All Known Implementing Classes:

BinaryReader, BinaryReader.SafeHeapReader, CodedInputStreamReader
```
@ExperimentalApi
@CheckReturnValue
interface Reader
```
A reader of fields from a serialized protobuf message.

Field Summary

Fields
Modifier and Type	Field	Description
`static int`	`READ_DONE`	Value used to indicate that the end of input has been reached.
`static int`	`TAG_UNKNOWN`	Value used to indicate that the reader does not know the tag about the field.

Method Summary

All Methods Instance Methods Abstract Methods Deprecated Methods
Modifier and Type	Method	Description
`int`	`getFieldNumber()`	Gets the field number for the current field being read.
`int`	`getTag()`	Gets the wire tag of the current field.
`<T> void`	`mergeGroupField(T target, Schema<T> schema, ExtensionRegistryLite extensionRegistry)`	Read a group field from the wire format and merge the results into the given target.
`<T> void`	`mergeMessageField(T target, Schema<T> schema, ExtensionRegistryLite extensionRegistry)`	Read a message field from the wire format and merge the results into the given target.
`boolean`	`readBool()`	Reads and returns the next field of type `BOOL` and advances the reader to the next field.
`void`	`readBoolList(java.util.List<java.lang.Boolean> target)`	Reads the next field of type `BOOL_LIST` or `BOOL_LIST_PACKED` and advances the reader to the next field.
`ByteString`	`readBytes()`	Reads and returns the next field of type `BYTES` and advances the reader to the next field.
`void`	`readBytesList(java.util.List<ByteString> target)`	Reads the next field of type `BYTES_LIST` and advances the reader to the next field.
`double`	`readDouble()`	Reads and returns the next field of type `DOUBLE` and advances the reader to the next field.
`void`	`readDoubleList(java.util.List<java.lang.Double> target)`	Reads the next field of type `DOUBLE_LIST` or `DOUBLE_LIST_PACKED` and advances the reader to the next field.
`int`	`readEnum()`	Reads and returns the next field of type `ENUM` and advances the reader to the next field.
`void`	`readEnumList(java.util.List<java.lang.Integer> target)`	Reads the next field of type `ENUM_LIST` or `ENUM_LIST_PACKED` and advances the reader to the next field.
`int`	`readFixed32()`	Reads and returns the next field of type `FIXED32` and advances the reader to the next field.
`void`	`readFixed32List(java.util.List<java.lang.Integer> target)`	Reads the next field of type `FIXED32_LIST` or `FIXED32_LIST_PACKED` and advances the reader to the next field.
`long`	`readFixed64()`	Reads and returns the next field of type `FIXED64` and advances the reader to the next field.
`void`	`readFixed64List(java.util.List<java.lang.Long> target)`	Reads the next field of type `FIXED64_LIST` or `FIXED64_LIST_PACKED` and advances the reader to the next field.
`float`	`readFloat()`	Reads and returns the next field of type `FLOAT` and advances the reader to the next field.
`void`	`readFloatList(java.util.List<java.lang.Float> target)`	Reads the next field of type `FLOAT_LIST` or `FLOAT_LIST_PACKED` and advances the reader to the next field.
`<T> T`	`readGroup(java.lang.Class<T> clazz, ExtensionRegistryLite extensionRegistry)`	Deprecated. groups fields are deprecated.
`<T> T`	`readGroupBySchemaWithCheck(Schema<T> schema, ExtensionRegistryLite extensionRegistry)`	Deprecated.
`<T> void`	`readGroupList(java.util.List<T> target, Schema<T> targetType, ExtensionRegistryLite extensionRegistry)`	Deprecated.
`<T> void`	`readGroupList(java.util.List<T> target, java.lang.Class<T> targetType, ExtensionRegistryLite extensionRegistry)`	Deprecated. groups fields are deprecated.
`int`	`readInt32()`	Reads and returns the next field of type `INT32` and advances the reader to the next field.
