\aws#220 Fix header case sensitivity (updated aws#234)

This solution builds upon @jeromevdl 's solution of PR aws#234 to fix the
issue of headers being case sensitive. Fixes @carlzogh 's comment
regarding breaking changes in setHeaders.

Author: parawanderer

aws-lambda-java-events/src/main/java/com/amazonaws/services/lambda/runtime/events/APIGatewayCustomAuthorizerEvent.java

@@ -1,5 +1,6 @@
 package com.amazonaws.services.lambda.runtime.events;
 
+import com.amazonaws.services.lambda.runtime.events.models.HttpHeaders;
 import lombok.AllArgsConstructor;
 import lombok.Builder;
 import lombok.Data;
@@ -26,7 +27,7 @@ public class APIGatewayCustomAuthorizerEvent {
     private String resource;
     private String path;
     private String httpMethod;
-    private Map<String, String> headers;
+    private HttpHeaders<String> headers;
     private Map<String, String> queryStringParameters;
     private Map<String, String> pathParameters;
     private Map<String, String> stageVariables;

aws-lambda-java-events/src/main/java/com/amazonaws/services/lambda/runtime/events/APIGatewayProxyRequestEvent.java

@@ -1,8 +1,9 @@
 package com.amazonaws.services.lambda.runtime.events;
 
+import com.amazonaws.services.lambda.runtime.events.models.HttpHeaders;
+
 import java.io.Serializable;
-import java.util.List;
-import java.util.Map;
+import java.util.*;
 
 /**
  * Class that represents an APIGatewayProxyRequestEvent
@@ -19,9 +20,9 @@ public class APIGatewayProxyRequestEvent implements Serializable, Cloneable {
 
     private String httpMethod;
 
-    private Map<String, String> headers;
+    private HttpHeaders<String> headers;
 
-    private Map<String, List<String>> multiValueHeaders;
+    private HttpHeaders<List<String>> multiValueHeaders;
 
     private Map<String, String> queryStringParameters;
 
@@ -69,7 +70,8 @@ public static class ProxyRequestContext implements Serializable, Cloneable {
         /**
          * default constructor
          */
-        public ProxyRequestContext() {}
+        public ProxyRequestContext() {
+        }
 
         /**
          * @return account id that owns Lambda function
@@ -103,7 +105,7 @@ public void setAuthorizer(final Map<String, Object> authorizer) {
         }
 
         /**
-         * @return  API Gateway stage name
+         * @return API Gateway stage name
          */
         public String getStage() {
             return stage;
@@ -288,14 +290,14 @@ public ProxyRequestContext withPath(String path) {
 
         /**
          * @return The name of the operation being performed
-         * */
+         */
         public String getOperationName() {
             return operationName;
         }
 
         /**
          * @param operationName The name of the operation being performed
-         * */
+         */
         public void setOperationName(String operationName) {
             this.operationName = operationName;
         }
@@ -309,7 +311,6 @@ public ProxyRequestContext withOperationName(String operationName) {
          * Returns a string representation of this object; useful for testing and debugging.
          *
          * @return A string representation of this object.
-         *
          * @see Object#toString()
          */
         @Override
@@ -414,7 +415,7 @@ public int hashCode() {
             hashCode = prime * hashCode + ((getApiId() == null) ? 0 : getApiId().hashCode());
             hashCode = prime * hashCode + ((getPath() == null) ? 0 : getPath().hashCode());
             hashCode = prime * hashCode + ((getAuthorizer() == null) ? 0 : getAuthorizer().hashCode());
-            hashCode = prime * hashCode + ((getOperationName() == null) ? 0: getOperationName().hashCode());
+            hashCode = prime * hashCode + ((getOperationName() == null) ? 0 : getOperationName().hashCode());
             return hashCode;
         }
 
@@ -461,7 +462,8 @@ public static class RequestIdentity implements Serializable, Cloneable {
         /**
          * default constructor
          */
-        public RequestIdentity() {}
+        public RequestIdentity() {
+        }
 
         /**
          * @return The Cognito identity pool id.
@@ -766,7 +768,6 @@ public RequestIdentity withAccessKey(String accessKey) {
          * Returns a string representation of this object; useful for testing and debugging.
          *
          * @return A string representation of this object.
-         *
          * @see Object#toString()
          */
         @Override
@@ -903,7 +904,8 @@ public RequestIdentity clone() {
     /**
      * default constructor
      */
-    public APIGatewayProxyRequestEvent() {}
+    public APIGatewayProxyRequestEvent() {
+    }
 
     /**
      * @return The payload format version
@@ -1008,7 +1010,7 @@ public Map<String, String> getHeaders() {
      * @param headers The headers sent with the request
      */
     public void setHeaders(Map<String, String> headers) {
-        this.headers = headers;
+        this.headers = HttpHeadersUtil.mergeOrReplace(headers);
     }
 
