Java/Design Pattern/Interpretor Pattern
Interpreter Pattern 2
<source lang="java">
//[C] 2002 Sun Microsystems, Inc.--- import java.io.Serializable; import java.lang.reflect.InvocationTargetException; import java.lang.reflect.Method; import java.util.ArrayList; import java.util.HashMap; import java.util.Iterator; public class RunInterpreterPattern {
public static void main(String[] arguments) {
System.out.println("Example for the Interpreter pattern");
System.out.println("In this demonstration, the syntax defined");
System.out.println(" by the Interpreter can be used to search");
System.out.println(" among a collection of Contacts, returning");
System.out.println(" the subset that match the given search criteria.");
ContactList candidates = makeContactList();
Context ctx = new Context();
System.out.println("Contents of the ContactList:");
System.out.println(candidates);
System.out.println();
Contact testContact = new ContactImpl();
VariableExpression varLName = new VariableExpression(testContact,
"getLastName");
ConstantExpression constLName = new ConstantExpression("u");
ContainsExpression eqLName = new ContainsExpression(varLName,
constLName);
System.out.println("Contents of the search on ContactList:");
System.out.println("(search was contains "u" in Lase Name)");
Object result = candidates.getContactsMatchingExpression(eqLName, ctx,
testContact);
System.out.println(result);
VariableExpression varTitle = new VariableExpression(testContact,
"getTitle");
ConstantExpression constTitle = new ConstantExpression("LT");
EqualsExpression eqTitle = new EqualsExpression(varTitle, constTitle);
System.out.println("Contents of the search on ContactList:");
System.out.println("(search was all LT personnel)");
result = candidates.getContactsMatchingExpression(eqTitle, ctx,
testContact);
System.out.println(result);
System.out.println();
VariableExpression varLastName = new VariableExpression(testContact,
"getLastName");
ConstantExpression constLastName = new ConstantExpression("S");
ContainsExpression cLName = new ContainsExpression(varLastName,
constLastName);
AndExpression andExpr = new AndExpression(eqTitle, cLName);
System.out.println("Contents of the search on ContactList:");
System.out
.println("(search was all LT personnel with "S" in Last Name)");
result = candidates.getContactsMatchingExpression(andExpr, ctx,
testContact);
System.out.println(result);
}
private static ContactList makeContactList() {
ContactList returnList = new ContactList();
returnList.addContact(new ContactImpl("James", "Kirk", "Captain",
"USS Enterprise"));
returnList.addContact(new ContactImpl("Mr.", "Spock",
"Science Officer", "USS Enterprise"));
returnList.addContact(new ContactImpl("LT", "Uhura", "LT",
"USS Enterprise"));
returnList.addContact(new ContactImpl("LT", "Sulu", "LT",
"USS Enterprise"));
returnList.addContact(new ContactImpl("Ensign", "Checkov", "Ensign",
"USS Enterprise"));
returnList.addContact(new ContactImpl("Dr.", "McCoy", "Ship"s Doctor",
"USS Enterprise"));
returnList.addContact(new ContactImpl("Montgomery", "Scott", "LT",
"USS Enterprise"));
return returnList;
}
} interface Contact extends Serializable {
public static final String SPACE = " "; public String getFirstName(); public String getLastName(); public String getTitle(); public String getOrganization(); public void setFirstName(String newFirstName); public void setLastName(String newLastName); public void setTitle(String newTitle); public void setOrganization(String newOrganization);
} class ContactImpl implements Contact {
private String firstName;
private String lastName;
private String title;
private String organization;
public ContactImpl() {
}
public ContactImpl(String newFirstName, String newLastName,
String newTitle, String newOrganization) {
firstName = newFirstName;
lastName = newLastName;
title = newTitle;
organization = newOrganization;
}
public String getFirstName() {
return firstName;
}
public String getLastName() {
return lastName;
}
public String getTitle() {
return title;
}
public String getOrganization() {
