Add REST API tools: client library, auth filter, validation, and tests

pom.xml

@@ -241,6 +241,28 @@
             <artifactId>bugsnag</artifactId>
         </dependency>
 
+        <!-- Test dependencies -->
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <version>${junit-version}</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.mockito</groupId>
+            <artifactId>mockito-core</artifactId>
+            <version>4.11.0</version>
+            <scope>test</scope>
+        </dependency>
+
+        <!-- Servlet API for filters -->
+        <dependency>
+            <groupId>javax.servlet</groupId>
+            <artifactId>javax.servlet-api</artifactId>
+            <version>3.1.0</version>
+            <scope>provided</scope>
+        </dependency>
+
     </dependencies>
     <properties>
         <maven-plugin-version>1.0.0</maven-plugin-version>

src/main/java/io/swagger/petstore/client/ApiClientConfig.java

@@ -0,0 +1,101 @@
+/**
+ * Copyright 2018 SmartBear Software
+ * <p>
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * <p>
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.swagger.petstore.client;
+
+/**
+ * Configuration class for the PetStore API client.
+ * Supports builder pattern for fluent configuration.
+ *
+ * Usage:
+ * <pre>
+ *   ApiClientConfig config = ApiClientConfig.builder()
+ *       .baseUrl("http://localhost:8080/api/v3")
+ *       .apiKey("special-key")
+ *       .connectTimeout(5000)
+ *       .readTimeout(10000)
+ *       .build();
+ *   PetStoreClient client = new PetStoreClient(config);
+ * </pre>
+ */
+public class ApiClientConfig {
+
+    private String baseUrl;
+    private String apiKey;
+    private int connectTimeout;
+    private int readTimeout;
+
+    private ApiClientConfig(Builder builder) {
+        this.baseUrl = builder.baseUrl;
+        this.apiKey = builder.apiKey;
+        this.connectTimeout = builder.connectTimeout;
+        this.readTimeout = builder.readTimeout;
+    }
+
+    public static Builder builder() {
+        return new Builder();
+    }
+
+    public String getBaseUrl() {
+        return baseUrl;
+    }
+
+    public String getApiKey() {
+        return apiKey;
+    }
+
+    public int getConnectTimeout() {
+        return connectTimeout;
+    }
+
+    public int getReadTimeout() {
+        return readTimeout;
+    }
+
+    public static class Builder {
+        private String baseUrl = "http://localhost:8080/api/v3";
+        private String apiKey = "";
+        private int connectTimeout = 5000;
+        private int readTimeout = 10000;
+
+        public Builder baseUrl(String baseUrl) {
+            this.baseUrl = baseUrl;
+            return this;
+        }
+
+        public Builder apiKey(String apiKey) {
+            this.apiKey = apiKey;
+            return this;
+        }
+
+        public Builder connectTimeout(int millis) {
+            this.connectTimeout = millis;
+            return this;
+        }
+
+        public Builder readTimeout(int millis) {
+            this.readTimeout = millis;
+            return this;
+        }
+
+        public ApiClientConfig build() {
+            if (baseUrl == null || baseUrl.isEmpty()) {
+                throw new IllegalArgumentException("baseUrl is required");
+            }
+            return new ApiClientConfig(this);
+        }
+    }
+}

src/main/java/io/swagger/petstore/client/ApiResponse.java

@@ -0,0 +1,80 @@
+/**
+ * Copyright 2018 SmartBear Software
+ * <p>
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * <p>
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.swagger.petstore.client;
+
+/**
+ * Generic API response wrapper that encapsulates the HTTP status code,
+ * parsed response body, and raw response string.
+ *
+ * @param <T> The type of the parsed response body
+ */
+public class ApiResponse<T> {
+
+    private int statusCode;
+    private T body;
+    private String rawBody;
+
+    public ApiResponse() {
+    }
+
+    public ApiResponse(int statusCode, T body, String rawBody) {
+        this.statusCode = statusCode;
+        this.body = body;
+        this.rawBody = rawBody;
+    }
+
+    public int getStatusCode() {
+        return statusCode;
+    }
+
+    public void setStatusCode(int statusCode) {
+        this.statusCode = statusCode;
+    }
+
+    public T getBody() {
+        return body;
+    }
+
+    public void setBody(T body) {
+        this.body = body;
+    }
+
+    public String getRawBody() {
+        return rawBody;
+    }
+
+    public void setRawBody(String rawBody) {
+        this.rawBody = rawBody;
+    }
+
+    public boolean isSuccess() {
+        return statusCode >= 200 && statusCode < 300;
+    }
+
+    public boolean isClientError() {
+        return statusCode >= 400 && statusCode < 500;
+    }
+
+    public boolean isServerError() {
+        return statusCode >= 500;
+    }
+
+    @Override
+    public String toString() {
+        return "ApiResponse{statusCode=" + statusCode + ", body=" + rawBody + "}";
+    }
+}