com.badlogic.gdx.utils

Class Json

java.lang.Object

com.badlogic.gdx.utils.Json

public class Json
extends Object

Reads/writes Java objects to/from JSON, automatically. See the wiki for usage: https://github.com/libgdx/libgdx/wiki/Reading-and-writing-JSON

Author:

Nathan Sweet

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Json.ReadOnlySerializer<T>
static interface	Json.Serializable
static interface	Json.Serializer<T>

Constructor Summary

Constructors

Constructor and Description
Json()
Json(JsonWriter.OutputType outputType)

Method Summary

Modifier and Type	Method and Description
void	addClassTag(String tag, Class type) Sets a tag to use instead of the fully qualifier class name.
void	copyFields(Object from, Object to) Each field on the to object is set to the value for the field with the same name on the from object.
<T> T	fromJson(Class<T> type, char[] data, int offset, int length)
<T> T	fromJson(Class<T> type, Class elementType, char[] data, int offset, int length)
<T> T	fromJson(Class<T> type, Class elementType, FileHandle file)
<T> T	fromJson(Class<T> type, Class elementType, InputStream input)
<T> T	fromJson(Class<T> type, Class elementType, Reader reader)
<T> T	fromJson(Class<T> type, Class elementType, String json)
<T> T	fromJson(Class<T> type, FileHandle file)
<T> T	fromJson(Class<T> type, InputStream input)
<T> T	fromJson(Class<T> type, Reader reader)
<T> T	fromJson(Class<T> type, String json)
Class	getClass(String tag) Returns the class for the specified tag, or null.
boolean	getIgnoreUnknownFields()
<T> Json.Serializer<T>	getSerializer(Class<T> type)
String	getTag(Class type) Returns the tag for the specified class, or null.
JsonWriter	getWriter()
String	prettyPrint(Object object)
String	prettyPrint(Object object, int singleLineColumns)
String	prettyPrint(Object object, JsonValue.PrettyPrintSettings settings)
String	prettyPrint(String json)
String	prettyPrint(String json, int singleLineColumns)
String	prettyPrint(String json, JsonValue.PrettyPrintSettings settings)
void	readField(Object object, Field field, String jsonName, Class elementType, JsonValue jsonMap)
void	readField(Object object, String name, Class elementType, JsonValue jsonData)
void	readField(Object object, String name, JsonValue jsonData)
void	readField(Object object, String fieldName, String jsonName, Class elementType, JsonValue jsonMap)
void	readField(Object object, String fieldName, String jsonName, JsonValue jsonData)
void	readFields(Object object, JsonValue jsonMap)
<T> T	readValue(Class<T> type, Class elementType, JsonValue jsonData)
<T> T	readValue(Class<T> type, Class elementType, T defaultValue, JsonValue jsonData)
<T> T	readValue(Class<T> type, JsonValue jsonData)
<T> T	readValue(String name, Class<T> type, Class elementType, JsonValue jsonMap)
<T> T	readValue(String name, Class<T> type, Class elementType, T defaultValue, JsonValue jsonMap)
<T> T	readValue(String name, Class<T> type, JsonValue jsonMap)
<T> T	readValue(String name, Class<T> type, T defaultValue, JsonValue jsonMap)
void	setDefaultSerializer(Json.Serializer defaultSerializer) Sets the serializer to use when the type being deserialized is not known (null).
void	setDeprecated(Class type, String fieldName, boolean deprecated) The specified field will be treated as if it has or does not have the Deprecated annotation.
void	setElementType(Class type, String fieldName, Class elementType) Sets the type of elements in a collection.
void	setEnumNames(boolean enumNames) When true, Enum.name() is used to write enum values.
