本文主要是介绍【开发新的】apache common BeanUtils忽略null值，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！
前言: BeanUtils默认的populate方法不会忽略空值和null值，在特定场景，我们需要原始的值避免被覆盖，所以这里提供一种自定义实现方式。
package com.hmwl.service.program;import lombok.extern.slf4j.Slf4j;
import org.apache.commons.beanutils.BeanUtilsBean;
import org.apache.commons.beanutils.ContextClassLoaderLocal;import java.lang.reflect.InvocationTargetException;
import java.util.Map;/*** @Author: martin* @Date: 2023/11/01 15:13 pm* @Description: apache common 原版populate不会过滤null值，不符合使用场景*/
@Slf4j
public class CustomBeanUtils extends BeanUtilsBean {private static final ContextClassLoaderLocal<CustomBeanUtils>BEANS_BY_CLASSLOADER = new ContextClassLoaderLocal<CustomBeanUtils>() {// Creates the default instance used when the context classloader is unavailable@Overrideprotected CustomBeanUtils initialValue() {return new CustomBeanUtils();}};public static CustomBeanUtils getInstance() {return BEANS_BY_CLASSLOADER.get();}public static void setInstance(final CustomBeanUtils newInstance) {BEANS_BY_CLASSLOADER.set(newInstance);}public static void populateIgnoreEmpty(final Object bean, final Map<String, ? extends Object> properties) {try {CustomBeanUtils.getInstance().populateIgnoreNull(bean, properties);} catch (IllegalAccessException e) {log.error(e.getMessage());} catch (InvocationTargetException e) {log.error(e.getMessage());}}private final void populateIgnoreNull(final Object bean, final Map<String, ? extends Object> properties)throws IllegalAccessException, InvocationTargetException {if ((bean == null) || (properties == null)) {return;}if (log.isDebugEnabled()) {log.debug("BeanUtils.populate(" + bean + ", " +properties + ")");}for (final Map.Entry<String, ? extends Object> entry : properties.entrySet()) {final String name = entry.getKey();// 增强下，因为可能多次调用，当value为null的时候不赋值if (name == null || entry.getValue() == null) {continue;}setProperty(bean, name, entry.getValue());}}
}
原版实现:
public void populate(final Object bean, final Map<String, ? extends Object> properties)throws IllegalAccessException, InvocationTargetException {// Do nothing unless both arguments have been specifiedif ((bean == null) || (properties == null)) {return;}if (log.isDebugEnabled()) {log.debug("BeanUtils.populate(" + bean + ", " +properties + ")");}// Loop through the property name/value pairs to be setfor(final Map.Entry<String, ? extends Object> entry : properties.entrySet()) {// Identify the property name and value(s) to be assignedfinal String name = entry.getKey();if (name == null) {continue;}// Perform the assignment for this propertysetProperty(bean, name, entry.getValue());}}
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