1 files changed, 246 insertions, 0 deletions
diff --git a/apiroute/apiroute-service/src/main/java/org/openo/msb/wrapper/consul/util/ClientUtil.java b/apiroute/apiroute-service/src/main/java/org/openo/msb/wrapper/consul/util/ClientUtil.java
new file mode 100644
index 0000000..ab184c1
--- /dev/null
+++ b/apiroute/apiroute-service/src/main/java/org/openo/msb/wrapper/consul/util/ClientUtil.java
@@ -0,0 +1,246 @@
+/**
+* Copyright (C) 2016 ZTE, Inc. and others. All rights reserved. (ZTE)
+*
+* 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.openo.msb.wrapper.consul.util;
+
+import com.google.common.base.Optional;
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableMap;
+
+import javax.ws.rs.ServerErrorException;
+import javax.ws.rs.WebApplicationException;
+import javax.ws.rs.client.InvocationCallback;
+import javax.ws.rs.client.WebTarget;
+import javax.ws.rs.core.GenericType;
+import javax.ws.rs.core.MediaType;
+import javax.ws.rs.core.Response;
+
+import org.openo.msb.wrapper.consul.ConsulException;
+import org.openo.msb.wrapper.consul.async.ConsulResponseCallback;
+import org.openo.msb.wrapper.consul.model.ConsulResponse;
+import org.openo.msb.wrapper.consul.option.CatalogOptions;
+import org.openo.msb.wrapper.consul.option.ParamAdder;
+import org.openo.msb.wrapper.consul.option.QueryOptions;
+
+import java.math.BigInteger;
+import java.util.List;
+import java.util.Map;
+
+/**
+ * A collection of stateless utility methods for use in constructing
+ * requests and responses to the Consul HTTP API.
+ */
+public class ClientUtil {
+
+    /**
+     * Applies all key/values from the params map to query string parameters.
+     *
+     * @param webTarget The JAX-RS target to apply the query parameters.
+     * @param params Map of parameters.
+     * @return The new target with the parameters applied.
+     */
+    public static WebTarget queryParams(WebTarget webTarget, Map<String, String> params) {
+        WebTarget target = webTarget;
+
+        if(params != null) {
+            for(Map.Entry<String, String> entry : params.entrySet()) {
+                target = target.queryParam(entry.getKey(), entry.getValue());
+            }
+        }
+
+        return target;
+    }
+
+    /**
+     * Given a {@link org.openo.msb.wrapper.consul.option.ParamAdder} object, adds the
+     * appropriate query string parameters to the request being built.
+     *
+     * @param webTarget The base {@link javax.ws.rs.client.WebTarget}.
+     * @param  paramAdder will add specific params to the target.
+     * @return A {@link javax.ws.rs.client.WebTarget} with all appropriate query
+     *  string parameters.
+     */
+    public static WebTarget addParams(WebTarget webTarget, ParamAdder paramAdder) {
+        return paramAdder == null ? webTarget : paramAdder.apply(webTarget);
+    }
+
+    /**
+     * Generates a {@link org.openo.msb.wrapper.consul.model.ConsulResponse} for a specific datacenter,
+     * set of {@link org.openo.msb.wrapper.consul.option.QueryOptions}, and a result type.
+     *
+     * @param target The base {@link javax.ws.rs.client.WebTarget}.
+     * @param catalogOptions Catalog specific options to use.
+     * @param queryOptions The Query Options to use.
+     * @param type The generic type to marshall the resulting data to.
+     * @param <T> The result type.
+     * @return A {@link org.openo.msb.wrapper.consul.model.ConsulResponse}.
+     */
+    public static <T> ConsulResponse<T> response(WebTarget target, CatalogOptions catalogOptions,
+                                                 QueryOptions queryOptions,
+                                                 GenericType<T> type) {
+        target = addParams(target, catalogOptions);
+        target = addParams(target, queryOptions);
+
+        return response(target, type);
+    }
+
+    /**
+     * Generates a {@link org.openo.msb.wrapper.consul.model.ConsulResponse} for a specific datacenter,
+     * set of {@link org.openo.msb.wrapper.consul.option.QueryOptions}, and a result type.
+     *
+     * @param target The base {@link javax.ws.rs.client.WebTarget}.
+     * @param catalogOptions Catalog specific options to use.
+     * @param queryOptions The Query Options to use.
+     * @param type The generic type to marshall the resulting data to.
+     * @param <T> The result type.
+     */
+    public static <T> void response(WebTarget target, CatalogOptions catalogOptions,
+                                                 QueryOptions queryOptions,
+                                                 GenericType<T> type,
+                                                 ConsulResponseCallback<T> callback) {
+
+        target = addParams(target, catalogOptions);
+        target = addParams(target, queryOptions);
+
+        response(target, type, callback);
+    }
+
+    /**
+     * Given a {@link javax.ws.rs.client.WebTarget} object and a type to marshall
+     * the result JSON into, complete the HTTP GET request.
