Groovy example source code file (GStringExpression.java)

This example Groovy source code file (GStringExpression.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Groovy tags/keywords

arraylist, cannot, constantexpression, expression, expression, gstringexpression, gstringexpression, list, list, nullpointerexception, object, string, string, stringbuffer, util

The Groovy GStringExpression.java source code

/*
 * Copyright 2003-2007 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.codehaus.groovy.ast.expr;

import java.util.ArrayList;
import java.util.List;

import org.codehaus.groovy.ast.ClassHelper;
import org.codehaus.groovy.ast.GroovyCodeVisitor;

/**
 * Represents a String expression which contains embedded values inside
 * it such as "hello there ${user} how are you" which is expanded lazily
 * 
 * @author <a href="mailto:james@coredevelopers.net">James Strachan
 * @version $Revision: 15807 $
 */
public class GStringExpression extends Expression {

    private String verbatimText;
    private List<ConstantExpression> strings = new ArrayList();
    private List<Expression> values = new ArrayList();
    
    public GStringExpression(String verbatimText) {
        this.verbatimText = verbatimText;
        super.setType(ClassHelper.GSTRING_TYPE);
    }

    public GStringExpression(String verbatimText, List<ConstantExpression> strings, List values) {
        this.verbatimText = verbatimText;
        this.strings = strings;
        this.values = values;
        super.setType(ClassHelper.GSTRING_TYPE);
    }

    public void visit(GroovyCodeVisitor visitor) {
        visitor.visitGStringExpression(this);
    }

    public Expression transformExpression(ExpressionTransformer transformer) {
        Expression ret = new GStringExpression(
                verbatimText,
                transformExpressions(strings, transformer, ConstantExpression.class),
                transformExpressions(values, transformer));
        ret.setSourcePosition(this);
        return ret;        
    }

    public String toString() {
        return super.toString() + "[strings: " + strings + " values: " + values + "]";
    }

    public String getText() {
        return verbatimText;
    }

    public List<ConstantExpression> getStrings() {
        return strings;
    }

    public List<Expression> getValues() {
        return values;
    }

    public void addString(ConstantExpression text) {
        if (text == null) {
            throw new NullPointerException("Cannot add a null text expression");
        }
        strings.add(text);
    }

    public void addValue(Expression value) {
        // If the first thing is an value, then we need a dummy empty string in front of it so that when we
        // toString it they come out in the correct order.
        if (strings.size() == 0)
            strings.add(ConstantExpression.EMPTY_STRING);
        values.add(value);
    }

    public Expression getValue(int idx) {
        return values.get(idx);
    }

    public boolean isConstantString() {
        return values.isEmpty();
    }

    public Expression asConstantString() {
        StringBuffer buffer = new StringBuffer();
        for (ConstantExpression expression : strings) {
            Object value = expression.getValue();
            if (value != null) {
                buffer.append(value);
            }
        }
        return new ConstantExpression(buffer.toString());
    }
}