Merge pull request #104 from cfg4j/builders

Add source builders and limit access to configuration source classes

cfg4j-consul/src/main/java/org/cfg4j/source/consul/ConsulConfigurationSource.java

@@ -24,47 +24,42 @@
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import java.net.URL;
 import java.nio.charset.StandardCharsets;
 import java.util.Base64;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Properties;
 
-public class ConsulConfigurationSource implements ConfigurationSource {
+/**
+ * Note: use {@link ConsulConfigurationSourceBuilder} for building instances of this class.
+ * <p>
+ * Read configuration from the Consul K-V store.
+ */
+class ConsulConfigurationSource implements ConfigurationSource {
 
   private static final Logger LOG = LoggerFactory.getLogger(ConsulConfigurationSource.class);
 
-  /**
-   * Default Consul HTTP API host.
-   */
-  public static final String DEFAULT_HTTP_HOST = "localhost";
-
-  /**
-   * Default Consul HTTP API port.
-   */
-  public static final int DEFAULT_HTTP_PORT = 8500;
-
   private final KeyValueClient kvClient;
   private Map<String, String> consulValues;
 
-  public ConsulConfigurationSource() {
-    this(DEFAULT_HTTP_HOST, DEFAULT_HTTP_PORT);
-  }
-
-  public ConsulConfigurationSource(URL url) {
-    this(url.getHost(), url.getPort());
-  }
-
-  private ConsulConfigurationSource(String host, int port) {
+  /**
+   * Note: use {@link ConsulConfigurationSourceBuilder} for building instances of this class.
+   * <p>
+   * Read configuration from the Consul K-V store located at {@code host}:{@code port}.
+   *
+   * @param host Consul host to connect to
+   * @param port Consul port to connect to
+   * @throws SourceCommunicationException when unable to connect to Consul client
+   */
+  ConsulConfigurationSource(String host, int port) {
     try {
       LOG.info("Connecting to Consul client at " + host + ":" + port);
 
       Consul consul = Consul.newClient(host, port);
       kvClient = consul.keyValueClient();
     } catch (Exception e) {
-      throw new SourceCommunicationException("Can't connect to host: " + host + ":" + port, e);
+      throw new SourceCommunicationException("Can't connect to host " + host + ":" + port, e);
     }
 
     reload();

cfg4j-consul/src/main/java/org/cfg4j/source/consul/ConsulConfigurationSourceBuilder.java

@@ -0,0 +1,78 @@
+/*
+ * Copyright 2015 Norbert Potocki (norbert.potocki@nort.pl)
+ *
+ * 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
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * 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 org.cfg4j.source.consul;
+
+/**
+ * Builder for {@link ConsulConfigurationSource}.
+ */
+public class ConsulConfigurationSourceBuilder {
+
+  private String host;
+  private int port;
+
+  /**
+   * Construct {@link ConsulConfigurationSource}s builder
+   * <p>
+   * Default setup (override using with*() methods)
+   * <ul>
+   * <li>host: localhost</li>
+   * <li>port: 8500</li>
+   * </ul>
+   */
+  public ConsulConfigurationSourceBuilder() {
+    host = "localhost";
+    port = 8500;
+  }
+
+  /**
+   * Set Consul host for {@link ConsulConfigurationSource}s built by this builder.
+   *
+   * @param host host to use
+   * @return this builder with Consul host set to provided parameter
+   */
+  public ConsulConfigurationSourceBuilder withHost(String host) {
+    this.host = host;
+    return this;
+  }
+
+  /**
+   * Set Consul port for {@link ConsulConfigurationSource}s built by this builder.
+   *
+   * @param port port to use
+   * @return this builder with Consul port set to provided parameter
+   */
+  public ConsulConfigurationSourceBuilder withPort(int port) {
+    this.port = port;
+    return this;
+  }
+
+  /**
+   * Build a {@link ConsulConfigurationSource} using this builder's configuration
+   *
+   * @return new {@link ConsulConfigurationSource}
+   */
+  public ConsulConfigurationSource build() {
+    return new ConsulConfigurationSource(host, port);
+  }
+
+  @Override
+  public String toString() {
+    return "ConsulConfigurationSource{" +
+        "host=" + host +
+        ", port=" + port +
+        '}';
+  }
+}

cfg4j-consul/src/test/java/org/cfg4j/source/consul/ConsulConfigurationSourceIntegrationTest.java

@@ -34,7 +34,6 @@
 import org.mockito.runners.MockitoJUnitRunner;
 
 import java.io.IOException;
-import java.net.URL;
 import java.util.concurrent.TimeUnit;
 
 
@@ -83,27 +82,20 @@ public MockResponse dispatch(RecordedRequest request) throws InterruptedExceptio
   @Before
   public void setUp() throws Exception {
     dispatcher = new ModifiableDispatcher();
-    runMockServerOnPort(ConsulConfigurationSource.DEFAULT_HTTP_PORT);
-    source = new ConsulConfigurationSource(server.getUrl(""));
+    runMockServer();
+    source = new ConsulConfigurationSourceBuilder()
+        .withHost(server.getHostName())
+        .withPort(server.getPort())
+        .build();
   }
 
