实现忽略大小写的copyProperties

实现的原因

Spring中的BeanUtils.copyProperties(source,target),不能忽略大小写，类型不同不能相互赋值。速度并不是特别理想。自己根据反射实现了工具类。 其中ReflectASM需要引入下面jar包

        
        <dependency>
            <groupId>com.esotericsoftwaregroupId> <artifactId>reflectasmartifactId> <version>1.11.7version> dependency> 

#具体代码

import com.esotericsoftware.reflectasm.MethodAccess;

import java.lang.reflect.Field;
import java.lang.reflect.Modifier;
import java.util.*;

/** * * @Auther: xjw * @Description: 此类主要用于反射，对反射的一些操作进行缓存起来。 */ public class BeanUtils { /** * 集合 copy * * @param sources * @param target * @param  * @return */ public static  List listCopyPropertiesASM(List sources, Class target) { List list = new ArrayList<>(sources.size()); sources.forEach(it -> { list.add(copyPropertiesASM(it, target)); }); return list; } /** * 通过 target的Class 复制 * target 必须有一个无参构造器 * * @param source * @param target * @param  * @return */ public static  T copyPropertiesASM(Object source, Class target) { T newT = null; try { newT = target.newInstance(); } catch (InstantiationException e) { e.printStackTrace(); } catch (IllegalAccessException e) { e.printStackTrace(); } return copyPropertiesASM(source, newT); } /** * 通过 ASM反射 速度比 Spring BeanUtils.copyProperties(source,target) 快一倍 * 大小写可以忽略 * 下划线 _ 被忽略 * * @param source 源对象 * @param target 目标实例化对象 * @param  * @return */ public static  T copyPropertiesASM(Object source, Object target) { MethodAccess sourceMethodAccess = CacheMethodAccess.getMethodAccess(source.getClass()); MethodAccess targetMethodAccess = CacheMethodAccess.getMethodAccess(target.getClass()); Map sourceGet = CacheAsmFiledMethod.getMethod("get", source.getClass()); Map targetSet = CacheAsmFiledMethod.getMethod("set", target.getClass()); CacheFieldMap.getFieldMap(target.getClass()).keySet().forEach((it) -> { String sourceIndex = sourceGet.get(it); if (sourceIndex != null) { Object value = sourceMethodAccess.invoke(source, sourceIndex); String setIndex = targetSet.get(it); targetMethodAccess.invoke(target, setIndex, value); } }); return (T) target; } /** * 模仿Spring中 BeanUtils.copyProperties(source,target) * 大小写可以忽略 * 下划线 _ 被忽略 * * @param source * @param target * @param  * @return */ public static  T copyProperties(Object source, Object target) { Map sourceMap = CacheFieldMap.getFieldMap(source.getClass()); CacheFieldMap.getFieldMap(target.getClass()).values().forEach((it) -> { Field field = sourceMap.get(it.getName().toLowerCase().replace("_", "")); if (field != null) { it.setAccessible(true); field.setAccessible(true); try { it.set(target, field.get(source)); } catch (IllegalAccessException e) { e.printStackTrace(); } } }); return (T) target; } private static class CacheAsmFiledMethod { private static Map> cacheGetMethod = new HashMap<>(); private static Map> cacheSetMethod = new HashMap<>(); private static Map getMethod(String type, Class clazz) { MethodAccess methodAccess = CacheMethodAccess.getMethodAccess(clazz); Map allFields = CacheFieldMap.getFieldMap(clazz); Map result = null; if (type.equals("get")) { result = cacheGetMethod.get(clazz.getName()); } else if (type.equals("set")) { result = cacheSetMethod.get(clazz.getName()); } if (result == null) { synchronized (CacheAsmFiledMethod.class) { if (result == null) { Map set = new HashMap<>(); Map get = new HashMap<>(); allFields.values().forEach((it) -> { //判断是否是静态 if (!Modifier.isStatic(it.getModifiers())) { //首字母大写 char[] f = it.getName().toCharArray(); f[0] -= 32; String fieldName = new String(f); get.put(fieldName.toLowerCase().replace("_", ""), "get" + fieldName); set.put(fieldName.toLowerCase().replace("_", ""), "set" + fieldName); } }); cacheGetMethod.put(clazz.getName(), get); cacheSetMethod.put(clazz.getName(), set); if (type.equals("get")) { result = cacheGetMethod.get(clazz.getName()); } else if (type.equals("set")) { result = cacheSetMethod.get(clazz.getName()); } } } } return result; } } private static class SingelClass { private static Map cacheObject = new HashMap<>(); private SingelClass() { } private static  T getObject(Class clazz) { T result = (T) cacheObject.get(clazz.getName()); if (result == null) { synchronized (SingelClass.class) { if (result == null) { try { cacheObject.put(clazz.getName(), clazz.newInstance()); result = (T) cacheObject.get(clazz.getName()); } catch (Exception e) { e.printStackTrace(); } } } } return result; } } private static class CacheMethodAccess { private CacheMethodAccess() { } private static Map cache = new HashMap<>(); private static MethodAccess getMethodAccess(Class clazz) { MethodAccess result = cache.get(clazz.getName()); if (result == null) { synchronized (CacheMethodAccess.class) { if (result == null) { cache.put(clazz.getName(), MethodAccess.get(clazz)); result = cache.get(clazz.getName()); } } } return result; } } private static class CacheFieldMap { private static Map> cacheMap = new HashMap<>(); private static Map getFieldMap(Class clazz) { Map result = cacheMap.get(clazz.getName()); if (result == null) { synchronized (CacheFieldMap.class) { if (result == null) { Map fieldMap = new HashMap<>(); for (Field field : clazz.getDeclaredFields()) { fieldMap.put(field.getName().toLowerCase().replace("_", ""), field); } cacheMap.put(clazz.getName(), fieldMap); result = cacheMap.get(clazz.getName()); } } } return result; } } } 

测试

    public static void main(String[] args) { Man man = new Man("name", 20); Woman woman = BeanUtils.copyPropertiesASM(man, Woman.class); System.out.println(woman); List manList = new ArrayList<>(); for (int i = 0; i < 100; i++) { manList.add(new Man("name" + i, i)); } List womens = BeanUtils.listCopyPropertiesASM(manList,Woman.class); System.out.println(womens); }