scriptella.configuration.XmlConfigurableBase Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of scriptella-core Show documentation
The newest version!
/*
 * Copyright 2006-2012 The Scriptella Project Team.
 *
 * 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 scriptella.configuration;

import scriptella.core.SystemException;

import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.List;
import java.util.regex.Pattern;


/**
 * Base class for configuration elements.
 */
public abstract class XmlConfigurableBase implements XmlConfigurable {
    private Location location;

    protected void setRequiredProperty(final XmlElement element,
                                       final String attribute, final String property) {
        setProperty(element, attribute, property);
        assertRequiredFieldPresent(element, attribute, property);
    }

    /**
     * @see #setProperty(XmlElement, String, String)
     */
    protected void setProperty(final XmlElement element, final String attribute) {
        setProperty(element, attribute, attribute);
    }

    /**
     * Sets property on this object using attribute value.
     *
     * @param element   element to get attribute.
     * @param attribute attribute name
     * @param property  property name.
     */
    protected void setProperty(final XmlElement element,
                               final String attribute, final String property) {
        String attributeValue = element.getAttribute(attribute);

        try {
            final Method method = findSetter(property);
            method.invoke(this, attributeValue);
        } catch (Exception e) {
            throw new ConfigurationException("Unable to set property " +
                    property + " from attribute " + attribute, e, element);
        }
    }

    /**
     * @see #setPatternProperty(XmlElement, String, String)
     */
    protected void setPatternProperty(final XmlElement element, final String property) {
        setPatternProperty(element, property, property);
    }

    /**
     * Sets {@link Pattern} property on this object using attribute value.
     *
     * @param element   element to get attribute.
     * @param attribute attribute name
     * @param property  property name.
     */
    protected void setPatternProperty(final XmlElement element,
                                      final String attribute, final String property) {
        String ptrStr = element.getAttribute(attribute);
        Pattern ptr = null;
        if (ptrStr != null) {
            try {
                //We use multiline+case insensitive patterns
                ptr = Pattern.compile(ptrStr, Pattern.CASE_INSENSITIVE + Pattern.DOTALL);
            } catch (Exception e) {
                throw new ConfigurationException("Attribute " + attribute + " requires valid regular expression, but was: " +
                        ptrStr, e, element);
            }
        }
        try {
            final Method method = getClass().getMethod(
                    "set" + Character.toUpperCase(property.charAt(0)) + property.substring(1), Pattern.class);
            method.invoke(this, ptr);
        } catch (Exception e) {
            throw new ConfigurationException("Unable to set property " +
                    property + " from attribute " + attribute, e, element);
        }


    }

    protected Method findSetter(final String property)
            throws NoSuchMethodException {
        //TODO Add methods cache
        return getClass()
                .getMethod("set" +
                        Character.toUpperCase(property.charAt(0)) + property.substring(1),
                        String.class);
    }

    protected Method findGetter(final String property)
            throws NoSuchMethodException {
        return getClass()
                .getMethod("get" + Character.toUpperCase(property.charAt(0)) + property.substring(1));
    }

    protected void setRequiredProperty(final XmlElement element,
                                       final String attribute) {
        setRequiredProperty(element, attribute, attribute);
    }

    protected  T loadClass(final XmlElement element, final String attribute,
                              final Class spec) {
        final String h = element.getAttribute(attribute);

        if (h == null) {
            return null;
        }

        Class c = null;

        try {
            c = Class.forName(h);
        } catch (ClassNotFoundException e) {
            throw new scriptella.configuration.ConfigurationException(
                    "Invalid class " + h, e, element);
        }

        if (!spec.isAssignableFrom(c)) {
            throw new scriptella.configuration.ConfigurationException("Class " +
                    c + " doesn't implement " + spec, element);
        }

        try {
            return (T) c.newInstance();
        } catch (Exception e) {
            throw new scriptella.configuration.ConfigurationException(
                    "Unable to instantiate class " + c, element);
        }
    }

    protected  List load(
            final List elements, final Class clazz) {
        if (elements == null) {
            return null;
        }

        List l = new ArrayList(elements.size());

        for (XmlElement element : elements) {
            try {
                T t = clazz.newInstance();
                t.configure(element);
                l.add(t);
            } catch (InstantiationException e) {
                throw new SystemException(e);
            } catch (IllegalAccessException e) {
                throw new SystemException(e);
            }
        }

        return l;
    }

    protected void assertRequiredFieldPresent(final XmlElement element,
                                              final String attribute, final String property) {
        try {
            final Method getter = findGetter(property);

            if (getter.invoke(this, (Object[]) null) == null) {
                throw new RequiredAttributeException(attribute, element);
            }
        } catch (ConfigurationException e) {
            throw e;
        } catch (Exception e) {
            throw new RequiredAttributeException(attribute, e, element);
        }
    }

    protected void assertRequiredFieldPresent(final XmlElement element,
                                              final String property) {
        assertRequiredFieldPresent(element, property, property);
    }

    /**
     * Called by elements wishing to report their location in XML.
     *
     * @param element  element to calculate location
     */
    protected void setLocation(XmlElement element) {
        location = new Location(element.getXPath());
    }

    protected void setLocation(Location location) {
        this.location = location;
    }

    protected Location getLocation() {
        return location;
    }
}