return organization;
}
public void setFirstName(String newFirstName) {
firstName = newFirstName;
}
public void setLastName(String newLastName) {
lastName = newLastName;
}
public void setTitle(String newTitle) {
title = newTitle;
}
public void setOrganization(String newOrganization) {
organization = newOrganization;
}
public String toString() {
return firstName + SPACE + lastName;
}
} class ContactList implements Serializable {
private ArrayList contacts = new ArrayList();
public ArrayList getContacts() {
return contacts;
}
public Contact[] getContactsAsArray() {
return (Contact[]) (contacts.toArray(new Contact[1]));
}
public ArrayList getContactsMatchingExpression(Expression expr,
Context ctx, Object key) {
ArrayList results = new ArrayList();
Iterator elements = contacts.iterator();
while (elements.hasNext()) {
Object currentElement = elements.next();
ctx.addVariable(key, currentElement);
expr.interpret(ctx);
Object interpretResult = ctx.get(expr);
if ((interpretResult != null)
&& (interpretResult.equals(Boolean.TRUE))) {
results.add(currentElement);
}
}
return results;
}
public void setContacts(ArrayList newContacts) {
contacts = newContacts;
}
public void addContact(Contact element) {
if (!contacts.contains(element)) {
contacts.add(element);
}
}
public void removeContact(Contact element) {
contacts.remove(element);
}
public String toString() {
return contacts.toString();
}
} class Context {
private HashMap map = new HashMap();
public Object get(Object name) {
return map.get(name);
}
public void addVariable(Object name, Object value) {
map.put(name, value);
}
} interface Expression {
void interpret(Context c);
} class OrExpression extends CompoundExpression {
public OrExpression(ComparisonExpression expressionA,
ComparisonExpression expressionB) {
super(expressionA, expressionB);
}
public void interpret(Context c) {
expressionA.interpret(c);
expressionB.interpret(c);
Boolean result = new Boolean(((Boolean) c.get(expressionA))
.booleanValue()
|| ((Boolean) c.get(expressionB)).booleanValue());
c.addVariable(this, result);
}
} abstract class CompoundExpression implements Expression {
protected ComparisonExpression expressionA;
protected ComparisonExpression expressionB;
public CompoundExpression(ComparisonExpression expressionA,
ComparisonExpression expressionB) {
this.expressionA = expressionA;
this.expressionB = expressionB;
}
} class ConstantExpression implements Expression {
private Object value;
public ConstantExpression(Object newValue) {
value = newValue;
}
public void interpret(Context c) {
c.addVariable(this, value);
}
} abstract class ComparisonExpression implements Expression {
protected Expression expressionA;
protected Expression expressionB;
public ComparisonExpression(Expression expressionA, Expression expressionB) {
this.expressionA = expressionA;
this.expressionB = expressionB;
}
} class AndExpression extends CompoundExpression {
public AndExpression(ComparisonExpression expressionA,
ComparisonExpression expressionB) {
super(expressionA, expressionB);
}
public void interpret(Context c) {
expressionA.interpret(c);
expressionB.interpret(c);
Boolean result = new Boolean(((Boolean) c.get(expressionA))
.booleanValue()
&& ((Boolean) c.get(expressionB)).booleanValue());
c.addVariable(this, result);
}
} class VariableExpression implements Expression {
private Object lookup;
private String methodName;
public VariableExpression(Object newLookup, String newMethodName) {
lookup = newLookup;
methodName = newMethodName;
}
public void interpret(Context c) {
try {
Object source = c.get(lookup);
if (source != null) {
Method method = source.getClass().getMethod(methodName, null);
Object result = method.invoke(source, null);
c.addVariable(this, result);
}
} catch (NoSuchMethodException exc) {
} catch (IllegalAccessException exc) {
} catch (InvocationTargetException exc) {
}
}
} class EqualsExpression extends ComparisonExpression {
public EqualsExpression(Expression expressionA, Expression expressionB) {
super(expressionA, expressionB);
}
public void interpret(Context c) {
