1. 鏈式程式設計原理：呼叫方法返回當前物件引用。

以模擬計算器的加減乘除為例
計算器類

public class Calc {
    private Integer value;

    public Calc() {
        this.value = 0;
    }

    public Calc add(Integer add) {
        this.value += add;
        return this;
    }

    public Calc sub(Integer sub) {
        this.value -= sub;
        return this;
    }

    public Calc mul(Integer mul) {
        this.value *= mul;
        return this;
    }

    public Calc div(Integer div) {
        this.value /= div;
        return this;
    }

    public Integer getValue() {
        return this.value;
    }
}
 

測試類

public class Main {
    public static void main(String[] args) {
        Calc calc = new Calc();
        calc.add(15).sub(5).mul(10).div(25);
        System.out.println(calc.getValue());
    }
}

效果

D:\Java_JDK\JDK8u202\bin\java.exe "-javaagent:D:\JetBrainsDeveloperTools\IntelliJ IDEA 2021.2\lib\idea_rt.jar=3225:D:\JetBrainsDeveloperTools\IntelliJ IDEA 2021.2\bin" -Dfile.encoding=UTF-8 -classpath "D:\Java_JDK\JDK8u202\jre\lib\charsets.jar;D:\Java_JDK\JDK8u202\jre\lib\deploy.jar;D:\Java_JDK\JDK8u202\jre\lib\ext\access-bridge-64.jar;D:\Java_JDK\JDK8u202\jre\lib\ext\cldrdata.jar;D:\Java_JDK\JDK8u202\jre\lib\ext\dnsns.jar;D:\Java_JDK\JDK8u202\jre\lib\ext\jaccess.jar;D:\Java_JDK\JDK8u202\jre\lib\ext\jfxrt.jar;D:\Java_JDK\JDK8u202\jre\lib\ext\localedata.jar;D:\Java_JDK\JDK8u202\jre\lib\ext\nashorn.jar;D:\Java_JDK\JDK8u202\jre\lib\ext\sunec.jar;D:\Java_JDK\JDK8u202\jre\lib\ext\sunjce_provider.jar;D:\Java_JDK\JDK8u202\jre\lib\ext\sunmscapi.jar;D:\Java_JDK\JDK8u202\jre\lib\ext\sunpkcs11.jar;D:\Java_JDK\JDK8u202\jre\lib\ext\zipfs.jar;D:\Java_JDK\JDK8u202\jre\lib\javaws.jar;D:\Java_JDK\JDK8u202\jre\lib\jce.jar;D:\Java_JDK\JDK8u202\jre\lib\jfr.jar;D:\Java_JDK\JDK8u202\jre\lib\jfxswt.jar;D:\Java_JDK\JDK8u202\jre\lib\jsse.jar;D:\Java_JDK\JDK8u202\jre\lib\management-agent.jar;D:\Java_JDK\JDK8u202\jre\lib\plugin.jar;D:\Java_JDK\JDK8u202\jre\lib\resources.jar;D:\Java_JDK\JDK8u202\jre\lib\rt.jar;D:\My Projects\SpringMVC\ssm_demo\out\production\test" top.harmonytqs.Main
4

Process finished with exit code 0
 

2. Lombok中可使用setter鏈式程式設計為屬性賦值

Person類

@Accessors(chain = true)//@Accessors(chain = true)使用此註解開啟鏈式程式設計
@Data
@NoArgsConstructor
public class Person {
    private String name;
    private Integer age;
    private String gender;
}

測試類

public class Main {
    public static void main(String[] args) {
        Person person = new Person();
        person.setName("張三").setAge(21).setGender("男");
        System.out.println(person);
    }
}
 

效果

D:\Java_JDK\JDK8u202\bin\java.exe "-javaagent:D:\JetBrainsDeveloperTools\IntelliJ IDEA 2021.2\lib\idea_rt.jar=10944:D:\JetBrainsDeveloperTools\IntelliJ IDEA 2021.2\bin" -Dfile.encoding=UTF-8 -classpath "D:\Java_JDK\JDK8u202\jre\lib\charsets.jar;D:\Java_JDK\JDK8u202\jre\lib\deploy.jar;D:\Java_JDK\JDK8u202\jre\lib\ext\access-bridge-64.jar;D:\Java_JDK\JDK8u202\jre\lib\ext\cldrdata.jar;D:\Java_JDK\JDK8u202\jre\lib\ext\dnsns.jar;D:\Java_JDK\JDK8u202\jre\lib\ext\jaccess.jar;D:\Java_JDK\JDK8u202\jre\lib\ext\jfxrt.jar;D:\Java_JDK\JDK8u202\jre\lib\ext\localedata.jar;D:\Java_JDK\JDK8u202\jre\lib\ext\nashorn.jar;D:\Java_JDK\JDK8u202\jre\lib\ext\sunec.jar;D:\Java_JDK\JDK8u202\jre\lib\ext\sunjce_provider.jar;D:\Java_JDK\JDK8u202\jre\lib\ext\sunmscapi.jar;D:\Java_JDK\JDK8u202\jre\lib\ext\sunpkcs11.jar;D:\Java_JDK\JDK8u202\jre\lib\ext\zipfs.jar;D:\Java_JDK\JDK8u202\jre\lib\javaws.jar;D:\Java_JDK\JDK8u202\jre\lib\jce.jar;D:\Java_JDK\JDK8u202\jre\lib\jfr.jar;D:\Java_JDK\JDK8u202\jre\lib\jfxswt.jar;D:\Java_JDK\JDK8u202\jre\lib\jsse.jar;D:\Java_JDK\JDK8u202\jre\lib\management-agent.jar;D:\Java_JDK\JDK8u202\jre\lib\plugin.jar;D:\Java_JDK\JDK8u202\jre\lib\resources.jar;D:\Java_JDK\JDK8u202\jre\lib\rt.jar;D:\My Projects\SpringMVC\ssm_demo\out\production\test;D:\My Projects\SpringMVC\ssm_demo\test\src\top\harmonytqs\lombok-1.18.20.jar" top.harmonytqs.Main
Person(name=張三, age=21, gender=男)

Process finished with exit code 0