Merge pull request #52 from nort/multi-env

support multiple environments

build.gradle

@@ -20,7 +20,7 @@ buildscript {
     ext {
         artifactGroup = "pl.nort"
         artifactName = "config"
-        artifactVersion = "1.2.0-SNAPSHOT"
+        artifactVersion = "2.0.0-SNAPSHOT"
     }
 
     repositories {

src/main/java/pl/nort/config/provider/ConfigurationProviderBuilder.java

@@ -19,6 +19,8 @@
 import org.slf4j.LoggerFactory;
 import pl.nort.config.source.ConfigurationSource;
 import pl.nort.config.source.EmptyConfigurationSource;
+import pl.nort.config.source.context.DefaultEnvironment;
+import pl.nort.config.source.context.Environment;
 import pl.nort.config.source.refresh.RefreshStrategy;
 import pl.nort.config.source.refresh.strategy.OnInitRefreshStrategy;
 
@@ -33,6 +35,7 @@ public class ConfigurationProviderBuilder {
 
   private ConfigurationSource configurationSource;
   private RefreshStrategy refreshStrategy;
+  private Environment environment;
 
   /**
    * Construct {@link ConfigurationProvider}s builder
@@ -41,11 +44,13 @@ public class ConfigurationProviderBuilder {
    * <ul>
    * <li>ConfigurationSource: {@link EmptyConfigurationSource}</li>
    * <li>RefreshStrategy: {@link OnInitRefreshStrategy}</li>
+   * <li>Environment: {@link DefaultEnvironment}</li>
    * </ul>
    */
   public ConfigurationProviderBuilder() {
     configurationSource = new EmptyConfigurationSource();
     refreshStrategy = new OnInitRefreshStrategy();
+    environment = new DefaultEnvironment();
   }
 
   /**
@@ -70,18 +75,30 @@ public ConfigurationProviderBuilder withRefreshStrategy(RefreshStrategy refreshS
     return this;
   }
 
+  /**
+   * Set {@link Environment} for {@link ConfigurationProviders}s built by this builder
+   *
+   * @param environment {@link Environment} to use
+   * @return this builder with {@link Environment} set to {@code environment}
+   */
+  public ConfigurationProviderBuilder withEnvironment(Environment environment) {
+    this.environment = environment;
+    return this;
+  }
+
   /**
    * Build a {@link ConfigurationProvider} using this builder's configuration
    *
    * @return new {@link ConfigurationProvider}
    */
   public ConfigurationProvider build() {
-    LOG.info("Initializing ConfigurationProvider with " + configurationSource.getClass() + " source and " +
-        refreshStrategy.getClass() + " refresh strategy.");
+    LOG.info("Initializing ConfigurationProvider with " + configurationSource.getClass() + " source, " +
+        refreshStrategy.getClass() + " refresh strategy and " + environment.getClass() + " environment" +
+        "selection strategy.");
 
     refreshStrategy.init(configurationSource);
 
-    return new SimpleConfigurationProvider(configurationSource);
+    return new SimpleConfigurationProvider(configurationSource, environment);
   }
 
 }

src/main/java/pl/nort/config/provider/ConfigurationProviders.java

@@ -16,7 +16,9 @@
 package pl.nort.config.provider;
 
 import pl.nort.config.source.ConfigurationSource;
-import pl.nort.config.source.GitConfigurationSource;
+import pl.nort.config.source.context.Environment;
+import pl.nort.config.source.git.GitConfigurationSource;
+import pl.nort.config.source.git.GitConfigurationSourceBuilder;
 
 /**
  * A factory producing {@link ConfigurationProvider}s.
@@ -31,7 +33,25 @@ public class ConfigurationProviders {
    */
   public static ConfigurationProvider backedByGit(String repositoryURI) {
     return new ConfigurationProviderBuilder()
-        .withConfigurationSource(new GitConfigurationSource(repositoryURI))
+        .withConfigurationSource(new GitConfigurationSourceBuilder()
+            .withRepositoryURI(repositoryURI)
+            .build())
+        .build();
+  }
+
+  /**
+   * A {@link ConfigurationProvider} backed by {@link GitConfigurationSource} and using {@code environment}.
+   *
+   * @param repositoryURI a git repository URI (can be remote)
+   * @param environment   {@link Environment} to use
+   * @return {@link ConfigurationProvider} using provided git repository as a {@link ConfigurationSource}
+   */
+  public static ConfigurationProvider backedByGit(String repositoryURI, Environment environment) {
+    return new ConfigurationProviderBuilder()
+        .withConfigurationSource(new GitConfigurationSourceBuilder()
+            .withRepositoryURI(repositoryURI)
+            .build())
+        .withEnvironment(environment)
         .build();
   }
 
@@ -47,4 +67,18 @@ public static ConfigurationProvider withSource(ConfigurationSource source) {
         .build();
   }
 
+  /**
+   * A {@link ConfigurationProvider} backed by a provided {@link ConfigurationSource} and using {@code environment}.
+   *
+   * @param source      {@link ConfigurationSource} used to supply provider with configuration
+   * @param environment {@link Environment} to use
+   * @return {@link ConfigurationProvider} backed by a {@code source}
+   */
+  public static ConfigurationProvider withSource(ConfigurationSource source, Environment environment) {
+    return new ConfigurationProviderBuilder()
+        .withConfigurationSource(source)
+        .withEnvironment(environment)
+        .build();
+  }
+
 }

src/main/java/pl/nort/config/provider/SimpleConfigurationProvider.java

@@ -20,9 +20,9 @@
 import com.github.drapostolos.typeparser.NoSuchRegisteredParserException;
 import com.github.drapostolos.typeparser.TypeParser;
 import com.github.drapostolos.typeparser.TypeParserException;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 import pl.nort.config.source.ConfigurationSource;
+import pl.nort.config.source.context.Environment;
+import pl.nort.config.source.context.MissingEnvironmentException;
 import pl.nort.config.validator.BindingValidator;
 
 import java.lang.reflect.InvocationHandler;
@@ -38,21 +38,24 @@
 public class SimpleConfigurationProvider implements ConfigurationProvider {
 
   private final ConfigurationSource configurationSource;
+  private final Environment environment;
 
