owsutils.java

电子地图服务器,搭建自己的地图服务

/* Copyright (c) 2001 - 2007 TOPP - www.openplans.org. All rights reserved.
 * This code is licensed under the GPL 2.0 license, availible at the root
 * application directory.
 */
package org.geoserver.ows.util;

import java.lang.reflect.Method;


/**
 * Utility class for performing reflective operations.
 *
 * @author Justin Deoliveira, The Open Planning Project
 *
 */
public class OwsUtils {
    
    /**
     * Returns a setter method for a property of java bean.
     * <p>
     * The <tt>type</tt> parameter may be <code>null</code> to indicate the 
     * the setter for the property should be returned regardless of the type. If
     * not null it will be used to filter the returned method.
     * </p>
     * @param clazz The type of the bean.
     * @param property The property name.
     * @param type The type of the property, may be <code>null</code>.
     *
     * @return The setter method, or <code>null</code> if not found.
     */
    public static Method setter(Class clazz, String property, Class type) {
        //TODO: this lookup doesn't deal with classes that might have two setters
        // that are in the same class hierachy
        Method[] methods = clazz.getMethods();

        final String methodName = "set" + property;
        for (int i = 0; i < methods.length; i++) {
            Method method = methods[i];

            if (method.getName().equalsIgnoreCase(methodName)) {
                if (method.getParameterTypes().length == 1) {
                    if ( type != null ) {
                        if (method.getParameterTypes()[0].isAssignableFrom(type)) {
                            return method;
                        }
                    }
                    else {
                        return method;
                    }
                }
            }
        }

        //nto found, check for case where setter property is primtive and the 
        // class specified is its wrapper class
        if ( type != null ) {
            for (int i = 0; i < methods.length; i++) {
                Method method = methods[i];

                if (method.getName().equalsIgnoreCase(methodName)) {
                    if ((method.getParameterTypes().length == 1)) {
                        Class target =  method.getParameterTypes()[0];
                        if ( target.isPrimitive() && type == wrapper( target ) ) {
                            return method;
                        }
                        
                        if ( type.isPrimitive() && target == wrapper( type ) ) {
                            return method;
                        }
                    }
                }
            }
        }
        
        
        //could not be found, try again with a more lax match
        String lax = lax(property);

        if (!lax.equals(property)) {
            return setter(clazz, lax, type);
        }

        return null;
    }

    /**
     * Returns a getter method for a property of java bean.
     *
     * @param clazz The type of the bean.
     * @param property The property name.
     * @param type The type of the property, may be null.
     *
     * @return The setter method, or <code>null</code> if not found.
     */
    public static Method getter(Class clazz, String property, Class type) {
        //TODO: this lookup doesn't deal with classes that might have two setters
        // that are in the same class hierachy
        Method[] methods = clazz.getMethods();

        for (int i = 0; i < methods.length; i++) {
            Method method = methods[i];

            if (method.getName().equalsIgnoreCase("get" + property)) {
                if (type != null) {
                    if (type.equals(method.getReturnType())) {
                        return method;
                    }
                } else {
                    return method;
                }
            }
        }

        //check for case where one of the classes is primitive and the other
        // is a wrapper
        if ( type != null ) {
            for (int i = 0; i < methods.length; i++) {
                Method method = methods[i];

                if (method.getName().equalsIgnoreCase("get" + property)) {
                   Class target = method.getReturnType();
                   if ( target != null ) {
                       
                       if ( target.isPrimitive() && type == wrapper( target ) ) {
                           return method;
                       }
                       if ( type.isPrimitive() && target == wrapper( type ) ) {
                           return method;
                       }

                   }
                }
            }
        }
       
        
        //could not be found, try again with a more lax match
        String lax = lax(property);

        if (!lax.equals(property)) {
            return getter(clazz, lax, type);
        }

        return null;
    }

    /**
     * Reflectivley retreives a propety from a java bean.
     *
     * @param object The java bean.
     * @param property The property to retreive.
     * @param type Teh type of the property to retreive.
     *
     * @return The property, or null if it could not be found..
     */
    public static Object property(Object object, String property, Class type) {
        Method getter = getter(object.getClass(), property, type);

        if (getter != null) {
            try {
                return getter.invoke(object, null);
            } catch (Exception e) {
                //TODO: log this
            }
        }

        return null;
    }

    /**
     * Returns a method with a pariticular name of a class, ignoring method
     * paramters.
     *
     * @param clazz The class
     * @param name The name of the method.
     *
     * @return The method, or <code>null</code> if it could not be found.
     */
    public static Method method(Class clazz, String name) {
        Method[] methods = clazz.getMethods();

        for (int i = 0; i < methods.length; i++) {
            Method method = methods[i];

            if (method.getName().equalsIgnoreCase(name)) {
                return method;
            }
        }

        return null;
    }

    /**
     * Returns an object of a particular type in a list of objects of
     * various types.
     *
     * @param parameters A list of objects, of various types.
     * @param type The type of paramter to be returned.
     *
     * @return The object of the specified type, or <code>null</code>
     */
    public static Object parameter(Object[] parameters, Class type) {
        for (int i = 0; i < parameters.length; i++) {
            Object parameter = parameters[i];

            if ((parameter != null) && type.isAssignableFrom(parameter.getClass())) {
                return parameter;
            }
        }

        return null;
    }

    /**
     * Returns the wrapper class for a primitive class.
     * 
     * @param primitive A primtive class, like int.class, double.class, etc...
     */
    static Class wrapper( Class primitive ) {
        if ( boolean.class == primitive ) {
            return Boolean.class;
        }
        if ( char.class == primitive ) {
            return Character.class;
        }
        if ( byte.class == primitive ) {
            return Byte.class;
        }
        if ( short.class == primitive ) {
            return Short.class;
        }
        if ( int.class == primitive ) {
            return Integer.class;
        }
        if ( long.class == primitive ) {
            return Long.class;
        }
        
        if ( float.class == primitive ) {
            return Float.class;
        }
        if ( double.class == primitive ) {
            return Double.class;
        }
        
        return null;
    }
    
    /**
     * Does some checks on the property name to turn it into a java bean property.
     * <p>
     * Checks include collapsing any "_" characters.
     * </p>
     */
    static String lax(String property) {
        return property.replaceAll("_", "");
    }
}