HADOOP-17518. Update the regex to A-Z (#5669). Contributed by Nishtha Shah.

Signed-off-by: Ayush Saxena <ayushsaxena@apache.org>

hadoop-hdfs-project/hadoop-hdfs-httpfs/src/main/java/org/apache/hadoop/lib/util/Check.java

@@ -106,13 +106,13 @@ public class Check {
     return list;
   }
 
-  private static final String IDENTIFIER_PATTERN_STR = "[a-zA-z_][a-zA-Z0-9_\\-]*";
+  private static final String IDENTIFIER_PATTERN_STR = "[a-zA-Z_][a-zA-Z0-9_\\-]*";
 
   private static final Pattern IDENTIFIER_PATTERN = Pattern.compile("^" + IDENTIFIER_PATTERN_STR + "$");
 
   /**
    * Verifies a value is a valid identifier,
-   * <code>[a-zA-z_][a-zA-Z0-9_\-]*</code>, up to a maximum length.
+   * <code>[a-zA-Z_][a-zA-Z0-9_\-]*</code>, up to a maximum length.
    *
    * @param value string to check if it is a valid identifier.
    * @param maxLen maximun length.

hadoop-hdfs-project/hadoop-hdfs-httpfs/src/test/java/org/apache/hadoop/lib/util/TestCheck.java

@@ -116,6 +116,16 @@ public class TestCheck extends HTestCase {
     Check.validIdentifier("1", 1, "");
   }
 
+  @Test(expected = IllegalArgumentException.class)
+  public void validIdentifierInvalid4() throws Exception {
+    Check.validIdentifier("`a", 2, "");
+  }
+
+  @Test(expected = IllegalArgumentException.class)
+  public void validIdentifierInvalid5() throws Exception {
+    Check.validIdentifier("[a", 2, "");
+  }
+
   @Test
   public void checkGTZeroGreater() {
     assertEquals(Check.gt0(120, "test"), 120);

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/test/java/org/apache/hadoop/yarn/resourcetypes/ResourceTypesTestHelper.java

@@ -36,7 +36,7 @@ import org.apache.hadoop.yarn.factory.providers.RecordFactoryProvider;
 public final class ResourceTypesTestHelper {
 
   private static final Pattern RESOURCE_VALUE_AND_UNIT_PATTERN =
-      Pattern.compile("(\\d+)([A-za-z]*)");
+      Pattern.compile("(\\d+)([A-Za-z]*)");
 
   private ResourceTypesTestHelper() {}