expressionA.interpret(c);
expressionB.interpret(c);
Boolean result = new Boolean(c.get(expressionA).equals(
c.get(expressionB)));
c.addVariable(this, result);
}
} class ContainsExpression extends ComparisonExpression {
public ContainsExpression(Expression expressionA, Expression expressionB) {
super(expressionA, expressionB);
}
public void interpret(Context c) {
expressionA.interpret(c);
expressionB.interpret(c);
Object exprAResult = c.get(expressionA);
Object exprBResult = c.get(expressionB);
if ((exprAResult instanceof String) && (exprBResult instanceof String)) {
if (((String) exprAResult).indexOf((String) exprBResult) != -1) {
c.addVariable(this, Boolean.TRUE);
return;
}
}
c.addVariable(this, Boolean.FALSE);
return;
}
}
</source>
Interpreter Pattern: Calculator
<source lang="java">
/* Software Architecture Design Patterns in Java by Partha Kuchana Auerbach Publications
- /
import java.util.HashMap; import java.util.Stack; public class Calculator {
private String expression;
private HashMap operators;
private Context ctx;
public static void main(String[] args) {
Calculator calc = new Calculator();
//instantiate the context
Context ctx = new Context();
//set the expression to evaluate
calc.setExpression("(a+b)*(c-d)");
//configure the calculator with the
// Context
calc.setContext(ctx);
//Display the result
System.out.println(" Variable Values: " + "a=" + ctx.getValue("a")
+ ", b=" + ctx.getValue("b") + ", c=" + ctx.getValue("c")
+ ", d=" + ctx.getValue("d"));
System.out.println(" Expression = (a+b)*(c-d)");
System.out.println(" Result = " + calc.evaluate());
}
public Calculator() {
operators = new HashMap();
operators.put("+", "1");
operators.put("-", "1");
operators.put("/", "2");
operators.put("*", "2");
operators.put("(", "0");
}
public void setContext(Context c) {
ctx = c;
}
public void setExpression(String expr) {
expression = expr;
}
public int evaluate() {
//infix to Postfix
String pfExpr = infixToPostFix(expression);
//build the Binary Tree
Expression rootNode = buildTree(pfExpr);
//Evaluate the tree
return rootNode.evaluate(ctx);
}
private NonTerminalExpression getNonTerminalExpression(String operation,
Expression l, Expression r) {
if (operation.trim().equals("+")) {
return new AddExpression(l, r);
}
if (operation.trim().equals("-")) {
return new SubtractExpression(l, r);
}
if (operation.trim().equals("*")) {
return new MultiplyExpression(l, r);
}
return null;
}
private Expression buildTree(String expr) {
Stack s = new Stack();
for (int i = 0; i < expr.length(); i++) {
String currChar = expr.substring(i, i + 1);
if (isOperator(currChar) == false) {
Expression e = new TerminalExpression(currChar);
s.push(e);
} else {
Expression r = (Expression) s.pop();
Expression l = (Expression) s.pop();
Expression n = getNonTerminalExpression(currChar, l, r);
s.push(n);
}
}//for
return (Expression) s.pop();
}
private String infixToPostFix(String str) {
Stack s = new Stack();
String pfExpr = "";
String tempStr = "";
String expr = str.trim();
for (int i = 0; i < str.length(); i++) {
String currChar = str.substring(i, i + 1);
if ((isOperator(currChar) == false) && (!currChar.equals("("))
&& (!currChar.equals(")"))) {
pfExpr = pfExpr + currChar;
}
if (currChar.equals("(")) {
s.push(currChar);
}
//for ")" pop all stack contents until "("
if (currChar.equals(")")) {
tempStr = (String) s.pop();
while (!tempStr.equals("(")) {
pfExpr = pfExpr + tempStr;
tempStr = (String) s.pop();
}
tempStr = "";
}
//if the current character is an
// operator
if (isOperator(currChar)) {
if (s.isEmpty() == false) {
tempStr = (String) s.pop();
String strVal1 = (String) operators.get(tempStr);
int val1 = new Integer(strVal1).intValue();
String strVal2 = (String) operators.get(currChar);
int val2 = new Integer(strVal2).intValue();
while ((val1 >= val2)) {
pfExpr = pfExpr + tempStr;
val1 = -100;
if (s.isEmpty() == false) {
tempStr = (String) s.pop();
strVal1 = (String) operators.get(tempStr);
val1 = new Integer(strVal1).intValue();
}
}
if ((val1 < val2) && (val1 != -100))
s.push(tempStr);
