60 lines
1.6 KiB
Java
60 lines
1.6 KiB
Java
package it.tdlight.util;
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import java.io.Console;
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import java.io.IOException;
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import java.io.InputStreamReader;
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import java.io.Reader;
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import java.util.regex.Matcher;
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import java.util.regex.Pattern;
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public final class ScannerUtils {
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private static final Object LOCK = new Object();
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private static InputStreamReader scanner = null;
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public static String askParameter(String displayName, String question) {
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synchronized (LOCK) {
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Console console = System.console();
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if (console != null) {
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return console.readLine("[%s] %s: ", displayName, question);
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} else {
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if (scanner == null) {
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scanner = new InputStreamReader(System.in);
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}
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System.out.printf("[%s] %s: ", displayName, question);
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try {
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return interruptibleReadLine(scanner);
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} catch (InterruptedException | IOException e) {
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throw new RuntimeException(e);
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}
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}
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}
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}
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/**
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* https://stackoverflow.com/questions/3595926/how-to-interrupt-bufferedreaders-readline
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*/
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private static String interruptibleReadLine(Reader reader) throws InterruptedException, IOException {
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Pattern line = Pattern.compile("^(.*)\\R");
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Matcher matcher;
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boolean interrupted;
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StringBuilder result = new StringBuilder();
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int chr = -1;
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do {
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if (reader.ready()) {
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chr = reader.read();
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}
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if (chr > -1) {
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result.append((char) chr);
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}
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matcher = line.matcher(result.toString());
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interrupted = Thread.interrupted(); // resets flag, call only once
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} while (!interrupted && !matcher.matches());
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if (interrupted) {
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throw new InterruptedException();
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}
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return (matcher.matches() ? matcher.group(1) : "");
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}
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}
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