Java Reader read(char[])方法及示例

Java中 Reader 类的 read(char[]) 方法是用来读取指定的字符到一个数组中。这个方法阻塞了流，直到。

语法

public int read(char[] charArray)

参数： 该方法接受一个强制性参数 charArray ，它是要写入流中的字符阵列。

返回值： 该方法返回一个 整数 ，即从流中读取的字符数。如果没有读取任何字符，则返回-1。

异常： 如果在输入-输出时发生错误，该方法会抛出 IOException 。下面的方法说明了read(char[])方法的工作。

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& quot;            ;             // 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]

计划3 。

// Use a BufferedReader to read characters from the console.import java.io.*; public class GFG {     public static void main(String args[])        throws IOException    {        char c;        BufferedReader br = new BufferedReader(            new InputStreamReader(System.in));        System.out.println(            "Enter the characters: , 'q' to quit.");         // read characters        do {            c = (char)br.read();            System.out.println(c);        } while (c != 'q');    }}

输出

gfgisbestgfgisbestq