abstractconfiguration.java

这是一个轻便的j2ee的web应用框架,是一个在多个项目中运用的实际框架,采用struts,hebinate,xml等技术,有丰富的tag,role,navigation,session,dictio

package com.esimple.framework.configuration;

/**
 * This is an abstract <code>Configuration</code> implementation that deals
 * with methods that can be abstracted away from underlying implementations.
 *
 */
abstract class AbstractConfiguration
    implements Configuration
{
    /**
     * Returns the prefix of the namespace.  This is only used as a serialization
     * hint, therefore is not part of the client API.  It should be included in
     * all Configuration implementations though.
     * @return A non-null String (defaults to "")
     * @throws ConfigurationException if no prefix was defined (prefix is
     * <code>null</code>.
     * @since 4.1
     */
    protected abstract String getPrefix() throws ConfigurationException;

    /**
     * Returns the value of the configuration element as an <code>int</code>.
     *
     * Hexadecimal numbers begin with 0x, Octal numbers begin with 0o and binary
     * numbers begin with 0b, all other values are assumed to be decimal.
     *
     * @throws ConfigurationException if an error occurs
     * @return the value
     */
    public int getValueAsInteger()
        throws ConfigurationException
    {
        final String value = getValue().trim();
        try
        {
            if( value.startsWith( "0x" ) )
            {
                return Integer.parseInt( value.substring( 2 ), 16 );
            }
            else if( value.startsWith( "0o" ) )
            {
                return Integer.parseInt( value.substring( 2 ), 8 );
            }
            else if( value.startsWith( "0b" ) )
            {
                return Integer.parseInt( value.substring( 2 ), 2 );
            }
            else
            {
                return Integer.parseInt( value );
            }
        }
        catch( final Exception nfe )
        {
            final String message =
                "Cannot parse the value \"" + value 
                + "\" as an integer in the configuration element \"" 
                + getName() + "\" at " + getLocation();
            throw new ConfigurationException( message );
        }
    }

    /**
     * Returns the value of the configuration element as an <code>int</code>.
     *
     * Hexadecimal numbers begin with 0x, Octal numbers begin with 0o and binary
     * numbers begin with 0b, all other values are assumed to be decimal.
     *
     * @param defaultValue the default value to return if value malformed or empty
     * @return the value
     */
    public int getValueAsInteger( final int defaultValue )
    {
        try
        {
            return getValueAsInteger();
        }
        catch( final ConfigurationException ce )
        {
            return defaultValue;
        }
    }

    /**
     * Returns the value of the configuration element as a <code>long</code>.
     *
     * Hexadecimal numbers begin with 0x, Octal numbers begin with 0o and binary
     * numbers begin with 0b, all other values are assumed to be decimal.
     *
     * @throws ConfigurationException if an error occurs
     * @return the value
     */
    public long getValueAsLong()
        throws ConfigurationException
    {
        final String value = getValue().trim();
        try
        {
            if( value.startsWith( "0x" ) )
            {
                return Long.parseLong( value.substring( 2 ), 16 );
            }
            else if( value.startsWith( "0o" ) )
            {
                return Long.parseLong( value.substring( 2 ), 8 );
            }
            else if( value.startsWith( "0b" ) )
            {
                return Long.parseLong( value.substring( 2 ), 2 );
            }
            else
            {
                return Long.parseLong( value );
            }
        }
        catch( final Exception nfe )
        {
            final String message =
                "Cannot parse the value \"" + value 
                + "\" as a long in the configuration element \"" 
                + getName() + "\" at " + getLocation();
            throw new ConfigurationException( message );
        }
    }

    /**
     * Returns the value of the configuration element as a <code>long</code>.
     *
     * Hexadecimal numbers begin with 0x, Octal numbers begin with 0o and binary
     * numbers begin with 0b, all other values are assumed to be decimal.
     *
     * @param defaultValue the default value to return if value malformed or empty
     * @return the value
     */
    public long getValueAsLong( final long defaultValue )
    {
        try
        {
            return getValueAsLong();
        }
        catch( final ConfigurationException ce )
        {
            return defaultValue;
        }
    }

    /**
     * Returns the value of the configuration element as a <code>float</code>.
     *
     * @throws ConfigurationException if an error occurs
     * @return the value
     */
    public float getValueAsFloat()
        throws ConfigurationException
    {
        final String value = getValue().trim();
        try
        {
            return Float.parseFloat( value );
        }
        catch( final Exception nfe )
        {
            final String message =
                "Cannot parse the value \"" + value 
                + "\" as a float in the configuration element \"" 
                + getName() + "\" at " + getLocation();
            throw new ConfigurationException( message );
        }
    }

    /**
     * Returns the value of the configuration element as a <code>float</code>.
     *
     * @param defaultValue the default value to return if value malformed or empty
     * @return the value
     */
    public float getValueAsFloat( final float defaultValue )
    {
        try
        {
            return getValueAsFloat();
        }
        catch( final ConfigurationException ce )
        {
            return ( defaultValue );
        }
    }

    /**
     * Returns the value of the configuration element as a <code>boolean</code>.
     *
     * @throws ConfigurationException if an error occurs
     * @return the value
     */
    public boolean getValueAsBoolean()
        throws ConfigurationException
    {
        final String value = getValue().trim();

        if( isTrue( value ) )
        {
            return true;
        }
        else if( isFalse( value ) )
        {
            return false;
        }
        else
        {
            final String message =
                "Cannot parse the value \"" + value 
                + "\" as a boolean in the configuration element \""
                + getName() + "\" at " + getLocation();
            throw new ConfigurationException( message );
        }
    }

    /**
     * Returns the value of the configuration element as a <code>boolean</code>.
     *
     * @param defaultValue the default value to return if value malformed or empty
     * @return the value
     */
    public boolean getValueAsBoolean( final boolean defaultValue )
    {
        try
        {
            return getValueAsBoolean();
        }
        catch( final ConfigurationException ce )
        {
            return defaultValue;
        }
    }

    /**
     * Returns the value of the configuration element as a <code>String</code>.
     *
     * @param defaultValue the default value to return if value malformed or empty
     * @return the value
     */
    public String getValue( final String defaultValue )
    {
        try
        {
            return getValue();
        }
        catch( final ConfigurationException ce )
        {
            return defaultValue;
        }
    }

    /**
     * Returns the value of the attribute specified by its name as an
     * <code>int</code>.
     *
     * Hexadecimal numbers begin with 0x, Octal numbers begin with 0o and binary
     * numbers begin with 0b, all other values are assumed to be decimal.
     *
     * @param name the name of the attribute
     * @throws ConfigurationException if an error occurs
     * @return the value
     */
    public int getAttributeAsInteger( final String name )
        throws ConfigurationException
    {
        final String value = getAttribute( name ).trim();
        try
        {
            if( value.startsWith( "0x" ) )
            {
                return Integer.parseInt( value.substring( 2 ), 16 );
            }
            else if( value.startsWith( "0o" ) )
            {
                return Integer.parseInt( value.substring( 2 ), 8 );
            }
            else if( value.startsWith( "0b" ) )
            {
                return Integer.parseInt( value.substring( 2 ), 2 );