Java Reader close()方法及实例
Java中Reader类的close()方法用于关闭流并释放在流中忙碌的资源，如果有的话。这个方法有以下结果。
如果流是开放的，它将关闭流，释放资源。如果流已经被关闭，它将没有任何影响。如果在关闭后对流进行任何读取或其他类似的操作，它将引发IOException。语法。
public abstract void close()
参数。这个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close()方法的工作。
程序 1:
// Java program to demonstrate// Reader close() method import java.io.*;import java.util.*; class GFG { public static void main(String[] args) { try { String str = "GeeksForGeeks"; // Create a Reader instance Reader reader = new StringReader(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: 71Actual character read: GInteger value of character read: 101Actual character read: eInteger value of character read: 101Actual character read: eInteger value of character read: 107Actual character read: kInteger value of character read: 115Actual character read: sStream Closed.
程序2。
// Java program to demonstrate// Reader close() method import java.io.*;import java.util.*; class GFG { public static void main(String[] args) { try { String str = "GeeksForGeeks"; // Create a Reader instance Reader reader = new StringReader(str); // Close the stream using close() reader.close(); System.out.println("Stream Closed."); // Check if the Reader is // ready to be read using ready() System.out.println("Is Reader ready " + "to be read" + reader.ready()); } catch (Exception e) { System.out.println(e); } }}输出:
Stream Closed.java.io.IOException: Stream closed
参考资料: https://docs.oracle.com/javase/9/docs/api/java/io/Reader.html#close-
