org.litesoft.networkaddress.IPaddress Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of ipaddress Show documentation
Format Verification and normalization of IPv4 and IPv6 address
The newest version!
package org.litesoft.networkaddress;

import org.litesoft.annotations.NotNull;
import org.litesoft.annotations.Significant;
import org.litesoft.pragmatics.Context;

public class IPaddress {
    private static final Context CONTEXT = new Context( "IPaddress" );
    private static final int IPV6_LENGTH = 39;
    private static final int IPV4_MIN_LENGTH = 7;

    public static String validate( @NotNull Context context, @Significant String ipAddress ) {
        return new IPaddress( context, ipAddress ).check_either();
    }

    @SuppressWarnings("unused")
    public static String validate_v4( @NotNull Context context, @Significant String ipAddress ) {
        return new IPaddress( context, ipAddress ).check_v4();
    }

    @SuppressWarnings("unused")
    public static String validate_v6( @NotNull Context context, @Significant String ipAddress ) {
        return new IPaddress( context, ipAddress ).check_v6();
    }

    private final Context context;
    private final String ipAddress;

    private IPaddress( Context context, String ipAddress ) {
        this.context = NotNull.ConstrainTo.valueOr( context, CONTEXT );
        this.ipAddress = Significant.AssertArgument.contextValue( this.context, ipAddress );
    }

    String check_either() {
        return (ipAddress.length() == IPV6_LENGTH) ? check_v6() : check_v4();
    }

    String check_v4() {
        int len = ipAddress.length();
        if ( len < IPV4_MIN_LENGTH ) {
            throw error( "IP V4 must be at least " + IPV4_MIN_LENGTH + " characters, but was " + len );
        }
        String[] parts = ipAddress.split( "\\." );
        if ( parts.length != 4 ) {
            throw error( "IP V4 must be 4 sections, but found " + parts.length );
        }
        StringBuilder sb = new StringBuilder();
        for ( int i = 0; i < 4; i++ ) {
            sb.append( '.' ).append( checkV4section( i, parts[i] ) );
        }
        return sb.deleteCharAt( 0 ).toString();
    }

    private int checkV4section( int offset, String part ) {
        part = part.trim();
        try {
            int value = Integer.parseInt( part );
            if ( (0 <= value) && (value <= 255) ) {
                return value;
            }
            throw error( "IP V4 section " + (offset + 1) + " value not in range (0-255), but was " + value );
        }
        catch ( NumberFormatException e ) {
            throw error( "IP V4 section " + (offset + 1) + " value not a number, but was '" + part + "'" );
        }
    }

    String check_v6() {
        int len = ipAddress.length();
        if ( len != IPV6_LENGTH ) {
            throw error( "IP V6 expected length of " + IPV6_LENGTH + ", but was " + len );
        }
        String[] parts = ipAddress.split( ":" );
        if ( parts.length != 8 ) {
            throw error( "IP V6 must be 8 sections, but found " + parts.length );
        }
        StringBuilder sb = new StringBuilder();
        for ( int i = 0; i < 8; i++ ) {
            sb.append( ':' ).append( checkV6section( i, parts[i] ) );
        }
        return sb.deleteCharAt( 0 ).toString();
    }

    private String checkV6section( int offset, String part ) {
        if ( part.length() == 4 ) {
            StringBuilder sb = new StringBuilder();
            for ( int i = 0; i < 4; i++ ) {
                sb.append( normalizeHex( part.charAt( i ) ) );
            }
            if ( sb.length() == 4 ) {
                return sb.toString();
            }
        }
        throw error( "IP V6 section " + (offset + 1) + " value not 4 Hexa-Decimal 'digits', but was '" + part + "'" );
    }

    private Character normalizeHex( char c ) {
        if ( ('0' <= c) && (c <= '9') ) {
            return c;
        }
        c = Character.toUpperCase( c );
        if ( ('A' <= c) && (c <= 'F') ) {
            return c;
        }
        return null;
    }

    IllegalArgumentException error( String why ) {
        return new IllegalArgumentException( context.get() + " " + why + ", IP Address was: " + ipAddress );
    }
}