Java CharArrayReader ready()方法及示例
Java中CharArrayReader类的ready()方法是用来检查这个CharArrayReader是否准备好被读取。它返回一个布尔值,说明阅读器是否准备好了。
语法。
public void ready()
参数。该方法不接受任何参数
返回值。这个方法返回一个布尔值,告诉你这个CharArrayReader是否准备好被读取。如果它准备好了,返回true。否则,它返回false。
异常。如果在输入-输出时发生一些错误,该方法会抛出 IOException 。
下面的方法说明了ready()方法的工作。
程序 1:
// Java program to demonstrate
// CharArrayReader ready() method
import java.io.*;
import java.util.*;
class GFG {
public static void main(String[] args)
{
try {
char[] str = { 'G', 'e', 'e', 'k', 's',
'F', 'o', 'r',
'G', 'e', 'e', 'k', 's' };
// Create a CharArrayReader instance
CharArrayReader reader
= new CharArrayReader(str);
// Check if the CharArrayReader is
// ready to be read using ready()
System.out.println("Is CharArrayReader ready "
+ "to be read: "
+ reader.ready());
// Get the character
// to be read from the stream
int ch;
// Read the first 5 characters
// to this reader using read() method
// This will put the str in the stream
// till it is read by the reader
for (int i = 0; i < 5; i++) {
ch = reader.read();
System.out.println("\nInteger value "
+ "of character read: "
+ ch);
System.out.println("Actual "
+ "character read: "
+ (char)ch);
}
reader.close();
}
catch (Exception e) {
System.out.println(e);
}
}
}
输出:
Is CharArrayReader ready to be read: true
Integer value of character read: 71
Actual character read: G
Integer value of character read: 101
Actual character read: e
Integer value of character read: 101
Actual character read: e
Integer value of character read: 107
Actual character read: k
Integer value of character read: 115
Actual character read: s
计划2。
// Java program to demonstrate
// CharArrayReader ready() method
import java.io.*;
import java.util.*;
class GFG {
public static void main(String[] args)
{
try {
char[] str = { 'G', 'e', 'e', 'k', 's',
'F', 'o', 'r',
'G', 'e', 'e', 'k', 's' };
// Create a CharArrayReader instance
CharArrayReader reader
= new CharArrayReader(str);
reader.close();
// Check if the CharArrayReader is
// ready to be read using ready()
System.out.println("Is CharArrayReader ready "
+ "to be read: "
+ reader.ready());
// Get the character
// to be read from the stream
int ch;
// Read the first character
// to this reader using read() method
// This will put the str in the stream
// till it is read by the reader
ch = reader.read();
System.out.println("\nInteger value "
+ "of character read: "
+ ch);
System.out.println("Actual "
+ "character read: "
+ (char)ch);
reader.close();
}
catch (Exception e) {
System.out.println(e);
}
}
}
输出:
java.io.IOException: Stream closed
参考资料: https://docs.oracle.com/javase/9/docs/api/java/io/CharArrayReader.html#ready-