change from builder to constructor

Author: MarketDataDev03

CHANGELOG.md

@@ -10,12 +10,15 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Added
 - Project scaffold per ADRs 001–006: Gradle Kotlin DSL build, JDK 17 toolchain,
   `integrationTest` source set, Spotless + JaCoCo, Vanniktech Maven Publish.
-- `MarketDataClient` skeleton with builder, default base URL
-  (`https://api.marketdata.app`), default API version (`v1`), 99 s request /
-  2 s connect timeouts, HTTP/2, demo mode, `validateOnStartup` toggle, and a
-  50-permit concurrency semaphore (wiring lands with the request layer).
-- Configuration cascade: explicit builder values → `MARKETDATA_*` environment
-  variables → `.env` file in CWD → built-in defaults.
+- `MarketDataClient` skeleton with two public constructors — a no-arg one
+  for production (everything resolved from the cascade) and a 4-arg one
+  (`apiKey`, `baseUrl`, `apiVersion`, `validateOnStartup`) for tests and
+  short-lived runtimes. Default base URL (`https://api.marketdata.app`),
+  default API version (`v1`), 99 s request / 2 s connect timeouts, HTTP/2,
+  demo mode, `validateOnStartup` toggle, and a 50-permit concurrency
+  semaphore (wiring lands with the request layer).
+- Configuration cascade: explicit constructor parameters → `MARKETDATA_*`
+  environment variables → `.env` file in CWD → built-in defaults.
 - Sealed `MarketDataException` hierarchy with the seven canonical subtypes
   (`AuthenticationError`, `BadRequestError`, `NotFoundError`, `RateLimitError`,
   `ServerError`, `NetworkError`, `ParseError`), each carrying support context

CLAUDE.md

@@ -60,9 +60,9 @@ If you find yourself reaching for Lombok, AutoValue, or an abstract-base excepti
 The Java SDK must also satisfy the canonical, cross-language [SDK Requirements](https://www.marketdata.app/docs/sdk/sdk-requirements/) (referenced from inside the ADRs as `../sdk-requirements.md`). The current scaffold applies the **foundational** rules from that doc; per-endpoint and per-request rules land alongside the request layer. Specifically:
 
 **Already wired in:**
-- §1.1 client object — `MarketDataClient` builder, default base URL `https://api.marketdata.app`, default API version `v1`, single shared `HttpClient`, `User-Agent: marketdata-sdk-java/{version}` (version auto-detected from JAR manifest), `close()` for resource release, `getRateLimits()` accessor.
-- §4 configuration cascade — `Configuration.resolve(...)` does explicit → `MARKETDATA_*` env var → `.env` in CWD → default. Env var names live in `internal.EnvVars`.
-- §5 demo mode + `validateOnStartup` toggle on the builder; token redaction via `internal.Tokens.redact` (matches the spec example `***…***YKT0`).
+- §1.1 client object — `MarketDataClient` with two public constructors: a no-arg one for production (everything from the cascade) and a 4-arg `(apiKey, baseUrl, apiVersion, validateOnStartup)` for tests and short-lived runtimes. All fields `final` (immutable). Default base URL `https://api.marketdata.app`, default API version `v1`, single shared `HttpClient`, `User-Agent: marketdata-sdk-java/{version}` (version auto-detected from JAR manifest), `close()` for resource release, `getRateLimits()` accessor.
+- §4 configuration cascade — `Configuration.resolve(...)` does explicit → `MARKETDATA_*` env var → `.env` in CWD → default. Env var names live in `internal.EnvVars`. The 4-arg constructor's parameters feed step 1; the no-arg constructor skips it and starts at step 2.
+- §5 demo mode + `validateOnStartup` parameter on the 4-arg constructor (defaults to `true` via the no-arg constructor); token redaction via `internal.Tokens.redact` (matches the spec example `***…***YKT0`).
 - §6 sealed `MarketDataException` hierarchy with the 7 canonical subtypes and full support context (`requestId`, `requestUrl`, `statusCode`, `timestamp`, `exceptionType`) + `getSupportInfo()`.
 - §10 timeouts: `REQUEST_TIMEOUT = 99s` and `CONNECT_TIMEOUT = 2s` exposed as constants on `MarketDataClient`. Connect timeout is wired into the `HttpClient`; the per-request 99 s timeout is a constant ready to be applied to `HttpRequest.Builder#timeout` when the request layer lands.
 - §12 concurrency: `Semaphore(50)` field on `MarketDataClient` (wiring of acquire/release lands with the request layer).

