Internal

java.lang.Object
- com.google.protobuf.Internal

```
public final class Internal
extends Object
```
The classes contained within are used internally by the Protocol Buffer library and generated message implementations. They are public only because those generated messages do not reside in the protobuf package. Others should not use this class directly.

Author:

kenton@google.com (Kenton Varda)

Nested Class Summary

Nested Classes
Modifier and Type	Class and Description
`static interface`	`Internal.BooleanList` A `List` implementation that avoids boxing the elements into Booleans if possible.
`static interface`	`Internal.DoubleList` A `List` implementation that avoids boxing the elements into Doubles if possible.
`static interface`	`Internal.EnumLite` Interface for an enum value or value descriptor, to be used in FieldSet.
`static interface`	`Internal.EnumLiteMap<T extends Internal.EnumLite>` Interface for an object which maps integers to `Internal.EnumLite`s.
`static interface`	`Internal.FloatList` A `List` implementation that avoids boxing the elements into Floats if possible.
`static interface`	`Internal.IntList` A `List` implementation that avoids boxing the elements into Integers if possible.
`static class`	`Internal.ListAdapter<F,T>` Provides an immutable view of `List<T>` around a `List<F>`.
`static interface`	`Internal.LongList` A `List` implementation that avoids boxing the elements into Longs if possible.
`static class`	`Internal.MapAdapter<K,V,RealValue>` Wrap around a `Map<K, RealValue>` and provide a `Map<K, V>` interface.
`static interface`	`Internal.ProtobufList<E>` Extends `List` to add the capability to make the list immutable and inspect if it is modifiable.

Field Summary

Fields
Modifier and Type	Field and Description
`static byte[]`	`EMPTY_BYTE_ARRAY` An empty byte array constant used in generated code.
`static ByteBuffer`	`EMPTY_BYTE_BUFFER` An empty byte array constant used in generated code.
`static CodedInputStream`	`EMPTY_CODED_INPUT_STREAM` An empty coded input stream constant used in generated code.

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method and Description
`static byte[]`	`byteArrayDefaultValue(String bytes)` Helper called by generated code to construct default values for bytes fields.
`static ByteBuffer`	`byteBufferDefaultValue(String bytes)` Helper called by generated code to construct default values for bytes fields.
`static ByteString`	`bytesDefaultValue(String bytes)` Helper called by generated code to construct default values for bytes fields.
`static ByteBuffer`	`copyByteBuffer(ByteBuffer source)` Create a new ByteBuffer and copy all the content of `source` ByteBuffer to the new ByteBuffer.
`static int`	`hashBoolean(boolean b)` Returns the hash of the given boolean.
`static int`	`hashCode(byte[] bytes)` Returns the hash code of the given byte array.
`static int`	`hashLong(long n)` Returns the hash of the given long.
`static boolean`	`isValidUtf8(byte[] byteArray)` Like `isValidUtf8(ByteString)` but for byte arrays.
`static boolean`	`isValidUtf8(ByteString byteString)` Helper called by generated code to determine if a byte array is a valid UTF-8 encoded string such that the original bytes can be converted to a String object and then back to a byte array round tripping the bytes without loss.
`static String`	`stringDefaultValue(String bytes)` Helper called by generated code to construct default values for string fields.
`static byte[]`	`toByteArray(String value)` Helper method to get the UTF-8 bytes of a string.
`static String`	`toStringUtf8(byte[] bytes)` Helper method to convert a byte array to a string using UTF-8 encoding.

Methods inherited from class java.lang.Object
clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - EMPTY_BYTE_ARRAY
```
public static final byte[] EMPTY_BYTE_ARRAY
```
    An empty byte array constant used in generated code.
  - EMPTY_BYTE_BUFFER
```
public static final ByteBuffer EMPTY_BYTE_BUFFER
```
    An empty byte array constant used in generated code.
  - EMPTY_CODED_INPUT_STREAM
```
public static final CodedInputStream EMPTY_CODED_INPUT_STREAM
```
    An empty coded input stream constant used in generated code.
- Method Detail
  - byteArrayDefaultValue
```
public static byte[] byteArrayDefaultValue(String bytes)
```
    Helper called by generated code to construct default values for bytes fields.
    This is like bytesDefaultValue(java.lang.String), but returns a byte array.
  - byteBufferDefaultValue
```
public static ByteBuffer byteBufferDefaultValue(String bytes)
```
    Helper called by generated code to construct default values for bytes fields.
    This is like bytesDefaultValue(java.lang.String), but returns a ByteBuffer.
  - bytesDefaultValue
```
public static ByteString bytesDefaultValue(String bytes)
```
    Helper called by generated code to construct default values for bytes fields.
    This is a lot like stringDefaultValue(java.lang.String), but for bytes fields. In this case we only need the second of the two hacks -- allowing us to embed raw bytes as a string literal with ISO-8859-1 encoding.
  - copyByteBuffer
```
public static ByteBuffer copyByteBuffer(ByteBuffer source)
```
    Create a new ByteBuffer and copy all the content of source ByteBuffer to the new ByteBuffer. The new ByteBuffer's limit and capacity will be source.capacity(), and its position will be 0. Note that the state of source ByteBuffer won't be changed.
  - hashBoolean
```
public static int hashBoolean(boolean b)
```
    Returns the hash of the given boolean.
    
