對象屬性複製幾種方式的效率

對象屬性複製的三種方法：

1.Apache提供的BeanUtil.copyProperties和PropertyUtil.copyProperties兩種方式

　　BeanUtils.copyProperties("轉換後的類", "要轉換的類"); //多一步類型轉換，比PropertyUtils效率還差

　　PropertyUtils.copyProperties("轉換後的類", "要轉換的類");

　　口訣：後付錢（後付前:後面的複製給前面）會拋異常

2.spring提供的BeanUtil.copyProperties方式

　　BeanUtils.copyProperties("要轉換的類", "轉換後的類"); 

　　和Apache參數順序相反

3.cglib提供的copy方式

　　BeanCopier copy=BeanCopier.create("要轉換的類", "轉換後的類", false);

　　copy.copy(from, to, null);

4.spring提供的copy方式

　　BeanCopier copy=BeanCopier.create("要轉換的類", "轉換後的類", false);

　　copy.copy(from, to, null);

1 /**
2  * Created by hunt on 2017/6/28.
3  */
4 @Data
5 public class TestFrom {
6     private String name;
7 }

1 import lombok.Data;
2 
3 /**
4  * Created by hunt on 2017/6/28.
5  */
6 @Data
7 public class TestTo {
8     private String name;
9 }

第一種Apache方式的BeanUtils效率測試：

 1 import org.apache.commons.beanutils.BeanUtils;
 2 
 3 import java.lang.reflect.InvocationTargetException;
 4 
 5 /**
 6  * Created by hunt on 2017/6/28.
 7  */
 8 public class TestDemo {
 9     public static void main(String[] args) throws InvocationTargetException, IllegalAccessException {
10         TestFrom testFrom = new TestFrom();
11         testFrom.setName("hunt");
12         TestTo testTo = new TestTo();
13         long begin = System.currentTimeMillis();
14         for (int i = 0; i <1000000 ; i++) {//一百萬次
15             BeanUtils.copyProperties(testTo,testFrom);
16         }
17         long end = System.currentTimeMillis();
18         long mis = end -begin;
19         System.out.println("apache的BeanUtils.copyProperties耗時" + mis +"毫秒");
20         System.out.println(testTo);
21     }
22 }

第一種Apache方式的PropertyUtils效率測試：

 1 import org.apache.commons.beanutils.PropertyUtils;
 2 
 3 import java.lang.reflect.InvocationTargetException;
 4 
 5 /**
 6  * Created by hunt on 2017/6/28.
 7  */
 8 public class TestDemo {
 9     public static void main(String[] args) throws IllegalAccessException, NoSuchMethodException, InvocationTargetException {
10         TestFrom testFrom = new TestFrom();
11         testFrom.setName("hunt");
12         TestTo testTo = new TestTo();
13         long begin = System.currentTimeMillis();
14         for (int i = 0; i <1000000 ; i++) {//一百萬次
15             PropertyUtils.copyProperties(testTo,testFrom);
16         }
17         long end = System.currentTimeMillis();
18         long mis = end -begin;
19         System.out.println("apache的PropertyUtils.copyProperties耗時" + mis +"毫秒");
20         System.out.println(testTo);
21     }
22 }

第二種Spring方式的BeanUtils效率測試：

 1 import org.springframework.beans.BeanUtils;
 2 
 3 /**
 4  * Created by hunt on 2017/6/28.
 5  */
 6 public class TestDemo {
 7     public static void main(String[] args) {
 8         TestFrom testFrom = new TestFrom();
 9         testFrom.setName("hunt");
10         TestTo testTo = new TestTo();
11         long begin = System.currentTimeMillis();
12         for (int i = 0; i <1000000 ; i++) {//一百萬次
13             BeanUtils.copyProperties(testFrom,testTo);//沒拋異常
14         }
15         long end = System.currentTimeMillis();
16         long mis = end -begin;
17         System.out.println("Spring的PropertyUtils.copyProperties耗時" + mis +"毫秒");
18         System.out.println(testTo);
19     }
20 }

第三種方式cglib的copy效率測試

 1 import net.sf.cglib.beans.BeanCopier;
 2 
 3 /**
 4  * Created by hunt on 2017/6/28.
 5  */
 6 public class TestDemo {
 7     public static void main(String[] args) {
 8         TestFrom testFrom = new TestFrom();
 9         testFrom.setName("hunt");
10         TestTo testTo = new TestTo();
11         long begin = System.currentTimeMillis();
12         for (int i = 0; i <1000000 ; i++) {//一百萬次
13             BeanCopier copier = BeanCopier.create(TestFrom.class,TestTo.class,false);
14             copier.copy(testFrom,testTo,null);
15         }
16         long end = System.currentTimeMillis();
17         long mis = end -begin;
18         System.out.println("cglib的copier.copy耗時" + mis +"毫秒");
19         System.out.println(testTo);
20     }
21 }

第四種方式Spring的copy效率測試

 1 import org.springframework.cglib.beans.BeanCopier;
 2 
 3 /**
 4  * Created by hunt on 2017/6/28.
 5  */
 6 public class TestDemo {
 7     public static void main(String[] args) {
 8         TestFrom testFrom = new TestFrom();
 9         testFrom.setName("hunt");
10         TestTo testTo = new TestTo();
11         long begin = System.currentTimeMillis();
12         for (int i = 0; i <1000000 ; i++) {//一百萬次
13             BeanCopier copier = BeanCopier.create(TestFrom.class,TestTo.class,false);
14             copier.copy(testFrom,testTo,null);
15         }
16         long end = System.currentTimeMillis();
17         long mis = end -begin;
18         System.out.println("Spring的copier.copy耗時" + mis +"毫秒");
19         System.out.println(testTo);
20     }
21 }

總結：這四種方式的效率是由低到高。（註意Apache的PropertyUtils不能進行類型轉換的問題）