poi/src/java/org/apache/poi/hssf/record/UnicodeString.java

887 lines
30 KiB
Java

/* ====================================================================
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.poi.hssf.record;
import org.apache.poi.util.BitField;
import org.apache.poi.util.BitFieldFactory;
import org.apache.poi.util.LittleEndian;
import org.apache.poi.util.HexDump;
import java.util.Iterator;
import java.util.List;
import java.util.ArrayList;
import java.util.Collections;
/**
* Title: Unicode String<P>
* Description: Unicode String record. We implement these as a record, although
* they are really just standard fields that are in several records.
* It is considered more desirable then repeating it in all of them.<P>
* REFERENCE: PG 264 Microsoft Excel 97 Developer's Kit (ISBN: 1-57231-498-2)<P>
* @author Andrew C. Oliver
* @author Marc Johnson (mjohnson at apache dot org)
* @author Glen Stampoultzis (glens at apache.org)
*/
public final class UnicodeString implements Comparable {
private short field_1_charCount; // = 0;
private byte field_2_optionflags; // = 0;
private String field_3_string; // = null;
private List field_4_format_runs;
private byte[] field_5_ext_rst;
private static final BitField highByte = BitFieldFactory.getInstance(0x1);
private static final BitField extBit = BitFieldFactory.getInstance(0x4);
private static final BitField richText = BitFieldFactory.getInstance(0x8);
public static class FormatRun implements Comparable {
short character;
short fontIndex;
public FormatRun(short character, short fontIndex) {
this.character = character;
this.fontIndex = fontIndex;
}
public short getCharacterPos() {
return character;
}
public short getFontIndex() {
return fontIndex;
}
public boolean equals(Object o) {
if ((o == null) || (o.getClass() != this.getClass()))
{
return false;
}
FormatRun other = ( FormatRun ) o;
return ((character == other.character) && (fontIndex == other.fontIndex));
}
public int compareTo(Object obj) {
FormatRun r = (FormatRun)obj;
if ((character == r.character) && (fontIndex == r.fontIndex))
return 0;
if (character == r.character)
return fontIndex - r.fontIndex;
else return character - r.character;
}
public String toString() {
return "character="+character+",fontIndex="+fontIndex;
}
}
private UnicodeString() {
//Used for clone method.
}
public UnicodeString(String str)
{
setString(str);
}
public int hashCode()
{
int stringHash = 0;
if (field_3_string != null)
stringHash = field_3_string.hashCode();
return field_1_charCount + stringHash;
}
/**
* Our handling of equals is inconsistent with compareTo. The trouble is because we don't truely understand
* rich text fields yet it's difficult to make a sound comparison.
*
* @param o The object to compare.
* @return true if the object is actually equal.
*/
public boolean equals(Object o)
{
if ((o == null) || (o.getClass() != this.getClass()))
{
return false;
}
UnicodeString other = ( UnicodeString ) o;
//Ok lets do this in stages to return a quickly, first check the actual string
boolean eq = ((field_1_charCount == other.field_1_charCount)
&& (field_2_optionflags == other.field_2_optionflags)
&& field_3_string.equals(other.field_3_string));
if (!eq) return false;
//OK string appears to be equal but now lets compare formatting runs
if ((field_4_format_runs == null) && (other.field_4_format_runs == null))
//Strings are equal, and there are not formatting runs.
return true;
if (((field_4_format_runs == null) && (other.field_4_format_runs != null)) ||
(field_4_format_runs != null) && (other.field_4_format_runs == null))
//Strings are equal, but one or the other has formatting runs
return false;
//Strings are equal, so now compare formatting runs.
int size = field_4_format_runs.size();
if (size != other.field_4_format_runs.size())
return false;
for (int i=0;i<size;i++) {
FormatRun run1 = (FormatRun)field_4_format_runs.get(i);
FormatRun run2 = (FormatRun)other.field_4_format_runs.get(i);
if (!run1.equals(run2))
return false;
}
//Well the format runs are equal as well!, better check the ExtRst data
//Which by the way we dont know how to decode!
