我们知道单例模式，其实就是返回一个被调用类的实例。

    在频繁的进行实例（Instance）创建过程，难免过多的进行new InstanceName()；我们可以只通过调用一个方法解决。

    在进行设计模式的程序实现中xiaobin使用已编写的SSL程序做演示。

    ------------------------------------------------------------------------------------------tdtc tech-----------------------------------------------------

    目   的：建立SSL连接

    类   图：

 

    源   码：

public class ConnectionSSL {		private final int DEFAULT_PORT = 7000;	public final String algorithm = "SSL";	private int port;	private String propertyPath;	private String keyPath;		private static ConnectionSSL conn = new ConnectionSSL();		private ConnectionSSL() {		// TODO Auto-generated constructor stub		propertyPath = getPropertyPath();				port = getPort(propertyPath);		if(port == 0) {			port = DEFAULT_PORT;		}		keyPath = getKeyPath(propertyPath);	}		public static ConnectionSSL getInstance() {		return conn;	}	private String getPropertyPath() {		String path = System.getProperty("user.dir") 			+ File.separator + "port.properties";		return path;	}	private String getKeyPath(String filePath) {		Properties p = new Properties();		try {			p.load(new FileInputStream(filePath));		} catch (Exception e) {			// TODO: handle exception		}		String path = p.getProperty("key");				return path;	}		private int getPort(String filePath) {		Properties p = new Properties();		try {			p.load(new FileInputStream(filePath));		} catch (Exception e) {			// TODO: handle exception		}				//p.clear();		String strPort = p.getProperty("port");		int port = Integer.parseInt(strPort);				return port;	}}