   @After
   public void tearDown() throws Exception {
     server.shutdown();
   }
 
-  @Test
-  public void shouldConnectToLocalhostAgentByDefault() throws Exception {
-    source = new ConsulConfigurationSource();
-    RecordedRequest request = server.takeRequest(0, TimeUnit.MILLISECONDS);
-    assertThat(request).isNotNull();
-  }
-
   @Test
   public void shouldConnectToSpecifiedAgent() throws Exception {
-    server.shutdown();
-    runMockServerOnPort(ConsulConfigurationSource.DEFAULT_HTTP_PORT + 1);
-    source = new ConsulConfigurationSource(new URL("http", "localhost", ConsulConfigurationSource.DEFAULT_HTTP_PORT + 1, ""));
     RecordedRequest request = server.takeRequest(0, TimeUnit.MILLISECONDS);
     assertThat(request).isNotNull();
   }
@@ -112,31 +104,28 @@ public void shouldConnectToSpecifiedAgent() throws Exception {
   public void shouldThrowOnConnectionFailure() throws Exception {
     server.shutdown();
     expectedException.expect(SourceCommunicationException.class);
-    source = new ConsulConfigurationSource();
-  }
-
-  @Test
-  public void shouldThrowOnConnectionFailure2() throws Exception {
-    expectedException.expect(SourceCommunicationException.class);
-    source = new ConsulConfigurationSource(new URL("http", "localhost", ConsulConfigurationSource.DEFAULT_HTTP_PORT + 1, ""));
+    source = new ConsulConfigurationSourceBuilder()
+        .withHost(server.getHostName())
+        .withPort(server.getPort())
+        .build();
   }
 
   @Test
-  public void getConfiguration2ShouldReturnAllKeysFromGivenEnvironment() throws Exception {
+  public void getConfigurationShouldReturnAllKeysFromGivenEnvironment() throws Exception {
     Environment environment = new ImmutableEnvironment("us-west-1");
 
     assertThat(source.getConfiguration(environment)).contains(MapEntry.entry("featureA.toggle", "disabled"));
   }
 
   @Test
-  public void getConfiguration2ShouldIgnoreLeadginSlashInGivenEnvironment() throws Exception {
+  public void getConfigurationShouldIgnoreLeadginSlashInGivenEnvironment() throws Exception {
     Environment environment = new ImmutableEnvironment("/us-west-1");
 
     assertThat(source.getConfiguration(environment)).contains(MapEntry.entry("featureA.toggle", "disabled"));
   }
 
   @Test
-  public void getConfiguration2ShouldBeUpdatedByReload() throws Exception {
+  public void getConfigurationShouldBeUpdatedByReload() throws Exception {
     dispatcher.toggleUsWest2();
 
     source.reload();
@@ -152,9 +141,9 @@ public void reloadShouldThrowOnConnectionFailure() throws Exception {
     source.reload();
   }
 
-  private void runMockServerOnPort(int port) throws IOException {
+  private void runMockServer() throws IOException {
     server = new MockWebServer();
     server.setDispatcher(dispatcher);
-    server.start(port);
+    server.start(0);
   }
 }

cfg4j-core/src/main/java/org/cfg4j/provider/SimpleConfigurationProvider.java

@@ -30,20 +30,21 @@
 import java.util.Properties;
 
 /**
- * Basic implementation of {@link ConfigurationProvider}
+ * Basic implementation of {@link ConfigurationProvider}. To construct this provider use {@link ConfigurationProviderBuilder}.
  */
-public class SimpleConfigurationProvider implements ConfigurationProvider {
+class SimpleConfigurationProvider implements ConfigurationProvider {
 
   private final ConfigurationSource configurationSource;
   private final Environment environment;
 
   /**
    * {@link ConfigurationProvider} backed by provided {@link ConfigurationSource} and using {@code environment}
-   * to select environment.
+   * to select environment. To construct this provider use {@link ConfigurationProviderBuilder}.
+   *
    * @param configurationSource source for configuration
-   * @param environment {@link Environment} to use
+   * @param environment         {@link Environment} to use
    */
-  public SimpleConfigurationProvider(ConfigurationSource configurationSource, Environment environment) {
+  SimpleConfigurationProvider(ConfigurationSource configurationSource, Environment environment) {
     this.configurationSource = requireNonNull(configurationSource);
     this.environment = requireNonNull(environment);
   }

cfg4j-git/src/main/java/org/cfg4j/source/git/GitConfigurationSource.java

@@ -44,7 +44,12 @@
 import java.util.stream.Collectors;
 import java.util.stream.StreamSupport;
 
-public class GitConfigurationSource implements ConfigurationSource, Closeable {
+/**
+ * Note: use {@link GitConfigurationSourceBuilder} for building instances of this class.
+ * <p>
+ * Read configuration from the remote GIT repository. Keeps a local clone of the repository.
+ */
+class GitConfigurationSource implements ConfigurationSource, Closeable {
 
   private static final Logger LOG = LoggerFactory.getLogger(GitConfigurationSource.class);