http-client-java, bug fix, array encoding support closed enum #9413

weidongxu-microsoft · 2026-01-20T05:17:04Z

test not yet published https://github.com/microsoft/typespec/blob/main/packages/http-specs/specs/encode/array/main.tsp#L44-L62

github-actions · 2026-01-20T05:20:00Z

No changes needing a change description found.

azure-sdk · 2026-01-20T05:32:51Z

You can try these changes here

🛝 Playground	🌐 Website	🛝 VSCode Extension

haolingdong-msft · 2026-01-20T07:54:33Z

could you please show the generated code diff by adding the fix?

weidongxu-microsoft · 2026-01-20T08:18:19Z

could you please show the generated code diff by adding the fix?

I cannot, because without this fix, emitter crashes, and there is no code generated.

Copilot

Pull request overview

This PR adds support for array encoding (comma-separated string representation) of closed enum types in the Java HTTP client generator. The change introduces a new ConvertFromJsonTypeTrait interface and updates the deserialization logic to properly handle enum values when deserializing from array-encoded strings.

Changes:

Introduced ConvertFromJsonTypeTrait interface for converting JSON wire values back to client types
Implemented the new trait on PrimitiveType, ClassType, and EnumType to support bidirectional conversion
Fixed array encoding deserialization logic in StreamSerializationModelTemplate to use the new conversion trait instead of relying on defaultValueExpression
Added unit tests for both ConvertToJsonTypeTrait and ConvertFromJsonTypeTrait conversion methods

Reviewed changes

Copilot reviewed 8 out of 8 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
ConvertFromJsonTypeTrait.java	New interface defining conversion from JSON wire type to client type
ConvertToJsonTypeTrait.java	Updated documentation to clarify it converts to JSON wire type
PrimitiveType.java	Implements `ConvertFromJsonTypeTrait` and updates `convertToJsonType` to properly handle client-to-wire conversion
ClassType.java	Implements `ConvertFromJsonTypeTrait` with explicit handling for various special types like DATE_TIME, DURATION, URL
EnumType.java	Implements `ConvertFromJsonTypeTrait` to support enum deserialization from JSON values
StreamSerializationModelTemplate.java	Fixes array encoding deserialization to use `ConvertFromJsonTypeTrait` instead of `defaultValueExpression`, with proper error handling
ConvertToJsonTypeTraitTests.java	New test file verifying type conversion to JSON representation
ConvertFromJsonTypeTraitTests.java	New test file verifying type conversion from JSON representation

...osoft/typespec/http/client/generator/core/model/clientmodel/ConvertToJsonTypeTraitTests.java

...oft/typespec/http/client/generator/core/model/clientmodel/ConvertFromJsonTypeTraitTests.java

...main/java/com/microsoft/typespec/http/client/generator/core/model/clientmodel/ClassType.java

…/src/main/java/com/microsoft/typespec/http/client/generator/core/model/clientmodel/ClassType.java Co-authored-by: Copilot <[email protected]>

Copilot

Pull request overview

Copilot reviewed 8 out of 8 changed files in this pull request and generated 2 comments.

...main/java/com/microsoft/typespec/http/client/generator/core/model/clientmodel/ClassType.java

.../java/com/microsoft/typespec/http/client/generator/core/model/clientmodel/PrimitiveType.java

XiaofeiCao · 2026-01-20T10:38:26Z

...main/java/com/microsoft/typespec/http/client/generator/core/model/clientmodel/ClassType.java

+        // TODO (weidxu): it may be better to refactor it to type initialization, similar as
+        // defaultValueExpressionConverter
+        if (this == ClassType.INTEGER_AS_STRING) {
+            return variableName + " == null ? null : Integer.parseInt(" + variableName + ")";
+        } else if (this == ClassType.LONG_AS_STRING) {
+            return variableName + " == null ? null : Long.parseInt(" + variableName + ")";
+        } else if (this == ClassType.DATE_TIME) {
+            return variableName + " == null ? null : OffsetDateTime.parse(" + variableName + ")";
+        } else if (this == ClassType.DATE_TIME_RFC_1123) {
+            return variableName + " == null ? null : new DateTimeRfc1123(" + variableName + ")";
+        } else if (this == ClassType.DURATION) {
+            return variableName + " == null ? null : Duration.parse(" + variableName + ")";
+        } else if (this == ClassType.URL) {
+            return variableName + " == null ? null : new URL(" + variableName + ")";
+        } else {
+            return convertToClientType(variableName);
+        }


Wonder can we put this into convertToClientType implementation?

And what's the difference between wireType and jsonType?

Wire type can be e.g. DateTimeRfc1123. JSON type would be JSON string/numeric/boolean etc. (object or array not counted)

The "wire type" in codegen may not be what you think "on wire".

It is more an "internal type" (compared to client type as "customer facing type").

For models, since codegen now own the serialization/de- (no Jackson needed), this "internal type" may not be useful at all. E.g. we should be able to directly convert a JSON string to OffsetDateTime, according to RFC1123/7231 protocol (instead of the usual RFC3339).

However, for proxy method, the core / clientcore still takes this "internal type" for request parameter / body / response body.

weidongxu-microsoft added 2 commits January 20, 2026 12:07

test for ConvertToJsonTypeTrait

8464593

handle convertFromJsonType

3ed9b18

microsoft-github-policy-service bot added the emitter:client:java Issue for the Java client emitter: @typespec/http-client-java label Jan 20, 2026

logic in StreamSerializationModelTemplate

8e7b15b

weidongxu-microsoft marked this pull request as ready for review January 20, 2026 05:53

weidongxu-microsoft requested review from XiaofeiCao, anuchandy, haolingdong-msft and srnagar as code owners January 20, 2026 05:53

weidongxu-microsoft requested a review from Copilot January 20, 2026 09:02

Copilot started reviewing on behalf of weidongxu-microsoft January 20, 2026 09:02 View session

Copilot AI reviewed Jan 20, 2026

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weidongxu-microsoft and others added 2 commits January 20, 2026 17:08

Update packages/http-client-java/generator/http-client-generator-core…

4a82a97

…/src/main/java/com/microsoft/typespec/http/client/generator/core/model/clientmodel/ClassType.java Co-authored-by: Copilot <[email protected]>

add UT for EnumType

56b3a56

weidongxu-microsoft requested a review from Copilot January 20, 2026 09:22

Copilot started reviewing on behalf of weidongxu-microsoft January 20, 2026 09:22 View session

Copilot AI reviewed Jan 20, 2026

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...main/java/com/microsoft/typespec/http/client/generator/core/model/clientmodel/ClassType.java Show resolved Hide resolved

.../java/com/microsoft/typespec/http/client/generator/core/model/clientmodel/PrimitiveType.java Show resolved Hide resolved

XiaofeiCao reviewed Jan 20, 2026

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weidongxu-microsoft added 2 commits January 20, 2026 21:14

generate more concise code with getNullable

d12f548

regen

6d463e4

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http-client-java, bug fix, array encoding support closed enum #9413

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