Java中的 CharBuffer get() 方法
Java.nio.CharBuffer类的get()方法用于读取给定缓冲区当前位置的字符，然后递增该位置。
句法：
public abstract char get()返回值：此方法返回缓冲区当前位置的 char 值。
异常：此方法抛出BufferUnderflowException – 如果缓冲区的当前位置不小于其限制，则抛出此异常。
以下是说明get()方法的示例：
示例 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
示例 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
获取（整数索引）
CharBuffer 的get(int index)方法用于读取指定索引处的文章。
句法 ：
public abstract char get(int index)参数：此方法将索引（将读取字符的索引）作为参数。
返回值：此方法返回给定索引处的char 值。
异常：此方法抛出IndexOutOfBoundsException 。如果 index 为负数或不小于缓冲区的限制，则会引发此异常。
以下是说明 get(int index) 方法的示例：
示例 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
示例 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