io.micronaut.serde.support

Class AbstractStreamDecoder

java.lang.Object

io.micronaut.serde.support.AbstractStreamDecoder

All Implemented Interfaces:

Decoder, java.lang.AutoCloseable

Direct Known Subclasses:

BsonReaderDecoder, JacksonDecoder, JsonParserDecoder

@Internal
public abstract class AbstractStreamDecoder
extends java.lang.Object
implements Decoder

Abstract base class for stream-based Decoders.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected static class	AbstractStreamDecoder.TokenType The token type.
static interface	AbstractStreamDecoder.ValueDecoder<R> Decoder function for a single value.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	AbstractStreamDecoder(AbstractStreamDecoder parent) Child constructor.
protected	AbstractStreamDecoder(java.lang.Class<?> view) Root constructor.

Method Summary

Modifier and Type	Method and Description
protected void	backFromChild(AbstractStreamDecoder child) Called when the old child has finished processing and returns control of the stream to the parent.
protected abstract java.lang.String	coerceScalarToString() Decode any non-null scalar value (number, string or boolean) to its string representation.
protected abstract AbstractStreamDecoder	createChildDecoder() Create a new child decoder using AbstractStreamDecoder(AbstractStreamDecoder).
protected abstract AbstractStreamDecoder.TokenType	currentToken()
java.lang.Object	decodeArbitrary() Decodes the current state into an arbitrary object.
Decoder	decodeArray(io.micronaut.core.type.Argument<?> type) Start decoding an array.
java.math.BigDecimal	decodeBigDecimal() Decodes a BigDecimal.
java.math.BigInteger	decodeBigInteger() Decodes a BigInteger.
boolean	decodeBoolean() Decodes a boolean.
Decoder	decodeBuffer() Buffer the whole subtree of this value and return it as a new Decoder.
byte	decodeByte() Decodes a byte.
char	decodeChar() Decodes a char.
protected <T> T	decodeCustom(AbstractStreamDecoder.ValueDecoder<T> readFunction) Decode a custom type.
protected <T> T	decodeCustom(AbstractStreamDecoder.ValueDecoder<T> readFunction, boolean callNext) Decode a custom type.
double	decodeDouble() Decodes a double.
float	decodeFloat() Decodes a float.
int	decodeInt() Decodes a int.
java.lang.String	decodeKey() Decodes a key, if there are no more keys to decode returns null.
long	decodeLong() Decodes a long.
boolean	decodeNull() Attempt to decode a null value.
protected <T> T	decodeNumber(AbstractStreamDecoder.ValueDecoder<T> fromNumberToken, java.util.function.Function<java.lang.String,T> fromString, T zero, T one) Decode a number type, applying all necessary coercions.
Decoder	decodeObject(io.micronaut.core.type.Argument<?> type) Decodes an object.
short	decodeShort() Decodes a short.
java.lang.String	decodeString() Decodes a string.
void	finishStructure()
protected abstract java.lang.Number	getBestNumber() Decode the current AbstractStreamDecoder.TokenType.NUMBER value as a Number value.
protected io.micronaut.json.tree.JsonNode	getBestNumberNode() Decode the current AbstractStreamDecoder.TokenType.NUMBER value as a numeric JsonNode.
protected abstract java.math.BigDecimal	getBigDecimal() Decode the current AbstractStreamDecoder.TokenType.NUMBER value as a BigDecimal value.
protected abstract java.math.BigInteger	getBigInteger() Decode the current AbstractStreamDecoder.TokenType.NUMBER value as a BigInteger value.
protected abstract boolean	getBoolean() Decode the current AbstractStreamDecoder.TokenType.BOOLEAN value.
protected abstract java.lang.String	getCurrentKey() Get the current object field name.
protected abstract double	getDouble() Decode the current AbstractStreamDecoder.TokenType.NUMBER value as a double value.
protected abstract long	getLong() Decode the current AbstractStreamDecoder.TokenType.NUMBER value as a long value.
boolean	hasNextArrayValue()
protected abstract void	nextToken() Move to the next token.
protected abstract void	skipChildren() If we are at a AbstractStreamDecoder.TokenType.START_OBJECT or AbstractStreamDecoder.TokenType.START_ARRAY, skip to the matching AbstractStreamDecoder.TokenType.END_OBJECT or AbstractStreamDecoder.TokenType.END_ARRAY.
void	skipValue() Skips the current value.
protected java.io.IOException	unexpectedToken(AbstractStreamDecoder.TokenType expected)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface io.micronaut.serde.Decoder

close, createDeserializationException, decodeArray, decodeObject

Constructor Detail

AbstractStreamDecoder

protected AbstractStreamDecoder(@NonNull
                                AbstractStreamDecoder parent)

Child constructor. Should inherit the parser from the parent.

