摘要: 對(duì)于volatile修飾的變量，jvm虛擬機(jī)只是保證從主內(nèi)存加載到線程工作內(nèi)存的值是最新的
例如假如線程1，線程2 在進(jìn)行read,load 操作中，發(fā)現(xiàn)主內(nèi)存中count的值都是5，那么都會(huì)加載這個(gè)最新的值
在線程1堆count進(jìn)行修改之后，會(huì)write到主內(nèi)存中，主內(nèi)存中的count變量就會(huì)變?yōu)?
線程2由于已經(jīng)進(jìn)行read,load操作，在進(jìn)行運(yùn)算之后，也會(huì)更新主內(nèi)存count的變量值為6
導(dǎo)致兩個(gè)線程及時(shí)用volatile關(guān)鍵字修改之后，還是會(huì)存在并發(fā)的情況。
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/*
*Author:tyfun
*DateTime:2002.12.19
*Package:com.westarsoft.function
*/
package com.westarsoft.function;
public class HtmlFilter {
/*USE:
*String escapeHTMLTags( String input , boolean htmlFlag )
*/
public static String escapeHTMLTags( String input , boolean htmlFlag ) {
if( input == null || input.length() == 0 || htmlFlag ) {
return input;
}
StringBuffer buf = new StringBuffer(input.length()+6);
char ch = '' '';
for( int i=0; i
'' ) {
buf.append( ">" );
}
else {
buf.append( ch );
}
}
return buf.toString();
}
/*USE:
*String replace( String line, String oldString, String newString )
*/
public static String replace( String line, String oldString, String newString ) {
int i=0;
if ( ( line == null || oldString == null ) ) {
return null;
}
if ( ( i=line.indexOf( oldString, i ) ) >= 0 ) {
int oLength = oldString.length();
int nLength = newString.length();
StringBuffer buf = new StringBuffer();
buf.append(line.substring(0,i)).append(newString);
i += oLength;
int j = i;
while( (i=line.indexOf(oldString,i)) > 0 ) {
buf.append(line.substring(j,i)).append(newString);
i += oLength;
j = i;
}
buf.append(line.substring(j));
return buf.toString();
}
return line;
}
/*USE:
*String replaceIgnoreCase( String line, String oldString, String newString )
*/
public static String replaceIgnoreCase( String line, String oldString, String newString ) {
if (line == null) {
return null;
}
String lcLine = line.toLowerCase();
String lcOldString = oldString.toLowerCase();
int i=0;
if ( ( i=lcLine.indexOf( lcOldString, i ) ) >= 0 ) {
char [] line2 = line.toCharArray();
char [] newString2 = newString.toCharArray();
int oLength = oldString.length();
StringBuffer buf = new StringBuffer(line2.length);
buf.append(line2, 0, i).append(newString2);
i += oLength;
int j = i;
while( ( i=lcLine.indexOf( lcOldString, i ) ) > 0 ) {
buf.append(line2, j, i-j).append(newString2);
i += oLength;
j = i;
}
buf.append(line2, j, line2.length - j);
return buf.toString();
}
return line;
}
/*USE:
*String convertUBB( String input )
*/
public static String convertUBB ( String input ) {
if( input == null || input.length() == 0 ) {
return input;
}
else {
input = replaceIgnoreCase( input , "<" ,"<" ) ;
input = replaceIgnoreCase( input , "<%" ,"<%" ) ;
input = replaceIgnoreCase( input , "%>" ,"%>" ) ;
input = replaceIgnoreCase( input , ">" ,">" ) ;
input = replaceIgnoreCase( input , "" ,"" ) ;
input = replaceIgnoreCase( input , "" ,"" ) ;
input = replaceIgnoreCase( input , "" ,"" ) ;
input = replaceIgnoreCase( input , "" ,"" ) ;
input = replaceIgnoreCase( input , "" ,"" ) ;
input = replaceIgnoreCase( input , "" ,"" ) ;
input = replaceIgnoreCase( input , "[red]" ,"" ) ;
input = replaceIgnoreCase( input , "[/red]" ,"" ) ;
input = replaceIgnoreCase( input , "
" ,"" ) ;
input = replaceIgnoreCase( input , "
" ,"
" ) ;
input = replaceIgnoreCase( input , "
" ,"" ) ;
input = replaceIgnoreCase( input , "" ,"" ) ;
input = replaceIgnoreCase ( input , "
