- Upgrade: Kotlin 1.7.0.
- Upgrade KotlinPoet 1.12.0.
- Moshi no longer shades kotlinpoet-ksp APIs, meaning they can be updated independently of Moshi updates.
- Upgrade: KSP 1.7.0-1.0.6.
- Upgrade: kotlinx-metadata 0.5.0, allowing reading of kotlin 1.8 APIs too.
2021-12-08
-
New: Support for Kotlin Symbol Processing (KSP). KSP is an alternative to annotation processing code gen. It's builds faster and better supports Kotlin language features.
To use KSP in your application you must enable the KSP Gradle plugin and add a KSP dependency on Moshi codegen.
plugins { id("com.google.devtools.ksp").version("1.6.0-1.0.1") } dependencies { ksp("com.squareup.moshi:moshi-kotlin-codegen:1.13.0") }
If you're switching from annotation processing (kapt) to KSP, you should remove the kapt plugin and the kapt Moshi dependency.
-
New:
@Json(ignore = true)
is a Moshi-specific way to exclude properties from JSON encoding and decoding. -
New: Support Java 16 records. (Moshi still requires Java 8 only; we're shipping a multi-release jar to better support modern JVMs.)
-
New: Option to disable generating R8/ProGuard files. These files prevent code shrinkers from removing files that support JSON processing. If you're not using ProGuard or R8, you can skip this step.
ksp { arg("moshi.generateProguardRules", "false") }
-
Upgrade: Kotlin 1.6.0.
2021-04-01
- New: Improve generated code performance when all properties are set.
- Fix: Don't crash on a missing type element like
@SuppressLint
. - Fix: Update the JVM metadata library to avoid problems on Kotlin 1.5.0-M2.
- Fix: Support generic arrays with defaults in generated adapters.
- Fix: Don't generate code with simple name collisions.
- Upgrade: Okio 2.10.0.
- Upgrade: Kotlin 1.4.31.
2020-10-04
-
New: Kotlin extension functions and properties. Use of these extensions is only possible from Kotlin, and requires the Kotlin stdlib dependency. This release does not have any Kotlin requirement and can be used Kotlin-free from Java.
/** Extension alternative to [Types.nextAnnotations()]. */ fun <reified T : Annotation> Set<Annotation>.nextAnnotations(): Set<Annotation>? /** Extension alternative to [Types.getRawType()]. */ val Type.rawType: Class<*> /** Extension alternative to [Types.arrayOf()]. */ fun KClass<*>.asArrayType(): GenericArrayType /** Extension alternative to [Types.arrayOf()]. */ fun Type.asArrayType(): GenericArrayType
-
New: Experimental Kotlin extensions. These depend on unreleased APIs and may break in a future release of Kotlin. If you are comfortable with this, add
@ExperimentalStdlibApi
at the callsite or add this argument to your Kotlin compiler:"-Xopt-in=kotlin.ExperimentalStdlibApi"
./** Returns the adapter for [T]. */ inline fun <reified T> Moshi.adapter(): JsonAdapter<T> /** Returns the adapter for [ktype]. */ fun <T> Moshi.adapter(ktype: KType): JsonAdapter<T> /** Adds an adapter for [T]. */ inline fun <reified T> Moshi.Builder.addAdapter(adapter: JsonAdapter<T>): Moshi.Builder /** Extension alternative to [Types.arrayOf()]. */ fun KType.asArrayType(): GenericArrayType /** Extension alternative to [Types.subtypeOf()]. */ inline fun <reified T> subtypeOf(): WildcardType /** Extension alternative to [Types.supertypeOf()]. */ inline fun <reified T> supertypeOf(): WildcardType
-
New:
JsonReader.nextSource()
. This returns an OkioBufferedSource
that streams the UTF-8 bytes of a JSON value. Use this to accept JSON values without decoding them, to delegate to another JSON processor, or for streaming access to very large embedded values. -
New:
Moshi.Builder.addLast()
. Use this when installing widely-applicable adapter factories likeKotlinJsonAdapterFactory
. Adapters registered withadd()
are preferred (in the order they were added), followed by all adapters registered withaddLast()
(also in the order they were added). This precedence is retained whenMoshi.newBuilder()
is used. -
New:
setTag()
,tag()
methods onJsonReader
andJsonWriter
. Use these as a side-channel between adapters and their uses. For example, a tag may be used to track use of unexpected data in a custom adapter. -
Fix: Don't crash with a
StackOverflowError
decoding backward-referencing type variables in Kotlin. This caused problems for parameterized types likeMyInterface<E : Enum<E>>
. -
Upgrade: Okio 1.17.5.
