📅 最后修改于: 2020-09-27 02:00:32 🧑 作者: Mango
Java FileInputStream类从文件获取输入字节。它用于读取面向字节的数据(原始字节流)，例如图像数据，音频，视频等。您还可以读取字符流数据。但是，为了读取字符流，建议使用FileReader类。
让我们看一下java.io.FileInputStream类的声明：
public class FileInputStream extends InputStream
| Method | Description |
|---|---|
| int available() | It is used to return the estimated number of bytes that can be read from the input stream. |
| int read() | It is used to read the byte of data from the input stream. |
| int read(byte[] b) | It is used to read up to b.length bytes of data from the input stream. |
| int read(byte[] b, int off, int len) | It is used to read up to len bytes of data from the input stream. |
| long skip(long x) | It is used to skip over and discards x bytes of data from the input stream. |
| FileChannel getChannel() | It is used to return the unique FileChannel object associated with the file input stream. |
| FileDescriptor getFD() | It is used to return the FileDescriptor object. |
| protected void finalize() | It is used to ensure that the close method is call when there is no more reference to the file input stream. |
| void close() | It is used to closes the stream. |
import java.io.FileInputStream;
public class DataStreamExample {
public static void main(String args[]){
try{
FileInputStream fin=new FileInputStream("D:\\testout.txt");
int i=fin.read();
System.out.print((char)i);
fin.close();
}catch(Exception e){System.out.println(e);}
}
}
注意：在运行代码之前，需要创建一个名为“ testout.txt”的文本文件。在此文件中，我们具有以下内容：
Welcome to javatpoint.
执行完上述程序后，您将从文件中获得一个字符，该字符为87(字节形式)。要查看文本，您需要将其转换为字符。
输出：
W
package com.javatpoint;
import java.io.FileInputStream;
public class DataStreamExample {
public static void main(String args[]){
try{
FileInputStream fin=new FileInputStream("D:\\testout.txt");
int i=0;
while((i=fin.read())!=-1){
System.out.print((char)i);
}
fin.close();
}catch(Exception e){System.out.println(e);}
}
}
输出：
Welcome to javaTpoint