com.github.croesch.util.StringArrayUtil Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of crhcomponents Show documentation
Provides some useful components for small Java projects.
There is a newer version: 1.3
package com.github.croesch.util;

import java.util.Arrays;

/**
 * Provides utilities for {@link String} arrays
 * 
 * @author croesch
 * @since Date: 17.02.2011 20:58:03
 */
@SuppressWarnings("nls")
public final class StringArrayUtil {

  /** the array to work with */
  private final String[] lines;

  /** performance reason to store whether this already has been trimmed */
  private boolean trimmed = false;

  /**
   * Constructs the utility class with the given array
   * 
   * @since Date: 17.02.2011
   * @param s the array of {@link String}s
   * @throws IllegalArgumentException if the array or one entry is {@code null}
   * @see com.github.croesch.util.Util#of(String[])
   */
  StringArrayUtil(final String[] s) throws IllegalArgumentException {
    if (s == null) {
      throw new IllegalArgumentException();
    }
    for (final String str : s) {
      if (str == null) {
        throw new IllegalArgumentException();
      }
    }
    this.lines = s.clone();
  }

  /**
   * Constructs the utility class with the given array
   * 
   * @since Date: 17.02.2011
   * @param s the array of {@link String}s
   * @param t if the given array is already trimmed
   * @throws IllegalArgumentException if the array or one entry is {@code null}
   * @see com.github.croesch.util.Util#of(String[])
   */
  private StringArrayUtil(final String[] s, final boolean t) throws IllegalArgumentException {
    this(s);
    this.trimmed = t;
  }

  /**
   * Trims the stored lines of the array and returns the instance of this analyser.
   * 
   * @since Date: 17.02.2011
   * @return this instance of the analyser
   * @see String#trim()
   */
  public StringArrayUtil trim() {

    if (this.trimmed) {
      return this;
    }

    final String[] lns = new String[this.lines.length];
    for (int i = 0; i < this.lines.length; ++i) {
      lns[i] = this.lines[i].trim();
    }

    // if nothing has changed then return this and store the information, that this array don't need to be trimmed.
    if (Arrays.equals(lns, this.lines)) {
      this.trimmed = true;
      return this;
    }

    return new StringArrayUtil(lns, true);
  }

  /**
   * Returns the length of the longest line in the array of lines.
   * 
   * @since Date: 17.02.2011
   * @return the length of the longest line
   */
  public int getMaxLineLength() {

    int maxLength = -1;
    for (final String ln : this.lines) {
      if (ln.length() > maxLength) {
        maxLength = ln.length();
      }
    }
    return maxLength;
  }

  /**
   * Returns the array stored in this utility class. But each row will have the same length and they will be filled up
   * with spaces, so that each entry is left aligned.
   * 
   * @since Date: 19.02.2011
   * @return the array left aligned, each row has the same number of chars
   * @see #toCentreAlignedArray()
   * @see #toRightAlignedArray()
   */
  public String[] toLeftAlignedArray() {
    final int maxLength = getMaxLineLength();

    for (int i = 0; i < this.lines.length; ++i) {
      this.lines[i] += new StringUtil(" ").toStringMultipliedWith(maxLength - this.lines[i].length());
    }
    return this.lines.clone();
  }

  /**
   * Returns the array stored in this utility class. But each row will have the same length and they will be filled up
   * with spaces, so that each entry is right aligned.
   * 
   * @since Date: 19.02.2011
   * @return the array right aligned, each row has the same number of chars
   * @see #toCentreAlignedArray()
   * @see #toLeftAlignedArray()
   */
  public String[] toRightAlignedArray() {
    final int maxLength = getMaxLineLength();

    for (int i = 0; i < this.lines.length; ++i) {
      this.lines[i] = new StringUtil(" ").toStringMultipliedWith(maxLength - this.lines[i].length()) + this.lines[i];
    }
    return this.lines.clone();
  }

  /**
   * Returns the array stored in this utility class. But each row will have the same length and they will be filled up
   * with spaces, so that each entry is centre aligned.
   * 
   * @since Date: 19.02.2011
   * @return the array centre aligned, each row has the same number of chars
   * @see #toLeftAlignedArray()
   * @see #toRightAlignedArray()
   */
  public String[] toCentreAlignedArray() {
    final int maxLength = getMaxLineLength();

    for (int i = 0; i < this.lines.length; ++i) {
      final int right = (maxLength - this.lines[i].length()) / 2;
      final String spaces = new StringUtil(" ").toStringMultipliedWith(maxLength - this.lines[i].length() - right);
      this.lines[i] = spaces + this.lines[i];
      this.lines[i] += new StringUtil(" ").toStringMultipliedWith(right);
    }
    return this.lines.clone();
  }

  @Override
  public int hashCode() {
    final int prime = 31;
    int result = 1;
    result = prime * result + Arrays.hashCode(this.lines);
    result = prime * result;
    if (this.trimmed) {
      result += prime;
    }
    return result;
  }

  @Override
  public boolean equals(final Object obj) {
    if (this == obj) {
      return true;
    }
    if (obj == null) {
      return false;
    }
    if (getClass() != obj.getClass()) {
      return false;
    }
    final StringArrayUtil other = (StringArrayUtil) obj;
    if (!Arrays.equals(this.lines, other.lines)) {
      return false;
    }
    if (this.trimmed != other.trimmed) {
      return false;
    }
    return true;
  }
}