org.apache.derby.iapi.util

Class StringUtil

java.lang.Object

org.apache.derby.iapi.util.StringUtil

public class StringUtil
extends java.lang.Object

A set of public static methods for dealing with Strings

Constructor Summary

Constructors

Constructor and Description
StringUtil()

Method Summary

Modifier and Type	Method and Description
static java.lang.String	compressQuotes(java.lang.String source, java.lang.String quotes) Compress 2 adjacent (single or double) quotes into a single (s or d) quote when found in the middle of a String.
static java.lang.String	ensureIndent(java.lang.String formatted, int depth) Utility for formatting which bends a multi-line string into shape for outputting it in a context where there is depth tabs.
static java.lang.String	formatForPrint(java.lang.String input) Used to print out a string for error messages, chops is off at 60 chars for historical reasons.
static byte[]	fromHexString(java.lang.String s, int offset, int length) Convert a hexidecimal string generated by toHexString() back into a byte array.
static byte[]	getAsciiBytes(java.lang.String input) Get 7-bit ASCII character array from input String.
static java.lang.String	hexDump(byte[] data) Convert a byte array to a human-readable String for debugging purposes.
static java.lang.String	normalizeSQLIdentifier(java.lang.String id) Normalize a SQL identifer, up-casing if , and handling of (SQL 2003, section 5.2).
static java.lang.String	quoteStringLiteral(java.lang.String string) Quote a string so that it can be used as a string literal in an SQL statement.
static java.lang.String	shortDBName(java.lang.String canonicalDBName, char separatorChar) Get the short database name from the canonical name.
static java.lang.String	slice(java.lang.String value, int beginOffset, int endOffset, boolean trim) Return a slice (substring) of the passed in value, optionally trimmed.
static boolean	SQLEqualsIgnoreCase(java.lang.String s1, java.lang.String s2) Compares two strings Strings will be uppercased in english and compared equivalent to s1.equalsIgnoreCase(s2) throws NPE if s1 is null
static java.lang.String	SQLToUpperCase(java.lang.String s) Convert string to uppercase Always use the java.util.ENGLISH locale
static java.lang.String	toHexString(byte[] data, int offset, int length) Convert a byte array to a String with a hexidecimal format.
static java.lang.String[]	toStringArray(java.lang.Object[] objArray) A method that receive an array of Objects and return a String array representation of that array.
static java.lang.String	trimTrailing(java.lang.String str) Trim off trailing blanks but not leading blanks
static java.lang.String	truncate(java.lang.String value, int length) Truncate a String to the given length with no warnings or error raised if it is bigger.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

StringUtil

public StringUtil()

Method Detail

formatForPrint

public static final java.lang.String formatForPrint(java.lang.String input)

Used to print out a string for error messages, chops is off at 60 chars for historical reasons.

toStringArray

public static java.lang.String[] toStringArray(java.lang.Object[] objArray)

A method that receive an array of Objects and return a String array representation of that array.

getAsciiBytes

public static byte[] getAsciiBytes(java.lang.String input)

Get 7-bit ASCII character array from input String. The lower 7 bits of each character in the input string is assumed to be the ASCII character value. Hexadecimal - Character | 00 NUL| 01 SOH| 02 STX| 03 ETX| 04 EOT| 05 ENQ| 06 ACK| 07 BEL| | 08 BS | 09 HT | 0A NL | 0B VT | 0C NP | 0D CR | 0E SO | 0F SI | | 10 DLE| 11 DC1| 12 DC2| 13 DC3| 14 DC4| 15 NAK| 16 SYN| 17 ETB| | 18 CAN| 19 EM | 1A SUB| 1B ESC| 1C FS | 1D GS | 1E RS | 1F US | | 20 SP | 21 ! | 22 " | 23 # | 24 $ | 25 % | 26 & | 27 ' | | 28 ( | 29 ) | 2A * | 2B + | 2C , | 2D - | 2E . | 2F / | | 30 0 | 31 1 | 32 2 | 33 3 | 34 4 | 35 5 | 36 6 | 37 7 | | 38 8 | 39 9 | 3A : | 3B ; | 3C < | 3D = | 3E > | 3F ? | | 40 @ | 41 A | 42 B | 43 C | 44 D | 45 E | 46 F | 47 G | | 48 H | 49 I | 4A J | 4B K | 4C L | 4D M | 4E N | 4F O | | 50 P | 51 Q | 52 R | 53 S | 54 T | 55 U | 56 V | 57 W | | 58 X | 59 Y | 5A Z | 5B [ | 5C \ | 5D ] | 5E ^ | 5F _ | | 60 ` | 61 a | 62 b | 63 c | 64 d | 65 e | 66 f | 67 g | | 68 h | 69 i | 6A j | 6B k | 6C l | 6D m | 6E n | 6F o | | 70 p | 71 q | 72 r | 73 s | 74 t | 75 u | 76 v | 77 w | | 78 x | 79 y | 7A z | 7B { | 7C | | 7D } | 7E ~ | 7F DEL|

trimTrailing

public static java.lang.String trimTrailing(java.lang.String str)

Trim off trailing blanks but not leading blanks

Parameters:

str -

Returns:

The input with trailing blanks stipped off

truncate

public static java.lang.String truncate(java.lang.String value,
                                        int length)

Truncate a String to the given length with no warnings or error raised if it is bigger.