README.md

@@ -32,15 +32,15 @@ common path is two lines (per SDK requirements §"Easy Default Requests"):
 ### Java
 
 ```java
-try (var client = MarketDataClient.builder().build()) {
+try (var client = new MarketDataClient()) {
     // endpoint methods land in subsequent iterations
 }
 ```
 
 ### Kotlin
 
 ```kotlin
-MarketDataClient.builder().build().use { client ->
+MarketDataClient().use { client ->
     // endpoint methods land in subsequent iterations
 }
 ```
@@ -50,7 +50,9 @@ MarketDataClient.builder().build().use { client ->
 Values are resolved through this cascade (highest priority first), per
 SDK requirements §4:
 
-1. Explicit builder methods — `apiKey(...)`, `baseUrl(...)`, `apiVersion(...)`
+1. Explicit constructor parameters — `apiKey`, `baseUrl`, `apiVersion`
+   (passed to `new MarketDataClient(apiKey, baseUrl, apiVersion, validateOnStartup)`;
+   the no-arg `new MarketDataClient()` skips this step and starts at #2)
 2. Environment variables (table below)
 3. `.env` file in the current working directory
 4. Built-in defaults

docs/java-sdk-requirements.md

@@ -118,9 +118,12 @@ The README and per-method docs must include at least one Kotlin usage
 example alongside the Java example for the quick-start path:
 
 ```kotlin
-val client = MarketDataClient.builder()
-    .apiKey("KEY")
-    .build()
+val client = MarketDataClient(
+    apiKey = "KEY",
+    baseUrl = null,
+    apiVersion = null,
+    validateOnStartup = true,
+)
 
 val quote = client.stocks().quote("AAPL")
 println(quote)

src/main/java/com/marketdata/sdk/MarketDataClient.java

@@ -19,10 +19,19 @@
  * (HTTP/2, 2 s connect timeout) for connection pooling (ADR-004) and a 50-permit semaphore that
  * gates the global concurrency pool required by SDK requirements §12.
  *
- * <p>Construction follows the configuration cascade in §4: explicit builder values → {@code
- * MARKETDATA_*} environment variables → values in a {@code .env} file in the working directory →
- * built-in defaults. Pass no token to enter <em>demo mode</em> (authenticated endpoints will fail;
- * the {@code Authorization} header is omitted).
+ * <p>Two constructors:
+ *
+ * <ul>
+ *   <li>{@link #MarketDataClient()} — production path. Resolves everything from the cascade in §4
+ *       ({@code MARKETDATA_*} environment variable → value in a {@code .env} file → built-in
+ *       default). With no token in the cascade, enters <em>demo mode</em> — authenticated endpoints
+ *       will fail and the {@code Authorization} header is omitted.
+ *   <li>{@link #MarketDataClient(String, String, String, boolean)} — explicit-control path for
+ *       tests and short-lived runtimes. Each parameter may still be {@code null} to defer to the
+ *       cascade for that single value.
+ * </ul>
+ *
+ * <p>Instances are immutable: every field is {@code final} and assigned in the constructor.
  */
 public final class MarketDataClient implements AutoCloseable {
 
@@ -48,18 +57,46 @@ public final class MarketDataClient implements AutoCloseable {
   private final boolean demoMode;
   private final boolean validateOnStartup;
 
-  private MarketDataClient(Builder builder) {
+  /**
+   * Production constructor. Resolves all settings from the configuration cascade in SDK
+   * requirements §4 (env var → {@code .env} → built-in default) and enables startup validation.
+   *
+   * <p>Equivalent to {@link #MarketDataClient(String, String, String, boolean) new
+   * MarketDataClient(null, null, null, true)}.
+   */
+  public MarketDataClient() {
+    this(null, null, null, true);
+  }
+
+  /**
+   * Explicit-control constructor for tests and short-lived runtimes. Each of {@code apiKey}, {@code
+   * baseUrl}, and {@code apiVersion} may be {@code null} to defer to the cascade in §4 for that
+   * single value.
+   *
+   * @param apiKey explicit API token, or {@code null} to resolve from {@code MARKETDATA_TOKEN} →
