Add readString to ParsableByteArray

library/src/androidTest/java/com/google/android/exoplayer/util/ParsableByteArrayTest.java

@@ -284,6 +284,7 @@ public class ParsableByteArrayTest extends TestCase {
         0x00, 0x00, 0x00, (byte) 0xFF
     });
     assertEquals(0xFF00000000000001L, byteArray.readLittleEndianLong());
+    assertEquals(8, byteArray.getPosition());
   }
 
   public void testReadLittleEndianUnsignedInt() {
@@ -291,6 +292,7 @@ public class ParsableByteArrayTest extends TestCase {
         0x10, 0x00, 0x00, (byte) 0xFF
     });
     assertEquals(0xFF000010L, byteArray.readLittleEndianUnsignedInt());
+    assertEquals(4, byteArray.getPosition());
   }
 
   public void testReadLittleEndianInt() {
@@ -298,12 +300,14 @@ public class ParsableByteArrayTest extends TestCase {
         0x01, 0x00, 0x00, (byte) 0xFF
     });
     assertEquals(0xFF000001, byteArray.readLittleEndianInt());
+    assertEquals(4, byteArray.getPosition());
   }
 
   public void testReadLittleEndianUnsignedInt24() {
     byte[] data = { 0x01, 0x02, (byte) 0xFF };
     ParsableByteArray byteArray = new ParsableByteArray(data);
     assertEquals(0xFF0201, byteArray.readLittleEndianUnsignedInt24());
+    assertEquals(3, byteArray.getPosition());
   }
 
   public void testReadLittleEndianUnsignedShort() {
@@ -311,7 +315,9 @@ public class ParsableByteArrayTest extends TestCase {
         0x01, (byte) 0xFF, 0x02, (byte) 0xFF
     });
     assertEquals(0xFF01, byteArray.readLittleEndianUnsignedShort());
+    assertEquals(2, byteArray.getPosition());
     assertEquals(0xFF02, byteArray.readLittleEndianUnsignedShort());
+    assertEquals(4, byteArray.getPosition());
   }
 
   public void testReadLittleEndianShort() {
@@ -319,7 +325,37 @@ public class ParsableByteArrayTest extends TestCase {
         0x01, (byte) 0xFF, 0x02, (byte) 0xFF
     });
     assertEquals((short) 0xFF01, byteArray.readLittleEndianShort());
+    assertEquals(2, byteArray.getPosition());
     assertEquals((short) 0xFF02, byteArray.readLittleEndianShort());
+    assertEquals(4, byteArray.getPosition());
+  }
+
+  public void testReadString() {
+    byte[] data = {
+        (byte) 0xC3, (byte) 0xA4, (byte) 0x20,
+        (byte) 0xC3, (byte) 0xB6, (byte) 0x20,
+        (byte) 0xC2, (byte) 0xAE, (byte) 0x20,
+        (byte) 0xCF, (byte) 0x80, (byte) 0x20,
+        (byte) 0xE2, (byte) 0x88, (byte) 0x9A, (byte) 0x20,
+        (byte) 0xC2, (byte) 0xB1, (byte) 0x20,
+        (byte) 0xE8, (byte) 0xB0, (byte) 0xA2, (byte) 0x20,
+    };
+    ParsableByteArray byteArray = new ParsableByteArray(data);
+    assertEquals("ä ö ® π √ ± 谢 ", byteArray.readString(data.length));
+    assertEquals(data.length, byteArray.getPosition());
+  }
+
+  public void testReadStringOutOfBoundsDoesNotMovePosition() {
+    byte[] data = {
+        (byte) 0xC3, (byte) 0xA4, (byte) 0x20
+    };
+    ParsableByteArray byteArray = new ParsableByteArray(data);
+    try {
+      byteArray.readString(data.length + 1);
+      fail();
+    } catch (StringIndexOutOfBoundsException e) {
+      assertEquals(0, byteArray.getPosition());
+    }
   }
 
   public void testReadEmptyString() {

library/src/main/java/com/google/android/exoplayer/util/ParsableByteArray.java

@@ -306,6 +306,18 @@ public final class ParsableByteArray {
     return result;
   }
 
+  /**
+   * Reads the next {@code length} bytes as UTF-8 characters.
+   *
+   * @param length the number of bytes to read.
+   * @return the UTF-8 {@code String} read.
+   */
+  public String readString(int length) {
+    String utf8String = new String(data, position, length);
+    position += length;
+    return utf8String;
+  }
+
   /**
    * Reads a line of text.
    * <p>
@@ -346,5 +358,4 @@ public final class ParsableByteArray {
     return line;
   }
 
-
 }