beanutilsbean.java

APACHE 公司出的java bean 工具包

            String[] results = new String[n];
            for (int i = 0; i < n; i++) {
                Object item = Array.get(value, i);
                if (item == null) {
                    results[i] = null;
                } else {
                    // convert to string using convert utils
                    results[i] = getConvertUtils().convert(item);
                }
            }
            return (results);
        } else {
            String[] results = new String[1];
            results[0] = getConvertUtils().convert(value);
            return (results);
        }

    }


    /**
     * Return the value of the specified indexed property of the specified
     * bean, as a String.  The zero-relative index of the
     * required value must be included (in square brackets) as a suffix to
     * the property name, or <code>IllegalArgumentException</code> will be
     * thrown.
     *
     * @param bean Bean whose property is to be extracted
     * @param name <code>propertyname[index]</code> of the property value
     *  to be extracted
     * @return The indexed property's value, converted to a String
     *
     * @exception IllegalAccessException if the caller does not have
     *  access to the property accessor method
     * @exception InvocationTargetException if the property accessor method
     *  throws an exception
     * @exception NoSuchMethodException if an accessor method for this
     *  property cannot be found
     */
    public String getIndexedProperty(Object bean, String name)
            throws IllegalAccessException, InvocationTargetException,
            NoSuchMethodException {

        Object value = getPropertyUtils().getIndexedProperty(bean, name);
        return (getConvertUtils().convert(value));

    }


    /**
     * Return the value of the specified indexed property of the specified
     * bean, as a String.  The index is specified as a method parameter and
     * must *not* be included in the property name expression
     *
     * @param bean Bean whose property is to be extracted
     * @param name Simple property name of the property value to be extracted
     * @param index Index of the property value to be extracted
     * @return The indexed property's value, converted to a String
     *
     * @exception IllegalAccessException if the caller does not have
     *  access to the property accessor method
     * @exception InvocationTargetException if the property accessor method
     *  throws an exception
     * @exception NoSuchMethodException if an accessor method for this
     *  property cannot be found
     */
    public String getIndexedProperty(Object bean,
                                            String name, int index)
            throws IllegalAccessException, InvocationTargetException,
            NoSuchMethodException {

        Object value = getPropertyUtils().getIndexedProperty(bean, name, index);
        return (getConvertUtils().convert(value));

    }


    /**
     * Return the value of the specified indexed property of the specified
     * bean, as a String.  The String-valued key of the required value
     * must be included (in parentheses) as a suffix to
     * the property name, or <code>IllegalArgumentException</code> will be
     * thrown.
     *
     * @param bean Bean whose property is to be extracted
     * @param name <code>propertyname(index)</code> of the property value
     *  to be extracted
     * @return The mapped property's value, converted to a String
     *
     * @exception IllegalAccessException if the caller does not have
     *  access to the property accessor method
     * @exception InvocationTargetException if the property accessor method
     *  throws an exception
     * @exception NoSuchMethodException if an accessor method for this
     *  property cannot be found
     */
    public String getMappedProperty(Object bean, String name)
            throws IllegalAccessException, InvocationTargetException,
            NoSuchMethodException {

        Object value = getPropertyUtils().getMappedProperty(bean, name);
        return (getConvertUtils().convert(value));

    }


    /**
     * Return the value of the specified mapped property of the specified
     * bean, as a String.  The key is specified as a method parameter and
     * must *not* be included in the property name expression
     *
     * @param bean Bean whose property is to be extracted
     * @param name Simple property name of the property value to be extracted
     * @param key Lookup key of the property value to be extracted
     * @return The mapped property's value, converted to a String
     *
     * @exception IllegalAccessException if the caller does not have
     *  access to the property accessor method
     * @exception InvocationTargetException if the property accessor method
     *  throws an exception
     * @exception NoSuchMethodException if an accessor method for this
     *  property cannot be found
     */
    public String getMappedProperty(Object bean,
                                           String name, String key)
            throws IllegalAccessException, InvocationTargetException,
            NoSuchMethodException {

        Object value = getPropertyUtils().getMappedProperty(bean, name, key);
        return (getConvertUtils().convert(value));