" , "
" ) ;
input = replaceIgnoreCase ( input , "
" , "
" ) ;
input = replace ( input , " " ," " ) ;
input = replace ( input , "\n" ,"
" ) ;
if ( input.indexOf("<") >= 0 ) {
int oldPre = input.indexOf( "<" , 0 ) ;
int oldEnd = input.indexOf( ">" , oldPre ) ;
int tempInt = 0 ;
StringBuffer setBlank = new StringBuffer () ;
while ( oldPre >= 0 && oldEnd > 0 ) {
setBlank = setBlank.append( input.substring( tempInt , oldPre) ) ;
setBlank = setBlank.append ( replace ( input.substring( oldPre ,oldEnd ) , " " , " " ) ) ;
tempInt = oldEnd ;
oldPre = input.indexOf( "<" , oldEnd ) ;
oldEnd = input.indexOf( ">" , oldPre ) ;
}
setBlank = setBlank.append ( input.substring( tempInt ) ) ;
input = setBlank.toString() ;
}
}
return input;
}
/*USE:
*String convertURL( String input , boolean urlFlag )
*/
public static String convertURL( String input , boolean urlFlag ) {
if( input == null || input.length() == 0 || urlFlag || input.indexOf("[url") != -1 ) {
return input;
}
else {
StringBuffer buf = new StringBuffer();
int i = 0, j = 0, oldend = 0;
int len = input.length();
char cur;
while ( ( i=input.indexOf( "http://", oldend) ) >= 0 ) {
j=i+7;
cur = input.charAt(j);
while (j < len) {
if (cur == '' '') break;
if (cur == ''<'') break;
if (cur == ''\n'') break;
if (cur == ''\r'' && j= 0 ) {
j = i + tagPreLength ;
j = input.indexOf( tagNameEnd , j ) ;
if ( j < 0 ) {
buf.append ( input.substring( oldend , len ) ) ;
errorFlag = true ;
break;
}
else {
buf.append( input.substring(oldend,i));
buf.append( tagContentPre );
buf.append( input.substring(i + tagPreLength ,j));
buf.append( tagContentEnd );
buf.append( input.substring(i + tagPreLength ,j)).append( tagAttach ) ;
}
oldend = j + tagEndLength ;
}
if ( !errorFlag ) {
buf.append(input.substring(j + tagEndLength,len));
}
return buf.toString();
}
catch ( IndexOutOfBoundsException IOBe ) {
return input;
}
catch ( Exception e ) {
return input;
}
}
}
//
public static String convertSpecialTage (
String input ,
String tagNamePre ,
String tagNameEnd ,
String tagContentPre ,
String tagContentEnd ) {
if( input == null || input.length() == 0 || input.indexOf( tagNamePre ) < 0 ) {
return input;
}
else {
try {
StringBuffer buf = new StringBuffer();
int i = 0, j = 0, oldend = 0;
int len = input.length();
int tagPreLength = tagNamePre.length() ;
int tagEndLength = tagNameEnd.length() ;
boolean errorFlag = false ;
char cur;
while ( ( i=input.indexOf( tagNamePre , oldend) ) >= 0 ) {
j = i + tagPreLength ;
j = input.indexOf( tagNameEnd , j ) ;
if ( j < 0 ) {
buf.append ( input.substring( oldend , len ) ) ;
errorFlag = true ;
break;
}
else {
buf.append( input.substring(oldend,i));
buf.append( tagContentPre );
buf.append( input.substring(i + tagPreLength ,j));
buf.append( tagContentEnd );
}
oldend = j + tagEndLength ;
}
if ( !errorFlag ) {
buf.append( input.substring(j + tagEndLength,len));
}
return buf.toString();
}
catch ( IndexOutOfBoundsException IOBe ) {
return input;
}
catch ( Exception e ) {
return input;
}
}
}
//
public static String convertSpecialTage (
String input ,
String tagNamePre ,
String tagNameEnd ,
String tagContentPre ,
String tagContentEnd ,
String tagAttach ,
String interval ) {
if( input == null || input.length() == 0 || input.indexOf( tagNamePre ) < 0 ) {
return input;
}
else {
try {
StringBuffer buf = new StringBuffer();
int i = 0, j = 0, oldend = 0;
int len = input.length();
