boolean ready()
描述 (Description)
java.io.InputStreamReader.ready()方法告知此流是否可以读取。
声明 (Declaration)
以下是java.io.InputStreamReader.ready()方法的声明 -
public boolean ready()
参数 (Parameters)
NA
返回值 (Return Value)
如果保证下一次读取不阻止输入,则该方法返回true,否则返回false。
异常 (Exception)
IOException - 如果发生I/O错误。
例子 (Example)
以下示例显示了java.io.InputStreamReader.ready()方法的用法。
package com.iowiki;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
public class InputStreamReaderDemo {
public static void main(String[] args) throws IOException {
FileInputStream fis = null;
InputStreamReader isr = null;
boolean bool = false;
int i;
char c;
try {
// new input stream reader is created
fis = new FileInputStream("C:/test.txt");
isr = new InputStreamReader(fis);
// reads into the char buffer
while((i = isr.read())!=-1) {
// converts int to char
c = (char)i;
// prints the character
System.out.println("Character read: "+c);
// true if the next read is guaranteed
bool = isr.ready();
// prints
System.out.println("Ready to read: "+bool);
}
} catch (Exception e) {
// print error
e.printStackTrace();
} finally {
// closes the stream and releases resources associated
if(fis!=null)
fis.close();
if(isr!=null)
isr.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 -
ABCDE
让我们编译并运行上面的程序,这将产生以下结果 -
Character read: A
Ready to read: true
Character read: B
Ready to read: true
Character read: C
Ready to read: true
Character read: D
Ready to read: true
Character read: E
Ready to read: false