java复制对象工具类

java复制对象工具类

import lombok.extern.slf4j.Slf4j;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.*;

/**
 * @Description: Class工具类
 */
@Slf4j
public class ClassUtil {

    /**
     * 利用反射实现对象之间相同属性复制
     *
     * @param source 要复制的
     * @param target 复制给
     */
    public static <T> T copyProperties(Object source, T target)  throws ClassCopyException {
        try {
            return copyPropertiesExclude(source, target, null);
        } catch (InvocationTargetException |IllegalAccessException e) {
            log.error(e.getMessage());
           throw   new ClassCopyException();
        }
    }

    /**
     * 复制对象属性
     *
     * @param from
     * @param to
     * @param excludsArray 排除属性列表
     * @throws Exception
     */
    public static <T> T copyPropertiesExclude(Object from, T to, String[] excludsArray) throws InvocationTargetException, IllegalAccessException {
        if (from == null) {
            return null;
        }
        List<String> excludesList = null;
        if (excludsArray != null && excludsArray.length > 0) {
            excludesList = Arrays.asList(excludsArray); // 构造列表对象
        }
        List<Method> fromMethodarr = new ArrayList<Method>();
        for (Class<?> clazz = from.getClass(); clazz != Object.class; clazz = clazz.getSuperclass()) {
            fromMethodarr.addAll(Arrays.asList(clazz.getDeclaredMethods()));
        }
        // Method[] fromMethods = from.getClass().getDeclaredMethods();
        List<Method> toMethodarr = new ArrayList<Method>();
        for (Class<?> clazz = to.getClass(); clazz != Object.class; clazz = clazz.getSuperclass()) {
            toMethodarr.addAll(Arrays.asList(clazz.getDeclaredMethods()));
        }
        // Method[] toMethods = to.getClass().getDeclaredMethods();
        Method fromMethod = null, toMethod = null;
        String fromMethodName = null, toMethodName = null;
        for (int i = 0; i < fromMethodarr.size(); i++) {
            fromMethod = fromMethodarr.get(i);
            fromMethodName = fromMethod.getName();
            if (!fromMethodName.contains("get")){
                continue;
            }
            // 排除列表检测
            if (excludesList != null && excludesList.contains(fromMethodName.substring(3).toLowerCase())) {
                continue;
            }
            toMethodName = "set" + fromMethodName.substring(3);
            toMethod = findMethodByName(toMethodarr, toMethodName);
            if (toMethod == null){
                continue;
            }
            Object value = fromMethod.invoke(from, new Object[0]);
            if (value == null){
                continue;
            }
            // 集合类判空处理
            if (value instanceof Collection) {
                Collection<?> newValue = (Collection<?>) value;
                if (newValue.size() <= 0){
                    continue;
                }
            }
            toMethod.invoke(to, new Object[]{value});
        }
        return to;
    }

    /**
     * 对象属性值复制，仅复制指定名称的属性值
     *
     * @param from
     * @param to
     * @param includsArray
     * @throws Exception
     */
    public static void copyPropertiesInclude(Object from, Object to, String[] includsArray) throws Exception {
        List<String> includesList = null;
        if (includsArray != null && includsArray.length > 0) {
            includesList = Arrays.asList(includsArray);
        } else {
            return;
        }
        List<Method> fromMethodarr = new ArrayList<Method>();
        for (Class<?> clazz = from.getClass(); clazz != Object.class; clazz = clazz.getSuperclass()) {
            fromMethodarr.addAll(Arrays.asList(clazz.getDeclaredMethods()));
        }
        // Method[] fromMethods = from.getClass().getDeclaredMethods();
        List<Method> toMethodarr = new ArrayList<Method>();
        for (Class<?> clazz = to.getClass(); clazz != Object.class; clazz = clazz.getSuperclass()) {
            toMethodarr.addAll(Arrays.asList(clazz.getDeclaredMethods()));
        }
        // Method[] toMethods = to.getClass().getDeclaredMethods();
        Method fromMethod = null, toMethod = null;
        String fromMethodName = null, toMethodName = null;
        for (int i = 0; i < fromMethodarr.size(); i++) {
            fromMethod = fromMethodarr.get(i);
            fromMethodName = fromMethod.getName();
            if (!fromMethodName.contains("get")){
                continue;
            }
            // 排除列表检测
            String str = fromMethodName.substring(3);
            if (!includesList.contains(str.substring(0, 1).toLowerCase() + str.substring(1))) {
                continue;
            }
            toMethodName = "set" + fromMethodName.substring(3);
            toMethod = findMethodByName(toMethodarr, toMethodName);
            if (toMethod == null){
                continue;
            }
            Object value = fromMethod.invoke(from, new Object[0]);
            if (value == null){
                continue;
            }
            // 集合类判空处理
            if (value instanceof Collection) {
                Collection<?> newValue = (Collection<?>) value;
                if (newValue.size() <= 0){
                    continue;
                }
            }
            toMethod.invoke(to, new Object[]{value});
        }
    }

    /**
     * 从方法数组中获取指定名称的方法
     *
     * @param methods
     * @param name
     * @return
     */
    public static Method findMethodByName(List<Method> methods, String name) {
        // System.out.println(name);
        Optional<Method> op = methods.stream().filter(method -> method.getName().equals(name)).findFirst();
        return op.isPresent() ? op.get() : null;
    }


    public static <T> List<T> listMapToListBean(List<Map<String,Object>> listMap,List<T> list,Class classz) throws IllegalAccessException, InstantiationException {
        if(listMap==null||listMap.size()==0){
            return list;
        }
        for (int i = 0; i < listMap.size(); i++) {
            Map<String,Object> map = listMap.get(i);
            T bean = (T)classz.newInstance();
            mapToBean(map,bean,classz);
            list.add(bean);
        }
        return list;
    }

    public static <T> T mapToBean(Map<String,Object> map,T bean,Class classz){
        // T-O-D-O 模仿 json 转对象
        return bean;
    }
}

原文地址：https://blog.csdn.net/hejiefeng111/article/details/140527952

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