Parameters:

parent - The parent decoder.

AbstractStreamDecoder

protected AbstractStreamDecoder(@NonNull
                                java.lang.Class<?> view)

Root constructor.

Parameters:

view - The selected view class.

Method Detail

currentToken

@Nullable
protected abstract AbstractStreamDecoder.TokenType currentToken()

Returns:

The current token.

nextToken

protected abstract void nextToken()
                           throws java.io.IOException

Move to the next token.

Throws:

java.io.IOException - if an unrecoverable error occurs

unexpectedToken

protected java.io.IOException unexpectedToken(AbstractStreamDecoder.TokenType expected)

Parameters:

expected - The token type that was expected in place of currentToken().

Returns:

The exception that should be thrown to signify an unexpected token.

finishStructure

public final void finishStructure()
                           throws java.io.IOException

Specified by:

finishStructure in interface Decoder

Throws:

java.io.IOException - If an unrecoverable error occurs

backFromChild

protected void backFromChild(AbstractStreamDecoder child)
                      throws java.io.IOException

Called when the old child has finished processing and returns control of the stream to the parent. Current token is assumed to be AbstractStreamDecoder.TokenType.END_ARRAY or AbstractStreamDecoder.TokenType.END_OBJECT. However we currentToken() may hold an outdated value until nextToken() is called, which this method does.

Parameters:

child - The now-invalid child decoder.

Throws:

java.io.IOException - if an unrecoverable error occurs

hasNextArrayValue

public final boolean hasNextArrayValue()

Specified by:

hasNextArrayValue in interface Decoder

Returns:

Returns true if another array value is available.

getCurrentKey

protected abstract java.lang.String getCurrentKey()
                                           throws java.io.IOException

Get the current object field name. Only called for AbstractStreamDecoder.TokenType.KEY.

Returns:

The current field key

Throws:

java.io.IOException - if an unrecoverable error occurs

decodeKey

@Nullable
public final java.lang.String decodeKey()
                                           throws java.io.IOException

Description copied from interface: Decoder

Decodes a key, if there are no more keys to decode returns null.

Specified by:

decodeKey in interface Decoder

Returns:

The key or null if there aren't any more keys

Throws:

java.io.IOException - If an unrecoverable error occurs

createChildDecoder

protected abstract AbstractStreamDecoder createChildDecoder()

Create a new child decoder using AbstractStreamDecoder(AbstractStreamDecoder).

Returns:

The new decoder

decodeArray

@NonNull
public final Decoder decodeArray(io.micronaut.core.type.Argument<?> type)
                                   throws java.io.IOException

Description copied from interface: Decoder

Start decoding an array.

Specified by:

decodeArray in interface Decoder

Parameters:

type - The array type

Returns:

The array decoder

Throws:

java.io.IOException - If an unrecoverable error occurs

decodeObject

@NonNull
public final Decoder decodeObject(io.micronaut.core.type.Argument<?> type)
                                    throws java.io.IOException

Description copied from interface: Decoder

Decodes an object.

Specified by:

decodeObject in interface Decoder

Parameters:

type - The type, never null

Returns:

The object decoder

Throws:

java.io.IOException - If an unrecoverable error occurs

coerceScalarToString

protected abstract java.lang.String coerceScalarToString()
                                                  throws java.io.IOException

Decode any non-null scalar value (number, string or boolean) to its string representation.

Returns:

The current value, coerced to a string

Throws:

java.io.IOException - if an unrecoverable error occurs

decodeString

@NonNull
public final java.lang.String decodeString()
                                             throws java.io.IOException

Description copied from interface: Decoder

Decodes a string.

Specified by:

decodeString in interface Decoder

Returns:

The string, never null

Throws:

java.io.IOException - If an unrecoverable error occurs

getBoolean

protected abstract boolean getBoolean()
                               throws java.io.IOException

Decode the current AbstractStreamDecoder.TokenType.BOOLEAN value. Called for no other token type.