if ((field_5_ext_rst == null) && (other.field_5_ext_rst == null))
return true;
if (((field_5_ext_rst == null) && (other.field_5_ext_rst != null)) ||
((field_5_ext_rst != null) && (other.field_5_ext_rst == null)))
return false;
size = field_5_ext_rst.length;
if (size != field_5_ext_rst.length)
return false;
//Check individual bytes!
for (int i=0;i<size;i++) {
if (field_5_ext_rst[i] != other.field_5_ext_rst[i])
return false;
}
//Phew!! After all of that we have finally worked out that the strings
//are identical.
return true;
}
/**
* construct a unicode string record and fill its fields, ID is ignored
* @param in the RecordInputstream to read the record from
*/
public UnicodeString(RecordInputStream in) {
field_1_charCount = in.readShort();
field_2_optionflags = in.readByte();
int runCount = 0;
int extensionLength = 0;
//Read the number of rich runs if rich text.
if ( isRichText() )
{
runCount = in.readShort();
}
//Read the size of extended data if present.
if ( isExtendedText() )
{
extensionLength = in.readInt();
}
boolean isCompressed = ((field_2_optionflags & 1) == 0);
if (isCompressed) {
field_3_string = in.readCompressedUnicode(field_1_charCount);
} else {
field_3_string = in.readUnicodeLEString(field_1_charCount);
}
if (isRichText() && (runCount > 0)) {
field_4_format_runs = new ArrayList(runCount);
for (int i=0;i<runCount;i++) {
field_4_format_runs.add(new FormatRun(in.readShort(), in.readShort()));
//read reserved
//in.readInt();
}
}
if (isExtendedText() && (extensionLength > 0)) {
field_5_ext_rst = new byte[extensionLength];
for (int i=0;i<extensionLength;i++) {
field_5_ext_rst[i] = in.readByte();
}
}
}
/**
* get the number of characters in the string
*
*
* @return number of characters
*
*/
public short getCharCount()
{
return field_1_charCount;
}
/**
* set the number of characters in the string
* @param cc - number of characters
*/
public void setCharCount(short cc)
{
field_1_charCount = cc;
}
/**
* get the option flags which among other things return if this is a 16-bit or
* 8 bit string
*
* @return optionflags bitmask
*
*/
public byte getOptionFlags()
{
return field_2_optionflags;
}
/**
* set the option flags which among other things return if this is a 16-bit or
* 8 bit string
*
* @param of optionflags bitmask
*
*/
public void setOptionFlags(byte of)
{
field_2_optionflags = of;
}
/**
* @return the actual string this contains as a java String object
*/
public String getString()
{
return field_3_string;
}
/**
* set the actual string this contains
* @param string the text
*/
public void setString(String string)
{
field_3_string = string;
setCharCount((short)field_3_string.length());
// scan for characters greater than 255 ... if any are
// present, we have to use 16-bit encoding. Otherwise, we
// can use 8-bit encoding
boolean useUTF16 = false;
int strlen = string.length();
for ( int j = 0; j < strlen; j++ )
{
if ( string.charAt( j ) > 255 )
{
useUTF16 = true;
break;
}
}
if (useUTF16)
//Set the uncompressed bit
field_2_optionflags = highByte.setByte(field_2_optionflags);
else field_2_optionflags = highByte.clearByte(field_2_optionflags);
}
public int getFormatRunCount() {
if (field_4_format_runs == null)
return 0;
return field_4_format_runs.size();
}
public FormatRun getFormatRun(int index) {
if (field_4_format_runs == null)
return null;
if ((index < 0) || (index >= field_4_format_runs.size()))
return null;
return (FormatRun)field_4_format_runs.get(index);
}
private int findFormatRunAt(int characterPos) {
int size = field_4_format_runs.size();
for (int i=0;i<size;i++) {
FormatRun r = (FormatRun)field_4_format_runs.get(i);
if (r.character == characterPos)
return i;
else if (r.character > characterPos)
return -1;
}
return -1;
}
/** Adds a font run to the formatted string.
*
* If a font run exists at the current charcter location, then it is
* replaced with the font run to be added.
