ErrLookup › google/gson

google/gson

A Java serialization/deserialization library to convert Java Objects into JSON and back · Java · 103 source files

Analyzed at 310ac341f2 on 2026-08-10. 134 documented errors.

Code / MessageTypeSeverityTags
See
exception error json, gson, parsing, malformed-json, strictness, java
requires type arguments, but got
exception error java, gson, generics, typetoken, validation
Incomplete document
exception error json, gson, streaming, resource-lifecycle, java
Primitive is neither a number nor a string
exception error gson, json, type-cast, unsupported-operation
Expected one JSON element but was
exception error json, serialization, tree-model, state-machine
String created by is not a valid JSON number
exception error java, gson, jsonwriter, numeric, custom-number
Adapter for type with cyclic dependency has been used…
exception error gson-core, cyclic-dependency, type-adapter, thread-safety
String contains non-ASCII characters
exception error json, deserialization, unicode, ascii, number-parsing
Raw type is not supported because it requires specifying an…
exception error java, gson, generics, typetoken, inner-class
JSON must have only one top-level value.
exception error json, gson, streaming, strictness, rfc8259, java
Failed to parse date
exception error date, utc-date-adapter, deserialization, iso8601, gson-extras
Unexpected token
exception error json, deserialization, type-mismatch, object-model, reader-state
Type argument does not satisfy bounds for type variable…
exception error java, gson, generics, typetoken, bounds
ReflectionAccessFilter does not permit using reflection for
exception error json, reflection, security, access-filter, serialization
cannot serialize because it already defines a field named
exception error runtime-type-adapter, polymorphism, serialization, field-collision
is not accessible and ReflectionAccessFilter does not…
exception error json, reflection, security, access-filter, jpms, encapsulation
Failed parsing JSON source to Json
exception error json-parsing, memory, stack-overflow, security, oom
cannot deserialize because it does not define a field named
exception error runtime-type-adapter, polymorphism, deserialization, discriminator
Unable to create instance of
exception error constructor, unsafe, reflection, instantiation, jdk16
Failed to invoke constructor
exception error record, deserialization, constructor, type-mismatch
Type adapter ' ' returned wrong type; requested but got…
exception error gson-core, type-adapter, classcast, type-safety
Failed parsing ' ' as BigInteger; at path
exception error gson, parsing, big-integer, json-syntax-exception, type-adapter
Nesting limit reached
exception error java, gson, jsonreader, security, nesting
Failed invoking canAccess
exception error gson, reflection, jigsaw, security, jvm
Not a JSON Object
exception error gson, json, type-cast, illegal-state
Cannot allocate . Usage of JDK sun.misc.Unsafe is enabled…
exception critical reflection, unsafe, instantiation, jdk-version, deserialization, android
Expected a long but was
exception error java, gson, jsonreader, numeric, parsing
types and labels must be unique
exception error runtime-type-adapter, polymorphism, configuration, gson-extras
cannot serialize ; did you forget to register a subtype?
exception error runtime-type-adapter, polymorphism, serialization, registration
Must specify owner type for
exception error gson, reflection, generics, type-token, inner-class
TypeToken type argument must not contain a type variable…
exception error gson, type-token, generics, type-erasure, type-variable, illegal-argument
End of input
exception error java, gson, jsonreader, eof, parsing
Unexpected IllegalAccessException occurred
exception error gson, reflection, reflection-access-filter, java-version, runtime-exception, illegal-access
Deserialization is unsupported
exception error gson, serialization, java-io
Did not consume the entire document.
exception error gson, json, parsing, syntax
No time zone indicator
exception error gson, date-parsing, iso8601, timezone, parse-exception
Expected a but was ; at path
exception error gson, type-mismatch, runtime-check, type-hierarchy-factory, inet-address, json-syntax-exception
GSON ( ) cannot handle
exception error gson-core, type-adapter, reflection, configuration
Primitive type is not allowed
exception error gson, reflection, generics, type-token
Did not expect a name
exception error json, serialization, tree-model, state-machine
Type adapter must implement JsonSerializer or…
exception error type-adapter, registration, configuration
${getClass().getSimpleName()}
exception error gson, json, type-cast, unsupported-operation
Mismatching time zone indicator
exception error gson, date-parsing, iso8601, timezone, offset, index-out-of-bounds
TypeToken captured `null` as type argument; probably a…
exception error gson, type-token, generics, eclipse-jdt, compiler-bug, jvm, illegal-argument
Unable to create instance of
exception error reflection-filter, security, instance-creator, reflection, jpms
Unexpected ReflectiveOperationException occurred
exception error gson, reflection, java-records, runtime-exception, jvm
cannot deserialize subtype named ; did you forget to…
exception error runtime-type-adapter, polymorphism, deserialization, security
Expecting number, got
exception error json, deserialization, type-mismatch, numeric
JsonReader is closed