Returns:

The boolean value

Throws:

java.io.IOException - if an unrecoverable error occurs

decodeBoolean

public final boolean decodeBoolean()
                            throws java.io.IOException

Description copied from interface: Decoder

Decodes a boolean.

Specified by:

decodeBoolean in interface Decoder

Returns:

The boolean

Throws:

java.io.IOException - If an unrecoverable error occurs

decodeByte

public final byte decodeByte()
                      throws java.io.IOException

Description copied from interface: Decoder

Decodes a byte.

Specified by:

decodeByte in interface Decoder

Returns:

The byte

Throws:

java.io.IOException - If an unrecoverable error occurs

decodeShort

public final short decodeShort()
                        throws java.io.IOException

Description copied from interface: Decoder

Decodes a short.

Specified by:

decodeShort in interface Decoder

Returns:

The short

Throws:

java.io.IOException - If an unrecoverable error occurs

decodeChar

public final char decodeChar()
                      throws java.io.IOException

Description copied from interface: Decoder

Decodes a char.

Specified by:

decodeChar in interface Decoder

Returns:

The char

Throws:

java.io.IOException - If an unrecoverable error occurs

decodeInt

public final int decodeInt()
                    throws java.io.IOException

Description copied from interface: Decoder

Decodes a int.

Specified by:

decodeInt in interface Decoder

Returns:

The int

Throws:

java.io.IOException - If an unrecoverable error occurs

decodeLong

public final long decodeLong()
                      throws java.io.IOException

Description copied from interface: Decoder

Decodes a long.

Specified by:

decodeLong in interface Decoder

Returns:

The long

Throws:

java.io.IOException - If an unrecoverable error occurs

getLong

protected abstract long getLong()
                         throws java.io.IOException

Decode the current AbstractStreamDecoder.TokenType.NUMBER value as a long value. Called for no other token type.

Returns:

The number value

Throws:

java.io.IOException - if an unrecoverable error occurs

getDouble

protected abstract double getDouble()
                             throws java.io.IOException

Decode the current AbstractStreamDecoder.TokenType.NUMBER value as a double value. Called for no other token type.

Returns:

The number value

Throws:

java.io.IOException - if an unrecoverable error occurs

getBigInteger

protected abstract java.math.BigInteger getBigInteger()
                                               throws java.io.IOException

Decode the current AbstractStreamDecoder.TokenType.NUMBER value as a BigInteger value. Called for no other token type.

Returns:

The number value

Throws:

java.io.IOException - if an unrecoverable error occurs

getBigDecimal

protected abstract java.math.BigDecimal getBigDecimal()
                                               throws java.io.IOException

Decode the current AbstractStreamDecoder.TokenType.NUMBER value as a BigDecimal value. Called for no other token type.

Returns:

The number value

Throws:

java.io.IOException - if an unrecoverable error occurs

getBestNumber

protected abstract java.lang.Number getBestNumber()
                                           throws java.io.IOException

Decode the current AbstractStreamDecoder.TokenType.NUMBER value as a Number value. Called for no other token type.

Returns:

The number value

Throws:

java.io.IOException - if an unrecoverable error occurs

getBestNumberNode

protected io.micronaut.json.tree.JsonNode getBestNumberNode()
                                                     throws java.io.IOException

Decode the current AbstractStreamDecoder.TokenType.NUMBER value as a numeric JsonNode. Called for no other token type. Default implementation tries to construct a node from getBestNumber().

Returns:

The number value

Throws:

java.io.IOException - if an unrecoverable error occurs

decodeFloat

public final float decodeFloat()
                        throws java.io.IOException

Description copied from interface: Decoder

Decodes a float.

Specified by:

decodeFloat in interface Decoder

Returns:

The float

Throws:

java.io.IOException - If an unrecoverable error occurs

decodeDouble

public final double decodeDouble()
                          throws java.io.IOException

Description copied from interface: Decoder

Decodes a double.

Specified by:

decodeDouble in interface Decoder

Returns:

The double

Throws:

java.io.IOException - If an unrecoverable error occurs

decodeBigInteger

@NonNull
public final java.math.BigInteger decodeBigInteger()
                                                     throws java.io.IOException

Description copied from interface: Decoder

Decodes a BigInteger.