`void`	`readInt32List(java.util.List<java.lang.Integer> target)`	Reads the next field of type `INT32_LIST` or `INT32_LIST_PACKED` and advances the reader to the next field.
`long`	`readInt64()`	Reads and returns the next field of type `INT64` and advances the reader to the next field.
`void`	`readInt64List(java.util.List<java.lang.Long> target)`	Reads the next field of type `INT64_LIST` or `INT64_LIST_PACKED` and advances the reader to the next field.
`<K,V> void`	`readMap(java.util.Map<K,V> target, MapEntryLite.Metadata<K,V> mapDefaultEntry, ExtensionRegistryLite extensionRegistry)`	Reads the next field of type `MAP` and advances the reader to the next field.
`<T> T`	`readMessage(java.lang.Class<T> clazz, ExtensionRegistryLite extensionRegistry)`	Reads and returns the next field of type `MESSAGE` and advances the reader to the next field.
`<T> T`	`readMessageBySchemaWithCheck(Schema<T> schema, ExtensionRegistryLite extensionRegistry)`
`<T> void`	`readMessageList(java.util.List<T> target, Schema<T> schema, ExtensionRegistryLite extensionRegistry)`	Reads the next field of type `MESSAGE_LIST` and advances the reader to the next field.
`<T> void`	`readMessageList(java.util.List<T> target, java.lang.Class<T> targetType, ExtensionRegistryLite extensionRegistry)`
`int`	`readSFixed32()`	Reads and returns the next field of type `SFIXED32` and advances the reader to the next field.
`void`	`readSFixed32List(java.util.List<java.lang.Integer> target)`	Reads the next field of type `SFIXED32_LIST` or `SFIXED32_LIST_PACKED` and advances the reader to the next field.
`long`	`readSFixed64()`	Reads and returns the next field of type `SFIXED64` and advances the reader to the next field.
`void`	`readSFixed64List(java.util.List<java.lang.Long> target)`	Reads the next field of type `SFIXED64_LIST` or `SFIXED64_LIST_PACKED` and advances the reader to the next field.
`int`	`readSInt32()`	Reads and returns the next field of type `SINT32` and advances the reader to the next field.
`void`	`readSInt32List(java.util.List<java.lang.Integer> target)`	Reads the next field of type `SINT32_LIST` or `SINT32_LIST_PACKED` and advances the reader to the next field.
`long`	`readSInt64()`	Reads and returns the next field of type `SINT64` and advances the reader to the next field.
`void`	`readSInt64List(java.util.List<java.lang.Long> target)`	Reads the next field of type `SINT64_LIST` or `SINT64_LIST_PACKED` and advances the reader to the next field.
`java.lang.String`	`readString()`	Reads and returns the next field of type `STRING` and advances the reader to the next field.
`void`	`readStringList(java.util.List<java.lang.String> target)`	Reads the next field of type `STRING_LIST` and advances the reader to the next field.
`void`	`readStringListRequireUtf8(java.util.List<java.lang.String> target)`	Reads the next field of type `STRING_LIST` and advances the reader to the next field.
`java.lang.String`	`readStringRequireUtf8()`	Reads and returns the next field of type `STRING` and advances the reader to the next field.
`int`	`readUInt32()`	Reads and returns the next field of type `UINT32` and advances the reader to the next field.
`void`	`readUInt32List(java.util.List<java.lang.Integer> target)`	Reads the next field of type `UINT32_LIST` or `UINT32_LIST_PACKED` and advances the reader to the next field.
`long`	`readUInt64()`	Reads and returns the next field of type `UINT64` and advances the reader to the next field.
`void`	`readUInt64List(java.util.List<java.lang.Long> target)`	Reads the next field of type `UINT64_LIST` or `UINT64_LIST_PACKED` and advances the reader to the next field.
`boolean`	`shouldDiscardUnknownFields()`
`boolean`	`skipField()`	Skips the current field and advances the reader to the next field.

