Add PrintStreamService (implements #5)

base/src/main/java/de/staropensource/sosengine/base/Engine.java

@@ -31,10 +31,7 @@ import de.staropensource.sosengine.base.exceptions.NoAccessException;
 import de.staropensource.sosengine.base.exceptions.dependency.UnmetDependenciesException;
 import de.staropensource.sosengine.base.internal.events.InternalEngineShutdownEvent;
 import de.staropensource.sosengine.base.internal.types.DependencySubsystemVector;
-import de.staropensource.sosengine.base.logging.CrashHandler;
-import de.staropensource.sosengine.base.logging.InitLogger;
-import de.staropensource.sosengine.base.logging.Logger;
-import de.staropensource.sosengine.base.logging.LoggerInstance;
+import de.staropensource.sosengine.base.logging.*;
 import de.staropensource.sosengine.base.types.DependencyVector;
 import de.staropensource.sosengine.base.types.EngineState;
 import de.staropensource.sosengine.base.types.immutable.ImmutableLinkedList;
@@ -241,6 +238,7 @@ public final class Engine extends SubsystemClass {
         new PlaceholderEngine();
 
         EngineInformation.update();
+        PrintStreamService.initializeStreams();
     }
 
     /**

base/src/main/java/de/staropensource/sosengine/base/logging/Logger.java

@@ -53,6 +53,27 @@ import java.util.Scanner;
  */
 @SuppressWarnings({ "JavadocDeclaration" })
 public final class Logger {
+
+    /**
+     * Contains a reference to the logging thread.
+     *
+     * @since v1-alpha1
+     * -- GETTER --
+     * Returns a reference the logging thread.
+     *
+     * @return logging thread reference
+     * @since v1-alpha1
+     */
+    @Getter
+    private static @Nullable Thread loggingThread;
+
+    /**
+     * Contains a list of {@link QueuedLogMessage}s.
+     *
+     * @since v1-alpha1
+     */
+    private static final LinkedList<QueuedLogMessage> queuedMessages = new LinkedList<>();
+
     /**
      * Refers to the active {@link LoggerImplementation} that is used to process and print log messages.
      *
@@ -75,26 +96,6 @@ public final class Logger {
     @Setter
     private static @NotNull LoggerImplementation loggerImplementation = new PlainLoggerImplementation();
 
-    /**
-     * Contains a reference to the logging thread.
-     *
-     * @since v1-alpha1
-     * -- GETTER --
-     * Returns a reference the logging thread.
-     *
-     * @return logging thread reference
-     * @since v1-alpha1
-     */
-    @Getter
-    private static @Nullable Thread loggingThread;
-
-    /**
-     * Contains a list of {@link QueuedLogMessage}s.
-     *
-     * @since v1-alpha1
-     */
-    private static final LinkedList<QueuedLogMessage> queuedMessages = new LinkedList<>();
-
     /**
      * Contains all active {@link LogRule}s.
      *

base/src/main/java/de/staropensource/sosengine/base/logging/PrintStreamService.java

