edu.stanford.nlp.ling.StringLabel.java Source code

Introduction

Here is the source code for edu.stanford.nlp.ling.StringLabel.java

Source

package edu.stanford.nlp.ling;

/**
 * A <code>StringLabel</code> object acts as a Label by containing a
 * single String, which it sets or returns in response to requests.
 * The hashCode() and compareTo() methods for this class assume that this
 * string value is non-null.  equals() is correctly implemented
 *
 * @author Christopher Manning
 * @version 2000/12/20
 */
public class StringLabel extends ValueLabel implements HasOffset {

    private String str;

    /**
     * Start position of the word in the original input string
     */
    private int beginPosition = -1;

    /**
     * End position of the word in the original input string
     */
    private int endPosition = -1;

    /**
     * Create a new <code>StringLabel</code> with a null content (i.e., str).
     */
    public StringLabel() {
    }

    /**
     * Create a new <code>StringLabel</code> with the given content.
     *
     * @param str The new label's content
     */
    public StringLabel(String str) {
        this.str = str;
    }

    /**
     * Create a new <code>StringLabel</code> with the given content.
     *
     * @param str The new label's content
     * @param beginPosition Start offset in original text
     * @param endPosition End offset in original text
     */
    public StringLabel(String str, int beginPosition, int endPosition) {
        this.str = str;
        setBeginPosition(beginPosition);
        setEndPosition(endPosition);
    }

    /**
     * Create a new <code>StringLabel</code> with the
     * <code>value()</code> of another label as its label.
     *
     * @param label The other label
     */
    public StringLabel(Label label) {
        this.str = label.value();
        if (label instanceof HasOffset) {
            HasOffset ofs = (HasOffset) label;
            setBeginPosition(ofs.beginPosition());
            setEndPosition(ofs.endPosition());
        }
    }

    /**
     * Return the word value of the label (or null if none).
     *
     * @return String the word value for the label
     */
    @Override
    public String value() {
        return str;
    }

    /**
     * Set the value for the label.
     *
     * @param value The value for the label
     */
    @Override
    public void setValue(final String value) {
        str = value;
    }

    /**
     * Set the label from a String.
     *
     * @param str The str for the label
     */
    @Override
    public void setFromString(final String str) {
        this.str = str;
    }

    @Override
    public String toString() {
        return str;
    }

    // extra class guarantees correct lazy loading (Bloch p.194)
    private static class StringLabelFactoryHolder {

        private StringLabelFactoryHolder() {
        }

        static final LabelFactory lf = new StringLabelFactory();
    }

    /**
     * Return a factory for this kind of label
     * (i.e., <code>StringLabel</code>).
     * The factory returned is always the same one (a singleton).
     *
     * @return The label factory
     */
    @Override
    public LabelFactory labelFactory() {
        return StringLabelFactoryHolder.lf;
    }

    /**
     * Return a factory for this kind of label.
     *
     * @return The label factory
     */
    public static LabelFactory factory() {
        return StringLabelFactoryHolder.lf;
    }

    public int beginPosition() {
        return beginPosition;
    }

    public int endPosition() {
        return endPosition;
    }

    public void setBeginPosition(int beginPosition) {
        this.beginPosition = beginPosition;
    }

    public void setEndPosition(int endPosition) {
        this.endPosition = endPosition;
    }

    private static final long serialVersionUID = -4153619273767524247L;

}