- Field Detail
  - READ_DONE
```
static final int READ_DONE
```
    Value used to indicate that the end of input has been reached.
    
    See Also:
    
    Constant Field Values
  - TAG_UNKNOWN
```
static final int TAG_UNKNOWN
```
    Value used to indicate that the reader does not know the tag about the field.
    
    See Also:
    
    Constant Field Values
- Method Detail
  - shouldDiscardUnknownFields
```
boolean shouldDiscardUnknownFields()
```
  - getFieldNumber
```
int getFieldNumber()
            throws java.io.IOException
```
    Gets the field number for the current field being read.
    TODO: Rename it to make it more explicit about the side effect on the underlying buffer.
    
    Returns:
    
    the current field number or READ_DONE if the end of input has been reached.
    
    Throws:
    
    java.io.IOException
  - getTag
```
int getTag()
```
    Gets the wire tag of the current field.
    
    Returns:
    
    the current wire tag or TAG_UNKNOWN if the reader does not know the tag of the current field.
  - skipField
```
boolean skipField()
           throws java.io.IOException
```
    Skips the current field and advances the reader to the next field.
    
    Returns:
    
    true if there are more fields or false if the end of input has been reached.
    
    Throws:
    
    java.io.IOException
  - readDouble
```
double readDouble()
           throws java.io.IOException
```
    Reads and returns the next field of type DOUBLE and advances the reader to the next field.
    
    Throws:
    
    java.io.IOException
  - readFloat
```
float readFloat()
         throws java.io.IOException
```
    Reads and returns the next field of type FLOAT and advances the reader to the next field.
    
    Throws:
    
    java.io.IOException
  - readUInt64
```
long readUInt64()
         throws java.io.IOException
```
    Reads and returns the next field of type UINT64 and advances the reader to the next field.
    
    Throws:
    
    java.io.IOException
  - readInt64
```
long readInt64()
        throws java.io.IOException
```
    Reads and returns the next field of type INT64 and advances the reader to the next field.
    
    Throws:
    
    java.io.IOException
  - readInt32
```
int readInt32()
       throws java.io.IOException
```
    Reads and returns the next field of type INT32 and advances the reader to the next field.
    
    Throws:
    
    java.io.IOException
  - readFixed64
```
long readFixed64()
          throws java.io.IOException
```
    Reads and returns the next field of type FIXED64 and advances the reader to the next field.
    
    Throws:
    
    java.io.IOException
  - readFixed32
```
int readFixed32()
         throws java.io.IOException
```
    Reads and returns the next field of type FIXED32 and advances the reader to the next field.
    
    Throws:
    
    java.io.IOException
  - readBool
```
boolean readBool()
          throws java.io.IOException
```
    Reads and returns the next field of type BOOL and advances the reader to the next field.
    
    Throws:
    
    java.io.IOException
  - readString
```
java.lang.String readString()
                     throws java.io.IOException
```
    Reads and returns the next field of type STRING and advances the reader to the next field. If the stream contains malformed UTF-8, replace the offending bytes with the standard UTF-8 replacement character.
    
    Throws:
    
    java.io.IOException
  - readStringRequireUtf8
```
java.lang.String readStringRequireUtf8()
                                throws java.io.IOException
```
    Reads and returns the next field of type STRING and advances the reader to the next field. If the stream contains malformed UTF-8, throw exception InvalidProtocolBufferException.
    
    Throws:
    
    java.io.IOException
  - readMessageBySchemaWithCheck
```
<T> T readMessageBySchemaWithCheck(Schema<T> schema,
                                   ExtensionRegistryLite extensionRegistry)
                            throws java.io.IOException
```
    Throws:
    
    java.io.IOException
  - readMessage
```
<T> T readMessage(java.lang.Class<T> clazz,
                  ExtensionRegistryLite extensionRegistry)
           throws java.io.IOException
```
    Reads and returns the next field of type MESSAGE and advances the reader to the next field.
    
