add a method to construct TypeToken from Class (#19)

zhongkechen · web-flow · commit 73e0f951b10f · 2026-01-26T11:27:52.000-08:00
* add a method to construct TypeToken from Class

* remove resultType from StepOperation

* fix tests and examples

* revert the accidental changes made by IntelliJ
diff --git a/examples/src/main/java/com/amazonaws/lambda/durable/examples/CustomConfigExample.java b/examples/src/main/java/com/amazonaws/lambda/durable/examples/CustomConfigExample.java
@@ -123,15 +123,6 @@ public String serialize(Object obj) {
             }
         }
 
-        @Override
-        public <T> T deserialize(String json, Class<T> clazz) {
-            try {
-                return objectMapper.readValue(json, clazz);
-            } catch (IOException e) {
-                throw new RuntimeException("Deserialization failed", e);
-            }
-        }
-
         @Override
         public <T> T deserialize(String json, TypeToken<T> typeToken) {
             try {
diff --git a/sdk-integration-tests/src/test/java/com/amazonaws/lambda/durable/CustomConfigIntegrationTest.java b/sdk-integration-tests/src/test/java/com/amazonaws/lambda/durable/CustomConfigIntegrationTest.java
@@ -34,12 +34,6 @@ public String serialize(Object value) {
             return delegate.serialize(value);
         }
 
-        @Override
-        public <T> T deserialize(String data, Class<T> type) {
-            deserializeCount.incrementAndGet();
-            return delegate.deserialize(data, type);
-        }
-
         @Override
         public <T> T deserialize(String data, TypeToken<T> typeToken) {
             deserializeCount.incrementAndGet();
diff --git a/sdk-integration-tests/src/test/java/com/amazonaws/lambda/durable/CustomSerDesIntegrationTest.java b/sdk-integration-tests/src/test/java/com/amazonaws/lambda/durable/CustomSerDesIntegrationTest.java
@@ -26,12 +26,6 @@ public String serialize(Object value) {
             return delegate.serialize(value);
         }
 
-        @Override
-        public <T> T deserialize(String data, Class<T> type) {
-            deserializeCount.incrementAndGet();
-            return delegate.deserialize(data, type);
-        }
-
         @Override
         public <T> T deserialize(String data, TypeToken<T> typeToken) {
             deserializeCount.incrementAndGet();
diff --git a/sdk-testing/src/main/java/com/amazonaws/lambda/durable/testing/TestOperation.java b/sdk-testing/src/main/java/com/amazonaws/lambda/durable/testing/TestOperation.java
@@ -2,6 +2,7 @@
 // SPDX-License-Identifier: Apache-2.0
 package com.amazonaws.lambda.durable.testing;
 
+import com.amazonaws.lambda.durable.TypeToken;
 import com.amazonaws.lambda.durable.serde.SerDes;
 import java.util.List;
 import software.amazon.awssdk.services.lambda.model.ErrorObject;
@@ -58,7 +59,7 @@ public <T> T getStepResult(Class<T> type) {
         if (details == null || details.result() == null) {
             return null;
         }
-        return serDes.deserialize(details.result(), type);
+        return serDes.deserialize(details.result(), TypeToken.get(type));
     }
 
     public ErrorObject getError() {
diff --git a/sdk-testing/src/main/java/com/amazonaws/lambda/durable/testing/TestResult.java b/sdk-testing/src/main/java/com/amazonaws/lambda/durable/testing/TestResult.java
@@ -2,6 +2,7 @@
 // SPDX-License-Identifier: Apache-2.0
 package com.amazonaws.lambda.durable.testing;
 
+import com.amazonaws.lambda.durable.TypeToken;
 import com.amazonaws.lambda.durable.model.ExecutionStatus;
 import com.amazonaws.lambda.durable.serde.SerDes;
 import java.util.List;
@@ -49,7 +50,7 @@ public <T> T getResult(Class<T> resultType) {
         if (resultPayload == null) {
             return null;
         }
-        return serDes.deserialize(resultPayload, resultType);
+        return serDes.deserialize(resultPayload, TypeToken.get(resultType));
     }
 