}
s.push(currChar);
}//if
}// for
while (s.isEmpty() == false) {
tempStr = (String) s.pop();
pfExpr = pfExpr + tempStr;
}
return pfExpr;
}
private boolean isOperator(String str) {
if ((str.equals("+")) || (str.equals("-")) || (str.equals("*"))
|| (str.equals("/")))
return true;
return false;
}
} // End of class class Context {
private HashMap varList = new HashMap();
public void assign(String var, int value) {
varList.put(var, new Integer(value));
}
public int getValue(String var) {
Integer objInt = (Integer) varList.get(var);
return objInt.intValue();
}
public Context() {
initialize();
}
//Values are hardcoded to keep the example simple
private void initialize() {
assign("a", 20);
assign("b", 40);
assign("c", 30);
assign("d", 10);
}
} class TerminalExpression implements Expression {
private String var;
public TerminalExpression(String v) {
var = v;
}
public int evaluate(Context c) {
return c.getValue(var);
}
} interface Expression {
public int evaluate(Context c);
} abstract class NonTerminalExpression implements Expression {
private Expression leftNode;
private Expression rightNode;
public NonTerminalExpression(Expression l, Expression r) {
setLeftNode(l);
setRightNode(r);
}
public void setLeftNode(Expression node) {
leftNode = node;
}
public void setRightNode(Expression node) {
rightNode = node;
}
public Expression getLeftNode() {
return leftNode;
}
public Expression getRightNode() {
return rightNode;
}
}// NonTerminalExpression class AddExpression extends NonTerminalExpression {
public int evaluate(Context c) {
return getLeftNode().evaluate(c) + getRightNode().evaluate(c);
}
public AddExpression(Expression l, Expression r) {
super(l, r);
}
}// AddExpression class SubtractExpression extends NonTerminalExpression {
public int evaluate(Context c) {
return getLeftNode().evaluate(c) - getRightNode().evaluate(c);
}
public SubtractExpression(Expression l, Expression r) {
super(l, r);
}
}// SubtractExpression class MultiplyExpression extends NonTerminalExpression {
public int evaluate(Context c) {
return getLeftNode().evaluate(c) * getRightNode().evaluate(c);
}
public MultiplyExpression(Expression l, Expression r) {
super(l, r);
}
}// MultiplyExpression
//File: Interprepter.properties /* a=10 b=20 c=30 d=40
- /
</source>
Interpreter pattern in Java
<source lang="java">
/* The Design Patterns Java Companion Copyright (C) 1998, by James W. Cooper IBM Thomas J. Watson Research Center
- /
import java.awt.BorderLayout; import java.awt.Dimension; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.awt.event.WindowAdapter; import java.awt.event.WindowEvent; import java.io.IOException; import java.io.RandomAccessFile; import java.util.StringTokenizer; import java.util.Vector; import javax.swing.AbstractListModel; import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JList; import javax.swing.JPanel; import javax.swing.JScrollPane; import javax.swing.JTextField; import javax.swing.event.ListSelectionEvent; import javax.swing.event.ListSelectionListener; //----------------------------------- public class InterpDemo extends JFrame implements ActionListener {
JButton Go;
JTextField tx;
KidData kdata;
JawtList ptable;
public InterpDemo() {
super("Interpreter Demo");
addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0);
}
});
tx = new JTextField(20);
Go = new JButton("Go");
JPanel p = new JPanel();
getContentPane().add(p);
p.setLayout(new BorderLayout());
JPanel np = new JPanel();
p.add("North", np);
np.add(tx);
np.add(Go);
Go.addActionListener(this);
ptable = new JawtList(20);
p.add("Center", ptable);
kdata = new KidData("50free.txt");
setSize(new Dimension(400, 200));
setVisible(true);
}
//----------------------------------------
public void actionPerformed(ActionEvent e) {
Parser p = new Parser(tx.getText());
p.setData(kdata, ptable);
p.Execute();
}
//----------------------------------------
static public void main(String argv[]) {
new InterpDemo();
}
} interface Command {
public void Execute();
} //this class is just a simple collection of arrays //of the data which has been selected class Data {
