Java中的 PrintWriter close() 方法及示例

Java中PrintWriter类的close()方法用于关闭流。关闭流会释放其中的任何值或与之关联的任何资源。 PrintWriter 实例一旦关闭将不起作用。此外，PrintWriter 实例一旦关闭就不能再次关闭。

句法：

public 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。它只是关闭流。

下面的方法说明了 close() 方法的工作：

方案一：

// Java program to demonstrate
// PrintWriter close() method
  
import java.io.*;
  
class GFG {
    public static void main(String[] args)
    {
  
        // The string to be written in the Writer
        String str = "GeeksForGeeks";
  
        try {
  
            // Create a PrintWriter instance
            PrintWriter writer
                = new PrintWriter(System.out);
  
            // Write the above string to this writer
            // This will put the string in the stream
            // till it is printed on the console
            writer.write(str);
  
            // Now close the stream
            // using close() method
            writer.close();
        }
        catch (Exception e) {
            System.out.println(e);
        }
    }
}

输出：

GeeksForGeeks

方案二：

// Java program to demonstrate
// PrintWriter close() method
  
import java.io.*;
  
class GFG {
    public static void main(String[] args)
    {
  
        try {
  
            // Create a PrintWriter instance
            PrintWriter writer
                = new PrintWriter(System.out);
  
            // Write the char to this writer
            // This will put the char in the stream
            // till it is printed on the console
            writer.write(65);
  
            // Now close the stream
            // using close() method
            writer.close();
        }
        catch (Exception e) {
            System.out.println(e);
        }
    }
}

输出：

A