1.利用构建器初始化的优点：利用构建器执行初始化进程，可以在编程时获得更大的灵活程度。因为我们可以在运行期调用方法和采取行动，从而“现场”决定初始化值。
2.构建器初始化的顺序：
<strong>class Bowl {
Bowl(int marker) {
System.out.println("Bowl(" + marker + ")");
}
void f(int marker) {
System.out.println("f(" + marker + ")");
}
}
class Table {
static Bowl b1 = new Bowl(1);
Table() {
System.out.println("Table()");
b2.f(1);
}
void f2(int marker) {
System.out.println("f2(" + marker + ")");
}
static Bowl b2 = new Bowl(2);
}
class Cupboard {
Bowl b3 = new Bowl(3);
static Bowl b4 = new Bowl(4);
Cupboard() {
System.out.println("Cupboard()");
b4.f(2);
}
void f3(int marker) {
System.out.println("f3(" + marker + ")");
}
static Bowl b5 = new Bowl(5);
}
public class StaticInitialization {
public static void main(String[] args) {
System.out.println(
"Creating new Cupboard() in main");
new Cupboard();
System.out.println(
"Creating new Cupboard() in main");
new Cupboard();
t2.f2(1);
t3.f3(1);
}
static Table t2 = new Table();
static Cupboard t3 = new Cupboard();
} ///:~</strong>程序输出结果:
Bowl(1)
Bowl(2)
Table()
f(1)
Bowl(4)
Bowl(5)
Bowl(3)
Cupboard()
f(2)
Creating new Cupboard() in main
Bowl(3)
Cupboard()
f(2)
Creating new Cupboard() in main
Bowl(3)
Cupboard()
f(2)
f2(1)
f3(1)
通过分析以上程序可总结一下规律：首先先初始化static对象（static对象的初始化只执行一次），再初始化非static对象。（static对象中有static对象也遵从这个规则）接着初始化基本类型的字段，最后执行构建器。