-
Upgrade: Kotlin 1.4.10.
2020-08-26
- New: Upgrade to Kotlin 1.4.0.
- New:
JsonReader.promoteNameToValue()
makes it easier to build customMap
adapters. - New:
Options.strings()
. - New:
PolymorphicJsonAdapterFactory.withFallbackJsonAdapter()
makes it possible to handle unrecognized types when encoding and decoding. - New: Add
JsonWriter.jsonValue
API - New: Code gen now generates precise proguard rules on-the-fly.
- New: Improve error when incorrectly trying to use a collection class like
ArrayList
instead ofList
- Fix: Prevent R8 from keeping all
@Metadata
annotations - Fix: Avoid VerifyErrors on Android 4.4 devices when using R8
- Fix: Fix resolution of types in superclass settable properties
2020-06-11
- Fix: Tweak a shrinker rule to mitigate an R8 bug which was causing classes unrelated to the Kotlin adpater code generation to be retained.
- Fix: Ensure that the Kotlin adapter code generation does not line wrap in the middle of a string if your JSON keys contain spaces.
- Fix: Strip type annotations before emitting type references like
Foo::class
in the Kotlin adapter code generation. - Fix: Separate the runtime check for Kotlin's
DefaultConstructorMarker
from the check forMetadata
. A shrinker may have removedMetadata
and we should still check forDefaultConstructorMarker
.
2019-11-17
- Fix: Generate correct adapters for several special cases including reified inline types, public
classes enclosed in internal classes, deprecated types with
-Werror
, primitives in type parameters, nullables in type parameters, and type aliases in type parameters.
2019-10-30
- Fix: "abstract function ... cannot have code" code gen crash when parsing Kotlin metadata.
- Fix: Generate code to support constructors with more than 32 parameters. The 1.9.0 release had a regression where classes with 33+ parameters would crash upon decoding.
- Fix: Generate code to support more constructor cases, such as classes with non-property parameters and classes with multiple constructors.
- Fix: Generate code to handle type aliases in type parameters.
2019-10-29
-
This release requires kotlin-reflect or moshi-kotlin-codegen for all Kotlin classes.
Previously Moshi wouldn't differentiate between Kotlin classes and Java classes if Kotlin was not configured. This caused bad runtime behavior such as putting null into non-nullable fields! If you attempt to create an adapter for a Kotlin type, Moshi will throw an
IllegalArgumentException
.Fix this with either the reflection adapter:
val moshi = Moshi.Builder() // ... add your own JsonAdapters and factories ... .add(KotlinJsonAdapterFactory()) .build()
Or the codegen annotation processor:
@JsonClass(generateAdapter = true) data class BlackjackHand( val hidden_card: Card, val visible_cards: List<Card> )
The Kotlin documentation explains the required build configuration changes.
-
New: Change how Moshi's generated adapters call constructors. Previous generated code used a combination of the constructor and
copy()
method to set properties that have default values. With this update we call the same synthetic constructor that Kotlin uses. This is less surprising though it requires us to generate some tricky code. -
New: Make
Rfc3339DateJsonAdapter
null-safe. Previously Moshi would refuse to decode null dates. Restore that behavior by explicitly forbidding nulls withRfc3339DateJsonAdapter().nonNull()
. -
New: Require Kotlin 1.3.50 or newer.
-
New:
JsonWriter.valueSink()
streams JSON-formatted data inline. Use this to do basic includes of raw JSON within a streamed document. -
New: Support Gradle incremental processing in code gen.
-
New: Improve error messages. This includes better errors when field names and JSON names disagree, and when failing on an unknown field.
-
New: Support default values in
PolymorphicJsonAdapterFactory
. -
New: Permit multiple labels for each subtype in
PolymorphicJsonAdapterFactory
. The first label is used when writing an object to JSON. -
New: Forbid automatic encoding of platform classes in
kotlinx
. As withjava.*
,android.*
, andkotlin.*
Moshi wants you to specify how to encode platform types. -
New:
@JsonClass(generator=...)
makes it possible for third-party libraries to provide generated adapters when Moshi's default adapters are insufficient. -
Fix: Simplify wildcard types like
List<? extends Number>
to their base typesList<Number>
when finding type adapters. This is especially useful with Kotlin where wildcards may be added automatically. -
Fix: Use the correct name when the
@Json
annotation uses field targeting like@field:Json
. -
Fix: Support multiple transient properties in
KotlinJsonAdapter
. -
Fix: Don't explode attempting to resolve self-referential type variables like in
Comparable<T extends Comparable<T>>
. -
Fix: Don't infinite loop on
skipValue()
at the end an object or array. Also disallow callingskipValue()
at the end of a document.
