how to merge properties from one Java object to another in Java using Spring [SpEL]? -


i'm using spring not familiar capabilities. looking way copy fields 1 java object instance another. i've seen how copy properties 1 java bean another? i'm looking more specific, here details:

suppose have 2 instances of class p, source & target, have getters , setters a,b,c,d , 20 others. want copy properties of of source target, properties in list of property names. not matter value of property in either source or target.
in other words, if list {"a", "b"}
want following happen: 

p source; p target; list<string> properties;   //source, target populated. properties {"a", "b"}   //now need spring (spel?) trick equivalent of: target.seta(source.geta()); target.setb(source.getb());

using java reflection:

field[] fields = source.getclass().getdeclaredfields();  (field f: fields) {     if (properties.contains(f.getname())) {          f.setaccessible(true);          f.set(destination, f.get(source));     } }

here tutorials on reflection:

http://www.oracle.com/technetwork/articles/java/javareflection-1536171.html

http://tutorials.jenkov.com/java-reflection/index.html

be careful though, reflection has specific use cases.

using spring beanwrapper:

beanwrapper srcwrap = propertyaccessorfactory.forbeanpropertyaccess(source); beanwrapper destwrap = propertyaccessorfactory.forbeanpropertyaccess(destination);  properties.foreach(p -> destwrap.setpropertyvalue(p, srcwrap.getpropertyvalue(p)));

credit spring beanwrapper example goes to: https://stackoverflow.com/a/5079864/6510058


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