     public Optional<ErrorObject> getError() {
diff --git a/sdk/src/main/java/com/amazonaws/lambda/durable/DurableContext.java b/sdk/src/main/java/com/amazonaws/lambda/durable/DurableContext.java
@@ -56,7 +56,7 @@ public class DurableContext {
     public <T> T step(String name, Class<T> resultType, Supplier<T> func) {
         return step(
                 name,
-                resultType,
+                TypeToken.get(resultType),
                 func,
                 StepConfig.builder()
                         .retryStrategy(RetryStrategies.Presets.NO_RETRY)
@@ -86,29 +86,15 @@ public <T> T step(String name, TypeToken<T> typeToken, Supplier<T> func, StepCon
     public <T> DurableFuture<T> stepAsync(String name, Class<T> resultType, Supplier<T> func) {
         return stepAsync(
                 name,
-                resultType,
+                TypeToken.get(resultType),
                 func,
                 StepConfig.builder()
                         .retryStrategy(RetryStrategies.Presets.NO_RETRY)
                         .build());
     }
 
     public <T> DurableFuture<T> stepAsync(String name, Class<T> resultType, Supplier<T> func, StepConfig config) {
-        var operationId = nextOperationId();
-
-        // Validate replay consistency
-        var existing = executionManager.getOperation(operationId);
-        if (existing != null) {
-            validateReplay(operationId, OperationType.STEP, name, existing);
-        }
-
-        // Create and start step operation
-        StepOperation<T> operation =
-                new StepOperation<>(operationId, name, func, resultType, config, executionManager, logger, serDes);
-
-        operation.execute(); // Start the step (returns immediately)
-
-        return new DurableFuture<>(operation);
+        return stepAsync(name, TypeToken.get(resultType), func, config);
     }
 
     public <T> DurableFuture<T> stepAsync(String name, TypeToken<T> typeToken, Supplier<T> func) {
diff --git a/sdk/src/main/java/com/amazonaws/lambda/durable/DurableExecutor.java b/sdk/src/main/java/com/amazonaws/lambda/durable/DurableExecutor.java
@@ -156,7 +156,7 @@ private static <I> I extractUserInput(Operation executionOp, SerDes serDes, Clas
         }
 
         var inputPayload = executionOp.executionDetails().inputPayload();
-        return serDes.deserialize(inputPayload, inputType);
+        return serDes.deserialize(inputPayload, TypeToken.get(inputType));
     }
 
     public static <I, O> RequestHandler<DurableExecutionInput, DurableExecutionOutput> wrap(
diff --git a/sdk/src/main/java/com/amazonaws/lambda/durable/TypeToken.java b/sdk/src/main/java/com/amazonaws/lambda/durable/TypeToken.java
@@ -44,6 +44,14 @@ protected TypeToken() {
         }
     }
 
+    private TypeToken(Type type) {
+        this.type = type;
+    }
+
+    public static <U> TypeToken<U> get(Class<U> clazz) {
+        return new TypeToken<>(clazz) {};
+    }
+
     /**
      * Returns the captured type.
      *
diff --git a/sdk/src/main/java/com/amazonaws/lambda/durable/operation/StepOperation.java b/sdk/src/main/java/com/amazonaws/lambda/durable/operation/StepOperation.java
@@ -33,26 +33,13 @@ public class StepOperation<T> implements DurableOperation<T> {
     private final String operationId;
     private final String name;
     private final Supplier<T> function;
-    private final Class<T> resultType;
     private final TypeToken<T> resultTypeToken;
     private final StepConfig config;
     private final ExecutionManager executionManager;
     private final DurableLogger durableLogger;
     private final SerDes serDes;
     private final Phaser phaser;
 
-    public StepOperation(
-            String operationId,
-            String name,
-            Supplier<T> function,
-            Class<T> resultType,
-            StepConfig config,
-            ExecutionManager executionManager,
-            DurableLogger durableLogger,
-            SerDes serDes) {
-        this(operationId, name, function, resultType, null, config, executionManager, durableLogger, serDes);
-    }
-
     public StepOperation(
             String operationId,
             String name,
@@ -62,30 +49,13 @@ public StepOperation(
             ExecutionManager executionManager,
             DurableLogger durableLogger,
             SerDes serDes) {
-        this(operationId, name, function, null, resultTypeToken, config, executionManager, durableLogger, serDes);
-    }
-
-    private StepOperation(
-            String operationId,
-            String name,
-            Supplier<T> function,
-            Class<T> resultType,
-            TypeToken<T> resultTypeToken,
-            StepConfig config,
-            ExecutionManager executionManager,
-            DurableLogger durableLogger,
-            SerDes serDes) {
-        if (resultType == null && resultTypeToken == null) {
+        if (resultTypeToken == null) {
             throw new IllegalArgumentException("Either resultType or resultTypeToken must be provided");
         }
-        if (resultType != null && resultTypeToken != null) {
-            throw new IllegalArgumentException("Cannot provide both resultType and resultTypeToken");
-        }
 
         this.operationId = operationId;
         this.name = name;
         this.function = function;
-        this.resultType = resultType;
         this.resultTypeToken = resultTypeToken;
         this.config = config;
         this.executionManager = executionManager;
@@ -337,12 +307,7 @@ public T get() {
             var stepDetails = op.stepDetails();
             var result = (stepDetails != null) ? stepDetails.result() : null;
 