2018-11-09
-
New: Support JSON objects that include type information in the JSON. The new
PolymorphicJsonAdapterFactory
writes a type field when encoding, and reads it when decoding. -
New: Fall back to the reflection-based
KotlinJsonAdapterFactory
if it is enabled and a generated adapter is not found. This makes it possible to use reflection-based JSON adapters in development (so you don't have to wait for code to be regenerated on every build) and generated JSON adapters in production (so you don't need the kotlin-reflect library). -
New: The
peekJson()
method onJsonReader
let you read ahead on a JSON stream without consuming it. This builds on Okio's newBuffer.peek()
API. -
New: The
beginFlatten()
andendFlatten()
methods onJsonWriter
suppress unwanted nesting when composing adapters. Previously it was necessary to flatten objects in memory before writing. -
New: Upgrade to Okio 1.16.0. We don't yet require Kotlin-friendly Okio 2.1 but Moshi works fine with that release.
implementation("com.squareup.okio:okio:1.16.0")
-
Fix: Don't return partially-constructed adapters when using a Moshi instance concurrently.
-
Fix: Eliminate warnings and errors in generated
.kt
triggered by type variance, primitive types, and required values. -
Fix: Improve the supplied rules (
moshi.pro
) to better retain symbols used by Moshi. We recommend R8 when shrinking code. -
Fix: Remove code generation companion objects. This API was neither complete nor necessary.
2018-09-24
-
New:
EnumJsonAdapter
makes it easy to specify a fallback value for unknown enum constants. By default Moshi throws anJsonDataException
if it reads an unknown enum constant. With this you can specify a fallback value or null.new Moshi.Builder() .add(EnumJsonAdapter.create(IsoCurrency.class) .withUnknownFallback(IsoCurrency.USD)) .build();
Note that this adapter is in the optional
moshi-adapters
module.implementation 'com.squareup.moshi:moshi-adapters:1.7.0'
-
New: Embed R8/ProGuard rules in the
.jar
file. -
New: Use
@CheckReturnValue
in more places. We hope this will encourage you to useskipName()
instead ofnextName()
for better performance! -
New: Forbid automatic encoding of platform classes in
androidx
. As withjava.*
,android.*
, andkotlin.*
Moshi wants you to specify how to encode platform types. -
New: Improve error reporting when creating an adapter fails.
-
New: Upgrade to Okio 1.15.0. We don't yet require Kotlin-friendly Okio 2.x but Moshi works fine with that release.
implementation 'com.squareup.okio:okio:1.15.0'
-
Fix: Return false from
JsonReader.hasNext()
at document's end. -
Fix: Improve code gen to handle several broken cases. Our generated adapters had problems with nulls, nested parameterized types, private transient properties, generic type aliases, fields with dollar signs in their names, and named companion objects.
2018-05-14
-
Moshi now supports codegen for Kotlin. We've added a new annotation processor that generates a small and fast JSON adapter for your Kotlin types. It can be used on its own or with the existing
KotlinJsonAdapterFactory
adapter. -
Moshi now resolves all type parameters. Previously Moshi wouldn't resolve type parameters on top-level classes.
-
New: Support up to 255 levels of nesting when reading and writing JSON. Previously Moshi would reject JSON input that contained more than 32 levels of nesting.
-
New: Write encoded JSON to a stream with
JsonWriter.value(BufferedSource)
. Use this to emit a JSON value without decoding it first. -
New:
JsonAdapter.nonNull()
returns a new JSON adapter that forbids explicit nulls in the JSON body. Use this to detect and fail eagerly on unwanted nulls. -
New:
JsonReader.skipName()
is likenextName()
but it avoids allocating when a name is unknown. Use this whenJsonReader.selectName()
returns -1. -
New: Automatic module name of
com.squareup.moshi
for use with the Java Platform Module System. This moves moshi-adapters into its own.adapters
package and forwards the existing adapter. It moves the moshi-kotlin into its own.kotlin.reflect
package and forwards the existing adapter. -
New: Upgrade to Okio 1.14.0.