Kid[] kids;
public Data(Kid[] kd) {
kids = kd;
}
public Kid[] getData() {
return kids;
}
} class ParseVar extends ParseObject {
static final int FRNAME = 0, LNAME = 1, AGE = 2, CLUB = 3, TIME = 4,
tabMAX = 5;
public ParseVar(String s) {
s = s.toLowerCase();
value = -1;
type = VAR;
if (s.equals("frname"))
value = FRNAME;
if (s.equals("lname"))
value = LNAME;
if (s.equals("age"))
value = AGE;
if (s.equals("club"))
value = CLUB;
if (s.equals("time"))
value = TIME;
}
//--------------------------------------
public boolean isLegal() {
return (value >= 0);
}
} class Parser implements Command {
Stack stk;
Vector actionList;
KidData kdata;
Data data;
//PrintTable ptable;
JawtList ptable;
public Parser(String line) {
stk = new Stack();
actionList = new Vector();
StringTokenizer tok = new StringTokenizer(line);
while (tok.hasMoreElements()) {
ParseObject token = tokenize(tok.nextToken());
if (token != null)
stk.push(token);
}
}
//----------------------------------------
public void setData(KidData k, JawtList pt) {
data = new Data(k.getData());
ptable = pt;
}
//----------------------------------------
//executes parse of command line
public void Execute() {
while (stk.hasMoreElements()) {
if (topStack(ParseObject.VAR, ParseObject.VAR)) {
//reduce (Var Var) to Multvar
ParseVar v = (ParseVar) stk.pop();
ParseVar v1 = (ParseVar) stk.pop();
MultVar mv = new MultVar(v1, v);
stk.push(mv);
}
//reduce MULTVAR VAR to MULTVAR
if (topStack(ParseObject.MULTVAR, ParseObject.VAR)) {
MultVar mv = new MultVar();
MultVar mvo = (MultVar) stk.pop();
ParseVar v = (ParseVar) stk.pop();
mv.add(v);
Vector mvec = mvo.getVector();
for (int i = 0; i < mvec.size(); i++)
mv.add((ParseVar) mvec.elementAt(i));
stk.push(mv);
}
if (topStack(ParseObject.VAR, ParseObject.MULTVAR)) {
//reduce (Multvar Var) to Multvar
ParseVar v = (ParseVar) stk.pop();
MultVar mv = (MultVar) stk.pop();
mv.add(v);
stk.push(mv);
}
//reduce Verb Var to Verb containing vars
if (topStack(ParseObject.VAR, ParseObject.VERB)) {
addArgsToVerb();
}
//reduce Verb MultVar to Verb containing vars
if (topStack(ParseObject.MULTVAR, ParseObject.VERB)) {
addArgsToVerb();
}
//move top verb to action list
if (stk.top().getType() == ParseObject.VERB) {
actionList.addElement(stk.pop());
}
}//while
//now execute the verbs
//data.setData(kdata.getData());
//for (int i = actionList.size() -1; i >= 0; i--)
for (int i = 0; i < actionList.size(); i++) {
Verb v = (Verb) actionList.elementAt(i);
v.setData(data, ptable);
v.Execute();
}
}
//----------------------------------------
private void addArgsToVerb() {
ParseObject v = stk.pop();
ParseVerb verb = (ParseVerb) stk.pop();
verb.addArgs(v);
stk.push(verb);
}
//----------------------------------------
private boolean topStack(int c1, int c2) {
return (stk.top().getType() == c1) && (stk.nextTop().getType() == c2);
}
//----------------------------------------
private ParseObject tokenize(String s) {
ParseObject obj = getVerb(s);
if (obj == null)
obj = getVar(s);
return obj;
}
//----------------------------------------
private ParseVerb getVerb(String s) {
ParseVerb v;
v = new ParseVerb(s);
if (v.isLegal())
return v.getVerb(s);
else
return null;
}
//----------------------------------------
private ParseVar getVar(String s) {
ParseVar v;
v = new ParseVar(s);
if (v.isLegal())
return v;
else
return null;
}
} class Kid {
String frname, lname, club;
int age;
float time;
//-------------------------------------
public Kid(String line) {
StringTokenizer tok = new StringTokenizer(line);
String lnum = tok.nextToken();
frname = tok.nextToken();
lname = tok.nextToken();
age = new Integer(tok.nextToken()).intValue();
club = tok.nextToken();
time = new Float(tok.nextToken()).floatValue();
}
//-------------------------------
public Object getData(int key) {
switch (key) {
case ParseVar.FRNAME:
return frname;
case ParseVar.LNAME:
return lname;
case ParseVar.CLUB:
return club;
case ParseVar.AGE:
return new Integer(age);
case ParseVar.TIME:
return new Float(time);
}
return null;
}
