4 種複製方法：

• Apache BeanUtils
• Apache PropertyUtils
• Spring BeanUtils
• Cglib BeanCopier

測試 Bean，FromBean 與 ToBean 屬性一致

public class FromBean {
    private String name;
    private int age;
    private double money;
 
    public double getMoney() {
        return money;
    }
    public void setMoney(double money) {
        this.money = money;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public int getAge() {
        return age;
    }
    public void setAge(int age) {
        this.age = age;
    }
}
 

測試方法

import org.apache.commons.beanutils.BeanUtils;
import org.apache.commons.beanutils.PropertyUtils;
import org.springframework.cglib.beans.BeanCopier;

public class Test {

	public static void main(String[] args) {
		FromBean fb = new FromBean();
		fb.setAge(20);
		fb.setMoney(30000.111);
		fb.setName("測試");

		int count = 10;

		convert((tb) -> BeanUtils.copyProperties(tb, fb), count, "Apache BeanUtils.copyProperties");

		convert((tb) -> PropertyUtils.copyProperties(tb, fb), count, "Apache PropertyUtils.copyProperties");

		convert((tb) -> org.springframework.beans.BeanUtils.copyProperties(fb, tb), count, "Spring BeanUtils.copyProperties");

		BeanCopier bc = BeanCopier.create(FromBean.class, ToBean.class, false);

		convert((tb) -> bc.copy(fb, tb, null), count, "Cglib BeanCopier.copy");

	}

	public static void convert(ConvertBean cb, int count, String type) {
		try {
			System.out.println(type + "開始進行測試");
			long start = System.currentTimeMillis();
			for (int i = 0; i < count; i++) {
				ToBean tobean = new ToBean();
				cb.convertMethod(tobean);
				System.out.println(tobean.getAge());
				System.out.println(tobean.getMoney());
				System.out.println(tobean.getName());
			}
			System.out.println("耗時 " + (System.currentTimeMillis() - start) + " ms");
			System.out.println("----------------------");
		} catch (Exception e) {
			System.out.println("Exception: " + e.getMessage());
			e.printStackTrace();
		}
	}
}

@FunctionalInterface
interface ConvertBean {

	void convertMethod(ToBean tb) throws Exception;
}
 

列印結果

Apache BeanUtils.copyProperties開始進行測試
耗時 1178 ms
----------------------
Apache PropertyUtils.copyProperties開始進行測試
耗時 5 ms
----------------------
Spring BeanUtils.copyProperties開始進行測試
耗時 172 ms
----------------------
Cglib BeanCopier.copy開始進行測試
耗時 0 ms
----------------------

測試結果

單位：ms

count：10

count：100

count：10000

結論

• 數量越大平均每次耗時越少
• 綜合 Cglib BeanCopier 效能最好，但在使用前，要先用 BeanCopier.create 定義

Cglib在測試的時候，先進行了例項的快取，這個也是他效能較好的原因

Spring BeanUtils 不能轉化 java.util.Date，可以支援它的子類 java.s