<dependency> <groupId>com.squareup.okio</groupId> <artifactId>okio</artifactId> <version>1.14.0</version> </dependency> com.squareup.okio:okio:1.14.0
-
Fix: Fail fast if there are trailing non-whitespace characters in the JSON passed to
JsonAdapter.fromJson(String)
. Previously such data was ignored! -
Fix: Fail fast when Kotlin types are abstract, inner, or object instances.
-
Fix: Fail fast if
name()
is called out of sequence. -
Fix: Handle asymmetric
Type.equals()
methods when doing type comparisons. Previously it was possible that a registered type adapter would not be used because itsType.equals()
method was not consistent with a user-provided type. -
Fix:
JsonValueReader.selectString()
now returns -1 for non-strings instead of throwing. -
Fix: Permit reading numbers as strings when the
JsonReader
was created from a JSON value. This was always supported when reading from a stream but broken when reading from a decoded value. -
Fix: Delegate to user-adapters in the adapter for Object.class. Previously when Moshi encountered an opaque Object it would only use the built-in adapters. With this change user-installed adapters for types like
String
will always be honored.
2017-05-14
-
Moshi now uses
@Nullable
to annotate all possibly-null values. We've added a compile-time dependency on the JSR 305 annotations. This is a provided dependency and does not need to be included in your build configuration,.jar
file, or.apk
. We use@ParametersAreNonnullByDefault
and all parameters and return types are never null unless explicitly annotated@Nullable
. -
Warning: Moshi APIs in this update are source-incompatible for Kotlin callers. Nullability was previously ambiguous and lenient but now the compiler will enforce strict null checks.
-
Kotlin models are now supported via the
moshi-kotlin
extension.KotlinJsonAdapterFactory
is the best way to use Kotlin with Moshi. It honors default values and is null-safe. Kotlin users that don't use this factory should write custom adapters for their JSON types. Otherwise Moshi cannot properly initialize delegated properties of the objects it decodes. -
New: Upgrade to Okio 1.13.0.
<dependency> <groupId>com.squareup.okio</groupId> <artifactId>okio</artifactId> <version>1.13.0</version> </dependency> com.squareup.okio:okio:1.13.0
-
New: You may now declare delegates in
@ToJson
and@FromJson
methods. If one of the arguments to the method is aJsonAdapter
of the same type, that will be the next eligible adapter for that type. This may be useful for composing adapters. -
New:
Types.equals(Type, Type)
makes it easier to compare types inJsonAdapter.Factory
. -
Fix: Retain the sign on negative zero.
2017-02-04
Moshi 1.4 is a major release that adds JSON values as a core part of the library. We consider any
Java object comprised of maps, lists, strings, numbers, booleans and nulls to be a JSON value. These
are equivalent to parsed JSON objects in JavaScript, Gson’s JsonElement
, and
Jackson’s JsonNode
. Unlike Jackson and Gson, Moshi just uses Java’s built-in types for
its values:
JSON type | Java type | |
---|---|---|
{...} | Object | Map<String, Object> |
[...] | Array | List<Object> |
"abc" | String | String |
123 | Number | Double, Long, or BigDecimal |
true | Boolean | Boolean |
null | null | null |
Moshi's new API JsonAdapter.toJsonValue()
converts your application classes to JSON values
comprised of the above types. Symmetrically, JsonAdapter.fromJsonValue()
converts JSON values to
your application classes.
- New:
JsonAdapter.toJsonValue()
andfromJsonValue()
. - New:
JsonReader.readJsonValue()
reads a JSON value from a stream. - New:
Moshi.adapter(Type, Class<? extends Annotation>)
lets you look up the adapter for a qualified type. - New:
JsonAdapter.serializeNulls()
andindent()
return JSON adapters that customize the format of the encoded JSON. - New:
JsonReader.selectName()
andselectString()
optimize decoding JSON with known names and values. - New:
Types.nextAnnotations()
reduces the amount of code required to implement a customJsonAdapter.Factory
. - Fix: Don't fail on large longs that have a fractional component like
9223372036854775806.0
.
2016-10-21
- Fix: Don't incorrectly report invalid input when a slash character is escaped. When we tightened
our invalid escape handling we missed the one character that is valid both escaped
\/
and unescaped/
.
2016-10-15
-
New: Permit
@ToJson
and@FromJson
methods to take any number ofJsonAdapter
parameters to delegate to. This is supported for@ToJson
methods that take aJsonWriter
and@FromJson
methods that take aJsonReader
. -
New: Throw
JsonEncodingException
when the incoming data is not valid JSON. Use this to differentiate data format problems from connectivity problems. -
New: Upgrade to Okio 1.11.0.
