Java CharBuffer get()方法

Java CharBuffer get()方法

java.nio.CharBuffer 类的 get() 方法用于读取指定缓冲区当前位置的char,然后增加该位置。

语法

public abstract char get()

返回值: 该方法返回缓冲区当前位置的char值。

异常: 该方法抛出BufferUnderflowException – 如果缓冲区的当前位置不小于其极限值,则抛出该异常。

下面是说明 get() 方法的例子。

例1 :

// Java program to demonstrate
// get() method
import java.nio.*;
import java.util.*;
  
public class GFG {
  
    public static void main(String[] args)
    {
  
        // Declaring the capacity of the CharBuffer
        int capacity = 5;
  
        // Creating the CharBuffer
        try {
  
            // creating object of Charbuffer
            // and allocating size capacity
            CharBuffer cb = CharBuffer.allocate(capacity);
  
            // putting the value in Charbuffer
            cb.put('a');
            cb.put('b');
            cb.put('c');
            cb.rewind();
  
            // print the CharBuffer
            System.out.println("Original CharBuffer: "
                               + Arrays.toString(cb.array()));
  
            // Reads the Int at this buffer's current position
            // using get() method
            char value = cb.get();
  
            // print the Int value
            System.out.println("Int Value: " + value);
  
            // Reads the Int at this buffer's next position
            // using get() method
            char value1 = cb.get();
  
            // print the Int value
            System.out.print("Next Int Value: " + value1);
        }
  
        catch (IllegalArgumentException e) {
  
            System.out.println("IllegalArgumentException catched");
        }
  
        catch (ReadOnlyBufferException e) {
  
            System.out.println("ReadOnlyBufferException catched");
        }
  
        catch (BufferUnderflowException e) {
  
            System.out.println("Exception throws: " + e);
        }
    }
}

输出:

Original CharBuffer: [a, b, c, , ]
Int Value: a
Next Int Value: b

例子 2 :

// Java program to demonstrate
// get() method
  
import java.nio.*;
import java.util.*;
  
public class GFG {
  
    public static void main(String[] args)
    {
  
        // Declaring the capacity of the CharBuffer
        int capacity = 3;
  
        // Creating the CharBuffer
        try {
  
            // creating object of Charbuffer
            // and allocating size capacity
            CharBuffer cb = CharBuffer.allocate(capacity);
  
            // putting the value in Charbuffer
            cb.put('a');
            cb.put('b');
  
            // print the CharBuffer
            System.out.println("Original CharBuffer: "
                               + Arrays.toString(cb.array()));
  
            // Reads the Char at this buffer's current position
            // using get() method
            char value = cb.get();
  
            // print the Char value
            System.out.println("Char Value: " + value);
  
            // Reads the Char at this buffer's next position
            // using get() method
            System.out.print("Since the buffer current position is incremented\n");
            System.out.print(" to greater than its limit ");
  
            char value1 = cb.get();
  
            // print the Char value
            System.out.print("Next Char Value: " + value1);
        }
  
        catch (IllegalArgumentException e) {
  
            System.out.println("IllegalArgumentException catched");
        }
  
        catch (ReadOnlyBufferException e) {
  
            System.out.println("ReadOnlyBufferException catched");
        }
  
        catch (BufferUnderflowException e) {
  
            System.out.println("Exception throws : " + e);
        }
    }
}

输出:

Original CharBuffer: [a, b, ]
Char Value: 
Since the buffer current position is incremented
to greater than its limit Exception throws : java.nio.BufferUnderflowException

get(int index)

CharBuffer的get(int index)方法用于读取指定索引处的文章。

语法:

public abstract char get(int index)

参数: 该方法以 index (将被读取的char的索引)为参数。

返回值: 该方法返回给定索引处的字符值。

异常: 该方法抛出 IndexOutOfBoundsException。 如果索引是负的或者不小于缓冲区的限制,就会抛出这个异常。

下面是说明get(int index)方法的例子。

例子 1 :

// Java program to demonstrate
// get(int index) method
  
import java.nio.*;
import java.util.*;
  
public class GFG {
  
    public static void main(String[] args)
    {
  
        // Declaring the capacity of the CharBuffer
        int capacity = 3;
  
        // Creating the CharBuffer
        try {
  
            // creating object of Charbuffer
            // and allocating size capacity
            CharBuffer cb = CharBuffer.allocate(capacity);
  
            // putting the value in Charbuffer
            cb.put('a');
            cb.put('b');
            cb.put('c');
  
            // print the CharBuffer
            System.out.println("Original CharBuffer: "
                               + Arrays.toString(cb.array()));
  
            // Reads the Char at the index 0 of the Charbuffer
            // using get() method
            char value0 = cb.get(0);
  
            // print the Char value
            System.out.println("Char Value at index 0: " + value0);
  
            // Reads the Char at the index 1 of the Charbuffer
            // using get() method
            char value1 = cb.get(1);
  
            // print the Char value
            System.out.println("Char Value at index 1: " + value1);
  
            // Reads the Char at the index 2 of the Charbuffer
            // using get() method
            char value2 = cb.get(2);
  
            // print the Char value
            System.out.println("Char Value at index 2: " + value2);
        }
  
        catch (IllegalArgumentException e) {
  
            System.out.println("IllegalArgumentException catched");
        }
  
        catch (IndexOutOfBoundsException e) {
  
            System.out.println("ReadOnlyBufferException catched");
        }
  
        catch (BufferUnderflowException e) {
  
            System.out.println("Exception throws : " + e);
        }
    }
}

输出:

Original CharBuffer: [a, b, c]
Char Value at index 0: a
Char Value at index 1: b
Char Value at index 2: c

例子 2:

// Java program to demonstrate
// get() method
  
import java.nio.*;
import java.util.*;
  
public class GFG {
  
    public static void main(String[] args)
    {
  
        // Declaring the capacity of the CharBuffer
        int capacity = 3;
  
        // Creating the CharBuffer
        try {
  
            // creating object of Charbuffer
            // and allocating size capacity
            CharBuffer cb = CharBuffer.allocate(capacity);
  
            // putting the value in Charbuffer
            cb.put('a');
            cb.put('b');
            cb.put('c');
  
            // print the CharBuffer
            System.out.println("Original CharBuffer: "
                               + Arrays.toString(cb.array()));
  
            // Reads the Char at the index 0 of the Charbuffer
            // using get() method
            char value0 = cb.get(0);
  
            // print the Char value
            System.out.println("Char Value at index 0: " + value0);
  
            // Reads the Char at the index 1 of the Charbuffer
            // using get() method
            char value1 = cb.get(1);
  
            // print the Char value
            System.out.println("Char Value at index 1: " + value1);
  
            // Reads the Char at the index 2 of the Charbuffer
            // using get() method
            System.out.println("Trying to get the Char"
                               + " of index greater than its limit ");
            char value2 = cb.get(4);
  
            // print the Char value
            System.out.println("Char Value at index 2: " + value2);
        }
  
        catch (IllegalArgumentException e) {
  
            System.out.println("IllegalArgumentException catched");
        }
  
        catch (IndexOutOfBoundsException e) {
  
            System.out.println("Exception thrown: " + e);
        }
  
        catch (BufferUnderflowException e) {
  
            System.out.println("Exception throws : " + e);
        }
    }
}

输出:

Original CharBuffer: [a, b, c]
Char Value at index 0: a
Char Value at index 1: b
Trying to get the Char of index greater than its limit 
Exception thrown: java.lang.IndexOutOfBoundsException

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