public class BeanEntity
{
private int variable1;//必选参数
private int variable2;//必选参数
private int variable3;//可选参数
private int variable4;//可选参数
private BeanEntity(Builder builder){
this.variable1 = builder.variable1;
this.variable2 = builder.variable2;
this.variable3 = builder.variable3;
this.variable4 = builder.variable4;
}
public static class Builder{
private int variable1;
private int variable2;
private int variable3;
private int variable4;
public Builder(int variable1, int variable2){
this.variable1 = variable1;
this.variable2 = variable2;
}
public Builder setVariable3(int variable3){
this.variable3= variable3;
return this;
}
public Builder setVariable4(int variable4){
this.variable4= variable4;
return this;
}
public BeanEntity build(){
return new BeanEntity(this);
}
}
}
使用
BeanEntity entity = new BeanEntity.Builder(100, 200)
.setVariable3(300)
.setVariable4(400)
.build();