Author: elecharny
Date: Sat Mar 2 10:11:18 2013
New Revision: 1451870
URL: http://svn.apache.org/r1451870
Log:
Added some utility methods
Added:
labs/mavibot/trunk/mavibot/src/main/java/org/apache/mavinot/
labs/mavibot/trunk/mavibot/src/main/java/org/apache/mavinot/btree/
labs/mavibot/trunk/mavibot/src/main/java/org/apache/mavinot/btree/utils/
labs/mavibot/trunk/mavibot/src/main/java/org/apache/mavinot/btree/utils/Strings.java
Added:
labs/mavibot/trunk/mavibot/src/main/java/org/apache/mavinot/btree/utils/Strings.java
URL:
http://svn.apache.org/viewvc/labs/mavibot/trunk/mavibot/src/main/java/org/apache/mavinot/btree/utils/Strings.java?rev=1451870&view=auto
==============================================================================
---
labs/mavibot/trunk/mavibot/src/main/java/org/apache/mavinot/btree/utils/Strings.java
(added)
+++
labs/mavibot/trunk/mavibot/src/main/java/org/apache/mavinot/btree/utils/Strings.java
Sat Mar 2 10:11:18 2013
@@ -0,0 +1,540 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you 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 org.apache.mavinot.btree.utils;
+
+
+import java.io.UnsupportedEncodingException;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+
+/**
+ * Various string manipulation methods that are more efficient then chaining
+ * string operations: all is done in the same buffer without creating a bunch
of
+ * string objects.
+ *
+ * @author <a href="mailto:[email protected]";>Mavibot labs Project</a>
+ */
+public final class Strings
+{
+ /** Hex chars */
+ private static final byte[] HEX_CHAR = new byte[]
+ { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C',
'D', 'E', 'F' };
+
+ /** A empty byte array */
+ public static final byte[] EMPTY_BYTES = new byte[0];
+
+
+ /**
+ * Helper function that dump an array of bytes in hex form
+ *
+ * @param buffer The bytes array to dump
+ * @return A string representation of the array of bytes
+ */
+ public static String dumpBytes( byte[] buffer )
+ {
+ if ( buffer == null )
+ {
+ return "";
+ }
+
+ StringBuffer sb = new StringBuffer();
+
+ for ( byte b : buffer )
+ {
+ sb.append( "0x" ).append( ( char ) ( HEX_CHAR[( b & 0x00F0 ) >> 4]
) ).append(
+ ( char ) ( HEX_CHAR[b & 0x000F] ) ).append( " " );
+ }
+
+ return sb.toString();
+ }
+
+
+ /**
+ * Helper function that dump a byte in hex form
+ *
+ * @param octet The byte to dump
+ * @return A string representation of the byte
+ */
+ public static String dumpByte( byte octet )
+ {
+ return new String( new byte[]
+ { '0', 'x', HEX_CHAR[( octet & 0x00F0 ) >> 4], HEX_CHAR[octet &
0x000F] } );
+ }
+
+
+ /**
+ * Helper function that returns a char from an hex
+ *
+ * @param hex The hex to dump
+ * @return A char representation of the hex
+ */
+ public static char dumpHex( byte hex )
+ {
+ return ( char ) HEX_CHAR[hex & 0x000F];
+ }
+
+
+ /**
+ * Helper function that dump an array of bytes in hex pair form,
+ * without '0x' and space chars
+ *
+ * @param buffer The bytes array to dump
+ * @return A string representation of the array of bytes
+ */
+ public static String dumpHexPairs( byte[] buffer )
+ {
+ if ( buffer == null )
+ {
+ return "";
+ }
+
+ char[] str = new char[buffer.length << 1];
+
+ int pos = 0;
+
+ for ( byte b : buffer )
+ {
+ str[pos++] = ( char ) ( HEX_CHAR[( b & 0x00F0 ) >> 4] );
+ str[pos++] = ( char ) ( HEX_CHAR[b & 0x000F] );
+ }
+
+ return new String( str );
+ }
+
+
+ /**
+ * Gets a hex string from byte array.
+ *
+ * @param res the byte array
+ * @return the hex string representing the binary values in the array
+ */
+ public static String toHexString( byte[] res )
+ {
+ StringBuffer buf = new StringBuffer( res.length << 1 );
+
+ for ( byte b : res )
+ {
+ String digit = Integer.toHexString( 0xFF & b );
+
+ if ( digit.length() == 1 )
+ {
+ digit = '0' + digit;
+ }
+
+ buf.append( digit );
+ }
+
+ return buf.toString().toUpperCase();
+ }
+
+
+ /**
+ * Get byte array from hex string
+ *
+ * @param hexString the hex string to convert to a byte array
+ * @return the byte form of the hex string.
