refactor code

src/main/java/com/microsoft/azure/functions/internal/spi/middleware/Middleware.java

@@ -3,21 +3,20 @@
  * Licensed under the MIT License. See License.txt in the project root for
  * license information.
  */
-package com.microsoft.azure.functions.middleware;
-
-import com.microsoft.azure.functions.internal.MiddlewareContext;
+package com.microsoft.azure.functions.internal.spi.middleware;
 
 /**
  * This interface is implemented by middlewares to include middleware core logics.
  *
- * @since 1.1.0
+ * <p>This class is internal and is hence not for public use at this time. Its APIs are unstable and can change
+ * at any time.
  */
-public interface FunctionWorkerMiddleware {
+public interface Middleware {
     /**
      * Middlewares will override this method to include their own logics.
      * @param context execution context that pass along middleware chain
-     * @param next function middleware chain {@link FunctionMiddlewareChain}
+     * @param chain middleware chain {@link MiddlewareChain}
      * @throws Exception any exception that is thrown out in next middleware
      */
-    void invoke(MiddlewareContext context, FunctionMiddlewareChain next) throws Exception;
+    void invoke(MiddlewareContext context, MiddlewareChain chain) throws Exception;
 }

src/main/java/com/microsoft/azure/functions/internal/spi/middleware/MiddlewareChain.java

@@ -3,18 +3,17 @@
  * Licensed under the MIT License. See License.txt in the project root for
  * license information.
  */
-package com.microsoft.azure.functions.middleware;
-
-import com.microsoft.azure.functions.internal.MiddlewareContext;
+package com.microsoft.azure.functions.internal.spi.middleware;
 
 /**
- * The function middleware chain.
+ * The middleware chain.
  *
- * @since 1.1.0
+ * <p>This class is internal and is hence not for public use at this time. Its APIs are unstable and can change
+ * at any time.
  */
-public interface FunctionMiddlewareChain {
+public interface MiddlewareChain {
     /**
-     * Invokes next middleware, usually used at the end of middleware to invoke next middleware in the middleware chain.
+     * Invokes next middleware in the chain.
      * @param context execution context that pass along middleware chain
      * @throws Exception any exception that happen along middleware chain
      */

src/main/java/com/microsoft/azure/functions/internal/spi/middleware/MiddlewareContext.java

@@ -4,16 +4,14 @@
  * license information.
  */
 
-package com.microsoft.azure.functions.internal;
+package com.microsoft.azure.functions.internal.spi.middleware;
 
 import com.microsoft.azure.functions.ExecutionContext;
 
-import java.util.Optional;
-
 /**
  * Middleware Execution Context
  *
- * <p>This class is internal and is hence not for public use. Its APIs are unstable and can change
+ * <p>This class is internal and is hence not for public use at this time. Its APIs are unstable and can change
  * at any time.
  */
 public interface MiddlewareContext extends ExecutionContext {
@@ -23,7 +21,8 @@ public interface MiddlewareContext extends ExecutionContext {
      * @param annotationSimpleClassName the simple class name of target annotation
      * @return the name of parameter defined in customer function
      */
-    Optional<String> getParameterName(String annotationSimpleClassName);
+    //TODO: @Nullable
+    String getParameterName(String annotationSimpleClassName);
 
     /**
      * Returns corresponding parameter value sent from host by the given the parameter name.
@@ -33,6 +32,7 @@ public interface MiddlewareContext extends ExecutionContext {
      * @param name the name of parameter
      * @return an object which will be String type that represents parameter value of customer function
      */
+    //TODO: @Nullable
     Object getParameterValue(String name);
 
     /**
@@ -47,6 +47,7 @@ public interface MiddlewareContext extends ExecutionContext {
      * Returns the return value from customer function invocation.
      * @return an object that is the return value of customer function
      */
+    //TODO: @Nullable
     Object getReturnValue();
 
     /**

src/main/java/com/microsoft/azure/functions/spi/inject/FunctionInstanceInjector.java

@@ -3,20 +3,20 @@
  * Licensed under the MIT License. See License.txt in the project root for
  * license information.
  */
-package com.microsoft.azure.functions.dihook;
+package com.microsoft.azure.functions.spi.inject;
 
 /**
  * The instance factory that used by DI framework to initialize function instance.
  *
  * @since 1.1.0
  */
-public interface FunctionInstanceFactory {
+public interface FunctionInstanceInjector {
     /**
      * This method is used by DI framework to initialize DI container. This method takes in the customer class and return
-     * an instance create by the DI framework, later customer function will be invoked base on this class instance.
+     * an instance create by the DI framework, later customer functions will be invoked on this class instance.
      * @param functionClass the class that contains customer functions
      * @param <T> customer functions class type
-     * @return the function instance that will be invoked on by azure functions java worker
+     * @return the instance that will be invoked on by azure functions java worker
      * @throws Exception any exception that is thrown out during DI framework create instance of  function class
      */
     <T> T getInstance(Class<T> functionClass) throws Exception;