     /**
@@ -1031,7 +1033,7 @@ public Map<String, List<String>> getMultiValueHeaders() {
      * @param multiValueHeaders The multi value headers sent with the request
      */
     public void setMultiValueHeaders(Map<String, List<String>> multiValueHeaders) {
-        this.multiValueHeaders = multiValueHeaders;
+        this.multiValueHeaders = HttpHeadersUtil.mergeOrReplace(multiValueHeaders);
     }
 
     /**
@@ -1224,7 +1226,6 @@ public APIGatewayProxyRequestEvent withIsBase64Encoded(Boolean isBase64Encoded)
      * Returns a string representation of this object; useful for testing and debugging.
      *
      * @return A string representation of this object.
-     *
      * @see Object#toString()
      */
     @Override

aws-lambda-java-events/src/main/java/com/amazonaws/services/lambda/runtime/events/APIGatewayProxyResponseEvent.java

@@ -1,5 +1,7 @@
 package com.amazonaws.services.lambda.runtime.events;
 
+import com.amazonaws.services.lambda.runtime.events.models.HttpHeaders;
+
 import java.io.Serializable;
 import java.util.List;
 import java.util.Map;
@@ -13,9 +15,9 @@ public class APIGatewayProxyResponseEvent implements Serializable, Cloneable {
 
     private Integer statusCode;
 
-    private Map<String, String> headers;
+    private HttpHeaders<String> headers;
 
-    private Map<String, List<String>> multiValueHeaders;
+    private HttpHeaders<List<String>> multiValueHeaders;
 
     private String body;
 
@@ -60,7 +62,7 @@ public Map<String, String> getHeaders() {
      * @param headers The Http headers return in the response
      */
     public void setHeaders(Map<String, String> headers) {
-        this.headers = headers;
+        this.headers = HttpHeadersUtil.mergeOrReplace(headers);
     }
 
     /**
@@ -83,7 +85,7 @@ public Map<String, List<String>> getMultiValueHeaders() {
      * @param multiValueHeaders the Http multi value headers to return in the response
      */
     public void setMultiValueHeaders(Map<String, List<String>> multiValueHeaders) {
-        this.multiValueHeaders = multiValueHeaders;
+        this.multiValueHeaders = HttpHeadersUtil.mergeOrReplace(multiValueHeaders);
     }
 
     /**

aws-lambda-java-events/src/main/java/com/amazonaws/services/lambda/runtime/events/APIGatewayV2CustomAuthorizerEvent.java

@@ -1,5 +1,6 @@
 package com.amazonaws.services.lambda.runtime.events;
 
+import com.amazonaws.services.lambda.runtime.events.models.HttpHeaders;
 import lombok.AllArgsConstructor;
 import lombok.Builder;
 import lombok.Data;
@@ -31,7 +32,7 @@ public class APIGatewayV2CustomAuthorizerEvent {
     private String rawPath;
     private String rawQueryString;
     private List<String> cookies;
-    private Map<String, String> headers;
+    private HttpHeaders<String> headers;
     private Map<String, String> queryStringParameters;
     private RequestContext requestContext;
     private Map<String, String> pathParameters;

aws-lambda-java-events/src/main/java/com/amazonaws/services/lambda/runtime/events/APIGatewayV2HTTPEvent.java

@@ -13,6 +13,7 @@
 
 package com.amazonaws.services.lambda.runtime.events;
 
+import com.amazonaws.services.lambda.runtime.events.models.HttpHeaders;
 import lombok.AllArgsConstructor;
 import lombok.Builder;
 import lombok.Data;
@@ -34,14 +35,18 @@ public class APIGatewayV2HTTPEvent {
     private String rawPath;
     private String rawQueryString;
     private List<String> cookies;
-    private Map<String, String> headers;
+    private HttpHeaders<String> headers;
     private Map<String, String> queryStringParameters;
     private Map<String, String> pathParameters;
     private Map<String, String> stageVariables;
     private String body;
     private boolean isBase64Encoded;
     private RequestContext requestContext;
 
+    public void setHeaders(Map<String, String> headers) {
+        this.headers = HttpHeadersUtil.mergeOrReplace(headers);
+    }
+
     @AllArgsConstructor
     @Builder(setterPrefix = "with")
     @Data

aws-lambda-java-events/src/main/java/com/amazonaws/services/lambda/runtime/events/APIGatewayV2HTTPResponse.java

@@ -13,6 +13,7 @@
 
 package com.amazonaws.services.lambda.runtime.events;
 
