使用reflectasm实现bean快速复制（缓存了生成的class对象）
1.导入reflectasm的依赖
<dependency>
<groupId>com.esotericsoftware</groupId>
<artifactId>reflectasm</artifactId>
<version>1.11.7</version>
</dependency>
2.浅复制代码
import java.lang.reflect.Field;
import java.lang.reflect.Modifier;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import com.esotericsoftware.reflectasm.MethodAccess;
public class BeanCopyUtils {
private static Map<Class<?>, MethodAccess> methodMap = new HashMap<Class<?>, MethodAccess>();
private static Map<Class<?>, Map<String, Integer>> methodIndexOfGet = new HashMap<>();
private static Map<Class<?>, Map<String, Integer>> methodIndexOfSet = new HashMap<>();
private static Map<Class<?>, Map<String, String>> methodIndexOfType = new HashMap<>();
/**
* 浅copy类属性,根据属性名匹配，而不是类型+属性匹配，当类型不同且原属性值为null时，不变动目标类此属性值
*
* @param desc
* 接收复制参数的类
* @param orgi
* 原始类
*/
public static void copyProperties(Object desc, Object orgi) {
MethodAccess descMethodAccess = methodAccessFactory(desc);
MethodAccess orgiMethodAccess = methodAccessFactory(orgi);
Map<String, Integer> get = methodIndexOfGet.get(orgi.getClass());
Map<String, Integer> set = methodIndexOfSet.get(desc.getClass());
Map<String, String> oritypemap = methodIndexOfType.get(orgi.getClass());
Map<String, String> desctypemap = methodIndexOfType.get(desc.getClass());
List<String> sameField = null;
if (get.size() < set.size()) {
sameField = new ArrayList<>(get.keySet());
sameField.retainAll(set.keySet());
} else {
sameField = new ArrayList<>(set.keySet());
sameField.retainAll(get.keySet());
}
for (String field : sameField) {
Integer setIndex = set.get(field);
Integer getIndex = get.get(field);
String oritype = oritypemap.get(field);
String desctype = desctypemap.get(field);
Object value = orgiMethodAccess.invoke(orgi, getIndex);
try {
if (!oritype.equalsIgnoreCase(desctype)) {
if (value == null) {
continue;
}
switch (desctype) {
case "java.lang.String":
descMethodAccess.invoke(desc, setIndex.intValue(), value.toString());
break;
case "java.lang.Integer":
case "int":
descMethodAccess.invoke(desc, setIndex.intValue(), Integer.valueOf(value.toString()));
break;
case "java.lang.Long":
case "long":
descMethodAccess.invoke(desc, setIndex.intValue(), Long.valueOf(value.toString()));
break;
case "java.lang.Float":
case "float":
descMethodAccess.invoke(desc, setIndex.intValue(), Long.valueOf(value.toString()));
break;
case "java.lang.Boolean":
case "boolean":
descMethodAccess.invoke(desc, setIndex.intValue(), Boolean.valueOf(value.toString()));
break;
case "java.lang.Double":
case "double":
descMethodAccess.invoke(desc, setIndex.intValue(), Double.valueOf(value.toString()));
break;
case "java.lang.Byte":
case "byte":
descMethodAccess.invoke(desc, setIndex.intValue(), Byte.valueOf(value.toString()));
break;
case "java.lang.Short":
case "short":
descMethodAccess.invoke(desc, setIndex.intValue(), Short.valueOf(value.toString()));
break;
default:
break;
}
} else {
descMethodAccess.invoke(desc, setIndex.intValue(), value);
}
} catch (Exception e) {
System.out.println(field + ":" + e.getMessage());
}
}
}
// double check
private static MethodAccess methodAccessFactory(Object obj) {
MethodAccess descMethodAccess = methodMap.get(obj.getClass());
if (descMethodAccess == null) {
synchronized (obj.getClass()) {
descMethodAccess = methodMap.get(obj.getClass());
if (descMethodAccess != null) {
return descMethodAccess;
}
Class<?> c = obj.getClass();
MethodAccess methodAccess = MethodAccess.get(c);
Field[] fields = c.getDeclaredFields();
Map<String, Integer> indexofget = new HashMap<>();
Map<String, Integer> indexofset = new HashMap<>();
Map<String, String> indexoftype = new HashMap<>();
for (Field field : fields) {
if (Modifier.isPrivate(field.getModifiers()) && !Modifier.isStatic(field.getModifiers())) { // 私有非静态
String fieldName = captureName(field.getName()); // 获取属性名称
int getIndex = methodAccess.getIndex("get" + fieldName); // 获取get方法的下标
int setIndex = methodAccess.getIndex("set" + fieldName); // 获取set方法的下标
