Simplified exceptions throwing using a Validator API

Author: pavly-gerges

snaploader/src/main/java/electrostatic4j/snaploader/filesystem/FileExtractor.java

@@ -34,6 +34,8 @@
 
 import electrostatic4j.snaploader.throwable.FilesystemResourceInitializationException;
 import electrostatic4j.snaploader.util.SnapLoaderLogger;
+import electrostatic4j.snaploader.util.StreamObjectValidator;
+
 import java.io.*;
 import java.util.logging.Level;
 
@@ -133,6 +135,7 @@ public void extract() throws IOException, FileNotFoundException {
              * pipe, and allocate memory according to the active bytes manipulated
              * by the pipeline. */
             InputStream fileStream = fileLocator.getFileInputStream();
+            StreamObjectValidator.validateAndThrow(fileStream, StreamObjectValidator.BROKEN_FILE_LOCATOR_PROVIDER);
 
             /* Extracts the shipped native files */
             /* Allocate a byte buffer for the buffered streams */

snaploader/src/main/java/electrostatic4j/snaploader/filesystem/FileLocator.java

@@ -34,6 +34,8 @@
 
 import electrostatic4j.snaploader.throwable.FilesystemResourceInitializationException;
 import electrostatic4j.snaploader.util.SnapLoaderLogger;
+import electrostatic4j.snaploader.util.StreamObjectValidator;
+
 import java.io.*;
 import java.util.logging.Level;
 import java.util.zip.ZipEntry;
@@ -129,20 +131,19 @@ public void initialize(int size) throws IOException {
                 externalCompressionRoutine(size);
             }
 
+            StreamObjectValidator.validateAndThrow(fileInputStream, StreamObjectValidator.BROKEN_FILE_LOCATOR_PROVIDER);
+
             // fire the success listener if the file localization has passed!
             if (fileLocalizingListener != null) {
                 fileLocalizingListener.onFileLocalizationSuccess(this);
             }
         } catch (Exception e) {
             close();
-            final FilesystemResourceInitializationException exception = new FilesystemResourceInitializationException(
-                    "Failed to initialize the file locator handler #" + getHashKey(), e);
             // fire the failure listener when file localization fails and pass
             // the causative exception
             if (fileLocalizingListener != null) {
-                fileLocalizingListener.onFileLocalizationFailure(this, exception);
+                fileLocalizingListener.onFileLocalizationFailure(this, e);
             }
-            throw exception;
         }
     }
 
@@ -164,9 +165,6 @@ protected void classPathRoutine() throws FilesystemResourceInitializationExcepti
         // getClassLoader() is invoked on them, it will return "null" pointer
         // indicating the invalidity of active loaders
         this.fileInputStream = getClass().getClassLoader().getResourceAsStream(filePath);
-        if (this.fileInputStream == null) {
-            throw new FilesystemResourceInitializationException("Classpath Routine failed: the file is not in the classpath!");
-        }
     }
 
     /**
@@ -178,11 +176,13 @@ protected void classPathRoutine() throws FilesystemResourceInitializationExcepti
      */
     protected void externalCompressionRoutine(int size) throws IOException {
         final ZipEntry zipEntry = compression.getEntry(filePath);
+        StreamObjectValidator.validateAndThrow(zipEntry, StreamObjectValidator.COMPRESSION_FILE_LOCALIZING_FAIL);
         if (size > 0) {
             this.fileInputStream = new BufferedInputStream(compression.getInputStream(zipEntry), size);
         } else {
             this.fileInputStream = compression.getInputStream(zipEntry);
         }
+
         SnapLoaderLogger.log(Level.INFO, getClass().getName(), "initialize(int)",
                 "File locator initialized using external compression routine with hash key #" + getHashKey());
     }

snaploader/src/main/java/electrostatic4j/snaploader/util/StreamObjectValidator.java

@@ -0,0 +1,64 @@
+/*
+ * Copyright (c) 2023-2024, The Electrostatic-Sandbox Distributed Simulation Framework, jSnapLoader
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ *
+ * * Redistributions in binary form must reproduce the above copyright
+ *   notice, this list of conditions and the following disclaimer in the
+ *   documentation and/or other materials provided with the distribution.
+ *
+ * * Neither the name of 'Electrostatic-Sandbox' nor the names of its contributors
+ *   may be used to endorse or promote products derived from this software
+ *   without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+package electrostatic4j.snaploader.util;
+
+import electrostatic4j.snaploader.filesystem.StreamProvider;
+import electrostatic4j.snaploader.throwable.FilesystemResourceInitializationException;
+
+/**
+ * Validates the stream providers tokens.
+ *
+ * @author pavl_g
+ */
+public final class StreamObjectValidator {
+
+    public static final String BROKEN_FILE_LOCATOR_PROVIDER = "Broken file locator stream provider!";
+    public static final String COMPRESSION_FILE_LOCALIZING_FAIL = "Cannot locate the file entry in the compression!";
+
+    private StreamObjectValidator() {
+    }
+
+    public static void validateAndThrow(final StreamProvider object, final String message, final Throwable cause) {
+        if (object != null) {
+            return;
+        }
+        throw new FilesystemResourceInitializationException(message, cause);
+    }
+
+    public static void validateAndThrow(final Object object, final String message) {
+        if (object != null) {
+            return;
+        }
+        throw new FilesystemResourceInitializationException(message);
+    }
+}