饿汉式
public class EagerSingleton {
private static final EagerSingleton instance = new EagerSingleton();
private EagerSingleton(){}
public static EagerSingleton getInstance() {
return instance;
}
}
懒汉式
public class LazySingleton {
private static LazySingleton instance = null;
private LazySingleton() {}
synchronized public static LazySingleton getInstance() {
if(instance == null) {
instance = new LazySingleton();
}
return instance;
}
}
Java语言中的单例模式
Java的Runtime对象
public class CmdTest {
public static void main(String[] args) throws IOException {
Process proc = Runtime.getRuntime().exec("notepad.exe");
}
}