Parameters:

value - String to be truncated

length - Maximum length of string

Returns:

Returns value if value is null or value.length() is less or equal to than length, otherwise a String representing value truncated to length.

slice

public static java.lang.String slice(java.lang.String value,
                                     int beginOffset,
                                     int endOffset,
                                     boolean trim)

Return a slice (substring) of the passed in value, optionally trimmed. WARNING - endOffset is inclusive for historical reasons, unlike String.substring() which has an exclusive ending offset.

Parameters:

value - Value to slice, must be non-null.

beginOffset - Inclusive start character

endOffset - Inclusive end character

trim - To trim or not to trim

Returns:

Sliceed value.

toHexString

public static java.lang.String toHexString(byte[] data,
                                           int offset,
                                           int length)

Convert a byte array to a String with a hexidecimal format. The String may be converted back to a byte array using fromHexString.
For each byte (b) two characaters are generated, the first character represents the high nibble (4 bits) in hexidecimal (b & 0xf0), the second character represents the low nibble (b & 0x0f).
The byte at data[offset] is represented by the first two characters in the returned String.

Parameters:

data - byte array

offset - starting byte (zero based) to convert.

length - number of bytes to convert.

Returns:

the String (with hexidecimal format) form of the byte array

fromHexString

public static byte[] fromHexString(java.lang.String s,
                                   int offset,
                                   int length)

Convert a hexidecimal string generated by toHexString() back into a byte array.

Parameters:

s - String to convert

offset - starting character (zero based) to convert.

length - number of characters to convert.

Returns:

the converted byte array. Returns null if the length is not a multiple of 2.

hexDump

public static java.lang.String hexDump(byte[] data)

Convert a byte array to a human-readable String for debugging purposes.

SQLToUpperCase

public static java.lang.String SQLToUpperCase(java.lang.String s)

Convert string to uppercase Always use the java.util.ENGLISH locale

Parameters:

s - string to uppercase

Returns:

uppercased string

SQLEqualsIgnoreCase

public static boolean SQLEqualsIgnoreCase(java.lang.String s1,
                                          java.lang.String s2)

Compares two strings Strings will be uppercased in english and compared equivalent to s1.equalsIgnoreCase(s2) throws NPE if s1 is null

Parameters:

s1 - first string to compare

s2 - second string to compare

Returns:

true if the two upppercased ENGLISH values are equal return false if s2 is null

normalizeSQLIdentifier

public static java.lang.String normalizeSQLIdentifier(java.lang.String id)

Normalize a SQL identifer, up-casing if , and handling of (SQL 2003, section 5.2). The normal form is used internally in Derby.

Parameters:

id - syntacically correct SQL identifier

compressQuotes

public static java.lang.String compressQuotes(java.lang.String source,
                                              java.lang.String quotes)

Compress 2 adjacent (single or double) quotes into a single (s or d) quote when found in the middle of a String. NOTE: """" or '''' will be compressed into "" or ''. This function assumes that the leading and trailing quote from a string or delimited identifier have already been removed.

Parameters:

source - string to be compressed

quotes - string containing two single or double quotes.

Returns:

String where quotes have been compressed

quoteStringLiteral

public static java.lang.String quoteStringLiteral(java.lang.String string)

Quote a string so that it can be used as a string literal in an SQL statement.

Parameters:

string - the string to quote

Returns:

the string surrounded by single quotes and with proper escaping of any single quotes inside the string

ensureIndent

public static java.lang.String ensureIndent(java.lang.String formatted,
                                            int depth)

Utility for formatting which bends a multi-line string into shape for outputting it in a context where there is depth tabs. Trailing newlines are discarded as well.

Replace "^[\t]*" with "depth" number of tabs.
Replace "\n+$" with "". Replace all "\n[\t]*" with "\n" + "depth" number of tabs.

Parameters:

formatted - string to sanitize

depth - indentation level the string is to be printed at (0,1,2..)

shortDBName

public static java.lang.String shortDBName(java.lang.String canonicalDBName,
                                           char separatorChar)

Get the short database name from the canonical name.