Java Reader read(char[])用法及代码示例

Java中Reader类的read(char [])方法用于将指定的字符读取到数组中。此方法将流阻塞到：

它已从流中获取了一些输入。
发生了一些IOException
阅读时已到达流的末尾。

用法:

public int read(char[] charArray)

参数：此方法接受强制参数charArray，这是要在Stream中写入的字符数组。

返回值：此方法返回一个整数值，该整数值是从流中读取的字符数。如果未读取任何字符，则返回-1。

异常：如果输入输出时发生某些错误，则此方法将引发IOException。

以下方法说明了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); 
        } 
    } 
}

输出：

[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); 
        } 
    } 
}

输出：

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

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

相关用法

注：本文由纯净天空筛选整理自Code_r大神的英文原创作品 Reader read(char[]) method in Java with Examples。非经特殊声明，原始代码版权归原作者所有，本译文未经允许或授权，请勿转载或复制。