备注

java项目中写测试用例时，经常要初始化bean，如果bean的属性比较多，一个个set起来比较麻烦，可以借助反射的方式遍历属性，并给每个属性赋值；

代码

jdk8及以上版本

pom依赖

<dependency>
    <groupId>org.apache.commons</groupId>
    <artifactId>commons-lang3</artifactId>
    <version>3.5</version>
</dependency>
<dependency>
    <groupId>org.apache.commons</groupId>
    <artifactId>commons-collections4</artifactId>
    <version>4.4</version>
</dependency>

java代码

import org.apache.commons.collections4.CollectionUtils;
import org.apache.commons.lang3.RandomUtils;

import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;

/**
 * <p>description：</p>
 * <p>copyright： copyright(C)2016-2099</p>
 * <p>Summary： </p>
 * <p>instructions： </p>
 * Date 2021/11/1</p>
 * Author mac
 *
 * @version 1.0
 */
public class BeanInitUtils {
    public static <T> T initBean(Class<T> clazz, List<String> ignoreFields) {
        if (clazz == null) {
            return null;
        }
        if (CollectionUtils.isEmpty(ignoreFields)) {
            ignoreFields = new ArrayList<>();
        }

        T obj = null;
        try {
            obj = clazz.newInstance();
            Field[] fields = clazz.getDeclaredFields();
            for (Field field : fields) {
                String fieldName = field.getName();
                if (ignoreFields.contains(fieldName)) {
                    continue;
                }
                field.setAccessible(true);
                // 优先使用字段的默认值
                if (field.get(obj) != null) {
                    if (!ignoreFields.contains(fieldName)) {
                        ignoreFields.add(fieldName);
                        continue;
                    }
                }
                if (field.getType().isInstance(int.class) || field.getType().isInstance((Integer.class))) {
                    field.set(obj, RandomUtils.nextInt(0, 100));
                } else if (field.getType() == String.class) {
                    field.set(obj, "test" + RandomUtils.nextInt(0, 100));
                } else if (field.getType() == double.class || field.getType() == Double.class) {
                    field.set(obj, RandomUtils.nextDouble(0, 100));
                } else if (field.getType() == float.class || field.getType() == Float.class) {
                    field.set(obj, RandomUtils.nextFloat(0, 100));
                } else if (field.getType() == byte.class || field.getType() == Byte.class) {
                    field.set(obj, RandomUtils.nextBytes(128));
                } else if (field.getType() == Date.class) {
                    field.set(obj, new Date());
                } else if (field.getType() == boolean.class || field.getType() == Boolean.class) {
                    field.set(obj, RandomUtils.nextBoolean());
                } else if (field.getType() == long.class || field.getType() == Long.class) {
                    field.set(obj, RandomUtils.nextLong(0, 100));
                } else if (field.getType() == char.class || field.getType() == Character.class) {
                    field.set(obj, RandomUtils.nextInt(Character.MIN_VALUE, Character.MAX_VALUE));
                } else {
                    if (!ignoreFields.contains(fieldName)) {
                        ignoreFields.add(fieldName);
                    }
                }
            }
            ignoreFields.forEach(item -> System.out.println(item + ":未初始化"));
        } catch (InstantiationException | IllegalAccessException e) {
            e.printStackTrace();
        }
        return obj;
    }

    static class Person {
        private int age = 0;
        private String name;
        private Date birthday;
        private String email;
        private float weight;

        @Override
        public String toString() {
            return "Person{" +
                    "age=" + age +
                    ", name='" + name + '\'' +
                    ", birthday=" + birthday +
                    ", email='" + email + '\'' +
                    ", weight=" + weight +
                    '}';
        }
    }

    public static void main(String[] args) {
        Person person = BeanInitUtils.initBean(Person.class, null);
        System.out.println(person);
    }
}

不足之处

只能初始化常用的基本类型，不能初始化其他的引用类型，需要进一步改进；