//--------------------------------
public int getAge() {
return age;
}
public float getTime() {
return time;
}
public String getFrname() {
return frname;
}
public String getLname() {
return lname;
}
public String getClub() {
return club;
}
} interface awtList {
public void add(String s); public void remove(String s); public String[] getSelectedItems();
} //this is a simple adapter class to //convert List awt methods to Swing methods class JawtList extends JScrollPane implements ListSelectionListener, awtList {
private JList listWindow;
private JListData listContents;
//-----------------------------------------
public JawtList(int rows) {
listContents = new JListData();
listWindow = new JList(listContents);
listWindow.setPrototypeCellValue("Abcdefg Hijkmnop");
getViewport().add(listWindow);
}
//-----------------------------------------
public void add(String s) {
listContents.addElement(s);
}
//-----------------------------------------
public void remove(String s) {
listContents.removeElement(s);
}
//-----------------------------------------
public void clear() {
listContents.clear();
}
//-----------------------------------------
public String[] getSelectedItems() {
Object[] obj = listWindow.getSelectedValues();
String[] s = new String[obj.length];
for (int i = 0; i < obj.length; i++)
s[i] = obj[i].toString();
return s;
}
//-----------------------------------------
public void valueChanged(ListSelectionEvent e) {
}
} // ========================================= class JListData extends AbstractListModel {
private Vector data;
//-----------------------------------------
public JListData() {
data = new Vector();
}
//-----------------------------------------
public int getSize() {
return data.size();
}
//-----------------------------------------
public Object getElementAt(int index) {
return data.elementAt(index);
}
//-----------------------------------------
public void addElement(String s) {
data.addElement(s);
fireIntervalAdded(this, data.size() - 1, data.size());
}
//-----------------------------------------
public void removeElement(String s) {
data.removeElement(s);
fireIntervalRemoved(this, 0, data.size());
}
//-----------------------------------------
public void clear() {
int size = data.size();
data = new Vector();
fireIntervalRemoved(this, 0, size);
}
} class ParseObject {
public static final int VERB = 1000, VAR = 1010, MULTVAR = 1020;
protected int value;
protected int type;
public int getValue() {
return value;
}
public int getType() {
return type;
}
} class ParseVerb extends ParseObject {
static public final int PRINT = 100, SORTBY = 110, THENBY = 120;
protected Vector args;
public ParseVerb(String s) {
args = new Vector();
s = s.toLowerCase();
value = -1;
type = VERB;
if (s.equals("print"))
value = PRINT;
if (s.equals("sortby"))
value = SORTBY;
}
//-----------------------------------
public ParseVerb getVerb(String s) {
switch (value) {
case PRINT:
return new Print(s);
case SORTBY:
return new Sort(s);
}
return null;
}
//-----------------------------------
public void addArgs(MultVar mv) {
args = mv.getVector();
}
//-----------------------------------
public void addArgs(ParseObject p) {
args.addElement(p);
}
//-----------------------------------
public boolean isLegal() {
return (value >= 0);
}
//-----------------------------------
} class Sort extends Verb {
Kid[] kids;
int pindex;
public Sort(String s) {
super(s);
value = SORTBY;
}
//-----------------------------------
public void Execute() {
int sortKey;
kids = data.getData();
for (int a = 0; a < args.size(); a++) {
ParseVar v = (ParseVar) args.elementAt(a);
if (v instanceof MultVar) {
MultVar mv = (MultVar) v;
Vector mvec = mv.getVector();
for (int k = mvec.size() - 1; k >= 0; k--) {
ParseVar pv = (ParseVar) mvec.elementAt(k);
sortKey = pv.getValue();
sortByKey(sortKey);
}
} else {
sortKey = v.getValue();
sortByKey(sortKey);
}
}
}
//----------------------------------------
private void sortByKey(int sortkey) {
System.out.println(sortkey);
for (int i = 0; i < kids.length; i++)
for (int j = i + 1; j < kids.length; j++)
