package 第二題;

import java.io.File;

import java.io.FileInputStream;

import java.io.FileNotFoundException;

import java.io.IOException;

import java.io.UnsupportedEncodingException;

import java.util.Arrays;​

public class MainTest {​

public static void main(String[] args) throws UnsupportedEncodingException {
// 創(chuàng)建File對(duì)象

File file = new File("D:\\filetest\\file4.txt");

FileInputStream fileInputStream = null;

try {
// 新建一個(gè)FileInputStream對(duì)象

fileInputStream = new FileInputStream(file);

// 新建一個(gè)字節(jié)數(shù)組

byte[] buf = new byte[2];

// read(buf)：此方法的返回值就是當(dāng)前讀取的字節(jié)個(gè)數(shù)，將數(shù)據(jù)讀取到buf數(shù)組

// 將readLen變量也就是read方法的返回值，當(dāng)此變量等于-1，則讀到文件末尾

int readLen = -1;

//讀取文件數(shù)據(jù)

while ((readLen = fileInputStream.read(buf)) != -1) {
int pos=0;//記錄負(fù)數(shù)的個(gè)數(shù)

for(byte v:buf)

{
if(v<0)

{
pos++;

}

}

//負(fù)數(shù)個(gè)數(shù)為偶數(shù)，讀取完整，沒有讀取到半個(gè)中文

if(pos%2==0)

{
// 將字節(jié)數(shù)組轉(zhuǎn)換成字符串

String content = new String(buf, 0, readLen);

System.out.print(content);

}else {//負(fù)數(shù)個(gè)數(shù)為奇數(shù)，讀取不完整，會(huì)亂碼

//再讀取下一位字節(jié)

int nextByteValue=fileInputStream.read();

int nextLen=readLen+1;

//字節(jié)數(shù)組擴(kuò)容一位

buf= Arrays.copyOf(buf,nextLen);

buf[readLen]= (byte) nextByteValue;

String content=new String(buf,0,nextLen);

System.out.print(content);

//奇數(shù)，字節(jié)補(bǔ)全

//針對(duì)數(shù)組擴(kuò)容一個(gè)字節(jié)單元

/* buf=Arrays.copyOf(buf, readLen+1);

int nextByteValue=fileInputStream.read();

buf[readLen]= (byte) nextByteValue;

String content = new String(buf, 0, readLen);

System.out.print(content);*/

}

}

} catch (FileNotFoundException e) {
// 輸出堆棧信息

e.printStackTrace();

} catch (IOException e) {
e.printStackTrace();

} finally {
try {
// 文件輸入流關(guān)閉(釋放資源)

fileInputStream.close();

} catch (IOException e) {
// TODO Auto-generated catch block

e.printStackTrace();

}

}

}

}