?

import java.util.List; import java.util.Vector;public class VectorTest {public static void main(String[] args) {List<String> vector = new Vector<>();vector.add("abc");} }

查看Vector構造方法：

/*** Constructs an empty vector so that its internal data array* has size {@code 10} and its standard capacity increment is* zero.*/public Vector() {this(10);}

查看this(10)

/*** Constructs an empty vector with the specified initial capacity and* with its capacity increment equal to zero.** @param initialCapacity the initial capacity of the vector* @throws IllegalArgumentException if the specified initial capacity* is negative*/public Vector(int initialCapacity) {this(initialCapacity, 0);}

再繼續看this(initialCapacity,0)

/*** Constructs an empty vector with the specified initial capacity and* capacity increment.** @param initialCapacity the initial capacity of the vector* @param capacityIncrement the amount by which the capacity is* increased when the vector overflows* @throws IllegalArgumentException if the specified initial capacity* is negative*/public Vector(int initialCapacity, int capacityIncrement) {super();if (initialCapacity < 0)throw new IllegalArgumentException("Illegal Capacity: "+initialCapacity);this.elementData = new Object[initialCapacity];this.capacityIncrement = capacityIncrement;}

此時initialCapacity為10，capacityIncrement為0，this.elementData為對象數組

/*** The array buffer into which the components of the vector are* stored. The capacity of the vector is the length of this array buffer,* and is at least large enough to contain all the vector's elements.** <p>Any array elements following the last element in the Vector are null.** @serial*/protected Object[] elementData;

所以Vector底層采用的是數組來存放元素的，大部分的public方法都是synchronized的。即同步的。使用不當會造成性能問題。

Vector和ArrayList底層數據結構都是數組。

總結

以上是生活随笔為你收集整理的Vector源码分析的全部內容，希望文章能夠幫你解決所遇到的問題。

如果覺得生活随笔網站內容還不錯，歡迎將生活随笔推薦給好友。