*/
public void addFormatRun(FormatRun r) {
if (field_4_format_runs == null)
field_4_format_runs = new ArrayList();
int index = findFormatRunAt(r.character);
if (index != -1)
field_4_format_runs.remove(index);
field_4_format_runs.add(r);
//Need to sort the font runs to ensure that the font runs appear in
//character order
Collections.sort(field_4_format_runs);
//Make sure that we now say that we are a rich string
field_2_optionflags = richText.setByte(field_2_optionflags);
}
public Iterator formatIterator() {
if (field_4_format_runs != null)
return field_4_format_runs.iterator();
return null;
}
public void removeFormatRun(FormatRun r) {
field_4_format_runs.remove(r);
if (field_4_format_runs.size() == 0) {
field_4_format_runs = null;
field_2_optionflags = richText.clearByte(field_2_optionflags);
}
}
public void clearFormatting() {
field_4_format_runs = null;
field_2_optionflags = richText.clearByte(field_2_optionflags);
}
public byte[] getExtendedRst() {
return this.field_5_ext_rst;
}
public void setExtendedRst(byte[] ext_rst) {
if (ext_rst != null)
field_2_optionflags = extBit.setByte(field_2_optionflags);
else field_2_optionflags = extBit.clearByte(field_2_optionflags);
this.field_5_ext_rst = ext_rst;
}
/**
* Swaps all use in the string of one font index
* for use of a different font index.
* Normally only called when fonts have been
* removed / re-ordered
*/
public void swapFontUse(short oldFontIndex, short newFontIndex) {
Iterator i = field_4_format_runs.iterator();
while(i.hasNext()) {
FormatRun run = (FormatRun)i.next();
if(run.fontIndex == oldFontIndex) {
run.fontIndex = newFontIndex;
}
}
}
/**
* unlike the real records we return the same as "getString()" rather than debug info
* @see #getDebugInfo()
* @return String value of the record
*/
public String toString()
{
return getString();
}
/**
* return a character representation of the fields of this record
*
*
* @return String of output for biffviewer etc.
*
*/
public String getDebugInfo()
{
StringBuffer buffer = new StringBuffer();
buffer.append("[UNICODESTRING]\n");
buffer.append(" .charcount = ")
.append(Integer.toHexString(getCharCount())).append("\n");
buffer.append(" .optionflags = ")
.append(Integer.toHexString(getOptionFlags())).append("\n");
buffer.append(" .string = ").append(getString()).append("\n");
if (field_4_format_runs != null) {
for (int i = 0; i < field_4_format_runs.size();i++) {
FormatRun r = (FormatRun)field_4_format_runs.get(i);
buffer.append(" .format_run"+i+" = ").append(r.toString()).append("\n");
}
}
if (field_5_ext_rst != null) {
buffer.append(" .field_5_ext_rst = ").append("\n").append(HexDump.toHex(field_5_ext_rst)).append("\n");
}
buffer.append("[/UNICODESTRING]\n");
return buffer.toString();
}
private int writeContinueIfRequired(UnicodeRecordStats stats, final int requiredSize, int offset, byte[] data) {
//Basic string overhead
if (stats.remainingSize < requiredSize) {
//Check if be are already in a continue record, if so make sure that
//we go back and write out our length
if (stats.lastLengthPos != -1) {
short lastRecordLength = (short)(offset - stats.lastLengthPos - 2);
if (lastRecordLength > 8224)
throw new InternalError();
LittleEndian.putShort(data, stats.lastLengthPos, lastRecordLength);
}
LittleEndian.putShort(data, offset, ContinueRecord.sid);
offset+=2;
//Record the location of the last continue length position, but don't write
//anything there yet (since we don't know what it will be!)
