org.apache.commons.configuration.GInterpolator.java Source code

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Here is the source code for org.apache.commons.configuration.GInterpolator.java

Source

package org.apache.commons.configuration;

import java.util.HashMap;
import java.util.Map;

import groovy.lang.Binding;
import groovy.lang.GroovyShell;

public class GInterpolator implements Interpolator {
    Binding _binding;
    GroovyShell _shell;
    Configuration _conf;
    Map _cache = null;
    String[] _imports = null;

    public GInterpolator(Configuration conf, boolean cache, String[] imports, Map utils) {
        _conf = conf;
        _binding = new ConfigurationBinding(conf, utils);
        _shell = new GroovyShell(_binding);
        setCache(cache);
        _imports = imports;
    }

    public GInterpolator(Configuration conf) {
        this(conf, false, null, null);
    }

    public void setCache(boolean cache) {
        if (cache)
            _cache = new HashMap();
    }

    public Object interpolate(Object value) {
        if (!(value instanceof String))
            return value;
        if (_cache != null) {
            Object cachedResult = _cache.get(value);
            if (cachedResult != null)
                return cachedResult;
        }
        String result = (String) value;
        int i = result.lastIndexOf("${");
        while (i != -1) {
            int r = getExpression(result, i + 2);
            String expression = result.substring(i + 2, r);
            String eval = evaluate(expression);
            String p1 = result.substring(0, i);
            String p2 = result.substring(r + 1);
            result = p1 + eval + p2;
            i = result.lastIndexOf("${");
        }
        if (_cache != null)
            _cache.put(value, result);
        return result;

    }

    private int getExpression(String value, int i) {
        int i1 = value.indexOf('{', i);
        int i2 = value.indexOf('}', i);
        while (i1 != -1 && i2 > i1) {
            i2 = value.indexOf('}', i1);
            i1 = value.indexOf('{', i1 + 1);
        }

        return i2;
    }

    private String evaluate(String value) {
        String result = (String) _conf.getString(value);
        if (result == null)
            try {
                if (_imports != null)
                    for (String im : _imports) {
                        value = "import " + im + "\n" + value;
                    }
                result = _shell.evaluate(value).toString();
            } catch (Exception ex) {
                ex.printStackTrace();
            }
        if (result == null)
            result = value;
        return result;

    }

}