+ */
+ public static byte[] toByteArray( String hexString )
+ {
+ int arrLength = hexString.length() >> 1;
+ byte[] buf = new byte[arrLength];
+
+ for ( int ii = 0; ii < arrLength; ii++ )
+ {
+ int index = ii << 1;
+
+ String digit = hexString.substring( index, index + 2 );
+ buf[ii] = ( byte ) Integer.parseInt( digit, 16 );
+ }
+
+ return buf;
+ }
+
+ private static final byte[] UTF8 = new byte[]
+ { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A,
+ 0x0B, 0x0C, 0x0D, 0x0E, 0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15,
0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C,
+ 0x1D, 0x1E, 0x1F, 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27,
0x28, 0x29, 0x2A, 0x2B, 0x2C, 0x2D, 0x2E,
+ 0x2F, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39,
0x3A, 0x3B, 0x3C, 0x3D, 0x3E, 0x3F, 0x40,
+ 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4A, 0x4B,
0x4C, 0x4D, 0x4E, 0x4F, 0x50, 0x51, 0x52,
+ 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59, 0x5A, 0x5B, 0x5C, 0x5D,
0x5E, 0x5F, 0x60, 0x61, 0x62, 0x63, 0x64,
+ 0x65, 0x66, 0x67, 0x68, 0x69, 0x6A, 0x6B, 0x6C, 0x6D, 0x6E, 0x6F,
0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76,
+ 0x77, 0x78, 0x79, 0x7A, 0x7B, 0x7C, 0x7D, 0x7E, 0x7F };
+
+
+ /**
+ * Return an UTF-8 encoded String
+ *
+ * @param bytes The byte array to be transformed to a String
+ * @return A String.
+ */
+ public static String utf8ToString( byte[] bytes )
+ {
+ if ( bytes == null )
+ {
+ return "";
+ }
+
+ char[] chars = new char[bytes.length];
+ int pos = 0;
+
+ try
+ {
+ for ( byte b : bytes )
+ {
+ chars[pos++] = ( char ) UTF8[b];
+ }
+ }
+ catch ( ArrayIndexOutOfBoundsException aioobe )
+ {
+ try
+ {
+ return new String( bytes, "UTF-8" );
+ }
+ catch ( UnsupportedEncodingException uee )
+ {
+ // if this happens something is really strange
+ throw new RuntimeException( uee );
+ }
+ }
+
+ return new String( chars );
+ }
+
+
+ /**
+ * Return an UTF-8 encoded String
+ *
+ * @param bytes The byte array to be transformed to a String
+ * @param length The length of the byte array to be converted
+ * @return A String.
+ */
+ public static String utf8ToString( byte[] bytes, int length )
+ {
+ if ( bytes == null )
+ {
+ return "";
+ }
+
+ try
+ {
+ return new String( bytes, 0, length, "UTF-8" );
+ }
+ catch ( UnsupportedEncodingException uee )
+ {
+ // if this happens something is really strange
+ throw new RuntimeException( uee );
+ }
+ }
+
+
+ /**
+ * Return an UTF-8 encoded String
+ *
+ * @param bytes The byte array to be transformed to a String
+ * @param start the starting position in the byte array
+ * @param length The length of the byte array to be converted
+ * @return A String.
+ */
+ public static String utf8ToString( byte[] bytes, int start, int length )
+ {
+ if ( bytes == null )
+ {
+ return "";
+ }
+
+ try
+ {
+ return new String( bytes, start, length, "UTF-8" );
+ }
+ catch ( UnsupportedEncodingException uee )
+ {
+ // if this happens something is really strange
+ throw new RuntimeException( uee );
+ }
+ }
+
+
+ /**
+ * <p>
+ * Checks if a String is empty ("") or null.
+ * </p>
+ *
+ * <pre>
+ * StringUtils.isEmpty(null) = true
+ * StringUtils.isEmpty("") = true
+ * StringUtils.isEmpty(" ") = false
+ * StringUtils.isEmpty("bob") = false
+ * StringUtils.isEmpty(" bob ") = false
+ * </pre>
+ *
+ * <p>
+ * NOTE: This method changed in Lang version 2.0. It no longer trims the
+ * String. That functionality is available in isBlank().
+ * </p>
+ *
+ * @param str the String to check, may be null
+ * @return <code>true</code> if the String is empty or null
+ */
+ public static boolean isEmpty( String str )
+ {
+ return ( str == null ) || ( str.length() == 0 );
+ }
+
+
+ /**
+ * Checks if a bytes array is empty or null.
+ *
+ * @param bytes The bytes array to check, may be null
+ * @return <code>true</code> if the bytes array is empty or null
+ */
+ public static boolean isEmpty( byte[] bytes )
+ {
+ return ( bytes == null ) || ( bytes.length == 0 );
+ }
+
+
+ /**
+ * Return UTF-8 encoded byte[] representation of a String
+ *
+ * @param string The string to be transformed to a byte array
+ * @return The transformed byte array
+ */
+ public static byte[] getBytesUtf8( String string )
+ {
+ if ( string == null )
+ {
+ return EMPTY_BYTES;
+ }
+
+ try
+ {
+ return string.getBytes( "UTF-8" );
+ }
+ catch ( UnsupportedEncodingException uee )
+ {
+ // if this happens something is really strange
+ throw new RuntimeException( uee );
+ }
+ }
+
+
+ /**
+ * When the string to convert to bytes is pure ascii, this is a faster
+ * method than the getBytesUtf8. Otherwise, it's slower.
