functions for regions

core/src/main/java/org/jclouds/location/functions/RegionToEndpoint.java

@@ -0,0 +1,60 @@
+/**
+ * Licensed to jclouds, Inc. (jclouds) under one or more
+ * contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  jclouds licenses this file
+ * to you 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.jclouds.location.functions;
+
+import static com.google.common.base.Preconditions.checkArgument;
+import static com.google.common.base.Preconditions.checkNotNull;
+import static com.google.common.base.Preconditions.checkState;
+
+import java.net.URI;
+import java.util.Map;
+
+import javax.inject.Inject;
+import javax.inject.Singleton;
+
+import org.jclouds.javax.annotation.Nullable;
+import org.jclouds.location.Region;
+
+import com.google.common.base.Function;
+import com.google.common.base.Supplier;
+
+/**
+ * 
+ * @author Adrian Cole
+ */
+@Singleton
+public class RegionToEndpoint implements Function<Object, URI> {
+
+   private final Supplier<Map<String, Supplier<URI>>> regionToEndpointSupplier;
+
+   @Inject
+   public RegionToEndpoint(@Region Supplier<Map<String, Supplier<URI>>> regionToEndpointSupplier) {
+      this.regionToEndpointSupplier = checkNotNull(regionToEndpointSupplier, "regionToEndpointSupplier");
+   }
+
+   @Override
+   public URI apply(@Nullable Object from) {
+      checkArgument(from != null && from instanceof String, "you must specify a region, as a String argument");
+      Map<String, Supplier<URI>> regionToEndpoint = regionToEndpointSupplier.get();
+      checkState(regionToEndpoint.size() > 0, "no region name to endpoint mappings configured!");
+      checkArgument(regionToEndpoint.containsKey(from),
+               "requested location %s, which is not in the configured locations: %s", from, regionToEndpoint);
+      return regionToEndpoint.get(from).get();
+   }
+}

core/src/test/java/org/jclouds/location/functions/RegionToEndpointTest.java

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+/**
+ * Licensed to jclouds, Inc. (jclouds) under one or more
+ * contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  jclouds licenses this file
+ * to you 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.jclouds.location.functions;
+
+import static org.testng.Assert.assertEquals;
+
+import java.io.File;
+import java.net.URI;
+import java.util.Map;
+
+import org.testng.annotations.Test;
+
+import com.google.common.base.Supplier;
+import com.google.common.base.Suppliers;
+import com.google.common.collect.ImmutableMap;
+
+/**
+ * Tests behavior of {@code RegionToEndpoint}
+ * 
+ * @author Adrian Cole
+ */
+@Test(groups = "unit", testName = "RegionToEndpointTest")
+public class RegionToEndpointTest {
+
+   @Test
+   public void testCorrect() {
+      RegionToEndpoint fn = new RegionToEndpoint(Suppliers.<Map<String, Supplier<URI>>> ofInstance(ImmutableMap.of("1",
+               Suppliers.ofInstance(URI.create("http://1")))));
+      assertEquals(fn.apply("1"), URI.create("http://1"));
+   }
+
+   @Test(expectedExceptions = IllegalArgumentException.class)
+   public void testMustBeString() {
+      RegionToEndpoint fn = new RegionToEndpoint(Suppliers.<Map<String, Supplier<URI>>> ofInstance(ImmutableMap.of("1",
+               Suppliers.ofInstance(URI.create("http://1")))));
+      fn.apply(new File("foo"));
+   }
+
+   @Test(expectedExceptions = IllegalStateException.class)
+   public void testMustHaveEndpoints() {
+      RegionToEndpoint fn = new RegionToEndpoint(Suppliers.<Map<String, Supplier<URI>>> ofInstance(ImmutableMap
+               .<String, Supplier<URI>> of()));
+      fn.apply("1");
+   }
+
+   @Test(expectedExceptions = IllegalArgumentException.class)
+   public void testNullIsIllegal() {
+      RegionToEndpoint fn = new RegionToEndpoint(Suppliers.<Map<String, Supplier<URI>>> ofInstance(ImmutableMap.of("1",
+               Suppliers.ofInstance(URI.create("http://1")))));
+      fn.apply(null);
+   }
+}