极客教程Java DoubleBuffer equals()方法及示例
java.nio.DoubleBuffe r类的 equals() 方法是用来检查给定的缓冲区是否等于另一个对象。
两个双缓冲区是相等的，当且仅当。
- 它们具有相同的元素类型。
- 它们有相同数量的剩余元素，并且
- 两个剩余元素的序列，独立于它们的起始位置考虑，是点状的 。
这个方法认为两个双元素a和b是相等的，如果(a == b) || (Double.isNaN(a) && Double.isNaN(b))。值-0.0和+0.0被认为是相等的，与Double.equals(Object)不同。
双重缓冲区不等于任何其他类型的对象。
语法
public boolean equals(Object ob)
参数： 该方法以 ob ，即该缓冲区所要比较的对象为参数。
返回值： 当且仅当这个缓冲区等于给定的对象时，该方法返回 真 。
下面是说明equals()方法的例子。
例1 :
// Java program to demonstrate
// equals() method
import java.nio.*;
import java.util.*;
public class GFG {
public static void main(String[] args)
{
// Declaring the capacity of the DoubleBuffer 1
int capacity1 = 10;
// Declaring the capacity of the DoubleBuffer 2
int capacity2 = 10;
// Creating the DoubleBuffer
try {
// creating object of Doublebuffer 1
// and allocating size capacity
DoubleBuffer db1 = DoubleBuffer.allocate(capacity1);
// creating object of Doublebuffer 2
// and allocating size capacity
DoubleBuffer db2 = DoubleBuffer.allocate(capacity2);
// putting the value in Doublebuffer 1
db1.put(8.56F);
db1.put(2, 9.61F);
db1.rewind();
// putting the value in Doublebuffer 2
db2.put(8.56F);
db2.put(2, 9.61F);
db2.rewind();
// print the DoubleBuffer 1
System.out.println(" DoubleBuffer 1: "
+ Arrays.toString(db1.array()));
// print the DoubleBuffer 2
System.out.println(" DoubleBuffer 2: "
+ Arrays.toString(db2.array()));
// checking the equality of both DoubleBuffer
boolean dbb = db1.equals(db2);
// checking if else condition
if (dbb)
System.out.println("both are equal");
else
System.out.println("both are not equal");
}
catch (IllegalArgumentException e) {
System.out.println("IllegalArgumentException catched");
}
catch (ReadOnlyBufferException e) {
System.out.println("ReadOnlyBufferException catched");
}
}
}
输出:
DoubleBuffer 1: [8.5600004196167, 0.0, 9.609999656677246, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0]
DoubleBuffer 2: [8.5600004196167, 0.0, 9.609999656677246, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0]
both are equal
例1:
// Java program to demonstrate
// equals() method
import java.nio.*;
import java.util.*;
public class GFG {
public static void main(String[] args)
{
// Declaring the capacity of the DoubleBuffer 1
int capacity1 = 10;
// Declaring the capacity of the DoubleBuffer 2
int capacity2 = 5;
// Creating the DoubleBuffer
try {
// creating object of Doublebuffer 1
// and allocating size capacity
DoubleBuffer db1 = DoubleBuffer.allocate(capacity1);
// creating object of Doublebuffer 2
// and allocating size capacity
DoubleBuffer db2 = DoubleBuffer.allocate(capacity2);
// putting the value in Doublebuffer 1
db1.put(8.56F);
db1.put(2, 9.61F);
db1.rewind();
// putting the value in Doublebuffer 2
db2.put(8.56F);
db2.put(2, 9.61F);
db2.rewind();
// print the DoubleBuffer 1
System.out.println(" DoubleBuffer 1: "
+ Arrays.toString(db1.array()));
// print the DoubleBuffer 2
System.out.println(" DoubleBuffer 2: "
+ Arrays.toString(db2.array()));
// checking the equality of both DoubleBuffer
boolean dbb = db1.equals(db2);
// checking if else condition
if (dbb)
System.out.println("both are equal");
else
System.out.println("both are not equal");
}
catch (IllegalArgumentException e) {
System.out.println("IllegalArgumentException catched");
}
catch (ReadOnlyBufferException e) {
System.out.println("ReadOnlyBufferException catched");
}
}
}
输出:
DoubleBuffer 1: [8.5600004196167, 0.0, 9.609999656677246, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0]
DoubleBuffer 2: [8.5600004196167, 0.0, 9.609999656677246, 0.0, 0.0]
both are not equal