+   *     {@code .env} → demo mode
+   * @param baseUrl override the API base URL, or {@code null} to resolve to {@link
+   *     Configuration#DEFAULT_BASE_URL}
+   * @param apiVersion override the API version segment, or {@code null} to resolve to {@link
+   *     Configuration#DEFAULT_API_VERSION}
+   * @param validateOnStartup whether to validate the token on construction by calling {@code
+   *     /user/} (SDK requirements §5). Pass {@code false} for short-lived runtimes where the
+   *     startup hit is undesirable.
+   */
+  public MarketDataClient(
+      @Nullable String apiKey,
+      @Nullable String baseUrl,
+      @Nullable String apiVersion,
+      boolean validateOnStartup) {
     Configuration config = Configuration.loadFromProcess();
-    this.token = config.resolve(builder.apiKey, EnvVars.TOKEN);
+    this.token = config.resolve(apiKey, EnvVars.TOKEN);
     this.baseUrl =
         trimTrailingSlash(
-            config.resolveOrDefault(
-                builder.baseUrl, EnvVars.BASE_URL, Configuration.DEFAULT_BASE_URL));
+            config.resolveOrDefault(baseUrl, EnvVars.BASE_URL, Configuration.DEFAULT_BASE_URL));
     this.apiVersion =
-        config.resolveOrDefault(
-            builder.apiVersion, EnvVars.API_VERSION, Configuration.DEFAULT_API_VERSION);
+        config.resolveOrDefault(apiVersion, EnvVars.API_VERSION, Configuration.DEFAULT_API_VERSION);
     this.demoMode = this.token == null;
-    this.validateOnStartup = builder.validateOnStartup;
+    this.validateOnStartup = validateOnStartup;
     this.userAgent = "marketdata-sdk-java/" + Version.current();
 
     this.httpClient =
@@ -73,23 +110,19 @@ private MarketDataClient(Builder builder) {
     LOG.log(
         Level.INFO,
         "Initialized Market Data SDK {0} (baseUrl={1}, apiVersion={2}, demoMode={3})",
-        new Object[] {Version.current(), baseUrl, apiVersion, demoMode});
-    if (demoMode) {
+        new Object[] {Version.current(), this.baseUrl, this.apiVersion, this.demoMode});
+    if (this.demoMode) {
       LOG.warning(
           "No API token provided — running in demo mode. Authenticated endpoints will"
               + " fail; rate-limit initialization is skipped.");
     } else if (LOG.isLoggable(Level.FINE)) {
-      LOG.log(Level.FINE, "Token: {0}", Tokens.redact(token));
+      LOG.log(Level.FINE, "Token: {0}", Tokens.redact(this.token));
     }
 
     // SDK requirements §5: validate on startup by default. The actual
     // /user/ call lands with the request layer; this flag is the seam.
   }
 
-  public static Builder builder() {
-    return new Builder();
-  }
-
   public String getBaseUrl() {
     return baseUrl;
   }
@@ -126,45 +159,4 @@ public void close() {
   private static String trimTrailingSlash(String url) {
     return url.endsWith("/") ? url.substring(0, url.length() - 1) : url;
   }
-
-  public static final class Builder {
-    private @Nullable String apiKey;
-    private @Nullable String baseUrl;
-    private @Nullable String apiVersion;
-    private boolean validateOnStartup = true;
-
-    private Builder() {}
-
-    /** Override the API token; otherwise resolved from {@code MARKETDATA_TOKEN} or {@code .env}. */
-    public Builder apiKey(String apiKey) {
-      this.apiKey = apiKey;
-      return this;
-    }
-
-    /** Override the base URL (default {@value Configuration#DEFAULT_BASE_URL}). */
-    public Builder baseUrl(String baseUrl) {
-      this.baseUrl = baseUrl;
-      return this;
-    }
-
-    /** Override the API version (default {@value Configuration#DEFAULT_API_VERSION}). */
-    public Builder apiVersion(String apiVersion) {
-      this.apiVersion = apiVersion;
-      return this;
-    }
-
-    /**
-     * Whether to validate the token at construction by calling {@code /user/} (SDK requirements
