Add Util.toHexString

PiperOrigin-RevId: 295539969

library/common/src/main/java/com/google/android/exoplayer2/util/Util.java

@@ -1255,6 +1255,22 @@ public final class Util {
     return data;
   }
 
+  /**
+   * Returns a string containing a lower-case hex representation of the bytes provided.
+   *
+   * @param bytes The byte data to convert to hex.
+   * @return A String containing the hex representation of {@code bytes}.
+   */
+  public static String toHexString(byte[] bytes) {
+    StringBuilder result = new StringBuilder(bytes.length * 2);
+    for (int i = 0; i < bytes.length; i++) {
+      result
+          .append(Character.forDigit((bytes[i] >> 4) & 0xF, 16))
+          .append(Character.forDigit(bytes[i] & 0xF, 16));
+    }
+    return result.toString();
+  }
+
   /**
    * Returns a string with comma delimited simple names of each object's class.
    *

library/common/src/test/java/com/google/android/exoplayer2/util/UtilTest.java

@@ -705,6 +705,13 @@ public class UtilTest {
     assertThat(Util.toLong(0xFEDCBA, 0x87654321)).isEqualTo(0xFEDCBA_87654321L);
   }
 
+  @Test
+  public void testToHexString() {
+    byte[] bytes = TestUtil.createByteArray(0x12, 0xFC, 0x06);
+
+    assertThat(Util.toHexString(bytes)).isEqualTo("12fc06");
+  }
+
   @Test
   public void testGetCodecsOfType() {
     assertThat(getCodecsOfType(null, C.TRACK_TYPE_VIDEO)).isNull();