Specified by:

decodeBigInteger in interface Decoder

Returns:

The BigInteger, never null

Throws:

java.io.IOException - If an unrecoverable error occurs

decodeBigDecimal

@NonNull
public final java.math.BigDecimal decodeBigDecimal()
                                                     throws java.io.IOException

Description copied from interface: Decoder

Decodes a BigDecimal.

Specified by:

decodeBigDecimal in interface Decoder

Returns:

The BigDecimal, never null

Throws:

java.io.IOException - If an unrecoverable error occurs

decodeNumber

protected final <T> T decodeNumber(AbstractStreamDecoder.ValueDecoder<T> fromNumberToken,
                                   java.util.function.Function<java.lang.String,T> fromString,
                                   T zero,
                                   T one)
                            throws java.io.IOException

Decode a number type, applying all necessary coercions.

Type Parameters:

T - The number type.

Parameters:

fromNumberToken - Called if currentToken() is a AbstractStreamDecoder.TokenType.NUMBER.

fromString - Called for the textual value if currentToken() is a AbstractStreamDecoder.TokenType.STRING. Should throw NumberFormatException on parse failure.

zero - The zero value.

one - The one value.

Returns:

The parsed number.

Throws:

java.io.IOException - if an unrecoverable error occurs

decodeCustom

protected final <T> T decodeCustom(AbstractStreamDecoder.ValueDecoder<T> readFunction)
                            throws java.io.IOException

Decode a custom type.

Type Parameters:

T - Value type

Parameters:

readFunction - Function to call for reading the value. The AbstractStreamDecoder parameter to the function will just be this, but this allows subclasses to avoid capturing this to avoid an allocation.

Returns:

The parsed value.

Throws:

java.io.IOException - if an unrecoverable error occurs

decodeCustom

protected final <T> T decodeCustom(AbstractStreamDecoder.ValueDecoder<T> readFunction,
                                   boolean callNext)
                            throws java.io.IOException

Decode a custom type.

Type Parameters:

T - Value type

Parameters:

readFunction - Function to call for reading the value. The AbstractStreamDecoder parameter to the function will just be this, but this allows subclasses to avoid capturing this to avoid an allocation.

callNext - Pass "true" if next token should be read after invocation

Returns:

The parsed value.

Throws:

java.io.IOException - if an unrecoverable error occurs

decodeNull

public final boolean decodeNull()
                         throws java.io.IOException

Description copied from interface: Decoder

Attempt to decode a null value. Returns false if this value is not null, and another method should be used for decoding. Returns true if this value was null, and the cursor has been advanced to the next value.

Specified by:

decodeNull in interface Decoder

Returns:

Returns true if the value was null

Throws:

java.io.IOException - If an unrecoverable error occurs

decodeBuffer

public Decoder decodeBuffer()
                     throws java.io.IOException

Description copied from interface: Decoder

Buffer the whole subtree of this value and return it as a new Decoder. The returned Decoder can be used independently to this Decoder. This means actual parsing of the subtree can be delayed.

The returned Decoder should behave identically to this Decoder. This means that for example decoder.decodeDouble() should be equivalent to decoder.decodeBuffer().decodeDouble().

Specified by:

decodeBuffer in interface Decoder

Returns:

An independent decoder that visits this subtree.

Throws:

java.io.IOException - If an unrecoverable error occurs

decodeArbitrary

@Nullable
public final java.lang.Object decodeArbitrary()
                                                 throws java.io.IOException

Description copied from interface: Decoder

Decodes the current state into an arbitrary object.

The following should be decoded by this method:

• Object types will be decoded into a Map
• Array types will be decoded into a List
• JSON primitive types into the equivalent Java wrapper type

Specified by:

decodeArbitrary in interface Decoder

Returns:

The decoded object

Throws:

java.io.IOException - If an unrecoverable error occurs

skipChildren

protected abstract void skipChildren()
                              throws java.io.IOException

If we are at a AbstractStreamDecoder.TokenType.START_OBJECT or AbstractStreamDecoder.TokenType.START_ARRAY, skip to the matching AbstractStreamDecoder.TokenType.END_OBJECT or AbstractStreamDecoder.TokenType.END_ARRAY. Else, do nothing.

Throws:

java.io.IOException - if an unrecoverable error occurs

skipValue

public final void skipValue()
                     throws java.io.IOException

Description copied from interface: Decoder

Skips the current value.

Specified by:

skipValue in interface Decoder

Throws:

java.io.IOException - If an unrecoverable error occurs