if (compare(i, j, sortkey)) {
Kid tmp = kids[i];
kids[i] = kids[j];
kids[j] = tmp;
}
}
//----------------------------------------
private boolean compare(int i, int j, int key) {
boolean cval;
switch (key) {
case ParseVar.FRNAME:
cval = kids[i].getFrname().rupareTo(kids[j].getFrname()) > 0;
break;
case ParseVar.LNAME:
cval = kids[i].getLname().rupareTo(kids[j].getLname()) > 0;
break;
case ParseVar.CLUB:
cval = kids[i].getClub().rupareTo(kids[j].getClub()) > 0;
break;
case ParseVar.AGE:
cval = kids[i].getAge() > kids[j].getAge();
break;
case ParseVar.TIME:
cval = kids[i].getTime() > kids[j].getTime();
break;
default:
cval = false;
}
return cval;
}
} class Verb extends ParseVerb implements Command {
protected Data data;
protected JawtList ptable;
public Verb(String s) {
super(s);
}
public void Execute() {
}
public void setData(Data dt, JawtList pt) {
data = dt;
ptable = pt;
}
} class Print extends Verb {
Kid[] kids;
public Print(String s) {
super(s);
value = PRINT;
}
//-----------------------------------
public void Execute() {
String pline;
kids = data.getData();
//ptable.setDims(kids.length, args.size());
ptable.clear();
for (int i = 0; i < kids.length; i++) {
pline = ""; //line in output list
for (int j = 0; j < args.size(); j++) {
ParseVar v = (ParseVar) args.elementAt(j);
if (v instanceof MultVar) {
MultVar mv = (MultVar) v;
Vector vlist = mv.getVector();
for (int k = 0; k < vlist.size(); k++) {
ParseVar pv = (ParseVar) vlist.elementAt(k);
//System.out.print(kids[i].getData(pv.getValue())+" ");
pline += kids[i].getData(pv.getValue()) + " ";
}
} else {
// System.out.print(kids[i].getData(v.getValue())+" ");
//ptable.setValueAt( kids[i].getData(v.getValue()), i, j);
pline += kids[i].getData(v.getValue()) + " ";
}
}
ptable.add(pline);
//System.out.println();
}
ptable.validate();
ptable.repaint();
}
//-----------------------------------
} class MultVar extends ParseVar {
Vector multVec;
public MultVar(ParseObject v1, ParseObject v2) {
super("");
multVec = new Vector();
multVec.addElement(v1);
multVec.addElement(v2);
type = MULTVAR;
}
public MultVar() {
super("");
multVec = new Vector();
type = MULTVAR;
}
public void add(ParseObject v1) {
multVec.addElement(v1);
}
public Vector getVector() {
return multVec;
}
} class KidData {
Vector kids;
//------------------------------------------
public KidData(String filename) {
kids = new Vector();
InputFile f = new InputFile(filename);
String s = f.readLine();
while (s != null) {
if (s.trim().length() > 0) {
Kid k = new Kid(s);
kids.addElement(k);
}
s = f.readLine();
}
}
//--------------------------------
public Kid[] getData() {
Kid[] kd = new Kid[kids.size()];
for (int i = 0; i < kids.size(); i++)
kd[i] = (Kid) kids.elementAt(i);
return kd;
}
//--------------------------------
public int size() {
return kids.size();
}
//--------------------------------
public Kid getKid(int i) {
return (Kid) kids.elementAt(i);
}
//--------------------------------
public Vector getKidData(int key) {
Vector v = new Vector();
for (int i = 0; i < kids.size(); i++)
v.addElement(getKid(i).getData(key));
return v;
}
//--------------------------------
public int getTableKey(String tabName) {
int key = -1;
tabName = tabName.toLowerCase();
if (tabName.equals("frname"))
key = ParseVar.FRNAME;
if (tabName.equals("lname"))
key = ParseVar.LNAME;
if (tabName.equals("age"))
key = ParseVar.AGE;
if (tabName.equals("club"))
key = ParseVar.CLUB;
if (tabName.equals("time"))
key = ParseVar.TIME;
return key;
}
//----------------------------
public String getTableName(int i) {
String name = "";
switch (i) {
case ParseVar.FRNAME:
name = "frname";
case ParseVar.LNAME:
name = "lname";
case ParseVar.AGE:
name = "age";
case ParseVar.CLUB:
name = "club";
case ParseVar.TIME:
name = "time";
}
return name;
}
//----------------------------
} class InputFile {
RandomAccessFile f = null;
boolean errflag;
String s = null;
public InputFile(String fname) {
errflag = false;
try {
//open file
f = new RandomAccessFile(fname, "r");
} catch (IOException e) {
//print error if not found
