Java中的 CharArrayReader close() 方法及示例
Java中CharArrayReader类的close()方法用于关闭流并释放流中繁忙的资源(如果有)。该方法有以下结果:
- 如果流是打开的,它会关闭释放资源的流
- 如果流已经关闭,它将无效。
- 如果对流执行任何读取或其他类似操作,则在关闭后,它会引发 IOException
句法:
public abstract void close()
参数:此方法不接受任何参数
返回值:此方法不返回任何值。
异常:如果输入输出时发生错误,此方法将抛出 IOException。
下面的方法说明了 close() 方法的工作:
方案一:
// Java program to demonstrate
// CharArrayReader close() 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);
// 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);
}
// Close the stream using close()
reader.close();
System.out.println("Stream Closed.");
}
catch (Exception e) {
System.out.println(e);
}
}
}
输出:
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
Stream Closed.
方案二:
// Java program to demonstrate
// CharArrayReader close() method
import java.io.*;
import java.util.*;
class GFG {
public static void main(String[] args)
{
try {
char[] str = { 'G', 'e', 'e', 'k', 's' };
// Create a CharArrayReader instance
CharArrayReader reader
= new CharArrayReader(str);
// Close the stream using close()
reader.close();
System.out.println("Stream Closed.");
// Check if the CharArrayReader is
// ready to be read using ready()
System.out.println("Is CharArrayReader ready "
+ "to be read"
+ reader.ready());
}
catch (Exception e) {
System.out.println(e);
}
}
}
输出:
Stream Closed.
java.io.IOException: Stream closed
参考: https://docs.oracle.com/javase/9/docs/api/ Java/io/CharArrayReader.html#close–