com.ninja_squad.dbsetup.generator.StringSequenceValueGenerator Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of DbSetup Show documentation
Helps you setup your database with test data
There is a newer version: 2.1.0
/*
 * The MIT License
 *
 * Copyright (c) 2013, Ninja Squad
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

package com.ninja_squad.dbsetup.generator;

import com.ninja_squad.dbsetup.util.Preconditions;

/**
 * A {@link ValueGenerator} that returns a string prefix followed by a sequence number, optionally left-padded
 * with 0 to ensure a correct ordering (for example: CODE_001, CODE_002, etc.). Instances of this generator
 * are created by {@link ValueGenerators#stringSequence(String)}.
 * @author JB
 */
public final class StringSequenceValueGenerator implements ValueGenerator {
    private String prefix;
    private long next;
    private int increment;

    /**
     * The length of the number once padded. 0 if no padding must be applied
     */
    private int paddedNumberLength;

    StringSequenceValueGenerator(String prefix) {
        this(prefix, 1L, 1, 0);
    }

    private StringSequenceValueGenerator(String prefix, long next, int increment, int paddedNumberLength) {
        this.prefix = prefix;
        this.next = next;
        this.increment = increment;
        this.paddedNumberLength = paddedNumberLength;
    }

    /**
     * Tells the generator to left-pad the number it generates with 0 until the length of the number is the given
     * length. For example, passing 3 to this method will generate numbers 001, 002, 003, 004, etc. If the generated
     * number, before padding, has a length already equal or larger that the given length, the number is not padded.
     * @param paddedNumberLength the length of the number once padded. Must be > 0.
     * @return this instance, for chaining
     */
    public StringSequenceValueGenerator withLeftPadding(int paddedNumberLength) {
        Preconditions.checkArgument(paddedNumberLength > 0, "paddedNumberLength must be > 0");
        this.paddedNumberLength = paddedNumberLength;
        return this;
    }

    /**
     * Tells the generator to avoid left-padding the number it generates with 0
     * @return this instance, for chaining
     */
    public StringSequenceValueGenerator withoutLeftPadding() {
        this.paddedNumberLength = 0;
        return this;
    }

    /**
     * Restarts the sequence at the given value
     * @param start the new starting value of the sequence
     * @return this instance, for chaining
     */
    public StringSequenceValueGenerator startingAt(long start) {
        this.next = start;
        return this;
    }

    /**
     * Increments the number by the given increment.
     * @return this instance, for chaining
     */
    public StringSequenceValueGenerator incrementingBy(int increment) {
        this.increment = increment;
        return this;
    }

    @Override
    public String nextValue() {
        long number = next;
        next += increment;
        return prefix + leftPadIfNecessary(number);
    }

    private String leftPadIfNecessary(long number) {
        String numberAsString = Long.toString(number);
        if (numberAsString.length() >= paddedNumberLength) {
            return numberAsString;
        }
        StringBuilder builder = new StringBuilder(paddedNumberLength);
        for (int i = 0; i < paddedNumberLength - numberAsString.length(); i++) {
            builder.append('0');
        }
        return builder.append(numberAsString).toString();
    }

    @Override
    public String toString() {
        return "StringSequenceValueGenerator["
               + "prefix='" + prefix + '\''
               + ", next=" + next
               + ", increment=" + increment
               + ", paddedNumberLength=" + paddedNumberLength
               + "]";
    }
}