markyao / beanutils

A wrapper for cglib BeanCopier providing conversion between JavaBeans

BeanUtils

A wrapper for cglib BeanCopier providing conversion between JavaBeans.

Introduction

Provides simple and convenient APIs to copy properties/do conversion between JavaBeans. For performance, cglib is chosen as the underlying library. Currently, there are two tool classes for conversion, BeanUtils and BeanConverter. BeanUtils provides a straight way to use but it requires that types of properties to map MUST be the same, while BeanConverter provides a more flexible way to use.

Usage

Maven Dependency

Add the following dependency to your project's pom.xml.

<dependency>
    <groupId>com.github.mottox</groupId>
    <artifactId>bean-utils</artifactId>
    <version>1.1.0</version>
</dependency>

API

BeanUtils provides the following methods:

• copyProperties(Object source, Object target)
  Copy the property values of the given source bean into the target bean.
• <T> T convert(Object source, Class<T> clazz)
  Convert the given source bean to a target bean of specified type.

BeanConverter provides the same methods above. Below is the list of differences between BeanUtils and BeanConverter.

1. The above two methods are static in BeanUtils, but non static in BeanConverter.
2. BeanConverter provides relatively flexible conversion strategy, so you can create your custom mapping method for a BeanConverter instance.

Examples

It's quite easy and convenient to use BeanUtils for JavaBean conversion.

BeanUtils

public class SourceBean {
    private String name;

    private Integer age;

    private Gender gender;

    private Double height;

    private BigDecimal wealth;

    SourceBean(String name, Integer age, Gender gender, Double height, BigDecimal wealth) {
        this.name = name;
        this.age = age;
        this.gender = gender;
        this.height = height;
        this.wealth = wealth;
    }

    // Getters and setters omitted
}

public class TargetBean {
    private String name;

    private Integer age;

    private Gender gender;

    private Double height;

    private BigDecimal wealth;

    TargetBean() {
    }

    TargetBean(String name, Integer age, Gender gender, Double height, BigDecimal wealth) {
        this.name = name;
        this.age = age;
        this.gender = gender;
        this.height = height;
        this.wealth = wealth;
    }

    // Getters and setters omitted
}

SourceBean source = new SourceBean("Peter", 34, Gender.MALE, 1.85, BigDecimal.valueOf(123456789.87654321));

TargetBean target = BeanUtils.convert(source, TargetBean.class);
Assert.assertEquals(source.name, target.name);
Assert.assertEquals(source.age, target.age);
Assert.assertEquals(source.gender, target.gender);
Assert.assertEquals(source.height, target.height);
Assert.assertEquals(source.wealth, target.wealth);

BeanConverter

public class SourceBean {
    private String name;

    private Integer age;

    private Gender gender;

    private Double height;

    private BigDecimal wealth;

    public SourceBean(String name, Integer age, Gender gender, Double height, BigDecimal wealth) {
        this.name = name;
        this.age = age;
        this.gender = gender;
        this.height = height;
        this.wealth = wealth;
    }

    // Getters and setters omitted
}

public class TargetBean {
    private String name;

    private int age;

    private int gender;

    private BigDecimal height;

    private String wealth;

    public TargetBean() {
    }

    public TargetBean(String name, int age, int gender, BigDecimal height, String wealth) {
        this.name = name;
        this.age = age;
        this.gender = gender;
        this.height = height;
        this.wealth = wealth;
    }

    // Getters and setters omitted
}

BeanConverter converter = BeanConverterBuilder.create()
        .registerConverter((TypeConverter<Gender, Integer>) Gender::getValue)
        .registerConverter((TypeConverter<Double, BigDecimal>) BigDecimal::valueOf)
        .registerConverter((TypeConverter<BigDecimal, String>) BigDecimal::toPlainString)
        .build();

TargetBean target = converter.convert(source, TargetBean.class);

Assert.assertEquals(source.name, target.name);
Assert.assertEquals((int) source.age, target.age);
Assert.assertEquals(source.gender.value, target.gender);
Assert.assertTrue(BigDecimal.valueOf(source.height).compareTo(target.height) == 0);
Assert.assertTrue(source.wealth.compareTo(new BigDecimal(target.wealth)) == 0);

Note that cglib BeanCopier will copy null properties.

License

MIT License