stats.lastLengthPos = offset;
offset += 2;
stats.recordSize += 4;
stats.remainingSize = SSTRecord.MAX_RECORD_SIZE-4;
}
return offset;
}
public int serialize(UnicodeRecordStats stats, final int offset, byte [] data)
{
int pos = offset;
//Basic string overhead
pos = writeContinueIfRequired(stats, 3, pos, data);
LittleEndian.putShort(data, pos, getCharCount());
pos += 2;
data[ pos ] = getOptionFlags();
pos += 1;
stats.recordSize += 3;
stats.remainingSize-= 3;
if (isRichText()) {
if (field_4_format_runs != null) {
pos = writeContinueIfRequired(stats, 2, pos, data);
LittleEndian.putShort(data, pos, (short) field_4_format_runs.size());
pos += 2;
stats.recordSize += 2;
stats.remainingSize -= 2;
}
}
if ( isExtendedText() )
{
if (this.field_5_ext_rst != null) {
pos = writeContinueIfRequired(stats, 4, pos, data);
LittleEndian.putInt(data, pos, field_5_ext_rst.length);
pos += 4;
stats.recordSize += 4;
stats.remainingSize -= 4;
}
}
int charsize = isUncompressedUnicode() ? 2 : 1;
int strSize = (getString().length() * charsize);
byte[] strBytes = null;
try {
String unicodeString = getString();
if (!isUncompressedUnicode())
{
strBytes = unicodeString.getBytes("ISO-8859-1");
}
else
{
strBytes = unicodeString.getBytes("UTF-16LE");
}
}
catch (Exception e) {
throw new InternalError();
}
if (strSize != strBytes.length)
throw new InternalError("That shouldnt have happened!");
//Check to see if the offset occurs mid string, if so then we need to add
//the byte to start with that represents the first byte of the continue record.
if (strSize > stats.remainingSize) {
//OK the offset occurs half way through the string, that means that
//we need an extra byte after the continue record ie we didnt finish
//writing out the string the 1st time through
//But hang on, how many continue records did we span? What if this is
//a REALLY long string. We need to work this all out.
int amountThatCantFit = strSize;
int strPos = 0;
while (amountThatCantFit > 0) {
int amountWritten = Math.min(stats.remainingSize, amountThatCantFit);
//Make sure that the amount that can't fit takes into account
//whether we are writing double byte unicode
if (isUncompressedUnicode()) {
//We have the '-1' here because whether this is the first record or
//subsequent continue records, there is always the case that the
//number of bytes in a string on double byte boundaries is actually odd.
if ( ( (amountWritten ) % 2) == 1)
amountWritten--;
}
System.arraycopy(strBytes, strPos, data, pos, amountWritten);
pos += amountWritten;
strPos += amountWritten;
stats.recordSize += amountWritten;
stats.remainingSize -= amountWritten;
//Ok lets subtract what we can write
amountThatCantFit -= amountWritten;
//Each iteration of this while loop is another continue record, unless
//everything now fits.
if (amountThatCantFit > 0) {
//We know that a continue WILL be requied, but use this common method
pos = writeContinueIfRequired(stats, amountThatCantFit, pos, data);
//The first byte after a continue mid string is the extra byte to
//indicate if this run is compressed or not.
data[pos] = (byte) (isUncompressedUnicode() ? 0x1 : 0x0);
pos++;
stats.recordSize++;
stats.remainingSize --;
}
}
} else {
if (strSize > (data.length-pos))
System.out.println("Hmm shouldnt happen");
//Ok the string fits nicely in the remaining size
System.arraycopy(strBytes, 0, data, pos, strSize);
pos += strSize;
stats.recordSize += strSize;
stats.remainingSize -= strSize;
}
if (isRichText() && (field_4_format_runs != null)) {
int count = field_4_format_runs.size();
//This will ensure that a run does not split a continue
for (int i=0;i<count;i++) {
pos = writeContinueIfRequired(stats, 4, pos, data);
FormatRun r = (FormatRun)field_4_format_runs.get(i);
LittleEndian.putShort(data, pos, r.character);
pos += 2;
LittleEndian.putShort(data, pos, r.fontIndex);
pos += 2;
//Each run count is four bytes
stats.recordSize += 4;
stats.remainingSize -=4;
}
}
if (isExtendedText() && (field_5_ext_rst != null)) {
//Ok ExtRst is actually not documented, so i am going to hope
//that we can actually continue on byte boundaries
int ammountThatCantFit = field_5_ext_rst.length - stats.remainingSize;
int extPos = 0;
if (ammountThatCantFit > 0) {
while (ammountThatCantFit > 0) {
//So for this record we have already written
int ammountWritten = Math.min(stats.remainingSize, ammountThatCantFit);
System.arraycopy(field_5_ext_rst, extPos, data, pos, ammountWritten);
pos += ammountWritten;
extPos += ammountWritten;
stats.recordSize += ammountWritten;
stats.remainingSize -= ammountWritten;
//Ok lets subtract what we can write
ammountThatCantFit -= ammountWritten;
if (ammountThatCantFit > 0) {
pos = writeContinueIfRequired(stats, 1, pos, data);
}
}
} else {
//We can fit wholey in what remains.
