Flow configuration loader classes

src/main/java/com/proofpoint/event/collector/ConfigLoadingException.java

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+package com.proofpoint.event.collector;
+
+public class ConfigLoadingException extends Exception
+{
+    public ConfigLoadingException(String message, Exception ex)
+    {
+        super(message, ex);
+    }
+}

src/main/java/com/proofpoint/event/collector/FlowConfiguration.java

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+package com.proofpoint.event.collector;
+
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonProperty;
+
+import javax.validation.constraints.NotNull;
+import java.util.Set;
+
+public class FlowConfiguration
+{
+    private Set<String> propertiesToSerialize;
+
+    @JsonCreator
+    public FlowConfiguration(@JsonProperty("propertiesToSerialize") Set<String> propertiesToSerialize)
+    {
+        this.propertiesToSerialize = propertiesToSerialize;
+    }
+
+    @NotNull(message = "is missing")
+    @JsonProperty
+    public Set<String> getPropertiesToSerialize()
+    {
+        return propertiesToSerialize;
+    }
+}

src/main/java/com/proofpoint/event/collector/FlowConfigurationLoader.java

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+package com.proofpoint.event.collector;
+
+import java.net.URI;
+
+public interface FlowConfigurationLoader
+{
+    public FlowConfiguration loadConfiguration(URI configurationLocation)
+            throws ConfigLoadingException;
+}

src/main/java/com/proofpoint/event/collector/ForFlowConfigurationLoader.java

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+package com.proofpoint.event.collector;
+
+public @interface ForFlowConfigurationLoader
+{
+}

src/main/java/com/proofpoint/event/collector/HttpFlowConfigurationLoader.java

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+package com.proofpoint.event.collector;
+
+import com.proofpoint.http.client.HttpClient;
+import com.proofpoint.http.client.Request;
+import com.proofpoint.json.JsonCodec;
+
+import javax.inject.Inject;
+import javax.ws.rs.core.HttpHeaders;
+import javax.ws.rs.core.MediaType;
+import java.net.URI;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+import static com.proofpoint.http.client.JsonResponseHandler.createJsonResponseHandler;
+import static java.lang.String.format;
+
+
+public class HttpFlowConfigurationLoader
+    implements FlowConfigurationLoader
+{
+    private static final String LOADING_EXCEPTION_MESSAGE = "Config could not be loaded from location %s";
+    private static final JsonCodec<FlowConfiguration> FLOW_CONFIGURATION_CODEC = JsonCodec.jsonCodec(FlowConfiguration.class);
+    private final HttpClient httpClient;
+
+    @Inject
+    public HttpFlowConfigurationLoader(@ForFlowConfigurationLoader HttpClient httpClient)
+    {
+        this.httpClient = checkNotNull(httpClient, "httpClient is null");
+    }
+
+    @Override
+    public FlowConfiguration loadConfiguration(URI configurationLocation)
+            throws ConfigLoadingException
+    {
+        checkNotNull(configurationLocation, "configurationLocation is null");
+        try {
+            Request.Builder requestBuilder = Request.builder().prepareGet().setUri(configurationLocation).setHeader(HttpHeaders.ACCEPT, MediaType.APPLICATION_JSON);
+            return httpClient.execute(requestBuilder.build(), createJsonResponseHandler(FLOW_CONFIGURATION_CODEC));
+        }
+        catch (Exception ex) {
+            throw new ConfigLoadingException(format(LOADING_EXCEPTION_MESSAGE, configurationLocation), ex);
+        }
+    }
+}

