feat: extension support for the genereated api client

Author: PhilippHeuer

.gitignore

@@ -50,9 +50,6 @@ client.log
 # JavaDoc
 /docs/javadoc/*
 
-# Example Code
-/src/main/java/me/philippheuer/twitch4j/example/*
-
 # Modules
 /modules/
 

build.gradle.kts

@@ -56,6 +56,7 @@ subprojects {
             // bom
             add("api", platform("io.github.openfeign:feign-bom:12.4"))
             add("api", platform("io.github.resilience4j:resilience4j-bom:2.1.0"))
+            add("api", platform("com.fasterxml.jackson:jackson-bom:2.15.2"))
         }
     }
 }

common/build.gradle.kts

@@ -0,0 +1,14 @@
+plugins {
+    `java-library`
+}
+
+projectConfiguration {
+    artifactId.set("common")
+    artifactDisplayName.set("common")
+    artifactDescription.set("common")
+}
+
+dependencies {
+    // annotations
+    implementation("org.jetbrains:annotations:24.0.1")
+}

common/src/main/java/io/github/primelib/primecodegenlib/java/common/api/ThrowingFunction.java

@@ -0,0 +1,26 @@
+package io.github.primelib.primecodegenlib.java.common.api;
+
+import lombok.SneakyThrows;
+
+import java.util.function.Function;
+
+/**
+ * A functional interface representing a function that may throw a checked exception.
+ * <p>
+ * This functional interface is similar to the standard {@link Function}
+ * interface, but it allows the implementation to throw a checked exception.
+ *
+ * @param <T> the type of the input to the function
+ * @param <R> the type of the result of the function
+ * @param <E> the type of the checked exception that may be thrown by the function
+ */
+@FunctionalInterface
+public interface ThrowingFunction<T, R, E extends Throwable> extends Function<T, R> {
+    R invoke(T t) throws E;
+
+    @Override
+    @SneakyThrows
+    default R apply(T t) {
+        return invoke(t);
+    }
+}

common/src/main/java/io/github/primelib/primecodegenlib/java/common/util/ServiceLoaderUtil.java

@@ -0,0 +1,36 @@
+package io.github.primelib.primecodegenlib.java.common.util;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.ServiceLoader;
+
+/**
+ * Utility class for loading classes using JDK {@link ServiceLoader} facility.
+ */
+public class ServiceLoaderUtil {
+
+    /**
+     * Method for locating available classes, using JDK {@link ServiceLoader} facility, along with module-provided SPI.
+     * <p>
+     * This method does not do any caching, so calls should be considered potentially expensive.
+     */
+    public static <T> List<T> find(Class<T> clazz) {
+        return find(clazz, null);
+    }
+
+    /**
+     * Method for locating available classes, using JDK {@link ServiceLoader} facility, along with module-provided SPI.
+     * <p>
+     * This method does not do any caching, so calls should be considered potentially expensive.
+     */
+    public static <T> List<T> find(Class<T> clazz, ClassLoader classLoader) {
+        ArrayList<T> modules = new ArrayList<>();
+        ServiceLoader<T> loader = ServiceLoader.load(clazz, classLoader == null ? Thread.currentThread().getContextClassLoader() : classLoader);
+
+        for (T extension : loader) {
+            modules.add(extension);
+        }
+
+        return modules;
+    }
+}

feign-blackbird/build.gradle.kts

@@ -0,0 +1,23 @@
+plugins {
+	`java-library`
+}
+
+projectConfiguration {
+	artifactId.set("feign-blackbird")
+	artifactDisplayName.set("Feign - Jackson Blackbird Extension")
+	artifactDescription.set("Feign - Jackson Blackbird Extension")
+}
+
+dependencies {
+	// modules
+	api(project(":feign-common"))
+
+	// annotations
+	implementation("org.jetbrains:annotations:24.0.1")
+
+	// feign
+	api("io.github.openfeign:feign-core")
+
+	// blackbird
+	api("com.fasterxml.jackson.module:jackson-module-blackbird")
+}

feign-blackbird/src/main/java/io/github/primelib/primecodegenlib/java/feign/blackbird/BlackbirdExtension.java

@@ -0,0 +1,22 @@
+package io.github.primelib.primecodegenlib.java.feign.blackbird;
+
+import com.fasterxml.jackson.databind.json.JsonMapper;
+import com.fasterxml.jackson.module.blackbird.BlackbirdModule;
+import io.github.primelib.primecodegenlib.java.feign.common.api.PrimeExtension;
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * Blackbird Module
+ * <p>
+ * This module adds the Blackbird Module to the Jackson ObjectMapper.
+ */
+public class BlackbirdExtension implements PrimeExtension {
+    public BlackbirdExtension() {
+
+    }
+
+    @Override
+    public void customizeObjectMapper(JsonMapper.@NotNull Builder builder) {
+        builder.addModule(new BlackbirdModule());
+    }
+}

feign-blackbird/src/main/resources/META-INF/services/io.github.primelib.primecodegenlib.java.feign.common.api.PrimeExtension

@@ -0,0 +1 @@
+io.github.primelib.primecodegenlib.java.feign.blackbird.BlackbirdExtension

feign-common/build.gradle.kts

@@ -9,9 +9,15 @@ projectConfiguration {
 }
 
 dependencies {
+    // modules
+    api(project(":common"))
+
     // annotations
     implementation("org.jetbrains:annotations:24.0.1")
 
     // feign
     api("io.github.openfeign:feign-core")
+
+    // jackson
+    compileOnly("com.fasterxml.jackson.core:jackson-databind")
 }

feign-common/src/main/java/io/github/primelib/primecodegenlib/java/feign/common/api/PrimeExtension.java

@@ -0,0 +1,39 @@
+package io.github.primelib.primecodegenlib.java.feign.common.api;
+
+import com.fasterxml.jackson.databind.json.JsonMapper;
+import feign.InvocationHandlerFactory;
+import feign.Target;
+import io.github.primelib.primecodegenlib.java.common.api.ThrowingFunction;
+import org.jetbrains.annotations.ApiStatus;
+import org.jetbrains.annotations.NotNull;
+
+import java.lang.reflect.Method;
+import java.util.Map;
+
+/**
+ * A Prime Extension.
+ */
+@ApiStatus.Internal
+public interface PrimeExtension {
+
+    /**
+     * Decorates the invocations of a function.
+     *
+     * @param backendName the name of the backend
+     * @param function the function to decorate
+     * @param dispatch the dispatch
+     * @param target the target
+     * @return the decorated method handler
+     */
+    @NotNull
+    default ThrowingFunction<Object[], Object, Throwable> decorateFeignInvocation(String backendName, ThrowingFunction<Object[], Object, Throwable> function, Map<Method, InvocationHandlerFactory.MethodHandler> dispatch, Target<?> target) {
+        return function;
+    }
+
+    /**
+     * Customize the Jackson ObjectMapper.
+     *
+     * @param builder the builder
+     */
+    default void customizeObjectMapper(@NotNull JsonMapper.Builder builder) {}
+}