stringdescription.java

Boosting算法软件包

package jboost.examples;

import java.util.HashMap;

import jboost.controller.Configuration;
import jboost.tokenizer.BadAttException;
import jboost.tokenizer.StringOp;

/**
 * the description for string attributes.
 */
class StringDescription extends AttributeDescription {
    StringDescription(String name, Configuration c) throws ClassNotFoundException {
	attributeName = name;
	attributeClass = Class.forName("jboost.examples.RealAttribute");

	crucial=c.getBool("crucial",false);
	ignoreAttribute=c.getBool("ignoreAttribute",false);
	caseSignificant=c.getBool("caseSignificant",false);
	punctuationSignificant=c.getBool("punctuationSignificant",false);
	existence=c.getBool("existence",false);
    }

    private HashMap map = new HashMap(); // mapping from string to int
    private int numStr = 0; // # strings seen so far 
                            // and value of current string (starts with 0)
    /** converts string int data file to string in attribute */
    public Attribute str2Att(String string) throws BadAttException {
	// System.err.println("DIAG: strAttReader.str2Att: string=<" + string + ">");
	string=string.trim();
	if(string.length()==0) return(new DiscreteAttribute());
	string = StringOp.shrinkWhitespace(string); // ok tho' immutable?
	if (!caseSignificant)
	    string=string.toLowerCase();
	if (!punctuationSignificant)
	    string= StringOp.removePunctuation(string);
	// System.err.println("DIAG strAttReader.str2Att: leaving");
	if (map.containsKey(string)) // string appeared before
	    return new DiscreteAttribute(((Integer)map.get(string)).intValue());
	else {
	    map.put(string, new Integer(numStr)); // put new key 
	    return new DiscreteAttribute(numStr++);
	}
    }

    public String toString() {
	String retval=new String(attributeName);
	retval+=" "+attributeClass.getName();
	retval+=" crucial: "+crucial;
	retval+=" ignoreAttribute: "+ignoreAttribute;
	retval+=" caseSignificant: "+caseSignificant;
	retval+=" punctuationSignificant: "+punctuationSignificant;
	retval+=" existence: "+existence;
	return(retval);
    }

    public String toString(Attribute attr) {
	String retval=new String();
	if(attr.isDefined()==false) return("UNDEFINED");
	int tok=((DiscreteAttribute)attr).getValue();
// This should be improved when the reader is integrated.
	retval+=tok;
	return(retval);
    }
}