-            // Use TypeToken if provided, otherwise use Class
-            if (resultTypeToken != null) {
-                return serDes.deserialize(result, resultTypeToken);
-            } else {
-                return serDes.deserialize(result, resultType);
-            }
+            return serDes.deserialize(result, resultTypeToken);
         } else {
             // It failed so there's some kind of throwable. If we're using a serDes with
             // type info, deserialize and rethrow the original
diff --git a/sdk/src/main/java/com/amazonaws/lambda/durable/serde/JacksonSerDes.java b/sdk/src/main/java/com/amazonaws/lambda/durable/serde/JacksonSerDes.java
@@ -54,16 +54,6 @@ public String serialize(Object value) {
         }
     }
 
-    @Override
-    public <T> T deserialize(String data, Class<T> type) {
-        if (data == null) return null;
-        try {
-            return mapper.readValue(data, type);
-        } catch (Exception e) {
-            throw new SerDesException("Deserialization failed for type: " + type.getName(), e);
-        }
-    }
-
     @Override
     public <T> T deserialize(String data, TypeToken<T> typeToken) {
         if (data == null) return null;
diff --git a/sdk/src/main/java/com/amazonaws/lambda/durable/serde/SerDes.java b/sdk/src/main/java/com/amazonaws/lambda/durable/serde/SerDes.java
@@ -18,16 +18,6 @@ public interface SerDes {
      */
     String serialize(Object value);
 
-    /**
-     * Deserializes a JSON string to an object of the specified type.
-     *
-     * @param data the JSON string to deserialize
-     * @param type the class of the target type
-     * @param <T> the target type
-     * @return the deserialized object, or null if data is null
-     */
-    <T> T deserialize(String data, Class<T> type);
-
     /**
      * Deserializes a JSON string to an object of the specified generic type.
      *
diff --git a/sdk/src/test/java/com/amazonaws/lambda/durable/DurableExecutionWrapperTest.java b/sdk/src/test/java/com/amazonaws/lambda/durable/DurableExecutionWrapperTest.java
@@ -4,8 +4,6 @@
 
 import static java.util.List.of;
 import static org.junit.jupiter.api.Assertions.*;
-import static org.mockito.ArgumentMatchers.*;
-import static org.mockito.Mockito.*;
 
 import com.amazonaws.lambda.durable.client.DurableExecutionClient;
 import com.amazonaws.lambda.durable.model.DurableExecutionInput;
@@ -78,7 +76,7 @@ void testWrapperPattern() {
         assertEquals(ExecutionStatus.SUCCEEDED, output.status());
         assertNotNull(output.result());
 
-        var result = serDes.deserialize(output.result(), TestOutput.class);
+        var result = serDes.deserialize(output.result(), TypeToken.get(TestOutput.class));
         assertEquals("Wrapped: test", result.result);
     }
 
@@ -108,7 +106,7 @@ void testWrapperWithMethodReference() {
         var output = handler.handleRequest(input, null);
 
         assertEquals(ExecutionStatus.SUCCEEDED, output.status());
-        var result = serDes.deserialize(output.result(), TestOutput.class);
+        var result = serDes.deserialize(output.result(), TypeToken.get(TestOutput.class));
         assertEquals("Method: method-ref", result.result);
     }
 
diff --git a/sdk/src/test/java/com/amazonaws/lambda/durable/operation/StepOperationTest.java b/sdk/src/test/java/com/amazonaws/lambda/durable/operation/StepOperationTest.java
@@ -5,6 +5,7 @@
 import static org.junit.jupiter.api.Assertions.*;
 import static org.mockito.Mockito.*;
 
