expression.java

一个工作流的原型

/*
 * Expression.java
 *
 * Created on 2005年1月9日, 上午10:17
 */

package workflow.xwfbox.tools;

import java.util.Vector;

import org.apache.oro.text.regex.*;

/**
 *
 * @author  Administrator
 */
public class Expression {
    
    /** Creates a new instance of Expression */
    public Expression() {
    }
    
    public Vector ParseCondition(String condtion) {
        Vector cond = new Vector();
        PatternCompiler compiler;
        PatternMatcher matcher;
        Pattern pattern   = null;
        String expression = "(\\D[a-zA-Z0-9_]*)\\s*(>=|<=|!=|<|>|==|)\\s*\\\"([^\"]*)\\\"";
        // Create Perl5Compiler and Perl5Matcher instances.
        compiler = new Perl5Compiler();
        matcher  = new Perl5Matcher();
        
        try {
          pattern = compiler.compile(expression);
        } catch(MalformedPatternException e) {
          System.err.println("Bad pattern.");
          System.err.println(e.getMessage());
        }
        
        if(matcher.matches(condtion, pattern)) {
          System.out.println("matches() Result: TRUE, EXACT MATCH");
          MatchResult result = matcher.getMatch();
          int i = result.groups();
          cond.add(result.group(1));
          cond.add(result.group(2));
          cond.add(result.group(3));
        } else 
          System.out.println("matches() Result: FALSE, NOT EXACT MATCH");
        
        return cond;
    }
    
    public static boolean computeExpression(String var1,String oper, String var2) {
        if (oper.equals("==")) {
            if (var1.compareTo(var2) == 0) return true; else return false;
        } else if (oper.equals("!=")) {
            if (var1.compareTo(var2) != 0) return true; else return false;
        } else if (oper.equals("<")) {
            if (var1.compareTo(var2) < 0) return true; else return false;
        } else if (oper.equals(">")) {
            if (var1.compareTo(var2) > 0) return true; else return false;
        } else if (oper.equals(">=")) {
            if (var1.compareTo(var2) >= 0) return true; else return false;
        } else if (oper.equals("<=")) {
            if (var1.compareTo(var2) <= 0) return true; else return false;
        }
        return false;
    }
}