PushbackReader类ready()方法 (PushbackReader Class ready() method)

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

  ready()方法在java.io包中可用。

• ready() method is used to check whether this stream is ready to be read or not.

  ready()方法用于检查此流是否已准备好被读取。

• ready() 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.

  ready()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。

• ready() method may throw an exception at the time of checking the state of the stream.

  在检查流的状态时， ready()方法可能会引发异常。

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

  IOException ：在执行过程中遇到任何输入/输出错误时，可能引发此异常。

Syntax:

句法：

    public boolean ready();

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 boolean, it returns true when input data is exists for the next read without blocking otherwise it returns false.

该方法的返回类型为boolean ，如果存在下一次​​读取的输入数据且没有阻塞，则返回true，否则返回false。

Example:

例：

// Java program to demonstrate the example 
// of boolean ready() method of
// PushbackReader
import java.io.*;
public class ReadyOfPBR {
public static void main(String[] args) throws Exception {
Reader r_stm = null;
PushbackReader pb_r = null;
try {
// Instantiates Reader and PushbackReader
r_stm = new StringReader("Java World!!!!");
pb_r = new PushbackReader(r_stm);
// By using ready() method is to
// check whether this stream is ready to
// be read or not
boolean status = pb_r.ready();
System.out.println("pb_r.ready(): " + status);
} 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 (r_stm != null) {
r_stm.close();
if (pb_r != null) {
pb_r.close();
}
}
}
}
}

Output

输出量

pb_r.ready(): true

翻译自: https://www.includehelp.com/java/pushbackreader-ready-method-with-example.aspx