    Throws:
    
    java.io.IOException
  - readGroup
```
@Deprecated
<T> T readGroup(java.lang.Class<T> clazz,
                ExtensionRegistryLite extensionRegistry)
         throws java.io.IOException
```
    Deprecated.
    groups fields are deprecated.
    
    Reads and returns the next field of type GROUP and advances the reader to the next field.
    
    Throws:
    
    java.io.IOException
  - readGroupBySchemaWithCheck
```
@Deprecated
<T> T readGroupBySchemaWithCheck(Schema<T> schema,
                                 ExtensionRegistryLite extensionRegistry)
                          throws java.io.IOException
```
    Deprecated.
    
    Throws:
    
    java.io.IOException
  - mergeMessageField
```
<T> void mergeMessageField(T target,
                           Schema<T> schema,
                           ExtensionRegistryLite extensionRegistry)
                    throws java.io.IOException
```
    Read a message field from the wire format and merge the results into the given target.
    
    Throws:
    
    java.io.IOException
  - mergeGroupField
```
<T> void mergeGroupField(T target,
                         Schema<T> schema,
                         ExtensionRegistryLite extensionRegistry)
                  throws java.io.IOException
```
    Read a group field from the wire format and merge the results into the given target.
    
    Throws:
    
    java.io.IOException
  - readBytes
```
ByteString readBytes()
              throws java.io.IOException
```
    Reads and returns the next field of type BYTES and advances the reader to the next field.
    
    Throws:
    
    java.io.IOException
  - readUInt32
```
int readUInt32()
        throws java.io.IOException
```
    Reads and returns the next field of type UINT32 and advances the reader to the next field.
    
    Throws:
    
    java.io.IOException
  - readEnum
```
int readEnum()
      throws java.io.IOException
```
    Reads and returns the next field of type ENUM and advances the reader to the next field.
    
    Throws:
    
    java.io.IOException
  - readSFixed32
```
int readSFixed32()
          throws java.io.IOException
```
    Reads and returns the next field of type SFIXED32 and advances the reader to the next field.
    
    Throws:
    
    java.io.IOException
  - readSFixed64
```
long readSFixed64()
           throws java.io.IOException
```
    Reads and returns the next field of type SFIXED64 and advances the reader to the next field.
    
    Throws:
    
    java.io.IOException
  - readSInt32
```
int readSInt32()
        throws java.io.IOException
```
    Reads and returns the next field of type SINT32 and advances the reader to the next field.
    
    Throws:
    
    java.io.IOException
  - readSInt64
```
long readSInt64()
         throws java.io.IOException
```
    Reads and returns the next field of type SINT64 and advances the reader to the next field.
    
    Throws:
    
    java.io.IOException
  - readDoubleList
```
void readDoubleList(java.util.List<java.lang.Double> target)
             throws java.io.IOException
```
    Reads the next field of type DOUBLE_LIST or DOUBLE_LIST_PACKED and advances the reader to the next field.
    
    Parameters:
    
    target - the list that will receive the read values.
    
    Throws:
    
    java.io.IOException
  - readFloatList
```
void readFloatList(java.util.List<java.lang.Float> target)
            throws java.io.IOException
```
    Reads the next field of type FLOAT_LIST or FLOAT_LIST_PACKED and advances the reader to the next field.
    
    Parameters:
    
    target - the list that will receive the read values.
    
    Throws:
    
    java.io.IOException
  - readUInt64List
```
void readUInt64List(java.util.List<java.lang.Long> target)
             throws java.io.IOException
```
    Reads the next field of type UINT64_LIST or UINT64_LIST_PACKED and advances the reader to the next field.
    
    Parameters:
    
    target - the list that will receive the read values.
    