+     *
+     * @param webTarget The JAX-RS target.
+     * @param responseType The class to marshall the JSON into.
+     * @param <T> The class to marshall the JSON into.
+     * @return A {@link org.openo.msb.wrapper.consul.model.ConsulResponse} containing the result.
+     */
+    public static <T> ConsulResponse<T> response(WebTarget webTarget, GenericType<T> responseType) {
+        Response response = webTarget.request().accept(MediaType.APPLICATION_JSON_TYPE).get();
+
+        return consulResponse(responseType, response);
+    }
+
+    /**
+     * Given a {@link javax.ws.rs.client.WebTarget} object and a type to marshall
+     * the result JSON into, complete the HTTP GET request.
+     *
+     * @param webTarget The JAX-RS target.
+     * @param responseType The class to marshall the JSON into.
+     * @param callback The callback object to handle the result on a different thread.
+     * @param <T> The class to marshall the JSON into.
+     */
+    public static <T> void response(WebTarget webTarget, final GenericType<T> responseType,
+                                    final ConsulResponseCallback<T> callback) {
+        webTarget.request().accept(MediaType.APPLICATION_JSON_TYPE).async().get(new InvocationCallback<Response>() {
+
+            @Override
+            public void completed(Response response) {
+                try {
+                    callback.onComplete(consulResponse(responseType, response));
+                } catch (Exception ex) {
+                    callback.onFailure(ex);
+                }
+            }
+
+            @Override
+            public void failed(Throwable throwable) {
+                callback.onFailure(throwable);
+            }
+        });
+    }
+
+    /**
+     * Extracts Consul specific headers and adds them to a {@link org.openo.msb.wrapper.consul.model.ConsulResponse}
+     * object, which also contains the returned JSON entity.
+     *
+     * @param responseType The class to marshall the JSON to.
+     * @param response The HTTP response.
+     * @param <T> The class to marshall the JSON to.
+     * @return A {@link org.openo.msb.wrapper.consul.model.ConsulResponse} object.
+     */
+    private static <T> ConsulResponse<T> consulResponse(GenericType<T> responseType, Response response) {
+        handleErrors(response);
+
+        String indexHeaderValue = response.getHeaderString("X-Consul-Index");
+        String lastContactHeaderValue = response.getHeaderString("X-Consul-Lastcontact");
+        String knownLeaderHeaderValue = response.getHeaderString("X-Consul-Knownleader");
+
+        BigInteger index = new BigInteger(indexHeaderValue);
+        long lastContact = lastContactHeaderValue == null ? -1 : Long.valueOf(lastContactHeaderValue);
+        boolean knownLeader = knownLeaderHeaderValue == null ? false : Boolean.valueOf(knownLeaderHeaderValue);
+
+        ConsulResponse<T> consulResponse = new ConsulResponse<T>(readResponse(response, responseType), lastContact, knownLeader, index);
+
+        response.close();
+
+        return consulResponse;
+    }
+
+    /**
+     * Converts a {@link Response} object to the generic type provided, or an empty
+     * representation if appropriate
+     *
+     * @param response response
+     * @param responseType response type
+     * @param <T>
+     * @return the re
+     */
+    private static <T> T readResponse(Response response, GenericType<T> responseType) {
+        if (response.getStatus() == Response.Status.NOT_FOUND.getStatusCode()) {
+            // would be nice I knew a better way to do this
+            if (responseType.getRawType() == List.class) {
+                return (T) ImmutableList.of();
+            } else if (responseType.getRawType() == Optional.class) {
+                return (T) Optional.absent();
+            } else if(responseType.getRawType() == Map.class) {
+                return (T) ImmutableMap.of();
+            } else {
+                // Not sure if this case will be reached, but if it is it'll be nice to know
+                throw new IllegalStateException("Cannot determine empty representation for " + responseType.getRawType());
+            }
+        }
+        return response.readEntity(responseType);
+    }
+
+    /**
+     * Since Consul returns plain text when an error occurs, check for
+     * unsuccessful HTTP status code, and throw an exception with the text
+     * from Consul as the message.
+     *
+     * @param response The HTTP response.
+     */
+    public static void handleErrors(Response response) {
+
+        if (response.getStatusInfo().getFamily() == Response.Status.Family.SUCCESSFUL
+                || response.getStatus() == Response.Status.NOT_FOUND.getStatusCode()) {
+            // not an error
+            return;
+        }
+
+        try {
+            final String message = response.hasEntity() ? response.readEntity(String.class) : null;
+            if (response.getStatusInfo().getFamily() ==  Response.Status.Family.SERVER_ERROR) {
+                throw new ServerErrorException(message, response);
+            } else {
+                throw new WebApplicationException(message, response);
+            }
+        } catch (Exception e) {
+            throw new ConsulException(e.getLocalizedMessage(), e);
+        } finally {
+            response.close();
+        }
+    }
+}