com.bestvike.collections.generic.StringComparer Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of linq Show documentation
LINQ to Objects for Java.
The newest version!
package com.bestvike.collections.generic;

import com.bestvike.CultureInfo;
import com.bestvike.linq.exception.ExceptionArgument;
import com.bestvike.linq.exception.ThrowHelper;

import java.text.Collator;
import java.util.Comparator;

/**
 * Created by 许崇雷 on 2019-04-29.
 */
public abstract class StringComparer implements Comparator, IEqualityComparer {
    public static final StringComparer CurrentCulture = new CultureAwareCaseSensitiveComparer(null);
    public static final StringComparer CurrentCultureIgnoreCase = new CultureAwareIgnoreCaseComparer(null);
    public static final StringComparer InvariantCulture = new CultureAwareCaseSensitiveComparer(CultureInfo.getInvariantCulture());
    public static final StringComparer InvariantCultureIgnoreCase = new CultureAwareIgnoreCaseComparer(CultureInfo.getInvariantCulture());
    public static final StringComparer Ordinal = new OrdinalCaseSensitiveComparer();
    public static final StringComparer OrdinalIgnoreCase = new OrdinalIgnoreCaseComparer();

    private StringComparer() {
    }

    public static StringComparer create(Collator collator, boolean ignoreCase) {
        if (collator == null)
            ThrowHelper.throwArgumentNullException(ExceptionArgument.collator);
        return ignoreCase ? new CultureAwareIgnoreCaseComparer(collator) : new CultureAwareCaseSensitiveComparer(collator);
    }


    private static class CultureAwareComparer extends StringComparer {
        final Collator collator;
        final boolean ignoreCase;

        private CultureAwareComparer(Collator collator, boolean ignoreCase) {
            this.collator = collator;
            this.ignoreCase = ignoreCase;
        }

        @Override
        public boolean equals(String x, String y) {
            //noinspection StringEquality
            if (x == y)
                return true;
            if (x == null || y == null)
                return false;
            return this.ignoreCase ? x.equalsIgnoreCase(y) : x.equals(y);
        }

        @Override
        public int hashCode(String obj) {
            return obj == null ? 0 : (this.ignoreCase ? obj.toUpperCase().hashCode() : obj.hashCode());
        }

        @Override
        public int compare(String x, String y) {
            //noinspection StringEquality
            if (x == y)
                return 0;
            if (x == null)
                return -1;
            if (y == null)
                return 1;
            Collator collator = this.collator == null ? CultureInfo.getCurrentCulture() : this.collator;
            return this.ignoreCase ? collator.compare(x.toUpperCase(), y.toUpperCase()) : collator.compare(x, y);
        }
    }


    private static final class CultureAwareCaseSensitiveComparer extends CultureAwareComparer {
        private CultureAwareCaseSensitiveComparer(Collator collator) {
            super(collator, false);
        }

        @Override
        public boolean equals(String x, String y) {
            //noinspection StringEquality
            if (x == y)
                return true;
            if (x == null || y == null)
                return false;
            return x.equals(y);
        }

        @Override
        public int hashCode(String obj) {
            return obj == null ? 0 : obj.hashCode();
        }

        @Override
        public int compare(String x, String y) {
            //noinspection StringEquality
            if (x == y)
                return 0;
            if (x == null)
                return -1;
            if (y == null)
                return 1;
            return (this.collator == null ? CultureInfo.getCurrentCulture() : this.collator).compare(x, y);
        }
    }


    private static final class CultureAwareIgnoreCaseComparer extends CultureAwareComparer {
        private CultureAwareIgnoreCaseComparer(Collator collator) {
            super(collator, true);
        }

        @Override
        public boolean equals(String x, String y) {
            //noinspection StringEquality
            if (x == y)
                return true;
            if (x == null || y == null)
                return false;
            return x.equalsIgnoreCase(y);
        }

        @Override
        public int hashCode(String obj) {
            return obj == null ? 0 : obj.toUpperCase().hashCode();
        }

        @Override
        public int compare(String x, String y) {
            //noinspection StringEquality
            if (x == y)
                return 0;
            if (x == null)
                return -1;
            if (y == null)
                return 1;
            return (this.collator == null ? CultureInfo.getCurrentCulture() : this.collator).compare(x.toUpperCase(), y.toUpperCase());
        }
    }


    private static class OrdinalComparer extends StringComparer {
        final boolean ignoreCase;

        private OrdinalComparer(boolean ignoreCase) {
            this.ignoreCase = ignoreCase;
        }

        @Override
        public boolean equals(String x, String y) {
            //noinspection StringEquality
            if (x == y)
                return true;
            if (x == null || y == null)
                return false;
            return this.ignoreCase ? x.equalsIgnoreCase(y) : x.equals(y);
        }

        @Override
        public int hashCode(String obj) {
            return obj == null ? 0 : (this.ignoreCase ? obj.toUpperCase().hashCode() : obj.hashCode());
        }

        @Override
        public int compare(String x, String y) {
            //noinspection StringEquality
            if (x == y)
                return 0;
            if (x == null)
                return -1;
            if (y == null)
                return 1;
            return this.ignoreCase ? x.compareToIgnoreCase(y) : x.compareTo(y);
        }
    }


    private static final class OrdinalCaseSensitiveComparer extends OrdinalComparer {
        private OrdinalCaseSensitiveComparer() {
            super(false);
        }

        @Override
        public boolean equals(String x, String y) {
            //noinspection StringEquality
            if (x == y)
                return true;
            if (x == null || y == null)
                return false;
            return x.equals(y);
        }

        @Override
        public int hashCode(String obj) {
            return obj == null ? 0 : obj.hashCode();
        }

        @Override
        public int compare(String x, String y) {
            //noinspection StringEquality
            if (x == y)
                return 0;
            if (x == null)
                return -1;
            if (y == null)
                return 1;
            return x.compareTo(y);
        }
    }


    private static final class OrdinalIgnoreCaseComparer extends OrdinalComparer {
        private OrdinalIgnoreCaseComparer() {
            super(true);
        }

        @Override
        public boolean equals(String x, String y) {
            //noinspection StringEquality
            if (x == y)
                return true;
            if (x == null || y == null)
                return false;
            return x.equalsIgnoreCase(y);
        }

        @Override
        public int hashCode(String obj) {
            return obj == null ? 0 : obj.toUpperCase().hashCode();
        }

        @Override
        public int compare(String x, String y) {
            //noinspection StringEquality
            if (x == y)
                return 0;
            if (x == null)
                return -1;
            if (y == null)
                return 1;
            return x.compareToIgnoreCase(y);
        }
    }
}