exception error java, gson, jsonreader, lifecycle, resource-management
JsonWriter is closed.
exception error java, gson, jsonwriter, lifecycle, resource-management
At most one lower bound is supported
exception error gson, reflection, generics, wildcard
is not a valid double value as per JSON specification. To…
exception error serialization, double, float, nan, infinity
Failed parsing JSON source
exception critical gson, json, memory, parsing, dos
Could not find the index in the constructor
exception error record, deserialization, reflection, obfuscation
Invalid number
exception error gson, date-parsing, iso8601, number-format, parse-exception
Unexpected when reading a JsonElement.
exception error json-tree-reader, json-element, reader-state, internal
JSON document was not fully consumed.
exception error gson-core, deserialization, malformed-json, strict
Missing id or totalSeconds field; at path
exception error java-time, zone, deserialization, schema
GSON cannot serialize or deserialize
exception error gson-core, type-adapter, delegate, factory-ordering
Cannot override built-in adapter for
exception error gson-builder, type-adapter, builtin-adapter, registration
Nesting problem.
exception error java, gson, jsonwriter, nesting, state-machine
Failed parsing ' ' as SQL Time; at path
exception error gson, date-parsing, sql-time, simple-date-format, locale, json-syntax-exception
Failed to invoke constructor
exception error constructor, reflection, instantiation, r8, proguard
Invalid attempt to bind an instance of
exception error jsonadapter, annotation, type-adapter, configuration
Class does not implement any supported type adapter class…
exception error gson-builder, type-adapter, configuration, registration
Array must have size 1, but has size
exception error jsonarray, jsonelement, coercion, deserialization
Accessor threw exception
exception error serialization, record, reflection
Failed making accessible; either increase its visibility or…
exception error gson, reflection, java-modules, jpms, inaccessible-object-exception, json-io-exception
Failed parsing ' ' as InetAddress; at path ; to allow DNS…
exception error gson, parsing, inet-address, dns, system-property, json-syntax-exception
The date pattern ' ' is not valid
exception error gson-builder, date-format, configuration, simpledateformat
TypeToken must be created with a type argument: new…
exception error gson, type-token, generics, proguard, r8, obfuscation, illegal-state
rawType must be of type Class, but was
exception error gson, type-token, generics, parameterized-type, illegal-argument
Failed parsing ' ' as SQL Date; at path
exception error gson, date-parsing, sql-date, simple-date-format, locale, json-syntax-exception
Failed parsing ' ' as Currency; at path
exception error gson, parsing, currency, iso-4217, json-syntax-exception, type-adapter
Must only create direct subclasses of TypeToken
exception error gson, type-token, generics, subclassing, illegal-state
When lower bound is specified, upper bound must be Object
exception error gson, reflection, generics, wildcard
Unable to create instance of
exception error unsafe, constructor, disable-unsafe, instantiation, instance-creator
Already wrote a name, expecting a value.
exception error java, gson, jsonwriter, state-machine, serialization
Couldn't write
exception error json-element, serialization, custom-subclass
Unknown DateFormat style
exception error gson, date, format, validation
Expected an int but was
exception error java, gson, jsonreader, numeric, overflow
Class declares multiple JSON fields named ' '; conflict is…
exception error serialization, field-naming, duplicate, inheritance
Failed parsing ' ' as BigDecimal; at path
exception error deserialization, bigdecimal, parsing, numeric
Cannot set value of 'static final
exception error deserialization, static-final, reflection, configuration
duplicate key
exception error json, deserialization, map, duplicate-keys
Expected but was at path
exception error json-tree-reader, structural-mismatch, deserialization, token
is not the same as or a subtype of
exception error type-resolution, generics, supertype, invariant
Element must be non-null
exception error gson, collections, null, list
JSON forbids NaN and infinities
exception error number-parsing, json-strictness, nan-infinity, deserialization
Expected a Class, ParameterizedType, or GenericArrayType…
exception error type-resolution, generics, reflection
Cannot parse ; at path
exception error number-parsing, deserialization, double
Dangling name
exception error java, gson, jsonwriter, state-machine, serialization
Please begin an object before writing a name.
exception error json, serialization, tree-model, state-machine
JSON forbids NaN and infinities
exception error json, serialization, numeric, nan-infinity
Only combinations of \n and \r are allowed in newline.
exception error formatting-style, pretty-printing, configuration, validation
Failed parsing ' ' as UUID; at path
exception error gson, parsing, uuid, json-syntax-exception, type-adapter
Missing field; at path
exception error java-time, deserialization, schema, missing-field
Interfaces can't be instantiated! Register an…
exception error interface, instantiation, instance-creator, deserialization
Unable to create instance of
exception error constructor, unsafe, instantiation, instance-creator
Invalid style
exception error gson-builder, date-format, configuration, validation