常用Lombok的都知道里面有一个@Builder注解很好用，但是这个注解的原理是什么呢，这里简单模拟一下。
这里使用了设计模式中的建造者模式。
package com.example.demoboot;import java.io.Serializable;/*** 数据源实例** @author starsray* @date 2021/11/20*/
public class DatasourceInstance implements Serializable {private String type;private String name;private String username;private String password;private String url;private String driver;public String getType() {return type;}public void setType(String type) {this.type = type;}public String getName() {return name;}public void setName(String name) {this.name = name;}public String getUsername() {return username;}public void setUsername(String username) {this.username = username;}public String getPassword() {return password;}public void setPassword(String password) {this.password = password;}public String getUrl() {return url;}public void setUrl(String url) {this.url = url;}public String getDriver() {return driver;}public void setDriver(String driver) {this.driver = driver;}private DatasourceInstance(Builder builder) {this.type = builder.type;this.name = builder.name;this.username = builder.username;this.password = builder.password;this.url = builder.url;this.driver = builder.driver;}public static Builder builder() {return new Builder();}public static class Builder {private String type;private String name;private String username;private String password;private String url;private String driver;public Builder type(String type) {this.type = type;return this;}public Builder name(String name) {this.name = name;return this;}public Builder username(String username) {this.username = username;return this;}public Builder password(String password) {this.password = password;return this;}public Builder url(String url) {this.url = url;return this;}public Builder driver(String driver) {this.driver = driver;return this;}public DatasourceInstance build() {return new DatasourceInstance(this);}}
}