int tagPreLength = tagNamePre.length() ;
int tagEndLength = tagNameEnd.length() ;
int intervalLength = interval.length() ;
boolean errorFlag = false ;
String tempString = null ;
char cur;
while ( ( i=input.indexOf( tagNamePre , oldend) ) >= 0 ) {
j = i + tagPreLength ;
j = input.indexOf( tagNameEnd , j ) ;
if ( j < 0 ) {
buf.append ( input.substring( oldend , len ) ) ;
errorFlag = true ;
break;
}
else {
int intervalPostion = input.indexOf( interval , i + tagPreLength ) ;
if ( intervalPostion + intervalLength >= j ) {
buf.append ( input.substring( oldend , len ) ) ;
errorFlag = true ;
break;
}
buf.append( input.substring(oldend,i));
buf.append( tagContentPre );
tempString = input.substring(i + tagPreLength ,intervalPostion ).trim() ;
if ( tempString.indexOf("\"") == 0 ) {
tempString = tempString.substring ( 1 , tempString.indexOf( "\"" , 1 ) ) ;
}
buf.append( tempString );
buf.append( tagContentEnd );
buf.append( input.substring( intervalPostion + intervalLength ,j ) ).append( tagAttach ) ;
}
oldend = j + tagEndLength ;
}
if ( !errorFlag ) {
buf.append(input.substring(j + tagEndLength,len));
}
return buf.toString();
}
catch ( IndexOutOfBoundsException IOBe ) {
return input;
}
catch ( Exception e ) {
return input;
}
}
}
/*USE:
*String convertIMG( String input )
*/
public static String convertIMG ( String input ) {
if( input == null || input.length() == 0 ) {
return input;
}
else {
return convertSpecialTage ( input , "" , "![](\"")
" ) ;
}
}
/*USE:
*String convertSupperUBB( String input , int level )
*/
public static String convertSupperUBB ( String input , int level ) {
if( input == null || input.length() == 0 ) {
return input;
}
else {
level++ ;
if ( level-- > 0 ) input = convertSpecialTage ( input , "" , "" , "" , "" ) ;
if ( level-- > 0 ) input = convertSpecialTage ( input , "[url=" , "][/url]" , "" , "" , "]" ) ;
if ( level-- > 0 ) input = convertSpecialTage ( input , "[color=" ,"][/color]" , "" , "" , "]" ) ;
if ( level-- > 0 ) input = convertSpecialTage ( input , "[size=" ,"][/size]" , "" , "" , "]" ) ;
if ( level-- > 0 ) input = convertSpecialTage ( input , "" , "" , "" , "" ) ;
if ( level-- > 0 ) input = convertSpecialTage ( input , "" , "" ) ;
if ( level-- > 0 ) input = convertSpecialTage ( input , "[swf]" , "[/swf]" ,
""
) ;
if ( level-- > 0 ) input = convertSpecialTage ( input , "[url2]" , "[/url2]" , "" , "" ) ;
if ( level-- > 0 ) input = convertSpecialTage ( input , "[url2=" , "][/url2]" , "" , "" , "]" ) ;
if ( level-- > 0 ) input = convertSpecialTage ( input , "[a]" ,"[/a]" , "" ) ;
if ( level-- > 0 ) input = convertSpecialTage ( input , "[div=" ,"][/div]" , "" , "
" , "]" ) ;
if ( level-- > 0 ) input = convertSpecialTage ( input , "[jsurl=" ,"][/jsurl]" , "" ,"" ,"]") ;
if ( level-- > 0 ) input = convertSpecialTage ( input , "[class=" ,"][/class]" , "" , "" , "]" ) ;
input = convertUBB ( input ) ;
return input ;
}
}
/*USE:
*String convertMAIL( String input )
*/
public static String convertMAIL ( String input ) {
if( input == null || input.length() == 0 ) {
return input;
}
else {
return convertSpecialTage ( input , "" , "" , "" , "" ) ;
}
}
/*USE:
*String convertSWF( String input )
*/
public static String convertSWF ( String input ) {
if( input == null || input.length() == 0 ) {
return input;
}
else {
return convertSpecialTage ( input , "[swf]" , "[/swf]" ,
""
) ;
}
}
}
今天開始寫了
歡迎訪問！