java工具类-bean转map
工作常常遇到将java的Bean对象转化为Map，或者将Map转为Bean对象。
常见的手段
- 通过json工具，将Bean转json，再将json转Map
效率低
- jdk的反射，获取类的属性，进行转化
比较麻烦，书写代码比较多
- 通过工具类
BeanMap来完成效率高，底层也是基于反射，不过做了些优化，比如缓存等手段 (推荐)
- 通过
Apache的BeanUtils来完成bean转化map是Map
循环转化1w次，对比下BeanMap和BeanUtils的耗时(毫秒)
| 方式 | bean转map | map转bean |
|---|---|---|
| BeanMap | 593 | 364 |
| BeanUtils | 1254 | 2430 |
由上测试结果，我们可以看出BeanMap效率高，所以推荐使用BeanMap
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1.BeanMap方式
BeanMap是org.springframework.cglib.beans.BeanMap，在springcore中
1-1.工具类BeanMapTool
package com.iworkh.test.restassured.utils;
import org.springframework.cglib.beans.BeanMap;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
/**
* bean和map互转
*
* @author: iworkh-沐雨云楼
* @date: 2020-06-18
*/
public class BeanMapTool {
public static <T> Map<String, ?> beanToMap(T bean) {
BeanMap beanMap = BeanMap.create(bean);
Map<String, Object> map = new HashMap<>();
beanMap.forEach((key, value) -> {
map.put(String.valueOf(key), value);
});
return map;
}
public static <T> T mapToBean(Map<String, ?> map, Class<T> clazz)
throws IllegalAccessException, InstantiationException {
T bean = clazz.newInstance();
BeanMap beanMap = BeanMap.create(bean);
beanMap.putAll(map);
return bean;
}
public static <T> List<Map<String, ?>> objectsToMaps(List<T> objList) {
List<Map<String, ?>> list = new ArrayList<>();
if (objList != null && objList.size() > 0) {
Map<String, ?> map = null;
T bean = null;
for (int i = 0, size = objList.size(); i < size; i++) {
bean = objList.get(i);
map = beanToMap(bean);
list.add(map);
}
}
return list;
}
public static <T> List<T> mapsToObjects(List<Map<String, ?>> maps, Class<T> clazz)
throws InstantiationException, IllegalAccessException {
List<T> list = new ArrayList<>();
if (maps != null && maps.size() > 0) {
Map<String, ?> map = null;
for (int i = 0, size = maps.size(); i < size; i++) {
map = maps.get(i);
T bean = mapToBean(map, clazz);
list.add(bean);
}
}
return list;
}
}
1-2.调用
public class BeanMapToolTest {
@Test
public void testBeanToMap() {
String[] hobbies = {
"football", "sing"};
UserVo user = new UserVo(1, "zhangsan", System.currentTimeMillis(), false, Arrays.asList(hobbies));
Map<String, ?> map = BeanMapTool.beanToMap(user);
System.out.println(map.get("name"));
}
@Test
public void testMapToBean() {
String[] hobbies = {
"football", "sing"};
Map<String, Object> map = new HashMap<>();
map.put("id", 1);
map.put("name", "zhangsan");
map.put("birthday", System.currentTimeMillis());
map.put("vip", false);
map.put("hobbies", Arrays.asList(hobbies));
try {
UserVo userVo = BeanMapTool.mapToBean(map, UserVo.class);
System.out.println(userVo.getHobbies());
} catch (IllegalAccessException | InstantiationException e) {
e.printStackTrace();
}
}
}
2.BeanUtils方式
导入pom依赖
<dependency>
<groupId>commons-beanutilsgroupId>
<artifactId>commons-beanutilsartifactId>
<version>1.9.3version>
dependency>
2-1.工具类BeanUtilsTool
package com.iworkh.test.restassured.utils;
import org.apache.commons.beanutils.BeanUtils;
import java.lang.reflect.InvocationTargetException;
import java.util.Map;
/**
* Apache BeanUtils工具类
*
* @author: iworkh-沐雨云楼
* @date: 2020-06-19
*/
public class BeanUtilsTool {
public static <T> Map<String, String> beanToMap(T bean)
throws IllegalAccessException, NoSuchMethodException, InvocationTargetException {
return BeanUtils.describe(bean);
}
public static <T> T mapToBean(Map<String, Object> map, Class<T> bean)
throws IllegalAccessException, InstantiationException, InvocationTargetException {
T t = bean.newInstance();
BeanUtils.populate(t, map);
return t;
}
}
2-2.调用
public class BeanUtilsToolTest {
@Test
public void testBeanToMap() {
String[] hobbies = {
"football", "sing"};
UserVo user = new UserVo(1, "zhangsan", System.currentTimeMillis(), false, Arrays.asList(hobbies));
try {
Map<String, String> map = BeanUtilsTool.beanToMap(user);
System.out.println(map.get("name"));
} catch (IllegalAccessException | NoSuchMethodException | InvocationTargetException e) {
e.printStackTrace();
}
}
@Test
public void testMapToBean() {
String[] hobbies = {
"football", "sing"};
Map<String, Object> map = new HashMap<>();
map.put("id", 1);
map.put("name", "zhangsan");
map.put("birthday", System.currentTimeMillis());
map.put("vip", false);
map.put("hobbies", Arrays.asList(hobbies));
try {
UserVo userVo = BeanUtilsTool.mapToBean(map, UserVo.class);
System.out.println(userVo.getHobbies());
} catch (IllegalAccessException | InstantiationException | InvocationTargetException e) {
e.printStackTrace();
}
}
}
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