Java中同一對象內的對象列表

Question

我有下一種情況：

public class Network {
   protected int mask;
   protected IPv4Address address;

   public Network(IPv4Address address, int maskLength) {
    blahblah
   }
   public mymethod() {
    Network[] privatnetworks = {new Network(new IPv4Address("10.0.0.0"), 8), new Network(new IPv4Address("172.16.0.0"), 12)}
}

每次我調用mymethod時，都需要創建對我而言效率不高的對象列表。 我可以以某種方式創建一次並將其用於所有方法嗎？ 抱歉，這個問題是簡單還是愚蠢-我是Java的新手。

Answer 1

將變量定義為實例變量：

public class Network {
   protected int mask;
   protected IPv4Address address;
   Network[] privatnetworks = {new Network(new IPv4Address("10.0.0.0"), 8), new Network(new IPv4Address("172.16.0.0"), 12)}

   public Network(IPv4Address address, int maskLength) {
    blahblah
   }
   public mymethod() {
    }

Answer 2

將Network設為static變量，它將僅初始化一次。

static Network[] privatnetworks = {new Network(new IPv4Address("10.0.0.0"), 8), new Network(new IPv4Address("172.16.0.0"), 12)}

Answer 3

用這個 ：

public class Network {
   protected int mask;
   protected IPv4Address address;

   private static  Network[] privatnetworks = {new Network(new IPv4Address("10.0.0.0"), 8), new Network(new IPv4Address("172.16.0.0"), 12)}

   public Network(IPv4Address address, int maskLength) {
    blahblah
   }
   public mymethod() {

}