Java Reader read(char[])用法及代碼示例

Java中Reader類的read(char [])方法用於將指定的字符讀取到數組中。此方法將流阻塞到：

它已從流中獲取了一些輸入。
發生了一些IOException
閱讀時已到達流的末尾。

用法:

public int read(char[] charArray)

參數：此方法接受強製參數charArray，這是要在Stream中寫入的字符數組。

返回值：此方法返回一個整數值，該整數值是從流中讀取的字符數。如果未讀取任何字符，則返回-1。

異常：如果輸入輸出時發生某些錯誤，則此方法將引發IOException。

以下方法說明了read(char [])方法的用法方式：

程序1:

// Java program to demonstrate 
// Reader read(char[]) 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 array 
            // to be read from the stream 
            char[] charArray = new char[5]; 
  
            // Read the charArray 
            // to this reader using read() method 
            // This will put the str in the stream 
            // till it is read by the reader 
            reader.read(charArray); 
  
            // Print the read charArray 
            System.out.println( 
                Arrays 
                    .toString(charArray)); 
  
            reader.close(); 
        } 
        catch (Exception e) { 
            System.out.println(e); 
        } 
    } 
}

輸出：

[G, e, e, k, s]

程序2:

// Java program to demonstrate 
// Reader read(char[]) 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 array 
            // to be read from the stream 
            char[] charArray 
                = new char[str.length()]; 
  
            // Read the charArray 
            // to this reader using read() method 
            // This will put the str in the stream 
            // till it is read by the reader 
            reader.read(charArray); 
  
            // Print the read charArray 
            System.out.println( 
                Arrays 
                    .toString(charArray)); 
  
            reader.close(); 
        } 
        catch (Exception e) { 
            System.out.println(e); 
        } 
    } 
}

輸出：

[G, e, e, k, s, F, o, r, G, e, e, k, s]

參考： https://docs.oracle.com/javase/9/docs/api/java/io/Reader.html#read-

相關用法

注：本文由純淨天空篩選整理自Code_r大神的英文原創作品 Reader read(char[]) method in Java with Examples。非經特殊聲明，原始代碼版權歸原作者所有，本譯文未經允許或授權，請勿轉載或複製。