gaffer.statistics.impl.SetOfStrings.java Source code

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Here is the source code for gaffer.statistics.impl.SetOfStrings.java

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/**
 * Copyright 2015 Crown Copyright
 *
 * 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 gaffer.statistics.impl;

import gaffer.statistics.Statistic;

import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
import java.util.HashSet;
import java.util.Set;

import org.apache.hadoop.io.Text;

/**
 * A simple {@link Statistic} that contains a set of strings. When two of these are merged,
 * the sets are merged.
 */
public class SetOfStrings implements Statistic {

    private static final long serialVersionUID = -1476567738515282646L;
    private Set<String> set = null;

    public SetOfStrings() {
        set = new HashSet<String>();
    }

    public SetOfStrings(Set<String> other) {
        this();
        set.addAll(other);
    }

    public SetOfStrings(String... strings) {
        this();
        for (String s : strings) {
            addString(s);
        }
    }

    public void merge(Statistic s) throws IllegalArgumentException {
        if (s instanceof SetOfStrings) {
            set.addAll(((SetOfStrings) s).getSet());
        } else {
            throw new IllegalArgumentException(
                    "Trying to merge a Statistic of type " + s.getClass() + " with a " + this.getClass());
        }
    }

    public void addString(String s) {
        set.add(s);
    }

    @Override
    public SetOfStrings clone() {
        return new SetOfStrings(this.set);
    }

    public Set<String> getSet() {
        return set;
    }

    /**
     * Removes all entries from this set.
     */
    public void clear() {
        set.clear();
    }

    @Override
    public String toString() {
        StringBuilder sb = new StringBuilder();
        int i = 0;
        for (String s : set) {
            if (i > 0) {
                sb.append(",");
            }
            sb.append(s);
            i++;
        }
        return sb.toString();
    }

    @Override
    public void readFields(DataInput in) throws IOException {
        clear();
        int setSize = in.readInt();
        for (int i = 0; i < setSize; i++) {
            set.add(Text.readString(in));
        }
    }

    @Override
    public void write(DataOutput out) throws IOException {
        out.writeInt(this.set.size());
        for (String s : this.set) {
            Text.writeString(out, s);
        }
    }

    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + ((set == null) ? 0 : set.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;
        SetOfStrings other = (SetOfStrings) obj;
        if (set == null) {
            if (other.set != null)
                return false;
        } else if (!set.equals(other.set))
            return false;
        return true;
    }

}