import java.io.FileNotFoundException;
import java.io.IOException;
public class Utf {
static String basePath="C:\\Users\\Administrator\\Desktop\\utf\\";
public static void main(String[] args) {
try {
System.out.println(isUtf(basePath+"web.xml"));
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
/**
* 用有限状态机写的
* @param filePath
* @return
* @throws IOException
*/
public static boolean isUtf(String filePath) throws IOException{
FileInputStream fis=new FileInputStream(filePath);
byte[] bbuf=new byte[1024];
int L=-1;
int status=0;//状态
int oneByteCount=0;
int twoByteCount=0;
int threeByteCount=0;
int fourByteCount=0;
int errorCount=0;
while((L=fis.read(bbuf))!=-1){
for (int i = 0; i <L; i++) {
byte b=bbuf[i];
// System.out.print(Integer.toHexString(b&0xff)+"|");
switch (status) {
case 0:
if(b>=0&&b<=(byte)0x7F)//一个字节的首字节范围
oneByteCount++;//一个字节的数量加一
else if(b>=(byte)0xC0&&b<=(byte)0xDF)//两个字节的首字节范围
status=2;//跳到状态2
else if(b>=(byte)0xE0&&b<=(byte)0XEF)//三个字节的首字节范围
status=4;//跳到状态4
else if(b>=(byte)0xF0&&b<=(byte)0xF7)//四个字节的首字节范围
status=7;//跳到状态7
else
errorCount++;
break;
case 1:
break;
case 2:
if(b>=(byte)0x80&&b<=(byte)0xBF){//两个字节的第二个字节范围
twoByteCount++;//
status=0;
}else{
errorCount+=2;
status=0;
}
break;
case 3:
break;
case 4:
if(b>=(byte)0x80&&b<=(byte)0xBF)//三个字节的第二个字节的范围
status=5;
else{
errorCount+=2;
status=0;
}
break;
case 5:
if(b>=(byte)0x80&&b<=(byte)0xBF){//三个字节的第三个字节的范围
threeByteCount++;
status=0;
}else{
errorCount+=3;
status=0;
}
break;
case 7:
if(b>=(byte)0x80&&b<=(byte)0xBF){//四个字节的第二个字节的范围
status=8;
}else{
errorCount+=2;
status=0;
}
break;
case 8:
if(b>=(byte)0x80&&b<=(byte)0xBF){//四个字节的第三个字节的范围
status=9;
}else{
errorCount+=3;
status=0;
}
break;
case 9:
if(b>=(byte)0x80&&b<=(byte)0xBF){//四个字节的第四个字节的范围
fourByteCount+=4;
status=0;
}else{
errorCount++;
status=0;
}
break;
default:
break;
}
}
}
System.out.println("一个字节的有："+oneByteCount);
System.out.println("两个字节的有："+twoByteCount);
System.out.println("三个字节的有："+threeByteCount);
System.out.println("四个字节的有："+fourByteCount);
System.out.println("错误个数："+errorCount);
System.out.println("总共字节数有："+(oneByteCount+twoByteCount*2+threeByteCount*3+fourByteCount*4+errorCount));
if(errorCount==0){
return true;
}
return false;
}
}
