BeanUtils.copyProperties忽略null值

最新推荐文章于 2023-10-22 23:41:54 发布

原创最新推荐文章于 2023-10-22 23:41:54 发布 · 1.2k 阅读

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该博客介绍了一个自定义的BeanCopyUtil工具类，继承自Apache Commons BeanUtilsBean，用于复制对象属性。该工具类包含一个方法，可以设置是否忽略源对象中的null值，避免在复制过程中将null值复制到目标对象。

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import Java.beans.PropertyDescriptor;
import java.lang.reflect.InvocationTargetException;
import java.util.Map;

import org.apache.commons.beanutils.BeanUtilsBean;
import org.apache.commons.beanutils.DynaBean;
import org.apache.commons.beanutils.DynaProperty;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class BeanCopyUtil extends BeanUtilsBean{

private static final Logger log=LoggerFactory.getLogger(BeanCopyUtil.class);
/**
*

@param dest 目标对象
@param orig 源对象
@param ignoreNullFlag 是否忽略null值
@throws IllegalAccessException

@throws InvocationTargetException
*/
public void copyProperties(Object dest, Object orig,boolean ignoreNullFlag)
throws IllegalAccessException, InvocationTargetException {

 // Validate existence of the specified beans
 if (dest == null) {
     throw new IllegalArgumentException
             ("No destination bean specified");
 }
 if (orig == null) {
     throw new IllegalArgumentException("No origin bean specified");
 }
 if (log.isDebugEnabled()) {
     log.debug("BeanUtils.copyProperties(" + dest + ", " +
               orig + "," + ignoreNullFlag + ")");
 }


 // Copy the properties, converting as necessary
 if (orig instanceof DynaBean) {
     DynaProperty[] origDescriptors =
         ((DynaBean) orig).getDynaClass().getDynaProperties();
     for (int i = 0; i < origDescriptors.length; i++) {
         String name = origDescriptors[i].getName();
         // Need to check isReadable() for WrapDynaBean
         // (see Jira issue# BEANUTILS-61)
         if (getPropertyUtils().isReadable(orig, name) &&
             getPropertyUtils().isWriteable(dest, name)) {
             Object value = ((DynaBean) orig).get(name);
             if(ignoreNullFlag){
             if(value!=null){
             copyProperty(dest, name, value);
             }
             }else{
             copyProperty(dest, name, value);
             }
         }
     }
 } else if (orig instanceof Map) {
     @SuppressWarnings("unchecked")
     // Map properties are always of type <String, Object>
     Map<String, Object> propMap = (Map<String, Object>) orig;
     for (Map.Entry<String, Object> entry : propMap.entrySet()) {
         String name = entry.getKey();
         Object value=entry.getValue();
         if (getPropertyUtils().isWriteable(dest, name)) {
             if(ignoreNullFlag){
             if(value!=null){
             copyProperty(dest, name, value);
             }
             }else{
             copyProperty(dest, name, value);
             }
         }
     }
 } else /* if (orig is a standard JavaBean) */ {
     PropertyDescriptor[] origDescriptors =
         getPropertyUtils().getPropertyDescriptors(orig);
     for (int i = 0; i < origDescriptors.length; i++) {
         String name = origDescriptors[i].getName();
         if ("class".equals(name)) {
             continue; // No point in trying to set an object's class
         }
         if (getPropertyUtils().isReadable(orig, name) &&
             getPropertyUtils().isWriteable(dest, name)) {
             try {
                 Object value =
                     getPropertyUtils().getSimpleProperty(orig, name);
                 if(ignoreNullFlag){
             if(value!=null){
             copyProperty(dest, name, value);
             }
             }else{
             copyProperty(dest, name, value);
             }
             } catch (NoSuchMethodException e) {
                 // Should not happen
             }
         }
     }
 }

}
}