Some tweaks to the API (de8d9527) · Commits · Zane Safi Mroue / hw1p3

src/edu/bu/ec504/hw1p3/compressors/CharByCharCompressor.java

+3 −1

Original line number	Diff line number	Diff line
		package edu.bu.ec504.hw1p3.compressors;

		import edu.bu.ec504.hw1p3.util.Atom;

		import java.io.BufferedReader;
		import java.io.IOException;
		import java.util.ArrayList;
		@@ -7,7 +9,7 @@ import java.util.ArrayList;
		/**
		* A simple implementation of the {@link Compressor} class.
		* This implementation ignores the dictionary entirely, and simply encodes each character of
		* the input as a trivial {@link Compressor.Atom}, indexed against the empty string.
		* the input as a trivial {@link Atom}, indexed against the empty string.
		*/
		public class CharByCharCompressor extends Compressor {

src/edu/bu/ec504/hw1p3/compressors/Compressor.java

+54 −69

Original line number	Diff line number	Diff line
		package edu.bu.ec504.hw1p3.compressors;

		import edu.bu.ec504.hw1p3.util.Atom;

		import java.io.BufferedReader;
		import java.io.Serializable;
		import java.util.ArrayList;
		@@ -8,40 +10,11 @@ import java.util.List;

		public abstract class Compressor implements Serializable {

		// nested classes
		/**
		* An immutable atom of compression that incorporates:
		* a. An integer representing an index into some dictionary.
		* b. A string that follows the dictionary word in a.
		*/
		static final class Atom implements Serializable {

		public Atom(int myIndex, String myNext) {
		index = myIndex;
		next = myNext;
		}

		public int getIndex() {
		return index;
		}

		public String getNext() {
		return next;
		}

		/**
		* Pretty print the atom.
		* @return A human-readable string representing this atom.
		* DEBUG==true prints debugging information during operation.
		* DEBUG==false does not print this debugging information
		*/
		@Override
		public String toString() {
		return "Atom{" + "index=" + index + ", next='" + next + '\'' + '}';
		}

		private static final long serialVersionUID = 2L; // for serialization
		private final int index;
		private final String next;
		}
		public boolean DEBUG = true;

		/**
		* An encapsulation of a list of Atoms.
		@@ -51,24 +24,32 @@ public abstract class Compressor implements Serializable {
		data = theData;
		}

		List<Atom> getList() { return data; }
		List<Atom> getList() {
		return data;
		}

		private final List<Atom> data;
		private static final long serialVersionUID = 3L; // for serialization
		}


		// METHODS

		// CONSTRUCTORS
		Compressor() { }

		/**
		* Process additional plaintext from <code>in</code> and incorporates it into this compressed object.
		*
		* @param in A BufferedReader linked to an input source.
		*/
		public abstract CompressedText processPlainText(BufferedReader in);

		/**
		* Decodes the meta-data stored within this object into an uncompressed text.
		* Reads the file, Atom by Atom, reconstructing the dictionary that was used
		* to produce it and the string that produced the dictionary.
		*
		* @return The uncompressed text corresponding to this object.
		*/
		final public String uncompress(CompressedText theCompressedText) {
		@@ -76,9 +57,13 @@ public abstract class Compressor implements Serializable {

		StringBuilder result = new StringBuilder();
		for (Atom anAtom : theCompressedText.getList()) {
		String nextStr=dict.get( anAtom.getIndex() ) + anAtom.getNext(); // the next String decoded from the theCompressedText
		String nextStr = dict.get(anAtom.getIndex()) + anAtom.getSuffix(); // the next String decoded from the theCompressedText
		result.append(nextStr);
		dict.add(nextStr); // add this string to the dictionary

		if (DEBUG) {
		System.out.println("Decoding Atom "+anAtom+ " to "+nextStr);
		}
		}
		return result.toString();
		}

src/edu/bu/ec504/hw1p3/compressors/LineByLineCompressor.java

+2 −0

Original line number	Diff line number	Diff line
		package edu.bu.ec504.hw1p3.compressors;

		import edu.bu.ec504.hw1p3.util.Atom;

		import java.io.BufferedReader;
		import java.io.IOException;
		import java.util.ArrayList;

src/edu/bu/ec504/hw1p3/util/Atom.java

0 → 100644

+41 −0

Original line number	Diff line number	Diff line
		package edu.bu.ec504.hw1p3.util;

		import java.io.Serializable;

		/**
		* An immutable atom that represents one string, and is built of two elements:
		* a. [prefix]: marked by an integer index into some compression dictionary.
		* The string at that index is a <i>prefix</i> of this atom's string.
		* b. [suffix]: a string that follows the prefix to complete the atom's string.
		* The string represented by this attom is this the concatenation of
		* [prefix] and [suffix]
		*/
		public final class Atom implements Serializable {

		public Atom(int myIndex, String mySuffix) {
		index = myIndex;
		suffix = mySuffix;
		}

		public int getIndex() {
		return index;
		}

		public String getSuffix() {
		return suffix;
		}

		/**
		* Pretty print the atom.
		*
		* @return A human-readable string representing this atom.
		*/
		@Override
		public String toString() {
		return "Atom{" + "index=" + index + ", next='" + suffix + '\'' + '}';
		}

		private static final long serialVersionUID = 2L; // for serialization
		private final int index;
		private final String suffix;
		}

src/edu/bu/ec504/hw1p3/util/ConvertToBase64.java

+3 −0

Original line number	Diff line number	Diff line
		@@ -29,6 +29,9 @@ public class ConvertToBase64 {
		Files.write(Paths.get(theOutputFile),decodedBytes);
		}

		/**
		* An example of how to convert the default input file into a base64 encoding.
		*/
		public static void main(String[] args) throws IOException {
		String base64 = toBase64(inputFileName);
		System.out.println("Base64:\n"+base64);