void	setIgnoreDeprecated(boolean ignoreDeprecated) When true, fields with the Deprecated annotation will not be read or written.
void	setIgnoreUnknownFields(boolean ignoreUnknownFields) When true, fields in the JSON that are not found on the class will not throw a SerializationException.
void	setOutputType(JsonWriter.OutputType outputType) Default is JsonWriter.OutputType.minimal.
void	setQuoteLongValues(boolean quoteLongValues) Default is false.
void	setReadDeprecated(boolean readDeprecated) When true, fields with the Deprecated annotation will be read (but not written) when setIgnoreDeprecated(boolean) is true.
<T> void	setSerializer(Class<T> type, Json.Serializer<T> serializer) Registers a serializer to use for the specified type instead of the default behavior of serializing all of an objects fields.
void	setSortFields(boolean sortFields) When true, fields are sorted alphabetically when written, otherwise the source code order is used.
void	setTypeName(String typeName) Sets the name of the JSON field to store the Java class name or class tag when required to avoid ambiguity during deserialization.
void	setUsePrototypes(boolean usePrototypes) When true, field values that are identical to a newly constructed instance are not written.
void	setWriter(Writer writer) Sets the writer where JSON output will be written.
String	toJson(Object object)
String	toJson(Object object, Class knownType)
String	toJson(Object object, Class knownType, Class elementType)
void	toJson(Object object, Class knownType, Class elementType, FileHandle file)
void	toJson(Object object, Class knownType, Class elementType, Writer writer)
void	toJson(Object object, Class knownType, FileHandle file)
void	toJson(Object object, Class knownType, Writer writer)
void	toJson(Object object, FileHandle file)
void	toJson(Object object, Writer writer)
void	writeArrayEnd()
void	writeArrayStart()
void	writeArrayStart(String name)
void	writeField(Object object, String name)
void	writeField(Object object, String name, Class elementType)
void	writeField(Object object, String fieldName, String jsonName)
void	writeField(Object object, String fieldName, String jsonName, Class elementType) Writes the specified field to the current JSON object.
void	writeFields(Object object) Writes all fields of the specified object to the current JSON object.
void	writeObjectEnd()
void	writeObjectStart()
void	writeObjectStart(Class actualType, Class knownType) Starts writing an object, writing the actualType to a field if needed.
void	writeObjectStart(String name)
void	writeObjectStart(String name, Class actualType, Class knownType)
void	writeType(Class type)
void	writeValue(Object value) Writes the value, without writing the class of the object.
void	writeValue(Object value, Class knownType) Writes the value, writing the class of the object if it differs from the specified known type.
void	writeValue(Object value, Class knownType, Class elementType) Writes the value, writing the class of the object if it differs from the specified known type.
void	writeValue(String name, Object value) Writes the value as a field on the current JSON object, without writing the actual class.
void	writeValue(String name, Object value, Class knownType) Writes the value as a field on the current JSON object, writing the class of the object if it differs from the specified known type.
void	writeValue(String name, Object value, Class knownType, Class elementType) Writes the value as a field on the current JSON object, writing the class of the object if it differs from the specified known type.