src/test/java/com/proofpoint/event/collector/TestFlowConfiguration.java

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+package com.proofpoint.event.collector;
+
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableMap;
+import com.google.common.collect.ImmutableSet;
+import com.google.common.collect.Maps;
+import com.proofpoint.json.JsonCodec;
+import org.testng.annotations.BeforeMethod;
+import org.testng.annotations.Test;
+
+import javax.validation.constraints.NotNull;
+import java.util.Map;
+
+import static com.proofpoint.json.JsonCodec.jsonCodec;
+import static com.proofpoint.json.testing.JsonTester.assertJsonEncode;
+import static com.proofpoint.json.testing.JsonTester.decodeJson;
+import static com.proofpoint.testing.ValidationAssertions.assertFailsValidation;
+import static com.proofpoint.testing.ValidationAssertions.assertValidates;
+
+
+public class TestFlowConfiguration
+{
+    private final JsonCodec<FlowConfiguration> codec = jsonCodec(FlowConfiguration.class);
+    private Map<String,?> map;
+
+    @BeforeMethod
+    public void setup() {
+        map = Maps.newHashMap(ImmutableMap.of("propertiesToSerialize", ImmutableList.of("property1")));
+    }
+
+    @Test
+    public void testNoPropertiesToSerializeInJsonDecode()
+    {
+        map.remove("propertiesToSerialize");
+        assertFailsValidation(decodeJson(codec, map), "propertiesToSerialize", "is missing", NotNull.class);
+    }
+
+    @Test
+    public void testJsonEncode()
+    {
+        assertJsonEncode(assertValidates(new FlowConfiguration(ImmutableSet.of("property1"))), map);
+    }
+
+    @Test
+    public void testNullPropertiesToSerialize()
+    {
+        FlowConfiguration flowConfig = new FlowConfiguration(null);
+        assertFailsValidation(flowConfig, "propertiesToSerialize", "is missing", NotNull.class);
+    }
+
+    @Test
+    public void testPassesValidation()
+    {
+        FlowConfiguration flowConfig = new FlowConfiguration(ImmutableSet.of("foo"));
+        assertValidates(flowConfig);
+    }
+
+    @Test
+    public void testEmptyPropertiesPassesValidation()
+    {
+        FlowConfiguration flowConfig = new FlowConfiguration(ImmutableSet.<String>of());
+        assertValidates(flowConfig);
+    }
+}

src/test/java/com/proofpoint/event/collector/TestHttpFlowConfigurationLoader.java

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+package com.proofpoint.event.collector;
+
+import com.google.common.collect.ImmutableSet;
+import com.proofpoint.http.client.HttpClient;
+import com.proofpoint.http.client.Request;
+import com.proofpoint.http.client.ResponseHandler;
+import org.testng.annotations.Test;
+
+import javax.ws.rs.core.HttpHeaders;
+import javax.ws.rs.core.MediaType;
+import java.net.URI;
+
+import static java.lang.String.format;
+import static org.mockito.Matchers.anyObject;
+import static org.mockito.Matchers.eq;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+import static org.testng.Assert.assertEquals;
+import static org.testng.Assert.assertSame;
+import static org.testng.Assert.fail;
+
+public class TestHttpFlowConfigurationLoader
+{
+    FlowConfiguration remoteConfig = new FlowConfiguration(ImmutableSet.of(""));
+
+    @Test
+    public void testBasicRemoteConfigurationLoad()
+            throws Exception
+    {
+        HttpClient client = mock(HttpClient.class);
+        URI configLocation = URI.create("http://www.remoteconfiglocation.com/");
+        Request.Builder requestBuilder = Request.builder().prepareGet().setUri(configLocation).setHeader(HttpHeaders.ACCEPT, MediaType.APPLICATION_JSON);
+        when(client.execute(eq(requestBuilder.build()), (ResponseHandler) anyObject())).thenReturn(remoteConfig);
+
+        FlowConfigurationLoader loader = new HttpFlowConfigurationLoader(client);
+        assertEquals(loader.loadConfiguration(configLocation), remoteConfig);
+    }
+
+    @Test(expectedExceptions = NullPointerException.class)
+    public void testNoRemoteConfigurationLocationLoad()
+            throws Exception
+    {
+        FlowConfigurationLoader loader = new HttpFlowConfigurationLoader(mock(HttpClient.class));
+        loader.loadConfiguration(null);
+        fail("Should have thrown", new NullPointerException("Config location was null"));
+    }
+
+    @Test()
+    public void testConfigLoadingExceptionMessage()
+            throws Exception
+    {
+        String configLocation = "http://www.remoteconfiglocation.com/foo.json";
+        HttpClient client = mock(HttpClient.class);
+        Exception thrownException = new Exception("Bad!");
+        when(client.execute((Request) anyObject(), (ResponseHandler) anyObject())).thenThrow(thrownException);
+
+        FlowConfigurationLoader loader = new HttpFlowConfigurationLoader(client);
+        try {
+            loader.loadConfiguration(URI.create(configLocation));
+            fail("expected ConfigLoadingException");
+        }
+        catch (ConfigLoadingException ex) {
+            assertEquals(ex.getMessage(), format("Config could not be loaded from location http://www.remoteconfiglocation.com/foo.json", configLocation));
+            assertSame(ex.getCause(), thrownException);
+        }
+    }
+}