Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF 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.apache.hadoop.registry.client.types; import com.fasterxml.jackson.annotation.JsonAnyGetter; import com.fasterxml.jackson.annotation.JsonAnySetter; import com.fasterxml.jackson.annotation.JsonInclude; import com.google.common.base.Preconditions; import org.apache.hadoop.classification.InterfaceAudience; import org.apache.hadoop.classification.InterfaceStability; import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map; /** * JSON-marshallable description of a single component. * It supports the deserialization of unknown attributes, but does * not support their creation. */ @InterfaceAudience.Public @InterfaceStability.Evolving @JsonInclude(JsonInclude.Include.NON_NULL) public class ServiceRecord implements Cloneable { /** * A type string which MUST be in the serialized json. This permits * fast discarding of invalid entries */ public static final String RECORD_TYPE = "JSONServiceRecord"; /** * The type field. This must be the string {@link #RECORD_TYPE} */ public String type = RECORD_TYPE; /** * Description string */ public String description; /** * map to handle unknown attributes. */ private Map<String, String> attributes = new HashMap<String, String>(4); /** * List of endpoints intended for use to external callers */ public List<Endpoint> external = new ArrayList<Endpoint>(); /** * List of endpoints for use <i>within</i> an application. */ public List<Endpoint> internal = new ArrayList<Endpoint>(); /** * Create a service record with no ID, description or registration time. * Endpoint lists are set to empty lists. */ public ServiceRecord() { } /** * Deep cloning constructor * @param that service record source */ public ServiceRecord(ServiceRecord that) { this.description = that.description; // others Map<String, String> thatAttrs = that.attributes; for (Map.Entry<String, String> entry : thatAttrs.entrySet()) { attributes.put(entry.getKey(), entry.getValue()); } // endpoints List<Endpoint> src = that.internal; if (src != null) { internal = new ArrayList<Endpoint>(src.size()); for (Endpoint endpoint : src) { internal.add(new Endpoint(endpoint)); } } src = that.external; if (src != null) { external = new ArrayList<Endpoint>(src.size()); for (Endpoint endpoint : src) { external.add(new Endpoint(endpoint)); } } } /** * Add an external endpoint * @param endpoint endpoint to set */ public void addExternalEndpoint(Endpoint endpoint) { Preconditions.checkArgument(endpoint != null); endpoint.validate(); external.add(endpoint); } /** * Add an internal endpoint * @param endpoint endpoint to set */ public void addInternalEndpoint(Endpoint endpoint) { Preconditions.checkArgument(endpoint != null); endpoint.validate(); internal.add(endpoint); } /** * Look up an internal endpoint * @param api API * @return the endpoint or null if there was no match */ public Endpoint getInternalEndpoint(String api) { return findByAPI(internal, api); } /** * Look up an external endpoint * @param api API * @return the endpoint or null if there was no match */ public Endpoint getExternalEndpoint(String api) { return findByAPI(external, api); } /** * Handle unknown attributes by storing them in the * {@link #attributes} map * @param key attribute name * @param value attribute value. */ @JsonAnySetter public void set(String key, Object value) { attributes.put(key, value.toString()); } /** * The map of "other" attributes set when parsing. These * are not included in the JSON value of this record when it * is generated. * @return a map of any unknown attributes in the deserialized JSON. */ @JsonAnyGetter public Map<String, String> attributes() { return attributes; } /** * Get the "other" attribute with a specific key * @param key key to look up * @return the value or null */ public String get(String key) { return attributes.get(key); } /** * Get the "other" attribute with a specific key. * @param key key to look up * @param defVal default value * @return the value as a string, * or <code>defval</code> if the value was not present */ public String get(String key, String defVal) { String val = attributes.get(key); return val != null ? val : defVal; } /** * Find an endpoint by its API * @param list list * @param api api name * @return the endpoint or null if there was no match */ private Endpoint findByAPI(List<Endpoint> list, String api) { for (Endpoint endpoint : list) { if (endpoint.api.equals(api)) { return endpoint; } } return null; } @Override public String toString() { final StringBuilder sb = new StringBuilder("ServiceRecord{"); sb.append("description='").append(description).append('\''); sb.append("; external endpoints: {"); for (Endpoint endpoint : external) { sb.append(endpoint).append("; "); } sb.append("}; internal endpoints: {"); for (Endpoint endpoint : internal) { sb.append(endpoint != null ? endpoint.toString() : "NULL ENDPOINT"); sb.append("; "); } sb.append('}'); if (!attributes.isEmpty()) { sb.append(", attributes: {"); for (Map.Entry<String, String> attr : attributes.entrySet()) { sb.append("\"").append(attr.getKey()).append("\"=\"").append(attr.getValue()).append("\" "); } } else { sb.append(", attributes: {"); } sb.append('}'); sb.append('}'); return sb.toString(); } /** * Shallow clone: all endpoints will be shared across instances * @return a clone of the instance * @throws CloneNotSupportedException */ @Override protected Object clone() throws CloneNotSupportedException { return super.clone(); } @Override public int hashCode() { // Generated by eclipse final int prime = 31; int result = 1; result = prime * result + ((attributes == null) ? 0 : attributes.hashCode()); result = prime * result + ((description == null) ? 0 : description.hashCode()); result = prime * result + ((external == null) ? 0 : external.hashCode()); result = prime * result + ((internal == null) ? 0 : internal.hashCode()); result = prime * result + ((type == null) ? 0 : type.hashCode()); return result; } @Override public boolean equals(Object obj) { if (this == obj) { return true; } if (obj == null) { return false; } if (getClass() != obj.getClass()) { return false; } ServiceRecord other = (ServiceRecord) obj; if (attributes == null) { if (other.attributes != null) { return false; } } else if (!attributes.equals(other.attributes)) { return false; } if (description == null) { if (other.description != null) { return false; } } else if (!description.equals(other.description)) { return false; } if (external == null) { if (other.external != null) { return false; } } else if (!external.equals(other.external)) { return false; } if (internal == null) { if (other.internal != null) { return false; } } else if (!internal.equals(other.internal)) { return false; } if (type == null) { if (other.type != null) { return false; } } else if (!type.equals(other.type)) { return false; } return true; } }