Better exception messages

Better unit test messages

Author: garydgregory

src/main/java/org/apache/commons/io/IOUtils.java

@@ -2898,15 +2898,16 @@ public static byte[] toByteArray(final InputStream input, final int size) throws
     public static byte[] toByteArray(final InputStream input, final int size, final int chunkSize) throws IOException {
         Objects.requireNonNull(input, "input");
         if (chunkSize <= 0) {
-            throw new IllegalArgumentException("Chunk size must be greater than zero: " + chunkSize);
+            throw new IllegalArgumentException(String.format("chunkSize <= 0, chunkSize = %,d", chunkSize));
         }
         if (size <= chunkSize) {
             // throws if size < 0
             return toByteArray(input::read, size);
         }
         final UnsynchronizedByteArrayOutputStream output = copyToOutputStream(input, size, chunkSize);
-         if (output.size() != size) {
-            throw new EOFException("Unexpected read size, current: " + output.size() + ", expected: " + size);
+        final int outSize = output.size();
+        if (outSize != size) {
+            throw new EOFException(String.format("Expected read size: %,d, actual: %,d", size, outSize));
         }
         return output.toByteArray();
     }
@@ -2930,7 +2931,7 @@ public static byte[] toByteArray(final InputStream input, final int size, final
      */
     public static byte[] toByteArray(final InputStream input, final long size) throws IOException {
         if (size > Integer.MAX_VALUE) {
-            throw new IllegalArgumentException("Size cannot be greater than Integer max value: " + size);
+            throw new IllegalArgumentException(String.format("size > Integer.MAX_VALUE, size = %,d", size));
         }
         return toByteArray(input, (int) size);
     }
@@ -2947,7 +2948,7 @@ public static byte[] toByteArray(final InputStream input, final long size) throw
      */
     static byte[] toByteArray(final IOTriFunction<byte[], Integer, Integer, Integer> input, final int size) throws IOException {
         if (size < 0) {
-            throw new IllegalArgumentException("Size must be equal or greater than zero: " + size);
+            throw new IllegalArgumentException(String.format("size < 0, size = %,d", size));
         }
         if (size == 0) {
             return EMPTY_BYTE_ARRAY;
@@ -2959,7 +2960,7 @@ static byte[] toByteArray(final IOTriFunction<byte[], Integer, Integer, Integer>
             offset += read;
         }
         if (offset != size) {
-            throw new EOFException("Unexpected read size, current: " + offset + ", expected: " + size);
+            throw new EOFException(String.format("Expected read size: %,d, actual: %,d", size, offset));
         }
         return data;
     }

src/main/java/org/apache/commons/io/input/ReadAheadInputStream.java

@@ -239,7 +239,7 @@ private ReadAheadInputStream(final InputStream inputStream, final int bufferSize
             final boolean shutdownExecutorService) {
         super(Objects.requireNonNull(inputStream, "inputStream"));
         if (bufferSizeInBytes <= 0) {
-            throw new IllegalArgumentException("bufferSizeInBytes should be greater than 0, but the value is " + bufferSizeInBytes);
+            throw new IllegalArgumentException(String.format("bufferSizeInBytes <= 0, bufferSizeInBytes = %,d", bufferSizeInBytes));
         }
         this.executorService = Objects.requireNonNull(executorService, "executorService");
         this.shutdownExecutorService = shutdownExecutorService;

src/test/java/org/apache/commons/io/IOUtilsTest.java

@@ -1772,10 +1772,8 @@ void testToByteArray_InputStream_LongerThanIntegerMaxValue() throws Exception {
     @Test
     void testToByteArray_InputStream_NegativeSize() throws Exception {
         try (InputStream fin = Files.newInputStream(testFilePath)) {
-            final IllegalArgumentException exc = assertThrows(IllegalArgumentException.class, () -> IOUtils.toByteArray(fin, -1),
-                    "Should have failed with IllegalArgumentException");
-            assertTrue(exc.getMessage().startsWith("Size must be equal or greater than zero"),
-                    "Exception message does not start with \"Size must be equal or greater than zero\"");
+            final IllegalArgumentException exc = assertThrows(IllegalArgumentException.class, () -> IOUtils.toByteArray(fin, -1));
+            assertTrue(exc.getMessage().startsWith("size < 0"), exc.getMessage());
         }
     }
 
@@ -1820,7 +1818,7 @@ void testToByteArray_InputStream_SizeIllegal() throws Exception {
         try (InputStream fin = Files.newInputStream(testFilePath)) {
             final IOException exc = assertThrows(IOException.class, () -> IOUtils.toByteArray(fin, testFile.length() + 1),
                     "Should have failed with IOException");
-            assertTrue(exc.getMessage().startsWith("Unexpected read size"), "Exception message does not start with \"Unexpected read size\"");
+            assertTrue(exc.getMessage().startsWith("Expected read size"), exc.getMessage());
         }
     }
 
@@ -1829,8 +1827,7 @@ void testToByteArray_InputStream_SizeLong() throws Exception {
         try (InputStream fin = Files.newInputStream(testFilePath)) {
             final IllegalArgumentException exc = assertThrows(IllegalArgumentException.class, () -> IOUtils.toByteArray(fin, (long) Integer.MAX_VALUE + 1),
                     "Should have failed with IllegalArgumentException");
-            assertTrue(exc.getMessage().startsWith("Size cannot be greater than Integer max value"),
-                    "Exception message does not start with \"Size cannot be greater than Integer max value\"");
+            assertTrue(exc.getMessage().startsWith("size > Integer.MAX_VALUE"), exc.getMessage());
         }
     }