System.arraycopy(field_5_ext_rst, 0, data, pos, field_5_ext_rst.length);
pos += field_5_ext_rst.length;
stats.remainingSize -= field_5_ext_rst.length;
stats.recordSize += field_5_ext_rst.length;
}
}
return pos - offset;
}
public void setCompressedUnicode() {
field_2_optionflags = highByte.setByte(field_2_optionflags);
}
public void setUncompressedUnicode() {
field_2_optionflags = highByte.clearByte(field_2_optionflags);
}
private boolean isUncompressedUnicode()
{
return highByte.isSet(getOptionFlags());
}
/** Returns the size of this record, given the amount of record space
* remaining, it will also include the size of writing a continue record.
*/
public static class UnicodeRecordStats {
public int recordSize;
public int remainingSize = SSTRecord.MAX_RECORD_SIZE;
public int lastLengthPos = -1;
}
public void getRecordSize(UnicodeRecordStats stats) {
//Basic string overhead
if (stats.remainingSize < 3) {
//Needs a continue
stats.recordSize += 4;
stats.remainingSize = SSTRecord.MAX_RECORD_SIZE-4;
}
stats.recordSize += 3;
stats.remainingSize-= 3;
//Read the number of rich runs if rich text.
if ( isRichText() )
{
//Run count
if (stats.remainingSize < 2) {
//Needs a continue
//Reset the available space.
stats.remainingSize = SSTRecord.MAX_RECORD_SIZE-4;
//continue record overhead
stats.recordSize+=4;
}
stats.recordSize += 2;
stats.remainingSize -=2;
}
//Read the size of extended data if present.
if ( isExtendedText() )
{
//Needs a continue
//extension length
if (stats.remainingSize < 4) {
//Reset the available space.
stats.remainingSize = SSTRecord.MAX_RECORD_SIZE-4;
//continue record overhead
stats.recordSize+=4;
}
stats.recordSize += 4;
stats.remainingSize -=4;
}
int charsize = isUncompressedUnicode() ? 2 : 1;
int strSize = (getString().length() * charsize);
//Check to see if the offset occurs mid string, if so then we need to add
//the byte to start with that represents the first byte of the continue record.
if (strSize > stats.remainingSize) {
//Ok the offset occurs half way through the string, that means that
//we need an extra byte after the continue record ie we didnt finish
//writing out the string the 1st time through
//But hang on, how many continue records did we span? What if this is
//a REALLY long string. We need to work this all out.
int ammountThatCantFit = strSize;
while (ammountThatCantFit > 0) {
int ammountWritten = Math.min(stats.remainingSize, ammountThatCantFit);
//Make sure that the ammount that cant fit takes into account
//whether we are writing double byte unicode
if (isUncompressedUnicode()) {
//We have the '-1' here because whether this is the first record or
//subsequent continue records, there is always the case that the
//number of bytes in a string on doube byte boundaries is actually odd.
if ( ( (ammountWritten) % 2) == 1)
ammountWritten--;
}
stats.recordSize += ammountWritten;
stats.remainingSize -= ammountWritten;
//Ok lets subtract what we can write
ammountThatCantFit -= ammountWritten;
//Each iteration of this while loop is another continue record, unless
//everything now fits.
if (ammountThatCantFit > 0) {
//Reset the available space.
stats.remainingSize = SSTRecord.MAX_RECORD_SIZE-4;
//continue record overhead
stats.recordSize+=4;
//The first byte after a continue mid string is the extra byte to
//indicate if this run is compressed or not.
stats.recordSize++;
stats.remainingSize --;
}
}
} else {
//Ok the string fits nicely in the remaining size
stats.recordSize += strSize;
stats.remainingSize -= strSize;
}
if (isRichText() && (field_4_format_runs != null)) {
int count = field_4_format_runs.size();
//This will ensure that a run does not split a continue
for (int i=0;i<count;i++) {
if (stats.remainingSize < 4) {
//Reset the available space.
