added new custom exceptions

src/main/java/core/basesyntax/dao/StorageDaoImpl.java

@@ -2,13 +2,10 @@
 
 import core.basesyntax.storage.Storage;
 import java.util.Map;
+import java.util.NoSuchElementException;
 
 public class StorageDaoImpl implements StorageDao {
-    private Storage storage;
-
-    public StorageDaoImpl() {
-        storage = new Storage();
-    }
+    private final Storage storage = new Storage();
 
     @Override
     public void save(String fruit, int quantity) {
@@ -25,6 +22,9 @@ public Map<String, Integer> getAll() {
 
     @Override
     public int getQuantityByFruitName(String key) {
+        if (!storage.getFruitStorage().containsKey(key)) {
+            throw new NoSuchElementException("No such key in storage: " + key);
+        }
         return storage.getFruitStorage().get(key);
     }
 }

src/main/java/core/basesyntax/service/DataConverterServiceImpl.java

@@ -9,6 +9,7 @@ public class DataConverterServiceImpl implements DataConverterService {
     private static final int OPERATION_TYPE_INDEX = 0;
     private static final int FRUIT_INDEX = 1;
     private static final int QUANTITY_INDEX = 2;
+    private static final int VALID_ARRAY_LENGTH = 3;
 
     @Override
     public List<FruitTransaction> convert(List<String> data) {
@@ -19,11 +20,26 @@ public List<FruitTransaction> convert(List<String> data) {
     }
 
     private FruitTransaction convertToFruitTransaction(String data) {
-        String[] dataSplit = data.split(COMMA_SEPARATOR);
+        String[] dataSplit = splitIfValid(data);
         FruitTransaction.Operation operation
                 = FruitTransaction.Operation.convertToOperation(dataSplit[OPERATION_TYPE_INDEX]);
         String fruit = dataSplit[FRUIT_INDEX];
         int quantity = Integer.parseInt(dataSplit[QUANTITY_INDEX]);
         return new FruitTransaction(operation, fruit, quantity);
     }
+
+    private String[] splitIfValid(String data) {
+        String[] dataSplit = data.split(COMMA_SEPARATOR);
+        if (dataSplit.length != VALID_ARRAY_LENGTH) {
+            throw new InvalidArraySplitLength("Data split length is not 3, but: "
+                    + dataSplit.length);
+        }
+        try {
+            Integer.parseInt(dataSplit[QUANTITY_INDEX]);
+        } catch (NumberFormatException e) {
+            throw new IllegalArgumentException("Expected a numeric value, but got: "
+                    + dataSplit[QUANTITY_INDEX]);
+        }
+        return dataSplit;
+    }
 }

src/main/java/core/basesyntax/service/InvalidArraySplitLength.java

@@ -0,0 +1,7 @@
+package core.basesyntax.service;
+
+public class InvalidArraySplitLength extends RuntimeException {
+    public InvalidArraySplitLength(String message) {
+        super(message);
+    }
+}

src/main/java/core/basesyntax/service/OperationStrategyImpl.java

@@ -3,9 +3,10 @@
 import core.basesyntax.model.FruitTransaction;
 import core.basesyntax.service.operation.OperationHandler;
 import java.util.Map;
+import java.util.NoSuchElementException;
 
 public class OperationStrategyImpl implements OperationStrategy {
-    private Map<FruitTransaction.Operation, OperationHandler> operationHandlerMap;
+    private final Map<FruitTransaction.Operation, OperationHandler> operationHandlerMap;
 
     public OperationStrategyImpl(Map<FruitTransaction.Operation, OperationHandler>
                                          operationHandlerMap) {
@@ -14,6 +15,9 @@ public OperationStrategyImpl(Map<FruitTransaction.Operation, OperationHandler>
 
     @Override
     public OperationHandler get(FruitTransaction.Operation operation) {
+        if (!operationHandlerMap.containsKey(operation)) {
+            throw new NoSuchElementException("No such operation in handler map: " + operation);
+        }
         return operationHandlerMap.get(operation);
     }
 }

src/main/java/core/basesyntax/service/file/FileReadException.java

@@ -0,0 +1,7 @@
+package core.basesyntax.service.file;
+
+public class FileReadException extends RuntimeException {
+    public FileReadException(String message) {
+        super(message);
+    }
+}

src/main/java/core/basesyntax/service/file/FileReaderServiceImpl.java

@@ -12,7 +12,7 @@ public List<String> read(String path) {
         try {
             return Files.readAllLines(Path.of(path));
         } catch (IOException e) {
-            throw new RuntimeException("Cannot read file: " + path, e);
+            throw new FileReadException("Cannot read file: " + path);
         }
     }
 }

src/main/java/core/basesyntax/service/file/FileWriteException.java

@@ -0,0 +1,7 @@
+package core.basesyntax.service.file;
+
+public class FileWriteException extends RuntimeException {
+    public FileWriteException(String message) {
+        super(message);
+    }
+}

src/main/java/core/basesyntax/service/file/FileWriterServiceImpl.java

@@ -10,7 +10,7 @@ public void write(String data, String path) {
         try (BufferedWriter writer = new BufferedWriter(new FileWriter(path))) {
             writer.write(data);
         } catch (IOException e) {
-            throw new RuntimeException("Cannot write to file: " + path, e);
+            throw new FileWriteException("Cannot write to file: " + path);
         }
     }
 }