+import com.amazonaws.lambda.durable.TypeToken;
 import com.amazonaws.lambda.durable.execution.ExecutionManager;
 import com.amazonaws.lambda.durable.execution.OperationContext;
 import com.amazonaws.lambda.durable.execution.ThreadType;
@@ -26,7 +27,7 @@ void getThrowsIllegalStateExceptionWhenCalledFromStepContext() {
                 "1",
                 "test-step",
                 () -> "result",
-                String.class,
+                TypeToken.get(String.class),
                 null,
                 executionManager,
                 mock(DurableLogger.class),
@@ -58,7 +59,7 @@ void getDoesNotThrowWhenCalledFromHandlerContext() {
                 "1",
                 "test-step",
                 () -> "result",
-                String.class,
+                TypeToken.get(String.class),
                 null,
                 executionManager,
                 mock(DurableLogger.class),
diff --git a/sdk/src/test/java/com/amazonaws/lambda/durable/serde/JacksonSerDesTest.java b/sdk/src/test/java/com/amazonaws/lambda/durable/serde/JacksonSerDesTest.java
@@ -8,6 +8,7 @@
 import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
+import com.amazonaws.lambda.durable.TypeToken;
 import com.amazonaws.lambda.durable.exception.SerDesException;
 import org.junit.jupiter.api.Test;
 
@@ -21,7 +22,7 @@ void testRoundTrip() {
         var original = new TestData("test", 42);
 
         var json = serDes.serialize(original);
-        var deserialized = serDes.deserialize(json, TestData.class);
+        var deserialized = serDes.deserialize(json, TypeToken.get(TestData.class));
 
         assertEquals(original, deserialized);
     }
@@ -31,7 +32,7 @@ void testNullHandling() {
         var serDes = new JacksonSerDes();
 
         assertNull(serDes.serialize(null));
-        assertNull(serDes.deserialize(null, String.class));
+        assertNull(serDes.deserialize(null, TypeToken.get(String.class)));
     }
 
     @Test
@@ -40,7 +41,7 @@ void testDeserializationThrowsSerDesException() {
         var invalidJson = "{invalid json}";
 
         var exception = assertThrows(SerDesException.class, () -> {
-            serDes.deserialize(invalidJson, TestData.class);
+            serDes.deserialize(invalidJson, TypeToken.get(TestData.class));
         });
 
         assertTrue(exception.getMessage().contains("Deserialization failed"));
@@ -79,7 +80,7 @@ void testSerDesExceptionExtendsRuntimeException() {
 
         // Verify SerDesException is a RuntimeException (unchecked)
         assertThrows(RuntimeException.class, () -> {
-            serDes.deserialize(invalidJson, TestData.class);
+            serDes.deserialize(invalidJson, TypeToken.get(TestData.class));
         });
     }
 }

Original file line number	Diff line number	Diff line change
`@@ -2,6 +2,7 @@`
`2`	`2`	`// SPDX-License-Identifier: Apache-2.0`
`3`	`3`	`package com.amazonaws.lambda.durable.testing;`
`4`	`4`
	`5`	`+import com.amazonaws.lambda.durable.TypeToken;`
`5`	`6`	`import com.amazonaws.lambda.durable.serde.SerDes;`
`6`	`7`	`import java.util.List;`
`7`	`8`	`import software.amazon.awssdk.services.lambda.model.ErrorObject;`
`@@ -58,7 +59,7 @@ public <T> T getStepResult(Class<T> type) {`
`58`	`59`	`if (details == null \|\| details.result() == null) {`
`59`	`60`	`return null;`
`60`	`61`	`}`
`61`		`- return serDes.deserialize(details.result(), type);`
	`62`	`+ return serDes.deserialize(details.result(), TypeToken.get(type));`
`62`	`63`	`}`
`63`	`64`
`64`	`65`	`public ErrorObject getError() {`
Original file line number	Diff line number	Diff line change
`@@ -156,7 +156,7 @@ private static <I> I extractUserInput(Operation executionOp, SerDes serDes, Clas`
`156`	`156`	`}`
`157`	`157`
`158`	`158`	`var inputPayload = executionOp.executionDetails().inputPayload();`
`159`		`- return serDes.deserialize(inputPayload, inputType);`
	`159`	`+ return serDes.deserialize(inputPayload, TypeToken.get(inputType));`
`160`	`160`	`}`
`161`	`161`
`162`	`162`	`public static <I, O> RequestHandler<DurableExecutionInput, DurableExecutionOutput> wrap(`
Original file line number	Diff line number	Diff line change
`@@ -44,6 +44,14 @@ protected TypeToken() {`
`44`	`44`	`}`
`45`	`45`	`}`
`46`	`46`
	`47`	`+ private TypeToken(Type type) {`
	`48`	`+ this.type = type;`
	`49`	`+ }`
	`50`	`+`
	`51`	`+ public static <U> TypeToken<U> get(Class<U> clazz) {`
	`52`	`+ return new TypeToken<>(clazz) {};`
	`53`	`+ }`
	`54`	`+`
`47`	`55`	`/**`
`48`	`56`	`* Returns the captured type.`
`49`	`57`	`*`