简介

定义算法族，分别封装起来，让它们之间可相互替换，此模式让算法的变化独立于使用算法的客户

实际应用场景

账单同步的功能。来自不同平台的账单，使用不同的文件保存，需要解析文件，校验数据，保存数据，归档账单

UML

代码实现

/**
 * 解析数据接口
 *
 * @author xiaoy
 * @since 2021-3-8 15:33
 */
public interface IParsingData {

    void parsingData();
}

/**
 * 校验数据接口
 *
 * @author xiaoy
 * @since 2021-3-8 15:37
 */
public interface ICheckData {

    void checkData();
}

/**
 * 保存数据接口
 *
 * @author xiaoy
 * @since 2021-3-8 15:38
 */
public interface ISaveData {

    void saveData();
}

/**
 * 上传数据
 *
 * @author xiaoy
 * @since 2021-3-8 15:39
 */
public interface IUploadData {
    void uploadData();
}

/**
 * @author xiaoy
 * @since 2021-3-8 15:41
 */
public class ParsingDataA implements IParsingData {
    @Override
    public void parsingData() {
        System.out.println("com.xiaoy.github.strategy.ParsingDataA.parsingData");
    }
}

/**
 * @author xiaoy
 * @since 2021-3-8 15:41
 */
public class ParsingDataB implements IParsingData {
    @Override
    public void parsingData() {
        System.out.println("com.xiaoy.github.strategy.ParsingDataB.parsingData");
    }
}

/**
 * @author xiaoy
 * @since 2021-3-8 15:40
 */
public class CheckDataA implements ICheckData {
    @Override
    public void checkData() {
        System.out.println("com.xiaoy.github.strategy.CheckDataA.checkData");
    }
}

/**
 * @author xiaoy
 * @since 2021-3-8 15:42
 */
public class SaveDataA implements ISaveData {
    @Override
    public void saveData() {
        System.out.println("com.xiaoy.github.strategy.SaveDataA.saveData");
    }
}

/**
 * @author xiaoy
 * @since 2021-3-8 15:42
 */
public class UploadDataA implements IUploadData {
    @Override
    public void uploadData() {
        System.out.println("com.xiaoy.github.strategy.UploadDataA.uploadData");
    }
}

/**
 * 账单数据同步
 *
 * @author xiaoy
 * @since 2021-3-8 15:45
 */
public abstract class BillSynchronization {

    protected String billNo;

    private IParsingData parsingData;
    private ICheckData checkData;
    private ISaveData saveData;
    private IUploadData uploadData;


    public void parsingData() {
        parsingData.parsingData();
    }

    public void checkData() {
        checkData.checkData();
    }

    public void saveData() {
        saveData.saveData();
    }

    public void uploadData() {
        uploadData.uploadData();
    }

    public BillSynchronization setParsingData(IParsingData parsingData) {
        this.parsingData = parsingData;
        return this;
    }

    public BillSynchronization setCheckData(ICheckData checkData) {
        this.checkData = checkData;
        return this;
    }

    public BillSynchronization setSaveData(ISaveData saveData) {
        this.saveData = saveData;
        return this;
    }

    public BillSynchronization setUploadData(IUploadData uploadData) {
        this.uploadData = uploadData;
        return this;
    }
}

/**
 * A 类型的账单
 *
 * @author xiaoy
 * @since 2021-3-8 15:51
 */
public class BillSynchronizationA extends BillSynchronization {

    public BillSynchronizationA(String billNo) {
        this.billNo = billNo;
    }
}

/**
 * @author xiaoy
 * @since 2021-3-8 15:53
 */
public class Main {

    public static void main(String[] args) {

        BillSynchronizationA billSynchronizationA = new BillSynchronizationA("AAA");
        billSynchronizationA.setCheckData(new CheckDataA())
                .setParsingData(new ParsingDataA())
                .setSaveData(new SaveDataA())
                .setUploadData(new UploadDataA());

        System.out.println(billSynchronizationA.billNo + " 开始执行:");
        billSynchronizationA.parsingData();
        billSynchronizationA.checkData();
        billSynchronizationA.saveData();
        billSynchronizationA.uploadData();


        BillSynchronizationA billSynchronizationB = new BillSynchronizationA("BBB");
        billSynchronizationB.setCheckData(new CheckDataA())
                .setParsingData(new ParsingDataB())
                .setSaveData(new SaveDataA())
                .setUploadData(new UploadDataA());

        System.out.println(billSynchronizationB.billNo + " 开始执行:");
        billSynchronizationB.parsingData();
        billSynchronizationB.checkData();
        billSynchronizationB.saveData();
        billSynchronizationB.uploadData();

    }
}

测试