ByteArrayInputStream類mark()方法 (ByteArrayInputStream Class mark() method)

• mark() method is available in java.util package.

  mark()方法在java.util包中可用。

• mark() method is used to set the current mark position in the stream from where read or write can be reset.

  mark()方法用于設置流中的當前標記位置，從該位置可以重置讀取或寫入。

• mark() 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.

  mark()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。

• mark() method may throw an exception at the time of seeking mark position.

  在尋求標記位置時， mark()方法可能會引發異常。

  IOException: This exception may throw while performing input/output operations.

  IOException ：在執行輸入/輸出操作時，可能會拋出此異常。

Syntax:

句法：

    public void mark(int read_from_here);

Parameter(s):

參數：

• int read_from_here – represents the mark position where reading or writing can start.

  int read_from_here –表示可以開始讀取或寫入的標記位置。

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 mark(int read_from_here) method of
// ByteArrayInputStream
import java.io.*;
public class MarkBAIS {
public static void main(String[] args) throws Exception {
byte[] by = {
97,
98,
98,
99
};
// Instantiates ByteArrayInputStream 
ByteArrayInputStream byte_s = new ByteArrayInputStream(by);
// By using available() method is to
// return the no. of bytes to be left 
// for reading
Integer n_byte = byte_s.available();
System.out.println("Left avail bytes = " + n_byte);
// Read character from the stream
char ch1 = (char) byte_s.read();
char ch2 = (char) byte_s.read();
char ch3 = (char) byte_s.read();
System.out.println("ch1: " + ch1);
System.out.println("ch2 : " + ch2);
System.out.println("byte_s.mark(5): ");
// By using mark() method isto
// set the limit the number of byte
// to be read 
byte_s.mark(5);
System.out.println("ch3: " + ch3);
System.out.println("buff_str.reset(): ");
// reset stream by using reset()
byte_s.reset();
// Read from the stread
char ch4 = (char) byte_s.read();
char ch5 = (char) byte_s.read();
// Display character
System.out.println("ch4: " + ch4);
System.out.println("ch5: " + ch5);
byte_s.close();
}
}

Output

輸出量

Left avail bytes = 4
ch1: a
ch2 : b
byte_s.mark(5):
ch3: b
buff_str.reset():
ch4: c
ch5: ?

翻譯自: https://www.includehelp.com/java/bytearrayinputstream-mark-method-with-example.aspx