From 6e7f8b97a2e107af251ad14b59d09b367f68c369 Mon Sep 17 00:00:00 2001
From: Andrea Cavalli <andrea@cavallium.it>
Date: Wed, 26 Aug 2020 18:25:36 +0200
Subject: [PATCH] ScannerUtils cleanup

---
 src/main/java/it/tdlight/tdlight/Log.java     |  10 +-
 .../tdlight/tdlight/utils/ScannerUtils.java   | 161 +-----------------
 2 files changed, 18 insertions(+), 153 deletions(-)

diff --git a/src/main/java/it/tdlight/tdlight/Log.java b/src/main/java/it/tdlight/tdlight/Log.java
index 4f45ad0..e982d63 100644
--- a/src/main/java/it/tdlight/tdlight/Log.java
+++ b/src/main/java/it/tdlight/tdlight/Log.java
@@ -2,6 +2,7 @@ package it.tdlight.tdlight;
 
 import it.tdlight.tdlib.NativeLog;
 import it.tdlight.tdlight.utils.ObjectsUtils;
+import java.io.PrintStream;
 
 /**
  * Interface for managing the internal logging of TDLib. By default TDLib writes logs to stderr or an OS specific log and uses a verbosity level of 5.
@@ -27,7 +28,14 @@ public class Log {
 	 * @return True on success, or false otherwise, i.e. if the file can't be opened for writing.
 	 */
 	public static boolean setFilePath(String filePath) {
-		return NativeLog.setFilePath(filePath);
+		PrintStream previousOut = System.out;
+		PrintStream previousErr = System.err;
+		try {
+			return NativeLog.setFilePath(filePath);
+		} finally {
+			System.setOut(previousOut);
+			System.setOut(previousErr);
+		}
 	}
 
 	/**
diff --git a/src/main/java/it/tdlight/tdlight/utils/ScannerUtils.java b/src/main/java/it/tdlight/tdlight/utils/ScannerUtils.java
index 31609be..acc4fa0 100644
--- a/src/main/java/it/tdlight/tdlight/utils/ScannerUtils.java
+++ b/src/main/java/it/tdlight/tdlight/utils/ScannerUtils.java
@@ -1,164 +1,21 @@
 package it.tdlight.tdlight.utils;
 
-import java.io.PrintStream;
 import java.util.Scanner;
-import java.util.concurrent.locks.ReentrantLock;
 
 public class ScannerUtils {
-	private static final Scanner scanner = new Scanner(System.in);
-	private static final ReentrantLock lock = new ReentrantLock();
-	private static final PrintStream emptyOut = new java.io.PrintStream(new java.io.OutputStream() {
-		@Override
-		public void write(int b) {
-		}
-	}) {
-		@Override
-		public void flush() {
-		}
+	private static final Scanner scanner;
+	private static final Object lock = new Object();
 
-		@Override
-		public void close() {
+	static {
+		synchronized (lock) {
+			scanner = new Scanner(System.in);
 		}
-
-		@Override
-		public void write(int b) {
-		}
-
-		@Override
-		public void write(byte[] b) {
-		}
-
-		@Override
-		public void write(byte[] buf, int off, int len) {
-		}
-
-		@Override
-		public void print(boolean b) {
-		}
-
-		@Override
-		public void print(char c) {
-		}
-
-		@Override
-		public void print(int i) {
-		}
-
-		@Override
-		public void print(long l) {
-		}
-
-		@Override
-		public void print(float f) {
-		}
-
-		@Override
-		public void print(double d) {
-		}
-
-		@Override
-		public void print(char[] s) {
-		}
-
-		@Override
-		public void print(String s) {
-		}
-
-		@Override
-		public void print(Object obj) {
-		}
-
-		@Override
-		public void println() {
-		}
-
-		@Override
-		public void println(boolean x) {
-		}
-
-		@Override
-		public void println(char x) {
-		}
-
-		@Override
-		public void println(int x) {
-		}
-
-		@Override
-		public void println(long x) {
-		}
-
-		@Override
-		public void println(float x) {
-		}
-
-		@Override
-		public void println(double x) {
-		}
-
-		@Override
-		public void println(char[] x) {
-		}
-
-		@Override
-		public void println(String x) {
-		}
-
-		@Override
-		public void println(Object x) {
-		}
-
-		@Override
-		public java.io.PrintStream printf(String format, Object... args) {
-			return this;
-		}
-
-		@Override
-		public java.io.PrintStream printf(java.util.Locale l, String format, Object... args) {
-			return this;
-		}
-
-		@Override
-		public java.io.PrintStream format(String format, Object... args) {
-			return this;
-		}
-
-		@Override
-		public java.io.PrintStream format(java.util.Locale l, String format, Object... args) {
-			return this;
-		}
-
-		@Override
-		public java.io.PrintStream append(CharSequence csq) {
-			return this;
-		}
-
-		@Override
-		public java.io.PrintStream append(CharSequence csq, int start, int end) {
-			return this;
-		}
-
-		@Override
-		public java.io.PrintStream append(char c) {
-			return this;
-		}
-	};
+	}
 
 	public static String askParameter(String displayName, String question) {
-		try {
-			lock.lock();
-			StringBuilder toPrint = new StringBuilder();
-			PrintStream oldOut = System.out;
-			PrintStream oldErr = System.err;
-			System.setOut(emptyOut);
-			System.setErr(emptyOut);
-			oldOut.print("[" + displayName + "] " + question + ": ");
-			String result = scanner.nextLine();
-			System.setOut(oldOut);
-			System.setErr(oldErr);
-			return result;
-		} finally {
-			lock.unlock();
+		synchronized (lock) {
+			System.out.print("[" + displayName + "] " + question + ": ");
+			return scanner.nextLine();
 		}
 	}
 }