Methods inherited from class java.lang.Object

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

Constructor Detail

Json

public Json()

Json

public Json(JsonWriter.OutputType outputType)

Method Detail

setIgnoreUnknownFields

public void setIgnoreUnknownFields(boolean ignoreUnknownFields)

When true, fields in the JSON that are not found on the class will not throw a SerializationException. Default is false.

getIgnoreUnknownFields

public boolean getIgnoreUnknownFields()

setIgnoreDeprecated

public void setIgnoreDeprecated(boolean ignoreDeprecated)

When true, fields with the Deprecated annotation will not be read or written. Default is false.

See Also:

setReadDeprecated(boolean), setDeprecated(Class, String, boolean)

setReadDeprecated

public void setReadDeprecated(boolean readDeprecated)

When true, fields with the Deprecated annotation will be read (but not written) when setIgnoreDeprecated(boolean) is true. Default is false.

See Also:

setDeprecated(Class, String, boolean)

setOutputType

public void setOutputType(JsonWriter.OutputType outputType)

Default is JsonWriter.OutputType.minimal.

See Also:

JsonWriter.setOutputType(OutputType)

setQuoteLongValues

public void setQuoteLongValues(boolean quoteLongValues)

Default is false.

See Also:

JsonWriter.setQuoteLongValues(boolean)

setEnumNames

public void setEnumNames(boolean enumNames)

When true, Enum.name() is used to write enum values. When false, Enum.toString() is used which may not be unique. Default is true.

addClassTag

public void addClassTag(String tag,
                        Class type)

Sets a tag to use instead of the fully qualifier class name. This can make the JSON easier to read.

getClass

@Null
public Class getClass(String tag)

Returns the class for the specified tag, or null.

getTag

@Null
public String getTag(Class type)

Returns the tag for the specified class, or null.

setTypeName

public void setTypeName(@Null
                        String typeName)

Sets the name of the JSON field to store the Java class name or class tag when required to avoid ambiguity during deserialization. Set to null to never output this information, but be warned that deserialization may fail. Default is "class".

setDefaultSerializer

public void setDefaultSerializer(@Null
                                 Json.Serializer defaultSerializer)

Sets the serializer to use when the type being deserialized is not known (null).

setSerializer

public <T> void setSerializer(Class<T> type,
                              Json.Serializer<T> serializer)

Registers a serializer to use for the specified type instead of the default behavior of serializing all of an objects fields.

getSerializer

public <T> Json.Serializer<T> getSerializer(Class<T> type)

setUsePrototypes

public void setUsePrototypes(boolean usePrototypes)

When true, field values that are identical to a newly constructed instance are not written. Default is true.

setElementType

public void setElementType(Class type,
                           String fieldName,
                           Class elementType)

Sets the type of elements in a collection. When the element type is known, the class for each element in the collection does not need to be written unless different from the element type.

setDeprecated

public void setDeprecated(Class type,
                          String fieldName,
                          boolean deprecated)

The specified field will be treated as if it has or does not have the Deprecated annotation.

See Also:

setIgnoreDeprecated(boolean), setReadDeprecated(boolean)

setSortFields

public void setSortFields(boolean sortFields)

When true, fields are sorted alphabetically when written, otherwise the source code order is used. Default is false.

toJson

public String toJson(@Null
                     Object object)

toJson

public String toJson(@Null
                     Object object,
                     @Null
                     Class knownType)

toJson

public String toJson(@Null
                     Object object,
                     @Null
                     Class knownType,
                     @Null
                     Class elementType)

Parameters:

knownType - May be null if the type is unknown.

elementType - May be null if the type is unknown.

toJson

public void toJson(@Null
                   Object object,
                   FileHandle file)

toJson

public void toJson(@Null
                   Object object,
                   @Null
                   Class knownType,
                   FileHandle file)

Parameters:

knownType - May be null if the type is unknown.

toJson

public void toJson(@Null
                   Object object,
                   @Null
                   Class knownType,
                   @Null
                   Class elementType,
                   FileHandle file)

Parameters:

knownType - May be null if the type is unknown.

elementType - May be null if the type is unknown.

toJson

public void toJson(@Null
                   Object object,
                   Writer writer)

toJson

public void toJson(@Null
                   Object object,
                   @Null
                   Class knownType,
                   Writer writer)

Parameters:

knownType - May be null if the type is unknown.

toJson

public void toJson(@Null
                   Object object,
                   @Null
                   Class knownType,
                   @Null
                   Class elementType,
                   Writer writer)

Parameters:

knownType - May be null if the type is unknown.

elementType - May be null if the type is unknown.

setWriter

public void setWriter(Writer writer)

Sets the writer where JSON output will be written. This is only necessary when not using the toJson methods.

getWriter

public JsonWriter getWriter()

writeFields

public void writeFields(Object object)

Writes all fields of the specified object to the current JSON object.

writeField

public void writeField(Object object,
                       String name)

See Also:

writeField(Object, String, String, Class)

writeField

public void writeField(Object object,
                       String name,
                       @Null
                       Class elementType)

Parameters:

elementType - May be null if the type is unknown.

