恶汉模式
public class DL{
public static DL dl = new DL();
private DL(){
}
public static DL getIntance(){
return dl;
}
}
懒汉模式
public class DL{
public static DL dl;
private DL(){
}
public synchronized static DL getIntance(){
if(dl==null){
dl = new DL();
}
return dl;
}
}
内部类单例模式
public class DL{
private DL(){}
static class DLHolder{
static DL dl = new DL():
}
private static DL getIntance(){
return DLHolder.dl;
}
}