    }


    /**
     * Return the value of the (possibly nested) property of the specified
     * name, for the specified bean, as a String.
     *
     * @param bean Bean whose property is to be extracted
     * @param name Possibly nested name of the property to be extracted
     * @return The nested property's value, converted to a String
     *
     * @exception IllegalAccessException if the caller does not have
     *  access to the property accessor method
     * @exception IllegalArgumentException if a nested reference to a
     *  property returns null
     * @exception InvocationTargetException if the property accessor method
     *  throws an exception
     * @exception NoSuchMethodException if an accessor method for this
     *  property cannot be found
     */
    public String getNestedProperty(Object bean, String name)
            throws IllegalAccessException, InvocationTargetException,
            NoSuchMethodException {

        Object value = getPropertyUtils().getNestedProperty(bean, name);
        return (getConvertUtils().convert(value));

    }


    /**
     * Return the value of the specified property of the specified bean,
     * no matter which property reference format is used, as a String.
     *
     * @param bean Bean whose property is to be extracted
     * @param name Possibly indexed and/or nested name of the property
     *  to be extracted
     * @return The property's value, converted to a String
     *
     * @exception IllegalAccessException if the caller does not have
     *  access to the property accessor method
     * @exception InvocationTargetException if the property accessor method
     *  throws an exception
     * @exception NoSuchMethodException if an accessor method for this
     *  property cannot be found
     */
    public String getProperty(Object bean, String name)
            throws IllegalAccessException, InvocationTargetException,
            NoSuchMethodException {

        return (getNestedProperty(bean, name));

    }


    /**
     * Return the value of the specified simple property of the specified
     * bean, converted to a String.
     *
     * @param bean Bean whose property is to be extracted
     * @param name Name of the property to be extracted
     * @return The property's value, converted to a String
     *
     * @exception IllegalAccessException if the caller does not have
     *  access to the property accessor method
     * @exception InvocationTargetException if the property accessor method
     *  throws an exception
     * @exception NoSuchMethodException if an accessor method for this
     *  property cannot be found
     */
    public String getSimpleProperty(Object bean, String name)
            throws IllegalAccessException, InvocationTargetException,
            NoSuchMethodException {

        Object value = getPropertyUtils().getSimpleProperty(bean, name);
        return (getConvertUtils().convert(value));

    }


    /**
     * <p>Populate the JavaBeans properties of the specified bean, based on
     * the specified name/value pairs.  This method uses Java reflection APIs
     * to identify corresponding "property setter" method names, and deals
     * with setter arguments of type <code>String</code>, <code>boolean</code>,
     * <code>int</code>, <code>long</code>, <code>float</code>, and
     * <code>double</code>.  In addition, array setters for these types (or the
     * corresponding primitive types) can also be identified.</p>
     * 
     * <p>The particular setter method to be called for each property is
     * determined using the usual JavaBeans introspection mechanisms.  Thus,
     * you may identify custom setter methods using a BeanInfo class that is
     * associated with the class of the bean itself.  If no such BeanInfo
     * class is available, the standard method name conversion ("set" plus
     * the capitalized name of the property in question) is used.</p>
     * 
     * <p><strong>NOTE</strong>:  It is contrary to the JavaBeans Specification
     * to have more than one setter method (with different argument
     * signatures) for the same property.</p>
     *
     * <p><strong>WARNING</strong> - The logic of this method is customized
     * for extracting String-based request parameters from an HTTP request.
     * It is probably not what you want for general property copying with
     * type conversion.  For that purpose, check out the
     * <code>copyProperties()</code> method instead.</p>
     *
     * @param bean JavaBean whose properties are being populated
     * @param properties Map keyed by property name, with the
     *  corresponding (String or String[]) value(s) to be set
     *
     * @exception IllegalAccessException if the caller does not have
     *  access to the property accessor method
     * @exception InvocationTargetException if the property accessor method
     *  throws an exception
     */
    public void populate(Object bean, Map properties)
        throws IllegalAccessException, InvocationTargetException {

        // Do nothing unless both arguments have been specified
        if ((bean == null) || (properties == null)) {
            return;
        }
        if (log.isDebugEnabled()) {
            log.debug("BeanUtils.populate(" + bean + ", " +
                    properties + ")");
        }

        // Loop through the property name/value pairs to be set
        Iterator names = properties.keySet().iterator();
        while (names.hasNext()) {

            // Identify the property name and value(s) to be assigned
            String name = (String) names.next();
            if (name == null) {
                continue;
            }
            Object value = properties.get(name);

            // Perform the assignment for this property
            setProperty(bean, name, value);

        }

    }


    /**
     * <p>Set the specified property value, performing type conversions as