package org.sample;
class Bread {
Bread() { System.out.println("Bread()"); }
}
class Cheese {
Cheese() { System.out.println("Cheese()"); }
}
class Lettuce {
Lettuce() { System.out.println("Lettuce()"); }
}
public class TestOrder {
static {
System.out.println("static block - 1 has been executed.");
}
{
System.out.println("non-static - 1 block has been executed.");
}
private static final Bread bread = new Bread();
private static final Cheese cheese = new Cheese();
static {
System.out.println("static block - 2 has been executed.");
}
private static final Lettuce lettuce = new Lettuce();
private final Bread bread1 = new Bread();
{
System.out.println("non-static - 2 block has been executed.");
}
private final Cheese cheese1 = new Cheese();
private final Lettuce lettuce1 = new Lettuce();
public static void run() {
System.out.println("run static method.");
}
public TestOrder() {
System.out.println("create object.");
}
public static void main(String[] args) {
TestOrder.run();
new TestOrder();
}
}
/*
output=
static block - 1 has been executed.
Bread()
Cheese()
static block - 2 has been executed.
Lettuce()
run static method.
non-static - 1 block has been executed.
Bread()
non-static - 2 block has been executed.
Cheese()
Lettuce()
create object.
*/
之所以补充上面的代码，主要是为了强调：【实例域以及初始化块】的执行也是依赖于代码书写顺序的（自上而下），而并非随机执行或者按照某种优先顺序。不过，一些特殊情况可能需要另当别论。