    Throws:
    
    java.io.IOException
  - readInt64List
```
void readInt64List(java.util.List<java.lang.Long> target)
            throws java.io.IOException
```
    Reads the next field of type INT64_LIST or INT64_LIST_PACKED and advances the reader to the next field.
    
    Parameters:
    
    target - the list that will receive the read values.
    
    Throws:
    
    java.io.IOException
  - readInt32List
```
void readInt32List(java.util.List<java.lang.Integer> target)
            throws java.io.IOException
```
    Reads the next field of type INT32_LIST or INT32_LIST_PACKED and advances the reader to the next field.
    
    Parameters:
    
    target - the list that will receive the read values.
    
    Throws:
    
    java.io.IOException
  - readFixed64List
```
void readFixed64List(java.util.List<java.lang.Long> target)
              throws java.io.IOException
```
    Reads the next field of type FIXED64_LIST or FIXED64_LIST_PACKED and advances the reader to the next field.
    
    Parameters:
    
    target - the list that will receive the read values.
    
    Throws:
    
    java.io.IOException
  - readFixed32List
```
void readFixed32List(java.util.List<java.lang.Integer> target)
              throws java.io.IOException
```
    Reads the next field of type FIXED32_LIST or FIXED32_LIST_PACKED and advances the reader to the next field.
    
    Parameters:
    
    target - the list that will receive the read values.
    
    Throws:
    
    java.io.IOException
  - readBoolList
```
void readBoolList(java.util.List<java.lang.Boolean> target)
           throws java.io.IOException
```
    Reads the next field of type BOOL_LIST or BOOL_LIST_PACKED and advances the reader to the next field.
    
    Parameters:
    
    target - the list that will receive the read values.
    
    Throws:
    
    java.io.IOException
  - readStringList
```
void readStringList(java.util.List<java.lang.String> target)
             throws java.io.IOException
```
    Reads the next field of type STRING_LIST and advances the reader to the next field.
    
    Parameters:
    
    target - the list that will receive the read values.
    
    Throws:
    
    java.io.IOException
  - readStringListRequireUtf8
```
void readStringListRequireUtf8(java.util.List<java.lang.String> target)
                        throws java.io.IOException
```
    Reads the next field of type STRING_LIST and advances the reader to the next field. If the stream contains malformed UTF-8, throw exception InvalidProtocolBufferException.
    
    Parameters:
    
    target - the list that will receive the read values.
    
    Throws:
    
    java.io.IOException
  - readMessageList
```
<T> void readMessageList(java.util.List<T> target,
                         Schema<T> schema,
                         ExtensionRegistryLite extensionRegistry)
                  throws java.io.IOException
```
    Reads the next field of type MESSAGE_LIST and advances the reader to the next field.
    
    Parameters:
    
    target - the list that will receive the read values.
    
    targetType - the type of the elements stored in the target list.
    
    Throws:
    
    java.io.IOException
  - readMessageList
```
<T> void readMessageList(java.util.List<T> target,
                         java.lang.Class<T> targetType,
                         ExtensionRegistryLite extensionRegistry)
                  throws java.io.IOException
```
    Throws:
    
    java.io.IOException
  - readGroupList
```
@Deprecated
<T> void readGroupList(java.util.List<T> target,
                       java.lang.Class<T> targetType,
                       ExtensionRegistryLite extensionRegistry)
                throws java.io.IOException
```
    Deprecated.
    groups fields are deprecated.
    
    Reads the next field of type GROUP_LIST and advances the reader to the next field.
    
    Parameters:
    
    target - the list that will receive the read values.
    
    targetType - the type of the elements stored in the target list.
    
    Throws:
    
    java.io.IOException
  - readGroupList
```
@Deprecated
<T> void readGroupList(java.util.List<T> target,
                       Schema<T> targetType,
                       ExtensionRegistryLite extensionRegistry)
                throws java.io.IOException
```
    Deprecated.
    