+ *
+ * @param string The string to convert to byte[]
+ * @return The bytes
+ */
+ public static byte[] getBytesUtf8Ascii( String string )
+ {
+ if ( string == null )
+ {
+ return new byte[0];
+ }
+
+ try
+ {
+ try
+ {
+ char[] chars = string.toCharArray();
+ byte[] bytes = new byte[chars.length];
+ int pos = 0;
+
+ for ( char c : chars )
+ {
+ bytes[pos++] = UTF8[c];
+ }
+
+ return bytes;
+ }
+ catch ( ArrayIndexOutOfBoundsException aioobe )
+ {
+ return string.getBytes( "UTF-8" );
+ }
+ }
+ catch ( UnsupportedEncodingException uee )
+ {
+ // if this happens something is really strange
+ throw new RuntimeException( uee );
+ }
+ }
+
+
+ /**
+ * Utility method that return a String representation of a list
+ *
+ * @param list The list to transform to a string
+ * @return A csv string
+ */
+ public static String listToString( List<?> list )
+ {
+ if ( ( list == null ) || ( list.size() == 0 ) )
+ {
+ return "";
+ }
+
+ StringBuilder sb = new StringBuilder();
+ boolean isFirst = true;
+
+ for ( Object elem : list )
+ {
+ if ( isFirst )
+ {
+ isFirst = false;
+ }
+ else
+ {
+ sb.append( ", " );
+ }
+
+ sb.append( elem );
+ }
+
+ return sb.toString();
+ }
+
+
+ /**
+ * Utility method that return a String representation of a set
+ *
+ * @param set The set to transform to a string
+ * @return A csv string
+ */
+ public static String setToString( Set<?> set )
+ {
+ if ( ( set == null ) || ( set.size() == 0 ) )
+ {
+ return "";
+ }
+
+ StringBuilder sb = new StringBuilder();
+ boolean isFirst = true;
+
+ for ( Object elem : set )
+ {
+ if ( isFirst )
+ {
+ isFirst = false;
+ }
+ else
+ {
+ sb.append( ", " );
+ }
+
+ sb.append( elem );
+ }
+
+ return sb.toString();
+ }
+
+
+ /**
+ * Utility method that return a String representation of a list
+ *
+ * @param list The list to transform to a string
+ * @param tabs The tabs to add in ffront of the elements
+ * @return A csv string
+ */
+ public static String listToString( List<?> list, String tabs )
+ {
+ if ( ( list == null ) || ( list.size() == 0 ) )
+ {
+ return "";
+ }
+
+ StringBuffer sb = new StringBuffer();
+
+ for ( Object elem : list )
+ {
+ sb.append( tabs );
+ sb.append( elem );
+ sb.append( '\n' );
+ }
+
+ return sb.toString();
+ }
+
+
+ /**
+ * Utility method that return a String representation of a map. The
elements
+ * will be represented as "key = value"
+ *
+ * @param map The map to transform to a string
+ * @return A csv string
+ */
+ public static String mapToString( Map<?, ?> map )
+ {
+ if ( ( map == null ) || ( map.size() == 0 ) )
+ {
+ return "";
+ }
+
+ StringBuffer sb = new StringBuffer();
+ boolean isFirst = true;
+
+ for ( Map.Entry<?, ?> entry : map.entrySet() )
+ {
+ if ( isFirst )
+ {
+ isFirst = false;
+ }
+ else
+ {
+ sb.append( ", " );
+ }
+
+ sb.append( entry.getKey() );
+ sb.append( " = '" ).append( entry.getValue() ).append( "'" );
+ }
+
+ return sb.toString();
+ }
+
+
+ /**
+ * Utility method that return a String representation of a map. The
elements
+ * will be represented as "key = value"
+ *
+ * @param map The map to transform to a string
+ * @param tabs The tabs to add in ffront of the elements
+ * @return A csv string
+ */
+ public static String mapToString( Map<?, ?> map, String tabs )
+ {
+ if ( ( map == null ) || ( map.size() == 0 ) )
+ {
+ return "";
+ }
+
+ StringBuffer sb = new StringBuffer();
+
+ for ( Map.Entry<?, ?> entry : map.entrySet() )
+ {
+ sb.append( tabs );
+ sb.append( entry.getKey() );
+
+ sb.append( " = '" ).append( entry.getValue().toString() ).append(
"'\n" );
+ }
+
+ return sb.toString();
+ }
+}
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