<dependency> <groupId>com.squareup.okio</groupId> <artifactId>okio</artifactId> <version>1.11.0</version> </dependency>
-
New: Omit Kotlin (
kotlin.*
) and Scala (scala.*
) platform types when encoding objects using their fields. This should make it easier to avoid unexpected dependencies on platform versions. -
Fix: Explicitly limit reading and writing to 31 levels of nested structure. Previously no specific limit was enforced, but deeply nested documents would fail with either an
ArrayIndexOutOfBoundsException
due to a bug inJsonWriter
's path management, or aStackOverflowError
due to excessive recursion. -
Fix: Require enclosed types to specify their enclosing type with
Types.newParameterizedTypeWithOwner()
. Previously this API did not exist and looking up adapters for enclosed parameterized types was not possible. -
Fix: Fail on invalid escapes. Previously any character could be escaped. With this fix only characters permitted to be escaped may be escaped. Use
JsonReader.setLenient(true)
to read JSON documents that escape characters that should not be escaped.
2016-05-28
-
New: Take advantage of Okio's new
Options
feature when reading field names and enum values. This has a significant impact on performance. We measured parsing performance improve from 89k ops/sec to 140k ops/sec on one benchmark on one machine. -
New: Upgrade to Okio 1.8.0.
<dependency> <groupId>com.squareup.okio</groupId> <artifactId>okio</artifactId> <version>1.8.0</version> </dependency>
-
New: Support types that lack no-argument constructors objects on Android releases prior to Gingerbread.
-
Fix: Add writer value overload for boxed booleans. Autoboxing resolves boxed longs and doubles to
value(Number)
, but a boxed boolean would otherwise resolve to value(boolean) with an implicit call to booleanValue() which has the potential to throw NPEs. -
Fix: Be more aggressive about canonicalizing types.
2016-01-19
- New: Support RFC 7159, the latest JSON specification. This removes the constraint that the root value must be an array or an object. It may now take any value: array, object, string, number, boolean, or null. Previously this was only permitted if the adapter was configured to be lenient.
- New: Enum constants may be annotated with
@Json
to customize their encoded value. - New: Create new builder from Moshi instance with
Moshi.newBuilder()
. - New:
Types.getRawType()
andTypes.collectionElementType()
APIs to assist in defining generic type adapter factories.
2015-09-27
- API Change: Replaced
new JsonReader()
withJsonReader.of()
andnew JsonWriter()
withJsonWriter.of()
. If your code calls either of these constructors it will need to be updated to call the static factory method instead. - API Change: Don’t throw
IOException
onJsonAdapter.toJson(T)
. Code that calls this method may need to be fixed to no longer catch an impossibleIOException
. - Fix: the JSON adapter for
Object
no longer fails when encounteringnull
in the stream. - New:
@Json
annotation can customize a field's name. This is particularly handy for fields whose names are Java keywords, likedefault
orpublic
. - New:
Rfc3339DateJsonAdapter
converts between ajava.util.Date
and a string formatted with RFC 3339 (like2015-09-26T18:23:50.250Z
). This class is in the newmoshi-adapters
subproject. You will need to register this adapter if you want this date formatting behavior. See it in action in the dates example. - New:
Moshi.adapter()
keeps a cache of all created adapters. For best efficiency, application code should keep a reference to required adapters in a field. - New: The
Types
factory class makes it possible to compose types likeList<Card>
orMap<String, Integer>
. This is useful to look up JSON adapters for parameterized types. - New:
JsonAdapter.failOnUnknown()
returns a new JSON adapter that throws if an unknown value is encountered on the stream. Use this in development and debug builds to detect typos in field names. This feature shouldn’t be used in production because it makes migrations very difficult.
2015-06-16
- Databinding for primitive types, strings, enums, arrays, collections, and maps.
- Databinding for plain old Java objects.
- JSONPath support for both
JsonReader
andJsonWriter
. - Throw
JsonDataException
when there’s a data binding problem. - Adapter methods:
@ToJson
and@FromJson
. - Qualifier annotations:
@JsonQualifier
to permit different type adapters for the same Java type. - Imported code from Gson:
JsonReader
,JsonWriter
. Also some internal classes:LinkedHashTreeMap
for hash-collision avoidance andTypes
for typesafe databinding.