System.out.println("no file found");
errflag = true; //and set flag
}
}
//-----------------------------------------
public boolean checkErr() {
return errflag;
}
//-----------------------------------------
public String read() {
//read a single field up to a comma or end of line
String ret = "";
if (s == null) //if no data in string
{
s = readLine(); //read next line
}
if (s != null) //if there is data
{
s.trim(); //trim off blanks
int i = s.indexOf(","); //find next comma
if (i <= 0) {
ret = s.trim(); //if no commas go to end of line
s = null; //and null out stored string
} else {
ret = s.substring(0, i).trim(); //return left of comma
s = s.substring(i + 1); //save right of comma
}
} else
ret = null;
return ret; //return string
}
//-----------------------------------------
public String readLine() {
//read in a line from the file
s = null;
try {
s = f.readLine(); //could throw error
} catch (IOException e) {
errflag = true;
System.out.println("File read error");
}
return s;
}
//-----------------------------------------
public void close() {
try {
f.close(); //close file
} catch (IOException e) {
System.out.println("File close error");
errflag = true;
}
}
//-----------------------------------------
} class Stack {
Vector stk;
public Stack() {
stk = new Vector();
}
//----------------------------------------
public void push(Object obj) {
stk.addElement(obj);
}
//----------------------------------------
public ParseObject pop() {
ParseObject obj = (ParseObject) stk.lastElement();
int i = stk.size() - 1;
stk.removeElementAt(i);
return obj;
}
//----------------------------------------
public void dump(String s) {
System.out.println(s);
dump();
}
//----------------------------------------
public void dump() {
for (int i = 0; i < stk.size(); i++) {
ParseObject p = (ParseObject) stk.elementAt(i);
System.out.println(i + " " + p.getType());
}
}
//----------------------------------------
public ParseObject top() {
return (ParseObject) stk.lastElement();
}
//----------------------------------------
public boolean hasMoreElements() {
return (stk.size() > 0);
}
//----------------------------------------
public ParseObject nextTop() {
int i = stk.size();
if (i > 1) {
return (ParseObject) stk.elementAt(i - 2);
} else
return null;
}
//----------------------------------------
public void pop2Push(ParseObject p) {
int i = stk.size();
if (i >= 2) {
pop();
pop();
push(p);
} else
push(p);
}
} //50free.txt /* 1 Amanda McCarthy 12 WCA 29.28 2 Jamie Falco 12 HNHS 29.80 3 Meaghan O"Donnell 12 EDST 30.00 4 Greer Gibbs 12 CDEV 30.04 5 Rhiannon Jeffrey 11 WYW 30.04 6 Sophie Connolly 12 WAC 30.05 7 Dana Helyer 12 ARAC 30.18 8 Lindsay Marotto 12 OAK 30.23 9 Sarah Treichel 12 WYW 30.35 10 Ashley McEntee 12 RAC 30.47 11 Rachel Brookman 12 CAT 30.51 12 Michelle Ducharme 12 LEHY 30.51 13 Karleen Danais 12 NES 30.70 14 Megan Loock 12 WAC 30.90 15 Kaitlyn Ament 12 HNHS 30.93 16 Tara Schoen 12 WYW 31.01 17 Kate Olshefski 12 NCY 31.01 18 Emma Zuidema 12 HMST 31.07 19 Katie Persing 12 OAK 31.14 20 Christina Monsees 11 RAC 31.27 21 Kimberly Watcke 12 CDEV 31.50 22 Colleen Smith 12 AJSC 31.52 23 Chloe Osborne 12 GYWD 31.74 24 Natalia Fugate 12 WAC 31.75 25 Lisa McHale 11 RAC 31.76 26 Lindsay Cowles 11 NES 31.79 27 Jacquelyn Yavarone 12 HNHS 31.83 28 Molly Fenn 12 WRAT 31.84 29 Karin Brudvig 12 HMST 31.84 30 Annie Duffy 12 MGAT 31.90 31 Nicole Coia 11 WCA 31.94 32 Elizabeth Rice 12 WYW 31.96 33 Yvette Landwehr 12 WRAT 32.00 34 Ashley Recklet 12 SHEL 32.24 35 Lauren McKenna 11 PSDY 32.27 36 Kristen Fontaine 12 EDST 32.28 37 Diana Cooke 12 ZEUS 32.33 38 Kimberly Gambino 11 NES 32.43 39 Jenny Morgan 11 NES 32.49 40 Colleen Coelho 12 CDEV 32.50 41 Leigh Gordon 12 CDEV 32.62 42 Caitlin Gillen 12 WYW 32.75 43 Kristen Skroski 12 HNHS 32.91 44 Sarah Greenberg 11 CDEV 32.97 45 Kathy Collins 12 EHBB 33.11 46 Morgan Bullock 12 ICSC 33.33 47 Brittany Medlin 12 CAT 33.33 48 Haley Ottenbreit 12 HNHS 33.35 49 Laura Kunces 11 WAC 33.64 50 Hayley Wolfgruber 12 WYW 33.73 51 Katie Duffy 12 MGAT 34.24
- /
</source>
