int read(byte[] b)
描述 (Description)
java.io.FilterInputStream.read(byte[] b)方法将来自此过滤器输入流的b.length数据读入字节数组。 此方法将阻止输入数据可用。
声明 (Declaration)
以下是java.io.FilterInputStream.read(byte[] b)方法的声明 -
public int read(byte[] b)
参数 (Parameters)
b - 目标缓冲区。
返回值 (Return Value)
该方法返回读入缓冲区的总字节数,如果没有更多数据要读取,则返回-1。
异常 (Exception)
IOException - 如果发生I/O错误
例子 (Example)
以下示例显示了java.io.FilterInputStream.read(byte [] b)方法的用法。
package com.iowiki;
import java.io.BufferedInputStream;
import java.io.FileInputStream;
import java.io.FilterInputStream;
import java.io.IOException;
import java.io.InputStream;
public class FilterInputStreamDemo {
public static void main(String[] args) throws Exception {
InputStream is = null;
FilterInputStream fis = null;
int i = 0;
char c;
byte[] buffer = new byte[6];
try {
// create input streams
is = new FileInputStream("C://test.txt");
fis = new BufferedInputStream(is);
// returns number of bytes read to buffer
i = fis.read(buffer);
// prints
System.out.println("Number of bytes read: "+i);
// for each byte in buffer
for(byte b:buffer) {
// converts byte to character
c = (char)b;
// prints
System.out.println("Character read: "+c);
}
} catch(IOException e) {
// if any I/O error occurs
e.printStackTrace();
} finally {
// releases any system resources associated with the stream
if(is!=null)
is.close();
if(fis!=null)
fis.close();
}
}
}
假设我们有一个文本文件c:/test.txt ,它具有以下内容。 该文件将用作示例程序的输入 -
ABCDEF
让我们编译并运行上面的程序,这将产生以下结果 -
Number of bytes read: 6
Character read: A
Character read: B
Character read: C
Character read: D
Character read: E
Character read: F