[jboss-cvs] jboss-seam/examples/wiki/src/main/org/jboss/seam/wiki/util ...

[Christian Bauer]

  User: cbauer  
  Date: 07/03/07 13:37:35

  Added:       examples/wiki/src/main/org/jboss/seam/wiki/util   Hash.java
                        Diff.java
  Log:
  Moved to hot-redeploy WAR build structure
  
  Revision  Changes    Path
  1.1      date: 2007/03/07 18:37:35;  author: cbauer;  state: Exp;jboss-seam/examples/wiki/src/main/org/jboss/seam/wiki/util/Hash.java
  
  Index: Hash.java
  ===================================================================
  package org.jboss.seam.wiki.util;
  
  import java.security.MessageDigest;
  
  import org.apache.commons.codec.binary.Hex;
  import org.jboss.seam.annotations.Name;
  import org.jboss.seam.annotations.AutoCreate;
  
  /**
   * Not reall save, should use a random salt, prepended later on the digest.
   * Should also iterate the hashing a few thousand times to make brute force
   * attacks more difficult. Basically, implement user password encryption with
   * the same technique as on a typical Linux distribution.
   *
   * TODO: Make this more secure - before releasing to public and breaking all stored passwords!
   */
  @Name("hashUtil")
  @AutoCreate
  public class Hash {
      String hashFunction = "MD5";
      String charset      = "UTF-8";
  
      public String hash(String text) {
          try {
              MessageDigest md = MessageDigest.getInstance(hashFunction);
              md.update(text.getBytes(charset));
              byte[] raw = md.digest();
              return new String(Hex.encodeHex(raw));
          }
          catch (Exception e) {
              throw new RuntimeException(e);
          }
      }
  
      public String getCharset() {
          return charset;
      }
  
      public void setCharset(String charset) {
          this.charset = charset;
      }
  
      public String getHashFunction() {
          return hashFunction;
      }
  
      public void setHashFunction(String hashFunction) {
          this.hashFunction = hashFunction;
      }
  
  }
  
  
  
  1.1      date: 2007/03/07 18:37:35;  author: cbauer;  state: Exp;jboss-seam/examples/wiki/src/main/org/jboss/seam/wiki/util/Diff.java
  
  Index: Diff.java
  ===================================================================
  package org.jboss.seam.wiki.util;
  
  import java.util.Arrays;
  import java.util.List;
  import java.util.ArrayList;
  
  /**
   * String comparison and diff algorithms with customizable result rendering.
   * <p>
   * TODO: Support new methods for word and character diff
   * <p>
   * @author Christian Bauer
   */
  public abstract class Diff {
  
      /**
       * Compares two strings, left and ride side, renders a new string with custom boundary markers
       * for deleted and added lines.
       *
       * @param x The "left" side of the comparison.
       * @param y The "right" side of the comparison.
       * @param ignoreStrings These strings are ignored and not marked as different.
       * @return String A result with all deletions and modifications highlighted with custom boundary markers.
       */
      public String[] renderDiff(String[] x, String[] y, String... ignoreStrings) {
          List<String> ignoreList = Arrays.asList(ignoreStrings);
  
          int M = x.length;
          int N = y.length;
  
          String[] result = new String[M + N]; // N + M? Not nice but safe
          int k = 0;
  
          int[][] opt = new int[M + 1][N + 1];
  
          for (int i = M - 1; i >= 0; i--) {
              for (int j = N - 1; j >= 0; j--) {
                  if (x[i].equals(y[j]))
                      opt[i][j] = opt[i + 1][j + 1] + 1;
                  else
                      opt[i][j] = Math.max(opt[i + 1][j], opt[i][j + 1]);
              }
          }
  
          int i = 0, j = 0;
          while (i < M && j < N) {
              if (x[i].equals(y[j])) {
                  result[k++] = (x[i]);
                  i++;
                  j++;
              } else if (opt[i + 1][j] >= opt[i][j + 1]) {
                  if (ignoreList.contains(x[i]) || "".equals(x[i]) ) {
                      result[k++] = x[i++];
                  } else {
                      result[k++] = getDeletionStartMarker() + x[i++] + getDeletionEndMarker();
                  }
              } else {
                  if (ignoreList.contains(y[j]) || "".equals(y[j]) ) {
                      result[k++] = y[j++];
                   } else {
                       result[k++] = getAdditionStartMarker() + y[j++] + getAdditionEndMarker();
                  }
              }
          }
  
          while (i < M || j < N) {
              if (j == N)  {
                  if (ignoreList.contains(x[i]) || "".equals(x[i]) ) {
                      result[k++] = x[i++];
                  } else {
                      result[k++] = getDeletionStartMarker() + x[i++] + getDeletionEndMarker();
                  }
              } else if (i == M) {
                  if (ignoreList.contains(y[j]) || "".equals(y[j]) ) {
                      result[k++] = y[j++];
                   } else {
                       result[k++] = getAdditionStartMarker() + y[j++] + getAdditionEndMarker();
                  }
              }
          }
          return result;
      }
  
      public static String renderWithDelimiter(String[] strings, String delimiter) {
          StringBuilder diff = new StringBuilder();
          for (String s: strings) {
              if (s != null) {
                  diff.append(s);
                  diff.append(delimiter);
              }
          }
          return diff.toString();
      }
  
  
      protected abstract String getDeletionStartMarker();
      protected abstract String getDeletionEndMarker();
      protected abstract String getAdditionStartMarker();
      protected abstract String getAdditionEndMarker();
  
  }