    Parameters:
    
    b - the boolean to get the hash from.
    
    Returns:
    
    the hash.
  - hashCode
```
public static int hashCode(byte[] bytes)
```
    Returns the hash code of the given byte array.
    
    Parameters:
    
    bytes - the byte array.
    
    Returns:
    
    the hash code.
  - hashLong
```
public static int hashLong(long n)
```
    Returns the hash of the given long.
    
    Parameters:
    
    n - the long to get the hash from.
    
    Returns:
    
    the hash.
  - isValidUtf8
```
public static boolean isValidUtf8(byte[] byteArray)
```
    Like isValidUtf8(ByteString) but for byte arrays.
  - isValidUtf8
```
public static boolean isValidUtf8(ByteString byteString)
```
    Helper called by generated code to determine if a byte array is a valid UTF-8 encoded string such that the original bytes can be converted to a String object and then back to a byte array round tripping the bytes without loss. More precisely, returns true whenever:
```
    
 Arrays.equals(byteString.toByteArray(),
     new String(byteString.toByteArray(), "UTF-8").getBytes("UTF-8"))
 
 
```
    This method rejects "overlong" byte sequences, as well as 3-byte sequences that would map to a surrogate character, in accordance with the restricted definition of UTF-8 introduced in Unicode 3.1. Note that the UTF-8 decoder included in Oracle's JDK has been modified to also reject "overlong" byte sequences, but currently (2011) still accepts 3-byte surrogate character byte sequences.
    See the Unicode Standard,
    Table 3-6. UTF-8 Bit Distribution,
    Table 3-7. Well Formed UTF-8 Byte Sequences.
    As of 2011-02, this method simply returns the result of ByteString.isValidUtf8(). Calling that method directly is preferred.
    Parameters:
    
    byteString - the string to check
    
    Returns:
    
    whether the byte array is round trippable
  - stringDefaultValue
```
public static String stringDefaultValue(String bytes)
```
    Helper called by generated code to construct default values for string fields.
    The protocol compiler does not actually contain a UTF-8 decoder -- it just pushes UTF-8-encoded text around without touching it. The one place where this presents a problem is when generating Java string literals. Unicode characters in the string literal would normally need to be encoded using a Unicode escape sequence, which would require decoding them. To get around this, protoc instead embeds the UTF-8 bytes into the generated code and leaves it to the runtime library to decode them.
    It gets worse, though. If protoc just generated a byte array, like: new byte[] {0x12, 0x34, 0x56, 0x78} Java actually generates *code* which allocates an array and then fills in each value. This is much less efficient than just embedding the bytes directly into the bytecode. To get around this, we need another work-around. String literals are embedded directly, so protoc actually generates a string literal corresponding to the bytes. The easiest way to do this is to use the ISO-8859-1 character set, which corresponds to the first 256 characters of the Unicode range. Protoc can then use good old CEscape to generate the string.
    So we have a string literal which represents a set of bytes which represents another string. This function -- stringDefaultValue -- converts from the generated string to the string we actually want. The generated code calls this automatically.
  - toByteArray
```
public static byte[] toByteArray(String value)
```
    Helper method to get the UTF-8 bytes of a string.
  - toStringUtf8
```
public static String toStringUtf8(byte[] bytes)
```
    Helper method to convert a byte array to a string using UTF-8 encoding.

Class Internal

Nested Class Summary

Field Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

EMPTY_BYTE_ARRAY

EMPTY_BYTE_BUFFER

EMPTY_CODED_INPUT_STREAM

Method Detail

byteArrayDefaultValue

byteBufferDefaultValue

bytesDefaultValue

copyByteBuffer

hashBoolean

hashCode

hashLong

isValidUtf8

isValidUtf8

stringDefaultValue

toByteArray

toStringUtf8