See Also:

writeField(Object, String, String, Class)

writeField

public void writeField(Object object,
                       String fieldName,
                       String jsonName)

See Also:

writeField(Object, String, String, Class)

writeField

public void writeField(Object object,
                       String fieldName,
                       String jsonName,
                       @Null
                       Class elementType)

Writes the specified field to the current JSON object.

Parameters:

elementType - May be null if the type is unknown.

writeValue

public void writeValue(String name,
                       @Null
                       Object value)

Writes the value as a field on the current JSON object, without writing the actual class.

Parameters:

value - May be null.

See Also:

writeValue(String, Object, Class, Class)

writeValue

public void writeValue(String name,
                       @Null
                       Object value,
                       @Null
                       Class knownType)

Writes the value as a field on the current JSON object, writing the class of the object if it differs from the specified known type.

Parameters:

value - May be null.

knownType - May be null if the type is unknown.

See Also:

writeValue(String, Object, Class, Class)

writeValue

public void writeValue(String name,
                       @Null
                       Object value,
                       @Null
                       Class knownType,
                       @Null
                       Class elementType)

Writes the value as a field on the current JSON object, writing the class of the object if it differs from the specified known type. The specified element type is used as the default type for collections.

Parameters:

value - May be null.

knownType - May be null if the type is unknown.

elementType - May be null if the type is unknown.

writeValue

public void writeValue(@Null
                       Object value)

Writes the value, without writing the class of the object.

Parameters:

value - May be null.

writeValue

public void writeValue(@Null
                       Object value,
                       @Null
                       Class knownType)

Writes the value, writing the class of the object if it differs from the specified known type.

Parameters:

value - May be null.

knownType - May be null if the type is unknown.

writeValue

public void writeValue(@Null
                       Object value,
                       @Null
                       Class knownType,
                       @Null
                       Class elementType)

Writes the value, writing the class of the object if it differs from the specified known type. The specified element type is used as the default type for collections.

Parameters:

value - May be null.

knownType - May be null if the type is unknown.

elementType - May be null if the type is unknown.

writeObjectStart

public void writeObjectStart(String name)

writeObjectStart

public void writeObjectStart(String name,
                             Class actualType,
                             @Null
                             Class knownType)

Parameters:

knownType - May be null if the type is unknown.

writeObjectStart

public void writeObjectStart()

writeObjectStart

public void writeObjectStart(Class actualType,
                             @Null
                             Class knownType)

Starts writing an object, writing the actualType to a field if needed.

Parameters:

knownType - May be null if the type is unknown.

writeObjectEnd

public void writeObjectEnd()

writeArrayStart

public void writeArrayStart(String name)

writeArrayStart

public void writeArrayStart()

writeArrayEnd

public void writeArrayEnd()

writeType

public void writeType(Class type)

fromJson

@Null
public <T> T fromJson(Class<T> type,
                             Reader reader)

Parameters:

type - May be null if the type is unknown.

Returns:

May be null.

fromJson

@Null
public <T> T fromJson(Class<T> type,
                             Class elementType,
                             Reader reader)

Parameters:

type - May be null if the type is unknown.

elementType - May be null if the type is unknown.

Returns:

May be null.

fromJson

@Null
public <T> T fromJson(Class<T> type,
                             InputStream input)

Parameters:

type - May be null if the type is unknown.

Returns:

May be null.

fromJson

@Null
public <T> T fromJson(Class<T> type,
                             Class elementType,
                             InputStream input)

Parameters:

type - May be null if the type is unknown.

elementType - May be null if the type is unknown.

Returns:

May be null.

fromJson

@Null
public <T> T fromJson(Class<T> type,
                             FileHandle file)

Parameters:

type - May be null if the type is unknown.

Returns:

May be null.

fromJson

@Null
public <T> T fromJson(Class<T> type,
                             Class elementType,
                             FileHandle file)

Parameters:

type - May be null if the type is unknown.

elementType - May be null if the type is unknown.

Returns:

May be null.

fromJson

@Null
public <T> T fromJson(Class<T> type,
                             char[] data,
                             int offset,
                             int length)

Parameters:

type - May be null if the type is unknown.

