//: reusing/Bath.java

// Constructor initialization with composition.

class Soap{

private String s;

Soap() {

System.out.println("Soap()");

s = "Constructed";

}

public String toString(){

return s;

}

}

public class Bath {

// Initialization at point of definition

// 1: 在定义对象的地方。这意味着它们总是能够在构造器被调用之前初始化。

private String s1 = "Happy", s2 = "Happy", s3, s4;

private Soap castille;

private int i;

private float toy;

public Bath() { // 2: 构造器初始化

System.out.println("Inside Bath()");

s3 = "Joy";

toy = 3.14f;

castille = new Soap();

}

// Instance initialization: 3: 实例初始化

{

i = 47;

}

public String toString() {

if(s4 == null) // Delayed initialization: 4 惰性初始化

s4 = "Joy"; // 就在对象正要使用之前。在生成对象不值得及不必要每次

return // 都要生成对象的情况下，这种方式可以减少额外的负担

"s1 = " + s1 + "\n" +

"s2 = " + s2 + "\n" +

"s3 = " + s3 + "\n" +

"s4 = " + s4 + "\n" +

"i = " + i + "\n" +

"toy = " + toy + "\n" +

"castille = " + castille;

}

public static void main(String[] args){

Bath b = new Bath();

System.out.println(b);

}

}