indexofget.put(fieldName, getIndex);
indexofset.put(fieldName, setIndex);
indexoftype.put(fieldName, field.getType().getName());
}
}
methodIndexOfGet.put(c, indexofget);
methodIndexOfSet.put(c, indexofset);
methodIndexOfType.put(c, indexoftype);
methodMap.put(c, methodAccess);
return methodAccess;
}
}
return descMethodAccess;
}
private static String captureName(String name) {
char[] cs = name.toCharArray();
cs[0] -= 32;
return String.valueOf(cs);
}
}
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版权声明：本文为CSDN博主「土豆番茄酱紫」的原创文章，遵循CC 4.0 BY-SA版权协议，转载请附上原文出处链接及本声明。
原文链接：https://blog.csdn.net/wyyrockking/article/details/84525440
自己改了一版
package xxx.util;
package xxx.util;
import java.lang.reflect.Field;
import java.lang.reflect.Modifier;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import com.esotericsoftware.reflectasm.MethodAccess;
/**
* @see http://acuilab.com:8080/articles/2020/05/26/1590461350391.html
* @author admin
*/
public class BeanCopyUtils {
private static Map<Class<?>, MethodAccess> methodMap = new HashMap<Class<?>, MethodAccess>();
private static Map<Class<?>, Map<String, Integer>> methodIndexOfGet = new HashMap<>();
private static Map<Class<?>, Map<String, Integer>> methodIndexOfSet = new HashMap<>();
private static Map<Class<?>, Map<String, String>> methodIndexOfType = new HashMap<>();
/**
* 浅copy类属性, 当类型相同且原属性值为不为null时，才变动目标类此属性值
*
* @param dest 目标类
* @param orgi 原始类
*/
public static void copyProperties(Object dest, Object orgi) {
MethodAccess destMethodAccess = methodAccessFactory(dest);
MethodAccess orgiMethodAccess = methodAccessFactory(orgi);
Map<String, Integer> get = methodIndexOfGet.get(orgi.getClass());
Map<String, Integer> set = methodIndexOfSet.get(dest.getClass());
Map<String, String> oritypemap = methodIndexOfType.get(orgi.getClass());
Map<String, String> desctypemap = methodIndexOfType.get(dest.getClass());
List<String> sameField = null;
if (get.size() < set.size()) {
sameField = new ArrayList<>(get.keySet());
sameField.retainAll(set.keySet());
} else {
sameField = new ArrayList<>(set.keySet());
sameField.retainAll(get.keySet());
}
for (String field : sameField) {
Integer setIndex = set.get(field);
Integer getIndex = get.get(field);
String oritype = oritypemap.get(field);
String desttype = desctypemap.get(field);
Object value = orgiMethodAccess.invoke(orgi, getIndex);
if (oritype.equalsIgnoreCase(desttype)) {
if (value == null) {
continue;
}
destMethodAccess.invoke(dest, setIndex, value);
}
}
}
// double check
private static MethodAccess methodAccessFactory(Object obj) {
MethodAccess descMethodAccess = methodMap.get(obj.getClass());
if (descMethodAccess == null) {
synchronized (obj.getClass()) {
descMethodAccess = methodMap.get(obj.getClass());
if (descMethodAccess != null) {
return descMethodAccess;
}
Class<?> c = obj.getClass();
MethodAccess methodAccess = MethodAccess.get(c);
Field[] fields = c.getDeclaredFields();
Map<String, Integer> indexofget = new HashMap<>();
Map<String, Integer> indexofset = new HashMap<>();
Map<String, String> indexoftype = new HashMap<>();
for (Field field : fields) {
if (Modifier.isPrivate(field.getModifiers()) && !Modifier.isStatic(field.getModifiers())) { // 私有非静态
String fieldName = captureName(field.getName()); // 获取属性名称
try {
int getIndex = methodAccess.getIndex("get" + fieldName); // 获取get方法的下标
indexofget.put(fieldName, getIndex);
} catch(java.lang.IllegalArgumentException ex) {
// 布尔型属性
int getIndex = methodAccess.getIndex("is" + fieldName);
indexofget.put(fieldName, getIndex);
}
int setIndex = methodAccess.getIndex("set" + fieldName); // 获取set方法的下标
indexofset.put(fieldName, setIndex);
indexoftype.put(fieldName, field.getType().getName());
}
}
methodIndexOfGet.put(c, indexofget);
methodIndexOfSet.put(c, indexofset);
methodIndexOfType.put(c, indexoftype);
methodMap.put(c, methodAccess);
return methodAccess;
}
}
return descMethodAccess;
}
private static String captureName(String name) {
char[] cs = name.toCharArray();
cs[0] -= 32;
return String.valueOf(cs);
}
}