+import com.amazonaws.services.lambda.runtime.events.models.HttpHeaders;
 import lombok.AllArgsConstructor;
 import lombok.Builder;
 import lombok.Data;
@@ -27,9 +28,28 @@
 @NoArgsConstructor
 public class APIGatewayV2HTTPResponse {
     private int statusCode;
-    private Map<String, String> headers;
-    private Map<String, List<String>> multiValueHeaders;
+    private HttpHeaders<String> headers;
+    private HttpHeaders<List<String>> multiValueHeaders;
     private List<String> cookies;
     private String body;
     private boolean isBase64Encoded;
+
+    public static APIGatewayV2HTTPResponseBuilder builder() {
+        return new APIGatewayV2HTTPResponseBuilder();
+    }
+
+    public static class APIGatewayV2HTTPResponseBuilder {
+        private HttpHeaders<String> headers;
+        private HttpHeaders<List<String>> multiValueHeaders;
+
+        public APIGatewayV2HTTPResponseBuilder withHeaders(Map<String, String> headers) {
+            this.headers = HttpHeadersUtil.mergeOrReplace(headers);
+            return this;
+        }
+
+        public APIGatewayV2HTTPResponseBuilder withMultiValueHeaders(Map<String, List<String>> multiValueHeaders) {
+            this.multiValueHeaders = HttpHeadersUtil.mergeOrReplace(multiValueHeaders);
+            return this;
+        }
+    }
 }

aws-lambda-java-events/src/main/java/com/amazonaws/services/lambda/runtime/events/APIGatewayV2WebSocketResponse.java

@@ -1,5 +1,7 @@
 package com.amazonaws.services.lambda.runtime.events;
 
+import com.amazonaws.services.lambda.runtime.events.models.HttpHeaders;
+
 import java.io.Serializable;
 import java.util.Map;
 
@@ -12,8 +14,8 @@ public class APIGatewayV2WebSocketResponse implements Serializable, Cloneable {
 
   private boolean isBase64Encoded = false;
   private int statusCode;
-  private Map<String, String> headers;
-  private Map<String, String[]> multiValueHeaders;
+  private HttpHeaders<String> headers;
+  private HttpHeaders<String[]> multiValueHeaders;
   private String body;
 
   public boolean isIsBase64Encoded() {
@@ -37,15 +39,15 @@ public Map<String, String> getHeaders() {
   }
 
   public void setHeaders(Map<String, String> headers) {
-    this.headers = headers;
+    this.headers = HttpHeadersUtil.mergeOrReplace(headers);
   }
 
   public Map<String, String[]> getMultiValueHeaders() {
     return multiValueHeaders;
   }
 
   public void setMultiValueHeaders(Map<String, String[]> multiValueHeaders) {
-    this.multiValueHeaders = multiValueHeaders;
+    this.multiValueHeaders = HttpHeadersUtil.mergeOrReplace(multiValueHeaders);
   }
 
   public String getBody() {

aws-lambda-java-events/src/main/java/com/amazonaws/services/lambda/runtime/events/ApplicationLoadBalancerRequestEvent.java

@@ -1,5 +1,6 @@
 package com.amazonaws.services.lambda.runtime.events;
 
+import com.amazonaws.services.lambda.runtime.events.models.HttpHeaders;
 import lombok.Data;
 import lombok.NoArgsConstructor;
 
@@ -40,8 +41,8 @@ public static class RequestContext implements Serializable, Cloneable {
     private String path;
     private Map<String, String> queryStringParameters;
     private Map<String, List<String>> multiValueQueryStringParameters;
-    private Map<String, String> headers;
-    private Map<String, List<String>> multiValueHeaders;
+    private HttpHeaders<String> headers;
+    private HttpHeaders<List<String>> multiValueHeaders;
     private String body;
     private boolean isBase64Encoded;
 

aws-lambda-java-events/src/main/java/com/amazonaws/services/lambda/runtime/events/ApplicationLoadBalancerResponseEvent.java

@@ -1,5 +1,6 @@
 package com.amazonaws.services.lambda.runtime.events;
 
+import com.amazonaws.services.lambda.runtime.events.models.HttpHeaders;
 import lombok.Data;
 import lombok.NoArgsConstructor;
 
@@ -22,8 +23,8 @@ public class ApplicationLoadBalancerResponseEvent implements Serializable, Clone
     private int statusCode;
     private String statusDescription;
     private boolean isBase64Encoded;
-    private Map<String, String> headers;
-    private Map<String, List<String>> multiValueHeaders;
+    private HttpHeaders<String> headers;
+    private HttpHeaders<List<String>> multiValueHeaders;
     private String body;
 
 }

aws-lambda-java-events/src/main/java/com/amazonaws/services/lambda/runtime/events/HttpHeadersUtil.java

@@ -0,0 +1,20 @@
+package com.amazonaws.services.lambda.runtime.events;
+
+import com.amazonaws.services.lambda.runtime.events.models.HttpHeaders;
+
+import java.util.Map;
+
+final class HttpHeadersUtil {
+    private HttpHeadersUtil() {}
+
+    public static <T> HttpHeaders<T> mergeOrReplace(Map<String, T> from) {
+        if (from == null) return null;
+        if (from instanceof HttpHeaders) return (HttpHeaders<T>) from;
+
+        HttpHeaders<T> out = new HttpHeaders<>();
+        if (from.isEmpty()) return out;
+
+        out.putAll(from);
+        return out;
+    }
+}