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author | Marcin Chrzanowski <marcin.j.chrzanowski@gmail.com> | 2019-10-21 19:31:52 +0200 |
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committer | Marcin Chrzanowski <marcin.j.chrzanowski@gmail.com> | 2019-10-21 19:31:52 +0200 |
commit | c2ccf4e675c68d8b1cca6f662dbfbf800449247a (patch) | |
tree | e441d0dd420b11542523bb7238ec6273a9d4dd73 /src/pl/edu/mimuw/cloudatlas/model/Attribute.java |
Intial commit - import scenario 2
Diffstat (limited to 'src/pl/edu/mimuw/cloudatlas/model/Attribute.java')
-rw-r--r-- | src/pl/edu/mimuw/cloudatlas/model/Attribute.java | 107 |
1 files changed, 107 insertions, 0 deletions
diff --git a/src/pl/edu/mimuw/cloudatlas/model/Attribute.java b/src/pl/edu/mimuw/cloudatlas/model/Attribute.java new file mode 100644 index 0000000..d0af5bb --- /dev/null +++ b/src/pl/edu/mimuw/cloudatlas/model/Attribute.java @@ -0,0 +1,107 @@ +/** + * Copyright (c) 2014, University of Warsaw + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without modification, are permitted + * provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, this list of + * conditions and the following disclaimer. + * + * 2. Redistributions in binary form must reproduce the above copyright notice, this list of + * conditions and the following disclaimer in the documentation and/or other materials provided + * with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND + * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR + * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, + * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY + * WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +package pl.edu.mimuw.cloudatlas.model; + +/** + * Represents an attribute (without value, name only). + * <p> + * A valid attribute name is an identifier starting with a letter and containing only letters and digits. It can + * additionally start with an ampersand - such names are reserved for queries. + * <p> + * This class is immutable. + */ +public class Attribute { + private final String name; + + /** + * Creates a new <code>Attribute</code> object with the specified <code>name</code>. + * + * @param name the name of the attribute + * @throws IllegalArgumentException if the <code>name</code> does not meet the rules + */ + public Attribute(String name) { + if(!name.matches("^&?[a-zA-Z]{1}[a-zA-z0-9_]*$")) + throw new IllegalArgumentException("Invalid name: may contain only letters, digits, underscores, " + + "must start with a letter and may optionally have an ampersand at the beginning."); + this.name = name; + } + + /** + * Indicates whether an <code>attribute</code> represents a query. This is true if and only if attribute name starts with an + * ampersand. + * + * @param attribute the attribute to check + * @return whether the <code>attribute</code> represents a query + */ + public static boolean isQuery(Attribute attribute) { + return attribute.getName().startsWith("&"); + } + + /** + * Gets the name of this attribute. + * + * @return string representing name + */ + public String getName() { + return name; + } + + /** + * Returns a hash code value for this attribute. For a proper behavior when using <code>Attribute</code> objects in + * <code>HashMap</code>, <code>HashSet</code> etc. this is the hash code of a string representing attribute name. + * + * @return hash code for this attribute + */ + @Override + public int hashCode() { + return name.hashCode(); + } + + /** + * Indicates whether another object is equal to this attribute. + * + * @param object the object to check + * @return true if and only if the <code>object</code> is an instance of <code>Attribute</code> class and has + * identical name + */ + @Override + public boolean equals(Object object) { + if(object == null) + return false; + if(getClass() != object.getClass()) + return false; + return name.equals(((Attribute)object).name); + } + + /** + * Returns a textual representation of this attribute. + * + * @return the name of this attribute + */ + @Override + public String toString() { + return name; + } +} |