[LIB-13] Add chesshog-scanner general purpose classes

[chesshog-scanner.git] / src / main / java / org / hedgecode / chess / scanner / ChessHogScannerProperties.java

diff --git a/src/main/java/org/hedgecode/chess/scanner/ChessHogScannerProperties.java b/src/main/java/org/hedgecode/chess/scanner/ChessHogScannerProperties.java
new file mode 100644 (file)
index 0000000..e7565bc
--- /dev/null
+++ b/src/main/java/org/hedgecode/chess/scanner/ChessHogScannerProperties.java
@@ -0,0 +1,91 @@
+/*
+ * Copyright (c) 2019-2020. Developed by Hedgecode.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.hedgecode.chess.scanner;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.Properties;
+
+/**
+ * ChessHogScanner properties holder.
+ *
+ * @author Dmitry Samoshin aka gotty
+ */
+public class ChessHogScannerProperties {
+
+    /** Properties file. */
+    private static final String PROPERTIES_FILE = "scanner.properties";
+
+    /** Properties. */
+    private static final Properties PROPERTIES;
+
+    /**
+     * Static properties initialization.
+     */
+    static {
+        PROPERTIES = new Properties();
+        readProperties(PROPERTIES_FILE, PROPERTIES, true);
+    }
+
+    /**
+     * @param propsFile Properties file name.
+     * @param props Properties.
+     * @param throwExc Flag indicating whether to throw an exception or not.
+     */
+    public static void readProperties(String propsFile, Properties props, boolean throwExc) {
+        try (InputStream is = ChessHogScannerProperties.class.getClassLoader().getResourceAsStream(propsFile))
+        {
+            if (is == null) {
+                if (throwExc) {
+                    throw new RuntimeException(
+                            String.format("Failed to find properties file: %s", propsFile)
+                    );
+                } else {
+                    return;
+                }
+            }
+            props.load(is);
+        } catch (IOException cause) {
+            throw new RuntimeException(
+                    String.format("Failed to read properties file: %s", propsFile),
+                    cause
+            );
+        }
+    }
+
+    /**
+     * Empty string for not found properties.
+     */
+    private static final String EMPTY = "";
+
+    /**
+     * Gets property value.
+     *
+     * @param key Property key.
+     * @return Property value (possibly empty string, but never {@code null}).
+     */
+    public static String get(String key) {
+        return PROPERTIES.getProperty(key, EMPTY);
+    }
+
+    /**
+     * Private constructor.
+     */
+    private ChessHogScannerProperties() {
+    }
+
+}