个输出流并将其添加到PrintStream对象中：

OutputStream output1 = new OutputStream() {
    @Override
    public void write(int b) throws IOException {
        textarea1.append(String.valueOf((char) b));
    }
};

OutputStream output2 = new OutputStream() {
    @Override
    public void write(int b) throws IOException {
        textarea2.append(String.valueOf((char) b));
    }
};

printStream = new PrintStream(new MultiOutputStream(System.out, output1, output2));

3. 创建一个MultiOutputStream类，该类将输出流转发到多个输出流：

class MultiOutputStream extends OutputStream {
    private final List<OutputStream> outputStreams;

    MultiOutputStream(OutputStream... outputStreams) {
        this.outputStreams = Arrays.asList(outputStreams);
    }

    @Override
    public void write(int b) throws IOException {
        for (OutputStream outputStream : outputStreams) {
            outputStream.write(b);
        }
    }

    @Override
    public void flush() throws IOException {
        for (OutputStream outputStream : outputStreams) {
            outputStream.flush();
        }
    }

    @Override
    public void close() throws IOException {
        for (OutputStream outputStream : outputStreams) {
            outputStream.close();
        }
    }
}

4. 使用setOut方法将PrintStream对象设置为System.out：

System.setOut(printStream);

现在，当您调用System.out.println时，输出将被转发到多个textarea上。