标签：参数 his beans 构建 highlight 创建 view pac java
构建者模式是为了把对象的构建和表现分离
当一个对象比较复杂时，我们需要如何做？
重载构造方法
public class BuildMode {
private String param1;
private String param2;
private String param3;
private String param4;
public BuildMode(){
new BuildMode(param1,"","","");
}
public BuildMode(String param1){
new BuildMode(param1,"","","");
}
public BuildMode(String param1,String param2){
new BuildMode(param1,param2,"","");
}
public BuildMode(String param1,String param2,String param3){
new BuildMode(param1,param2,param3,"");
}
public BuildMode(String param1,String param2,String param3,String param4){
this.param1 = param1;
this.param2 = param2;
this.param3 = param3;
this.param4 = param4;
}
}
构造方法重用 ，使用者根据参数来创建对象，代码比较繁琐
javaBeans方式
public class BuildMode { private String param1; private String param2; private String param3; private String param4; public String getParam1() { return param1; } public void setParam1(String param1) { this.param1 = param1; } public String getParam2() { return param2; } public void setParam2(String param2) { this.param2 = param2; } public String getParam3() { return param3; } public void setParam3(String param3) { this.param3 = param3; } public String getParam4() { return param4; } public void setParam4(String param4) { this.param4 = param4; } }
使用：
BuildMode buildMode = new BuildMode()
buildMode.setParam1("param1");
buildMode.setParam2("param2");
buildMode.setParam3("param3");
buildMode.setParam4("param4");
代码可读行不好。
构建者模式
package com.yangfei.design; public class BuildMode { private String param1; private String param2; private String param3; private String param4; public BuildMode(Build build){ this.param1 = build.param1; this.param2 = build.param2; this.param3 = build.param3; this.param4 = build.param4; } public static final class Build{ private String param1; private String param2; private String param3; private String param4; public Build(String required){ this.param4 = required; } public Build setParam1(String param1) { this.param1 = param1; return this; } public Build setParam2(String param2) { this.param2 = param2; return this; } public Build setParam3(String param3) { this.param3 = param3; return this; } public BuildMode build() { return new BuildMode(this); } } public static void main(String[] args) { BuildMode.Build build = new BuildMode.Build("required"); //使用建造者模式 可读行更好 BuildMode buildModeInstance = build.setParam1("param1") .setParam2("param2") .setParam3("param3").build(); } }
当参数越来越多时 推荐使用建造者模式！
标签：参数 his beans 构建 highlight 创建 view pac java
原文地址：https://www.cnblogs.com/yangfei629/p/11373306.html
