Fix odd-length hex string in Parquet CLI

Author: nastra

parquet-cli/src/main/java/org/apache/parquet/cli/BaseCommand.java

@@ -20,6 +20,7 @@
 package org.apache.parquet.cli;
 
 import com.beust.jcommander.internal.Lists;
+import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.Preconditions;
 import com.google.common.io.CharStreams;
 import com.google.common.io.Resources;
@@ -428,13 +429,16 @@ private void parseAndSetColumnKeys(String columnKeysStr, ConfigurableKeyRetrieve
     }
   }
 
-  private byte[] hexToBytes(String hex) {
-
+  @VisibleForTesting
+  byte[] hexToBytes(String hex) {
+    String originalHex = hex;
     if (hex.startsWith("0x") || hex.startsWith("0X")) {
       hex = hex.substring(2);
     }
 
     int len = hex.length();
+    Preconditions.checkArgument(len % 2 == 0, "Invalid hex string: %s", originalHex);
+
     byte[] data = new byte[len / 2];
     for (int i = 0; i < len; i += 2) {
       data[i / 2] = (byte) ((Character.digit(hex.charAt(i), 16) << 4) + Character.digit(hex.charAt(i + 1), 16));

parquet-cli/src/test/java/org/apache/parquet/cli/BaseCommandTest.java

@@ -62,6 +62,18 @@ public void qualifiedURIResourceURITest() throws IOException {
     Assert.assertEquals("/a", uri.getPath());
   }
 
+  @Test
+  public void hexToBytes() {
+    Assert.assertArrayEquals(new byte[] {0x10}, this.command.hexToBytes("0x10"));
+    Assert.assertArrayEquals(new byte[] {0x05, 0x06}, this.command.hexToBytes("0x0506"));
+    Assert.assertArrayEquals(new byte[] {0x01, 0x02, 0x03}, this.command.hexToBytes("0x010203"));
+  }
+
+  @Test(expected = IllegalArgumentException.class)
+  public void hexToBytesRejectsOddLengthKey() {
+    this.command.hexToBytes("0x011");
+  }
+
   // For Windows
   @Test
   public void qualifiedPathTestForWindows() throws IOException {