在队列中寻找字符串算法

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在一个队列destQ中，从前向后搜索是否有字符串flag，下面是算法实现以及测试程序。回溯功能暂未实现。

private int findFlag( final LinkedBlockingQueue destQ,

final String flag) {

byte [] flagArr = flag.getBytes();

Byte[] destArr = destQ.toArray( new Byte[0]);

int matchCount = 0; // 已匹配的字节数

int flagPos = -1; // 标志末尾的编号

int i = 0;

int backupIndex = 0; // 用于回溯的索引

while (i <= destQ.size()) {

if (flag.length() <= matchCount) {

flagPos = i;

break ;

} else {

if (destArr[i] == flagArr[matchCount]) {

matchCount++;

} else {

matchCount = 0;

// i = backupIndex;

}

}

i = i + 1;

if (matchCount == 1) {

backupIndex = i;

}

}

return flagPos;

}

@Test

public void runFindFlag() {

LinkedBlockingQueue analyzerBuffer = new LinkedBlockingQueue();

for ( int i = 33; i < 123; i++) {

analyzerBuffer.offer( new Byte(( byte ) i));

}

String endFlag = "123" ;

int endFlagPos = findFlag(analyzerBuffer, endFlag);

List cmplXmlStr = new ArrayList();

analyzerBuffer.drainTo(cmplXmlStr, endFlagPos);

System. out .println(cmplXmlStr);

}

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