    Throws:
    
    java.io.IOException
  - readBytesList
```
void readBytesList(java.util.List<ByteString> target)
            throws java.io.IOException
```
    Reads the next field of type BYTES_LIST and advances the reader to the next field.
    
    Parameters:
    
    target - the list that will receive the read values.
    
    Throws:
    
    java.io.IOException
  - readUInt32List
```
void readUInt32List(java.util.List<java.lang.Integer> target)
             throws java.io.IOException
```
    Reads the next field of type UINT32_LIST or UINT32_LIST_PACKED and advances the reader to the next field.
    
    Parameters:
    
    target - the list that will receive the read values.
    
    Throws:
    
    java.io.IOException
  - readEnumList
```
void readEnumList(java.util.List<java.lang.Integer> target)
           throws java.io.IOException
```
    Reads the next field of type ENUM_LIST or ENUM_LIST_PACKED and advances the reader to the next field.
    
    Parameters:
    
    target - the list that will receive the read values.
    
    Throws:
    
    java.io.IOException
  - readSFixed32List
```
void readSFixed32List(java.util.List<java.lang.Integer> target)
               throws java.io.IOException
```
    Reads the next field of type SFIXED32_LIST or SFIXED32_LIST_PACKED and advances the reader to the next field.
    
    Parameters:
    
    target - the list that will receive the read values.
    
    Throws:
    
    java.io.IOException
  - readSFixed64List
```
void readSFixed64List(java.util.List<java.lang.Long> target)
               throws java.io.IOException
```
    Reads the next field of type SFIXED64_LIST or SFIXED64_LIST_PACKED and advances the reader to the next field.
    
    Parameters:
    
    target - the list that will receive the read values.
    
    Throws:
    
    java.io.IOException
  - readSInt32List
```
void readSInt32List(java.util.List<java.lang.Integer> target)
             throws java.io.IOException
```
    Reads the next field of type SINT32_LIST or SINT32_LIST_PACKED and advances the reader to the next field.
    
    Parameters:
    
    target - the list that will receive the read values.
    
    Throws:
    
    java.io.IOException
  - readSInt64List
```
void readSInt64List(java.util.List<java.lang.Long> target)
             throws java.io.IOException
```
    Reads the next field of type SINT64_LIST or SINT64_LIST_PACKED and advances the reader to the next field.
    
    Parameters:
    
    target - the list that will receive the read values.
    
    Throws:
    
    java.io.IOException
  - readMap
```
<K,V> void readMap(java.util.Map<K,V> target,
                         MapEntryLite.Metadata<K,V> mapDefaultEntry,
                         ExtensionRegistryLite extensionRegistry)
                  throws java.io.IOException
```
    Reads the next field of type MAP and advances the reader to the next field.
    
    Parameters:
    
    target - the mutable map that will receive the read values.
    
    mapDefaultEntry - the default entry of the map field.
    
    extensionRegistry - the extension registry for parsing message value fields.
    
    Throws:
    
    java.io.IOException

Interface Reader

Field Summary

Method Summary

Field Detail

READ_DONE

TAG_UNKNOWN

Method Detail

shouldDiscardUnknownFields

getFieldNumber

getTag

skipField

readDouble

readFloat

readUInt64

readInt64

readInt32

readFixed64

readFixed32

readBool

readString

readStringRequireUtf8

readMessageBySchemaWithCheck

readMessage

readGroup

readGroupBySchemaWithCheck

mergeMessageField

mergeGroupField

readBytes

readUInt32

readEnum

readSFixed32

readSFixed64

readSInt32

readSInt64

readDoubleList

readFloatList

readUInt64List

readInt64List

readInt32List

readFixed64List

readFixed32List

readBoolList

readStringList

readStringListRequireUtf8

readMessageList

readMessageList

readGroupList

readGroupList

readBytesList

readUInt32List

readEnumList

readSFixed32List

readSFixed64List

readSInt32List

readSInt64List

readMap