Java PrintWriter setError()方法及示例
Java中PrintWriter类的setError()方法是用来设置这个PrintWriter实例的错误状态。这个方法被用作指示器,以表明流中发生了错误。它是受保护的,因此需要通过派生PrintWriter类来实现,以使用它。
语法。
protected void setError()
参数。此方法不接受任何参数。
返回值。这个方法不返回任何东西。
下面的方法说明了setError()方法的工作。
程序 1:
// Java program to demonstrate
// PrintWriter setError() method
import java.io.*;
// extending the PrintWriter Class
class GFG extends PrintWriter {
// Defining the protected constructor
public GFG(OutputStream out)
{
super(System.out);
}
// Driver Code
public static void main(String[] args)
{
// The string to be written in the Writer
String str = "GeeksForGeeks";
try {
// Create a GFG instance
GFG writer
= new GFG(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);
writer.flush();
// Use the protected setError() method
writer.setError();
}
catch (Exception e) {
System.out.println(e);
}
}
}
输出:
GeeksForGeeks
程序2。
// Java program to demonstrate
// PrintWriter setError() method
import java.io.*;
// extending the PrintWriter Class
class GFG extends PrintWriter {
// Defining the protected constructor
public GFG(OutputStream out)
{
super(System.out);
}
// Driver Code
public static void main(String[] args)
{
try {
// Create a GFG instance
GFG writer
= new GFG(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);
writer.flush();
// Use the protected setError() method
writer.setError();
}
catch (Exception e) {
System.out.println(e);
}
}
}
输出:
A