Java tutorial
/* * Copyright 2013 the original author or authors. * * 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.springframework.hateoas; import java.util.ArrayList; import java.util.Arrays; import java.util.Iterator; import java.util.List; import javax.xml.bind.annotation.XmlAttribute; import javax.xml.bind.annotation.XmlElement; import javax.xml.bind.annotation.XmlRootElement; import javax.xml.bind.annotation.XmlType; import org.springframework.util.Assert; import org.springframework.util.StringUtils; import com.fasterxml.jackson.annotation.JsonCreator; import com.fasterxml.jackson.annotation.JsonProperty; import com.fasterxml.jackson.annotation.JsonValue; /** * A representation model class to be rendered as specified for the media type {@code application/vnd.error}. * * @see https://github.com/blongden/vnd.error * @author Oliver Gierke */ @XmlRootElement(name = "errors") public class VndErrors implements Iterable<VndErrors.VndError> { @XmlElement(name = "error") // private final List<VndError> vndErrors; /** * Creates a new {@link VndErrors} instance containing a single {@link VndError} with the given logref, message and * optional {@link Link}s. * * @param logref must not be {@literal null} or empty. * @param message must not be {@literal null} or empty. * @param links */ public VndErrors(String logref, String message, Link... links) { this(new VndError(logref, message, links)); } /** * Creates a new {@link VndErrors} wrapper for at least one {@link VndError}. * * @param errors must not be {@literal null}. * @param errors */ public VndErrors(VndError error, VndError... errors) { Assert.notNull(error, "Error must not be null"); this.vndErrors = new ArrayList<VndError>(errors.length + 1); this.vndErrors.add(error); this.vndErrors.addAll(Arrays.asList(errors)); } /** * Creates a new {@link VndErrors} wrapper for the given {@link VndErrors}. * * @param errors must not be {@literal null} or empty. */ @JsonCreator public VndErrors(List<VndError> errors) { Assert.notNull(errors, "Errors must not be null!"); Assert.isTrue(!errors.isEmpty(), "Errors must not be empty!"); this.vndErrors = errors; } /** * Protected default constructor to allow JAXB marshalling. */ protected VndErrors() { this.vndErrors = new ArrayList<VndError>(); } /** * Adds an additional {@link VndError} to the wrapper. * * @param errors */ public VndErrors add(VndError error) { this.vndErrors.add(error); return this; } /** * Dummy method to allow {@link JsonValue} to be configured. * * @return the vndErrors */ @JsonValue private List<VndError> getErrors() { return vndErrors; } /* * (non-Javadoc) * @see java.lang.Iterable#iterator() */ @Override public Iterator<VndErrors.VndError> iterator() { return this.vndErrors.iterator(); } /* * (non-Javadoc) * @see java.lang.Object#toString() */ @Override public String toString() { return String.format("VndErrors[%s]", StringUtils.collectionToCommaDelimitedString(vndErrors)); } /* * (non-Javadoc) * @see java.lang.Object#hashCode() */ @Override public int hashCode() { return vndErrors.hashCode(); } /* * (non-Javadoc) * @see java.lang.Object#equals(java.lang.Object) */ @Override public boolean equals(Object obj) { if (this == obj) { return true; } if (!(obj instanceof VndErrors)) { return false; } VndErrors that = (VndErrors) obj; return this.vndErrors.equals(that.vndErrors); } /** * A single {@link VndError}. * * @author Oliver Gierke */ @XmlType public static class VndError extends ResourceSupport { @XmlAttribute @JsonProperty private final String logref; @XmlElement @JsonProperty private final String message; /** * Creates a new {@link VndError} with the given logref, a message as well as some {@link Link}s. * * @param logref must not be {@literal null} or empty. * @param message must not be {@literal null} or empty. * @param links */ public VndError(String logref, String message, Link... links) { Assert.hasText(logref, "Logref must not be null or empty!"); Assert.hasText(message, "Message must not be null or empty!"); this.logref = logref; this.message = message; this.add(Arrays.asList(links)); } /** * Protected default constructor to allow JAXB marshalling. */ protected VndError() { this.logref = null; this.message = null; } /** * Returns the logref of the error. * * @return the logref */ public String getLogref() { return logref; } /** * Returns the message of the error. * * @return the message */ public String getMessage() { return message; } /* * (non-Javadoc) * @see org.springframework.hateoas.ResourceSupport#toString() */ @Override public String toString() { return String.format("VndError[logref: %s, message: %s, links: [%s]]", logref, message, StringUtils.collectionToCommaDelimitedString(getLinks())); } /* * (non-Javadoc) * @see org.springframework.hateoas.ResourceSupport#hashCode() */ @Override public int hashCode() { int result = 17; result += 31 * logref.hashCode(); result += 31 * message.hashCode(); return result; } /* * (non-Javadoc) * @see org.springframework.hateoas.ResourceSupport#equals(java.lang.Object) */ @Override public boolean equals(Object obj) { if (obj == this) { return true; } if (!(obj instanceof VndError)) { return false; } VndError that = (VndError) obj; return this.logref.equals(that.logref) && this.message.equals(that.message); } } }