stats.remainingSize = SSTRecord.MAX_RECORD_SIZE-4;
//continue record overhead
stats.recordSize+=4;
}
//Each run count is four bytes
stats.recordSize += 4;
stats.remainingSize -=4;
}
}
if (isExtendedText() && (field_5_ext_rst != null)) {
//Ok ExtRst is actually not documented, so i am going to hope
//that we can actually continue on byte boundaries
int ammountThatCantFit = field_5_ext_rst.length - stats.remainingSize;
if (ammountThatCantFit > 0) {
while (ammountThatCantFit > 0) {
//So for this record we have already written
int ammountWritten = Math.min(stats.remainingSize, ammountThatCantFit);
stats.recordSize += ammountWritten;
stats.remainingSize -= ammountWritten;
//Ok lets subtract what we can write
ammountThatCantFit -= ammountWritten;
if (ammountThatCantFit > 0) {
//Each iteration of this while loop is another continue record.
//Reset the available space.
stats.remainingSize = SSTRecord.MAX_RECORD_SIZE-4;
//continue record overhead
stats.recordSize += 4;
}
}
} else {
//We can fit wholey in what remains.
stats.remainingSize -= field_5_ext_rst.length;
stats.recordSize += field_5_ext_rst.length;
}
}
}
public int compareTo(Object obj)
{
UnicodeString str = ( UnicodeString ) obj;
int result = getString().compareTo(str.getString());
//As per the equals method lets do this in stages
if (result != 0)
return result;
//Ok string appears to be equal but now lets compare formatting runs
if ((field_4_format_runs == null) && (str.field_4_format_runs == null))
//Strings are equal, and there are no formtting runs.
return 0;
if ((field_4_format_runs == null) && (str.field_4_format_runs != null))
//Strings are equal, but one or the other has formatting runs
return 1;
if ((field_4_format_runs != null) && (str.field_4_format_runs == null))
//Strings are equal, but one or the other has formatting runs
return -1;
//Strings are equal, so now compare formatting runs.
int size = field_4_format_runs.size();
if (size != str.field_4_format_runs.size())
return size - str.field_4_format_runs.size();
for (int i=0;i<size;i++) {
FormatRun run1 = (FormatRun)field_4_format_runs.get(i);
FormatRun run2 = (FormatRun)str.field_4_format_runs.get(i);
result = run1.compareTo(run2);
if (result != 0)
return result;
}
//Well the format runs are equal as well!, better check the ExtRst data
//Which by the way we don't know how to decode!
if ((field_5_ext_rst == null) && (str.field_5_ext_rst == null))
return 0;
if ((field_5_ext_rst == null) && (str.field_5_ext_rst != null))
return 1;
if ((field_5_ext_rst != null) && (str.field_5_ext_rst == null))
return -1;
size = field_5_ext_rst.length;
if (size != field_5_ext_rst.length)
return size - field_5_ext_rst.length;
//Check individual bytes!
for (int i=0;i<size;i++) {
if (field_5_ext_rst[i] != str.field_5_ext_rst[i])
return field_5_ext_rst[i] - str.field_5_ext_rst[i];
}
//Phew!! After all of that we have finally worked out that the strings
//are identical.
return 0;
}
public boolean isRichText()
{
return richText.isSet(getOptionFlags());
}
public boolean isExtendedText()
{
return extBit.isSet(getOptionFlags());
}
public Object clone() {
UnicodeString str = new UnicodeString();
str.field_1_charCount = field_1_charCount;
str.field_2_optionflags = field_2_optionflags;
str.field_3_string = field_3_string;
if (field_4_format_runs != null) {
str.field_4_format_runs = new ArrayList();
int size = field_4_format_runs.size();
for (int i = 0; i < size; i++) {
FormatRun r = (FormatRun) field_4_format_runs.get(i);
str.field_4_format_runs.add(new FormatRun(r.character, r.fontIndex));
}
}
if (field_5_ext_rst != null) {
str.field_5_ext_rst = new byte[field_5_ext_rst.length];
System.arraycopy(field_5_ext_rst, 0, str.field_5_ext_rst, 0,
field_5_ext_rst.length);
}
return str;
}
}