-     * §5). Defaults to {@code true}. Disable for short-lived runtimes where the startup hit is
-     * undesirable.
-     */
-    public Builder validateOnStartup(boolean validateOnStartup) {
-      this.validateOnStartup = validateOnStartup;
-      return this;
-    }
-
-    public MarketDataClient build() {
-      return new MarketDataClient(this);
-    }
-  }
 }

src/test/java/com/marketdata/sdk/MarketDataClientTest.java

@@ -9,7 +9,7 @@ class MarketDataClientTest {
 
   @Test
   void buildsWithExplicitToken() {
-    try (var client = MarketDataClient.builder().apiKey("test-key").build()) {
+    try (var client = new MarketDataClient("test-key", null, null, true)) {
       assertThat(client.isDemoMode()).isFalse();
       assertThat(client.getBaseUrl()).isEqualTo(Configuration.DEFAULT_BASE_URL);
       assertThat(client.getApiVersion()).isEqualTo(Configuration.DEFAULT_API_VERSION);
@@ -18,26 +18,41 @@ void buildsWithExplicitToken() {
 
   @Test
   void demoModeWhenNoTokenAvailable() {
-    // No apiKey set on the builder. Demo mode iff the env/dotenv
+    // No apiKey passed to the constructor. Demo mode iff the env/dotenv
     // cascade also yields nothing — true on any CI environment that
     // doesn't export MARKETDATA_TOKEN. This assertion is conditional
     // so the test stays valid in both cases.
-    try (var client = MarketDataClient.builder().build()) {
+    try (var client = new MarketDataClient()) {
       String envToken = System.getenv("MARKETDATA_TOKEN");
       boolean expectDemo = envToken == null || envToken.isBlank();
       assertThat(client.isDemoMode()).isEqualTo(expectDemo);
     }
   }
 
+  @Test
+  void noArgConstructorAppliesProductionDefaults() {
+    // The no-arg constructor must be equivalent to `new MarketDataClient(null, null, null,
+    // true)` — production path with everything resolved from the cascade and startup
+    // validation enabled. validateOnStartup and the userAgent format are env-independent,
+    // so we assert them unconditionally; baseUrl/apiVersion fall back to the documented
+    // defaults only when the cascade has no override, so we gate those assertions on the
+    // env vars being unset (mirrors the demo-mode test above).
+    try (var client = new MarketDataClient()) {
+      assertThat(client.isValidateOnStartup()).isTrue();
+      assertThat(client.getUserAgent()).startsWith("marketdata-sdk-java/");
+
+      if (System.getenv("MARKETDATA_BASE_URL") == null) {
+        assertThat(client.getBaseUrl()).isEqualTo(Configuration.DEFAULT_BASE_URL);
+      }
+      if (System.getenv("MARKETDATA_API_VERSION") == null) {
+        assertThat(client.getApiVersion()).isEqualTo(Configuration.DEFAULT_API_VERSION);
+      }
+    }
+  }
+
   @Test
   void overridesAreHonored() {
-    try (var client =
-        MarketDataClient.builder()
-            .apiKey("KEY")
-            .baseUrl("https://example.test/")
-            .apiVersion("v2")
-            .validateOnStartup(false)
-            .build()) {
+    try (var client = new MarketDataClient("KEY", "https://example.test/", "v2", false)) {
       assertThat(client.getBaseUrl()).isEqualTo("https://example.test"); // trailing slash trimmed
       assertThat(client.getApiVersion()).isEqualTo("v2");
       assertThat(client.isValidateOnStartup()).isFalse();
@@ -46,14 +61,14 @@ void overridesAreHonored() {
 
   @Test
   void userAgentMatchesSpec() {
-    try (var client = MarketDataClient.builder().apiKey("KEY").build()) {
+    try (var client = new MarketDataClient("KEY", null, null, true)) {
       assertThat(client.getUserAgent()).startsWith("marketdata-sdk-java/");
     }
   }
 
   @Test
   void rateLimitsStartUnpopulated() {
-    try (var client = MarketDataClient.builder().apiKey("KEY").build()) {
+    try (var client = new MarketDataClient("KEY", null, null, true)) {
       assertThat(client.getRateLimits()).isNull();
     }
   }