总结
首先它们的底层实现不同，Arraylist和vector都是基于数组实现的，而Linkedlist是基于链表实现的
另外虽然vector和arraylist都同样是基于数组实现的，但vector的源码中有很多synchronized方法，说明是线程安全的，同步的，而Arraylist是线程不安全的，非同步的
由于加了很多synchronized方法，造成vector会慢
比如我同样往这两种数据结构中加入2,000,000个同样的字符串，比较其插入的时间
86 millis has passed when using Arraylist.
124 millis has passed when using Vector.
测试代码
public class ArraylistAndLinkedlistAndVector {
private static final String base = " base string. ";
private static final int count = 2000000;
public static void ArraylistTest() {
long begin, end;
begin = System.currentTimeMillis();
ArrayList list = new ArrayList<>();
for (int i = 0; i < count; i++) {
list.add(" add ");
}
end = System.currentTimeMillis();
System.out.println((end - begin)
+ " millis has passed when using Arraylist. ");
}
public static void linkedlistTest() {
long begin, end;
begin = System.currentTimeMillis();
LinkedList list = new LinkedList<>();
for (int i = 0; i < count; i++) {
list.add("add");
}
end = System.currentTimeMillis();
System.out.println((end - begin)
+ " millis has passed when using Linkedlist. ");
}
public static void vectorTest() {
long begin, end;
begin = System.currentTimeMillis();
Vector vector = new Vector<>();
StringBuilder test = new StringBuilder(base);
for (int i = 0; i < count; i++) {
vector.add("add");
}
end = System.currentTimeMillis();
System.out.println((end - begin)
+ " millis has passed when using Vector. ");
}
public static void main(String[] args) {
ArraylistTest();
linkedlistTest();
vectorTest();
}