@@ -0,0 +1,237 @@
+/*
+ * STAROPENSOURCE ENGINE SOURCE FILE
+ * Copyright (c) 2024 The StarOpenSource Engine Contributors
+ * Licensed under the GNU Affero General Public License v3
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package de.staropensource.sosengine.base.logging;
+
+import de.staropensource.sosengine.base.types.logging.LogLevel;
+import lombok.Getter;
+import org.jetbrains.annotations.NotNull;
+
+import java.io.OutputStream;
+import java.io.PrintStream;
+import java.nio.charset.StandardCharsets;
+
+/**
+ * Contains {@link java.io.PrintStream}s for the standard
+ * output and standard error streams, which redirect
+ * their input into the engine's logging infrastructure.
+ *
+ * @since v1-alpha4
+ */
+public final class PrintStreamService {
+
+    /**
+     * Contains the {@link LoggerInstance} for this instance.
+     *
+     * @see LoggerInstance
+     * @since v1-alpha4
+     */
+    private static final @NotNull LoggerInstance logger = new LoggerInstance.Builder().setClazz(PrintStreamService.class).setOrigin("ENGINE").build();
+
+    /**
+     * Contains the diagnostic stream.
+     * Anything sent will be redirected to
+     * {@link Logger#info(Class, String, String, String)}
+     *
+     * @since v1-alpha4
+     */
+    @Getter
+    private static PrintStream diag = null;
+
+    /**
+     * Contains the verbose stream.
+     * Anything sent will be redirected to
+     * {@link Logger#error(Class, String, String, String)}
+     *
+     * @since v1-alpha4
+     */
+    @Getter
+    private static PrintStream verb = null;
+
+    /**
+     * Contains the silent warning stream.
+     * Anything sent will be redirected to
+     * {@link Logger#error(Class, String, String, String)}
+     *
+     * @since v1-alpha4
+     */
+    @Getter
+    private static PrintStream sarn = null;
+
+    /**
+     * Contains the informational stream.
+     * Anything sent will be redirected to
+     * {@link Logger#info(Class, String, String, String)}
+     *
+     * @since v1-alpha4
+     */
+    @Getter
+    private static PrintStream info = null;
+
+    /**
+     * Contains the warning stream.
+     * Anything sent will be redirected to
+     * {@link Logger#error(Class, String, String, String)}
+     *
+     * @since v1-alpha4
+     */
+    @Getter
+    private static PrintStream warn = null;
+
+    /**
+     * Contains the error stream.
+     * Anything sent will be redirected to
+     * {@link Logger#info(Class, String, String, String)}
+     *
+     * @since v1-alpha4
+     */
+    @Getter
+    private static PrintStream error = null;
+
+    /**
+     * Contains the crash stream.
+     * Anything sent will be redirected to
+     * {@link Logger#error(Class, String, String, String)}
+     *
+     * @since v1-alpha4
+     */
+    @Getter
+    private static PrintStream crash = null;
+
+    /**
+     * Initializes all {@link PrintStream}s offered by this class.
+     *
+     * @since v1-alpha4
+     */
+    public static void initializeStreams() {
+        // Close all existing streams
+        if (diag != null) diag.close();
+        if (verb != null) verb.close();
+        if (sarn != null) sarn.close();
+        if (info != null) info.close();
+        if (warn != null) warn.close();
+        if (error != null) error.close();
+        if (crash != null) crash.close();
+
+        // Create streams
+        diag = LogStream.createPrintStream(LogLevel.DIAGNOSTIC);
+        verb = LogStream.createPrintStream(LogLevel.VERBOSE);
+        sarn = LogStream.createPrintStream(LogLevel.SILENT_WARNING);
+        info = LogStream.createPrintStream(LogLevel.INFORMATIONAL);
+        warn = LogStream.createPrintStream(LogLevel.WARNING);
+        error = LogStream.createPrintStream(LogLevel.ERROR);
+        crash = LogStream.createPrintStream(LogLevel.CRASH);
+    }
+
+    /**
+     * Returns the standard output stream.
+     *
+     * @return standard output stream
+     * @since v1-alpha4
+     */
+    public static @NotNull PrintStream getStdOut() {
+        return info;
+    }
+
+    /**
+     * Returns the standard error stream.
+     *
+     * @return standard error stream
+     * @since v1-alpha4
+     */
+    public static @NotNull PrintStream getStdErr() {
+        return error;
+    }
+
+    /**
+     * Extends {@link PrintStream} to allow for redirecting log messages.
+     * 
+     * @since v1-alpha4
+     */
+    private static final class LogStream extends OutputStream {
+        /**
+         * Contains the current sequence of characters written.
+         *
+         * @since v1-alpha4
+         */
+        private @NotNull StringBuilder sequence = new StringBuilder();
+
+        /**
+         * Contains the {@link LogLevel} to write log messages in.
+         *
+         * @since v1-alpha4
+         */
+        private final @NotNull LogLevel level;
+
+        /**
+         * Constructs this class.
+         *
+         * @param level level to write log messages in
+         * @since v1-alpha4
+         */
+        public LogStream(@NotNull LogLevel level) {
+            this.level = level;
+        }
+
+        /**
+         * Creates a new {@link LogStream} and returns a {@link PrintStream}
+         * using the newly created {@link LogStream} instance.
+         *
+         * @param level level to write log messages in
+         * @return {@link PrintStream} using a newly created {@link LogStream} instance
+         * @since v1-alpha4
+         */
+        public static @NotNull PrintStream createPrintStream(@NotNull LogLevel level) {
+            //noinspection resource // obvious why
+            return new LogStream(level).toPrintStream();
+        }
+
+        /**
+         * Returns a new {@link PrintStream} using this {@link LogStream} instance.
+         *
+         * @return {@link PrintStream} using this instance
+         * @since v1-alpha4
+         */
+        public @NotNull PrintStream toPrintStream() {
+            return new PrintStream(this, true, StandardCharsets.UTF_8);
+        }
+
+        /** {@inheritDoc} */
+        @Override
+        public synchronized void write(int byteChar) {
+            // Convert to String and append to 'sequence'
+            sequence.append(new String(new byte[]{ (byte) byteChar }, StandardCharsets.UTF_8));
+
+            // Check for newline
+            if (sequence.indexOf("\n") != -1) {
+                switch (level) {
+                    case DIAGNOSTIC -> logger.diag(sequence.toString());
+                    case VERBOSE -> logger.verb(sequence.toString());
+                    case SILENT_WARNING -> logger.sarn(sequence.toString());
+                    case INFORMATIONAL -> logger.info(sequence.toString());
+                    case WARNING -> logger.warn(sequence.toString());
+                    case ERROR -> logger.error(sequence.toString());
+                    case CRASH -> logger.crash(sequence.toString());
+                }
+
+                sequence = new StringBuilder();
+            }
+        }
+    }
+}