Returns:

May be null.

fromJson

@Null
public <T> T fromJson(Class<T> type,
                             Class elementType,
                             char[] data,
                             int offset,
                             int length)

Parameters:

type - May be null if the type is unknown.

elementType - May be null if the type is unknown.

Returns:

May be null.

fromJson

@Null
public <T> T fromJson(Class<T> type,
                             String json)

Parameters:

type - May be null if the type is unknown.

Returns:

May be null.

fromJson

@Null
public <T> T fromJson(Class<T> type,
                             Class elementType,
                             String json)

Parameters:

type - May be null if the type is unknown.

Returns:

May be null.

readField

public void readField(Object object,
                      String name,
                      JsonValue jsonData)

readField

public void readField(Object object,
                      String name,
                      @Null
                      Class elementType,
                      JsonValue jsonData)

readField

public void readField(Object object,
                      String fieldName,
                      String jsonName,
                      JsonValue jsonData)

readField

public void readField(Object object,
                      String fieldName,
                      String jsonName,
                      @Null
                      Class elementType,
                      JsonValue jsonMap)

Parameters:

elementType - May be null if the type is unknown.

readField

public void readField(@Null
                      Object object,
                      Field field,
                      String jsonName,
                      @Null
                      Class elementType,
                      JsonValue jsonMap)

Parameters:

object - May be null if the field is static.

elementType - May be null if the type is unknown.

readFields

public void readFields(Object object,
                       JsonValue jsonMap)

readValue

@Null
public <T> T readValue(String name,
                              @Null
                              Class<T> type,
                              JsonValue jsonMap)

Parameters:

type - May be null if the type is unknown.

Returns:

May be null.

readValue

@Null
public <T> T readValue(String name,
                              @Null
                              Class<T> type,
                              T defaultValue,
                              JsonValue jsonMap)

Parameters:

type - May be null if the type is unknown.

Returns:

May be null.

readValue

@Null
public <T> T readValue(String name,
                              @Null
                              Class<T> type,
                              @Null
                              Class elementType,
                              JsonValue jsonMap)

Parameters:

type - May be null if the type is unknown.

elementType - May be null if the type is unknown.

Returns:

May be null.

readValue

@Null
public <T> T readValue(String name,
                              @Null
                              Class<T> type,
                              @Null
                              Class elementType,
                              T defaultValue,
                              JsonValue jsonMap)

Parameters:

type - May be null if the type is unknown.

elementType - May be null if the type is unknown.

Returns:

May be null.

readValue

@Null
public <T> T readValue(@Null
                              Class<T> type,
                              @Null
                              Class elementType,
                              T defaultValue,
                              JsonValue jsonData)

Parameters:

type - May be null if the type is unknown.

elementType - May be null if the type is unknown.

Returns:

May be null.

readValue

@Null
public <T> T readValue(@Null
                              Class<T> type,
                              JsonValue jsonData)

Parameters:

type - May be null if the type is unknown.

Returns:

May be null.

readValue

@Null
public <T> T readValue(@Null
                              Class<T> type,
                              @Null
                              Class elementType,
                              JsonValue jsonData)

Parameters:

type - May be null if the type is unknown.

elementType - May be null if the type is unknown.

Returns:

May be null.

copyFields

public void copyFields(Object from,
                       Object to)

Each field on the to object is set to the value for the field with the same name on the from object. The to object must have at least all the fields of the from object with the same name and type.

prettyPrint

public String prettyPrint(@Null
                          Object object)

prettyPrint

public String prettyPrint(String json)

prettyPrint

public String prettyPrint(@Null
                          Object object,
                          int singleLineColumns)

prettyPrint

public String prettyPrint(String json,
                          int singleLineColumns)

prettyPrint

public String prettyPrint(@Null
                          Object object,
                          JsonValue.PrettyPrintSettings settings)

prettyPrint

public String prettyPrint(String json,
                          JsonValue.PrettyPrintSettings settings)