inputstream示例

InputStream类的available()方法 (InputStream Class available() method)

• available() method is available in java.io package.

  available()方法在java.io包中可用。

• available() method is used to return the number of available bytes left for reading from this InputStream without blocking by the next call of the method from this InputStream.

  available()方法用于返回可从此InputStream读取的剩余可用字节数，而不会被该InputStream的下一次调用阻塞。

• available() method is a non-static method, it is accessible with the class object only and if we try to access the method with the class name then we will get an error.

  available()方法是一种非静态方法，只能通过类对象访问，如果尝试使用类名称访问该方法，则会收到错误消息。

• available() method may throw an exception at the time of returning available bytes.

  available()方法在返回可用字节时可能会引发异常。

  IOException: This exception may throw when getting any input/output error.

  IOException ：遇到任何输入/输出错误时，可能引发此异常。

Syntax:

句法：

    public int available();

Parameter(s):

参数：

• It does not accept any parameter.

  它不接受任何参数。

Return value:

返回值：

The return type of the method is int, it returns the number of bytes left that can be read.

该方法的返回类型为int ，它返回可以读取的剩余字节数。

Example:

例：

// Java program to demonstrate the example 
// of int available() method of InputStream
import java.io.*;
public class AvailableOfIS {
public static void main(String[] args) throws Exception {
InputStream is_stm = null;
int val = 0;
try {
// Instantiates FileInputStream
is_stm = new FileInputStream("D:\\includehelp.txt");
// Loop to read until available
// bytes left
while ((val = is_stm.read()) != -1) {
// By using available() method is to
// return the available bytes to be read
int avail_bytes = is_stm.available();
// Display corresponding byte value
byte b = (byte) val;
// Display value of avail_bytes and b
System.out.print("is_stm.available(): " + avail_bytes);
System.out.println(" : " + "byte: " + b);
}
} catch (Exception ex) {
System.out.println(ex.toString());
} finally {
// with the help of this block is to
// free all necessary resources linked
// with the stream
if (is_stm != null) {
is_stm.close();
}
}
}
}

Output

输出量

is_stm.available(): 3 : byte: 74
is_stm.available(): 2 : byte: 65
is_stm.available(): 1 : byte: 86
is_stm.available(): 0 : byte: 65

翻译自: https://www.includehelp.com/java/inputstream-available-method-with-example.aspx

inputstream示例