java reader

讀取器類的reset()方法 (Reader Class reset() method)

• reset() method is available in java.io package.

  reset()方法在java.io包中可用。

• reset() method is used to reset this stream to the mark set by mark() method most recently.

  reset()方法用于將此流重置為mark()方法最近設置的標記。

• reset() method is a non-static method, it is accessible with the class object only and if we try to access the method with the class name then we will get an error.

  reset()方法是一種非靜態方法，只能通過類對象訪問，如果嘗試使用類名稱訪問該方法，則會收到錯誤消息。

• reset() method may throw an exception at the time of resetting the stream.

  reset()方法在重置流時可能會引發異常。

  IOException: This exception may throw when getting any input/output error or unsupported reset() method.

  IOException ：當遇到任何輸入/輸出錯誤或不受支持的reset()方法時，可能引發此異常。

Syntax:

句法：

    public void reset();

Parameter(s):

參數：

• It does not accept any parameter.

  它不接受任何參數。

Return value:

返回值：

The return type of the method is void, it returns nothing.

該方法的返回類型為void ，不返回任何內容。

Example:

例：

// Java program to demonstrate the example 
// of void reset() method of Reader
import java.io.*;
public class ResetOfR {
public static void main(String[] args) throws Exception {
Reader r_stm = null;
try {
// Instantiates Reader
r_stm = new StringReader("JavaWorld!!!!");
// By using read() method isto 
// read the character from r_stm
char ch1 = (char) r_stm.read();
char ch2 = (char) r_stm.read();
char ch3 = (char) r_stm.read();
System.out.println("ch1: " + ch1);
System.out.println("ch2: " + ch2);
System.out.println("ch3: " + ch3);
// By using mark() method isto
// set the current position in this
// r_stm
System.out.println("r_stm.mark(1): ");
r_stm.mark(1);
char ch4 = (char) r_stm.read();
char ch5 = (char) r_stm.read();
System.out.println("ch4: " + ch4);
System.out.println("ch5: " + ch5);
// By using reset() method isto
// reset the stream to the position 
// set by the call mark() method
System.out.println("r_stm.reset(): ");
r_stm.reset();
char ch6 = (char) r_stm.read();
char ch7 = (char) r_stm.read();
char ch8 = (char) r_stm.read();
char ch9 = (char) r_stm.read();
char ch10 = (char) r_stm.read();
char ch11 = (char) r_stm.read();
char ch12 = (char) r_stm.read();
System.out.println("ch4: " + ch6);
System.out.println("ch5: " + ch7);
System.out.println("ch6: " + ch8);
System.out.println("ch7: " + ch9);
System.out.println("ch8: " + ch10);
System.out.println("ch9: " + ch11);
System.out.println("ch10: " + ch12);
} catch (Exception ex) {
System.out.println(ex.toString());
} finally {
// with the help of this block is to
// free all necessary resources linked
// with the stream
if (r_stm != null) {
r_stm.close();
}
}
}
}

Output

輸出量

ch1: J
ch2: a
ch3: v
r_stm.mark(1): 
ch4: a
ch5: W
r_stm.reset(): 
ch4: a
ch5: W
ch6: o
ch7: r
ch8: l
ch9: d
ch10: !

翻譯自: https://www.includehelp.com/java/reader-reset-method-with-example.aspx

java reader