Initial commit

src/main/java/org/scribe/builder/ServiceBuilder.java

@@ -0,0 +1,107 @@
+package org.scribe.builder;
+
+import org.scribe.builder.api.*;
+import org.scribe.exceptions.*;
+
+import org.scribe.model.*;
+import org.scribe.oauth.*;
+import org.scribe.utils.*;
+
+/**
+ * Implementation of the Builder pattern, with a fluent interface that creates a
+ * {@link OAuthService}
+ * 
+ * @author Pablo Fernandez
+ *
+ */
+public class ServiceBuilder
+{
+  private String apiKey;
+  private String apiSecret;
+  private String callback;
+  private Api api;
+  
+  public ServiceBuilder()
+  {
+    this.callback = OAuthConstants.OUT_OF_BAND;
+  }
+  
+  /**
+   * Configures the {@link Api}
+   * 
+   * @param apiClass the class of one of the existent {@link Api}s on org.scribe.api package
+   * @return the {@link ServiceBuilder} instance for method chaining
+   */
+  public ServiceBuilder provider(Class<? extends Api> apiClass)
+  {
+    this.api = createApi(apiClass);
+    return this;
+  }
+
+  private Api createApi(Class<? extends Api> apiClass)
+  {
+    Preconditions.checkNotNull(apiClass, "Api class cannot be null");
+    Api api;
+    try
+    {
+      api = apiClass.newInstance();  
+    }
+    catch(Exception e)
+    {
+      throw new OAuthException("Error while creating the Api object", e);
+    }
+    return api;
+  }
+  
+  /**
+   * Adds an OAuth callback url
+   * 
+   * @param callback callback url. Must be a valid url or 'oob' for out of band OAuth
+   * @return the {@link ServiceBuilder} instance for method chaining
+   */
+  public ServiceBuilder callback(String callback)
+  {
+    Preconditions.checkValidOAuthCallback(callback, "Callback must be a valid URL or 'oob'");
+    this.callback = callback;
+    return this;
+  }
+  
+  /**
+   * Configures the api key
+   * 
+   * @param apiKey The api key for your application
+   * @return the {@link ServiceBuilder} instance for method chaining
+   */
+  public ServiceBuilder apiKey(String apiKey)
+  {
+    Preconditions.checkEmptyString(apiKey, "Invalid Api key");
+    this.apiKey = apiKey;
+    return this;
+  }
+  
+  /**
+   * Configures the api secret
+   * 
+   * @param apiSecret The api secret for your application
+   * @return the {@link ServiceBuilder} instance for method chaining
+   */
+  public ServiceBuilder apiSecret(String apiSecret)
+  {
+    Preconditions.checkEmptyString(apiSecret, "Invalid Api secret");
+    this.apiSecret = apiSecret;
+    return this;
+  }
+  
+  /**
+   * Returns the fully configured {@link OAuthService}
+   * 
+   * @return fully configured {@link OAuthService}
+   */
+  public OAuthService build()
+  {
+    Preconditions.checkNotNull(api, "You must specify a valid api through the provider() method");
+    Preconditions.checkEmptyString(apiKey, "You must provide an api key");
+    Preconditions.checkEmptyString(apiSecret, "You must provide an api secret");
+    return api.createService(apiKey, apiSecret, callback);
+  }
+}