   /**
-   * {@link ConfigurationProvider} backed by provided {@link ConfigurationSource}
-   *
+   * {@link ConfigurationProvider} backed by provided {@link ConfigurationSource} and using {@code environment}
+   * to select environment.
    * @param configurationSource source for configuration
+   * @param environment {@link Environment} to use
    */
-  public SimpleConfigurationProvider(ConfigurationSource configurationSource) {
+  public SimpleConfigurationProvider(ConfigurationSource configurationSource, Environment environment) {
     this.configurationSource = checkNotNull(configurationSource);
+    this.environment = checkNotNull(environment);
   }
 
   @Override
   public Properties allConfigurationAsProperties() {
     try {
-      return configurationSource.getConfiguration();
-    } catch (IllegalStateException e) {
+      return configurationSource.getConfiguration(environment);
+    } catch (IllegalStateException | MissingEnvironmentException e) {
       throw new IllegalStateException("Couldn't fetch configuration from configuration source", e);
     }
   }

src/main/java/pl/nort/config/source/ConfigurationSource.java

@@ -15,6 +15,8 @@
  */
 package pl.nort.config.source;
 
+import pl.nort.config.source.context.Environment;
+import pl.nort.config.source.context.MissingEnvironmentException;
 import pl.nort.config.source.refresh.Refreshable;
 
 import java.util.Properties;
@@ -25,11 +27,20 @@
 public interface ConfigurationSource extends Refreshable {
 
   /**
-   * Get full configuration set from this source in a form of {@link Properties}.
+   * Get configuration set from this source in a form of {@link Properties}. Uses default environment.
    *
-   * @return full configuration set
+   * @return configuration set for default environment
    * @throws IllegalStateException when unable to fetch configuration
    */
   Properties getConfiguration();
 
+  /**
+   * Get configuration set for a given environment from this source in a form of {@link Properties}.
+   * Provided {@link Environment} will be used to determine which environment to use.
+   *
+   * @return full configuration set
+   * @throws MissingEnvironmentException when requested environment couldn't be found
+   * @throws IllegalStateException when unable to fetch configuration
+   */
+  Properties getConfiguration(Environment environment);
 }

src/main/java/pl/nort/config/source/EmptyConfigurationSource.java

@@ -15,20 +15,27 @@
  */
 package pl.nort.config.source;
 
+import pl.nort.config.source.context.Environment;
+
 import java.util.Properties;
 
 /**
  * Empty {@link ConfigurationSource}
  */
 public class EmptyConfigurationSource implements ConfigurationSource {
 
-  private final Properties properties = new Properties();
+  private static final Properties properties = new Properties();
 
   @Override
   public Properties getConfiguration() {
     return properties;
   }
 
+  @Override
+  public Properties getConfiguration(Environment environment) {
+    return properties;
+  }
+
   @Override
   public void refresh() {
     // NOP

src/main/java/pl/nort/config/source/context/DefaultEnvironment.java

@@ -0,0 +1,28 @@
+/*
+ * 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 pl.nort.config.source.context;
+
+/**
+ * Environment named "" (empty string).
+ */
+public class DefaultEnvironment extends ImmutableEnvironment {
+  /**
+   * Constructs environment named "" (empty string).
+   */
+  public DefaultEnvironment() {
+    super("");
+  }
+}

src/main/java/pl/nort/config/source/context/Environment.java

@@ -0,0 +1,30 @@
+/*
+ * 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 pl.nort.config.source.context;
+
+/**
+ * Configuration environment.
+ */
+public interface Environment {
+
+  /**
+   * Name of the environment.
+   *
+   * @return environment name
+   */
+  String getName();
+
+}

src/main/java/pl/nort/config/source/context/ImmutableEnvironment.java

@@ -0,0 +1,40 @@
+/*
+ * 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 pl.nort.config.source.context;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+/**
+ * {@link Environment} that never changes.
+ */
+public class ImmutableEnvironment implements Environment {
+
+  private final String envName;
+
+  /**
+   * Construct environment named {@code envName}. This name never changes.
+   *
+   * @param envName environment name to use
+   */
+  public ImmutableEnvironment(String envName) {
+    this.envName = checkNotNull(envName);
+  }
+
+  @Override
+  public String getName() {
+    return envName;
+  }
+}

src/main/java/pl/nort/config/source/context/MissingEnvironmentException.java

@@ -0,0 +1,34 @@
+/*
+ * 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 pl.nort.config.source.context;
+
+/**
+ * Indicates missing configuration environment
+ */
+public class MissingEnvironmentException extends RuntimeException {
+
+  private static final String MISSING_ENV_MSG = "Missing environment: ";
+
+  /**
+   * Environment named {@code envName} is missing.
+   *
+   * @param envName environment name
+   * @param cause root cause
+   */
+  public MissingEnvironmentException(String envName, Throwable cause) {
+    super(MISSING_ENV_MSG + envName, cause);
+  }
+}