由于常见的单例模式,饿汉式单例和懒汉式单例,构造方法都私有了,因此不能被继承.
最近在开发中遇到问题了,恰好需要继承单例类.找资料才找到了这个解决办法---登记式单例.
登记式单例类是为了克服饿汉式单例类及懒汉式单例类均不可继承的缺点而设计的。当单例类需要被继承时适用.
代码清单3：登记式单例类
import java.util.HashMap;
public class RegSingleton
{
static private HashMap m_registry = new HashMap();
private List<Player> plsyers=new linkedList<Player>();
static
{
RegSingleton x = new RegSingleton();
m_registry.put( x.getClass().getName() ， x);
}
/**
* 保护的默认构造子
*/
protected RegSingleton() {}
/**
* 静态工厂方法，返还此类惟一的实例
*/
static public RegSingleton getInstance(String name)
{
if (name == null)
{
name = "com.javapatterns.singleton.demos.RegSingleton";
}
if (m_registry.get(name) == null)
{
try
{
m_registry.put( name，
Class.forName(name).newInstance() ) ;
}
catch(Exception e)
{
System.out.println("Error happe ......
原贴内容请见: http://topic.csdn.net/u/20100116/17/6a204504-9e70-435f-be55-f0630ed12fdf.html?seed=942806558&r=62778073#r_62778073
请大牛指正.
产品类:
package selfimpr.producerCustomer;
/**
* 产品
* @author selfimpr
* @blog http://blog.csdn.net/lgg201
* @email lgg860911@yahoo.com.cn
*
*/
public class Product {
private int id;
private String name;
public Product(int id, String name) {
this.id = id;
this.name = name;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String toString() {
return "Product: {id: " + this.id + ", name: " + this.name + "};";
}
}
生产者类:
package selfimpr.producerCustomer;
import java.util.List;
/**
* 生产者线程, 将database实现
* @author selfimpr
* @blog http://blog.csdn.net/lgg201
* @email lgg860911@yahoo.com.cn
*
*/
public class Produc ......
Java 推荐读物与源代码阅读
江苏无锡 缪小东
1. Java语言基础
谈到Java语言基础学习的书籍，大家肯定会推荐Bruce Eckel的《Thinking in Java》。它是一本写的相当深刻的技术书籍，Java语言基础部分基本没有其它任何一本书可以超越它。该书的作者Bruce Eckel在网络上被称为天才的投机者，作者的《Thinking in C++》在1995年曾获SoftwareDevelopment Jolt Award最佳书籍大奖，《Thinking in Java》被评为1999年Java World“最爱读者欢迎图书”，并且赢得了编辑首选图书奖。作者从1986年至今，已经发表了超过150篇计算机技术文章，出版了6本书（其中4本是关于C++的），并且在全世界做了数百次演讲。他是《Thinking in Java》、《Thinking in C++》、《C++ Inside & Out》《Using C++》和《Thinking in ......
public class SHA1 {
private final int[] abcde = {
0x67452301, 0xefcdab89, 0x98badcfe, 0x10325476, 0xc3d2e1f0
};
// 摘要数据存储数组
private int[] digestInt = new int[5];
// 计算过程中的临时数据存储数组
private int[] tmpData = new int[80];
// 计算sha-1摘要
private int process_input_bytes(byte[] bytedata) {
// 初试化常量
System.arraycopy(abcde, 0, digestInt, 0, abcde.length);
// 格式化输入字节数组，补10及长度数据
byte[] newbyte = byteArrayFormatData(bytedata);
// 获取数据摘要计算的数据单元个数
......
public class DES {
// 声明常量字节数组
private static final int[] IP = {
58, 50, 42, 34, 26, 18, 10, 2, 60, 52, 44, 36, 28, 20, 12, 4, 62, 54,
46, 38, 30, 22, 14, 6, 64, 56, 48, 40, 32, 24, 16, 8, 57, 49, 41, 33,
25, 17, 9, 1, 59, 51, 43, 35, 27, 19, 11, 3, 61, 53, 45, 37, 29, 21,
13, 5, 63, 55, 47, 39, 31, 23, 15, 7
}; // 64
private static final int[] IP_1 = {
40, 8, 48, 16, 56, 24, 64, 32, 39, 7, 47, 15, 55, 23, 63, 31, 38, 6,
46, 14, 54, 22, 62, 30, 37, 5, 45, 13, 53, 21, 61, 29, ......
加密后是一个32位大写字母组合形式，并且本加密方法不可逆！
public String kljm(String dm,String kl)
{
String mw, cmm;
int k, i, tmp, a, hf, lf, bytes = 16;
int mm[], l,rand_seed;
rand_seed = 12345;
int len=kl.length();
if(len>=12) len=12;
mw =kl.substring(0,len) + dm.trim();
l = mw.length();
if (bytes > 100) bytes = 100;
if (l < bytes)
{
for (l = l;l<=bytes;l++)
{
rand_seed = (31527 * rand_seed + 3) % 32768;
a = rand_seed % 256;
if (a < 32 || a > 127) a = (int)(´a´);
mw = mw + (char)(a);
}
}
mm=new int[100];
for (l = 0;l<100;l++)
mm[l]=0;
for (l = 0;l<bytes;l++)
{
a = (int)mw.charAt(l);
for (i = 1;i<= 8;i++)
{
if (a >= 128)
{
a -= 128;
for (k = 0;k<bytes;k++)
{
rand_seed = (31527 * rand_seed + 3) % 32768;
mm[k] += rand_seed % 256;
}
}
else
{
for (k = 1;k<=bytes;k++)
rand_seed = (31527 * rand_seed + 3) % 32768;
}
a *= 2;
}
}
for (k = bytes-1;k>=0; ......
最新文章 : java