mapstruct 使用 expression——迹忆客-ag捕鱼王app官网

mapstruct 允许调用自定义逻辑的转换方法。 我们可以使用表达式来实现相同的目的，我们可以传递任何 java 对象并调用其方法进行转换。

语法

@mapping(target = "target-property",
expression = "java(target-method())")

• target-property - 我们正在为其进行映射的属性。
• expression - 映射器将调用表达式中编写的 java 方法。
• target-method - 目标方法是要调用的方法。 如果方法存在于不同的类中，请使用 new class-name.target-method()

示例

打开使用 dateformat 映射 章节中更新的项目映射。

使用以下代码更新 carentity.java

carentity.java

package com.jiyik.entity;
import java.util.gregoriancalendar;
public class carentity {
    private int id;
    private double price;
    private gregoriancalendar manufacturingdate;
    public int getid() {
        return id;
    }
    public void setid(int id) {
        this.id = id;
    }
    public double getprice() {
        return price;
    }
    public void setprice(double price) {
        this.price = price;
    }
    public gregoriancalendar getmanufacturingdate() {
        return manufacturingdate;
    }
    public void setmanufacturingdate(gregoriancalendar manufacturingdate) {
        this.manufacturingdate = manufacturingdate;
    }
}

使用以下代码更新 car.java

car.java

package com.jiyik.model;
public class car {
    private int id;
    private string price;
    private string manufacturingdate;
    public int getid() {
        return id;
    }
    public void setid(int id) {
        this.id = id;
    }
    public string getprice() {
        return price;
    }
    public void setprice(string price) {
        this.price = price;
    }
    public string getmanufacturingdate() {
        return manufacturingdate;
    }
    public void setmanufacturingdate(string manufacturingdate) {
        this.manufacturingdate = manufacturingdate;
    }
}

使用以下代码更新 carmapper.java

carmapper.java

package com.jiyik.mapper;
import com.jiyik.entity.carentity;
import com.jiyik.model.car;
import org.mapstruct.mapper;
import org.mapstruct.mapping;
import java.text.simpledateformat;
import java.util.date;
import java.util.gregoriancalendar;
@mapper
public interface carmapper {
    @mapping(source = "price", target = "price", numberformat = "$#.00")
    @mapping(target = "manufacturingdate",
            expression = "java(getmanufacturingdate(carentity.getmanufacturingdate()))")
    car getmodelfromentity(carentity carentity);
    default string getmanufacturingdate(gregoriancalendar manufacturingdate) {
        date d = manufacturingdate.gettime();
        simpledateformat sdf = new simpledateformat( "dd.mm.yyyy" );
        return sdf.format( d );
    }
}

使用以下代码更新 carmappertest.java

carmappertest.java

import com.jiyik.entity.carentity;
import com.jiyik.mapper.carmapper;
import com.jiyik.model.car;
import org.junit.test;
import org.mapstruct.factory.mappers;
import java.util.gregoriancalendar;
import static org.junit.assert.assertequals;
public class carmappertest {
    private carmapper carmapper = mappers.getmapper(carmapper.class);
    @test
    public void testentitytomodel() {
        carentity entity = new carentity();
        entity.setprice(345000);
        entity.setid(1);
        entity.setmanufacturingdate(new gregoriancalendar(2015, 3, 5));
        car model = carmapper.getmodelfromentity(entity);
        assertequals(model.getprice(), "$345000.00");
        assertequals(entity.getid(), model.getid());
        assertequals("05.04.2015", model.getmanufacturingdate());
    }
}

运行以下命令来测试映射。

$ mvn clean test

执行结果如下