Java copies simple objects through reflection

Code Implementation

Package me. andy. practice. annotation; import Java. lang. reflect. constructor; import Java. lang. reflect. field; import Java. lang. reflect. method; public class reflectutils {public static object copy (Object Resource) throws exception {class <? Extends Object> classtype = resource. getclass (); object newobject = classtype. newinstance (); field [] declaredfields = classtype. getdeclaredfields (); For (field filed: declaredfields) {string firstletter = filed. getname (). substring (0, 1 ). touppercase (); string getmethodname = "get" + firstletter + filed. getname (). substring (1); string setmethodname = "set" + firstletter + filed. getname (). substring (1); Method getmethod = classtype. getmethod (getmethodname, new class [] {}); Method setmethod = classtype. getmethod (setmethodname, new class [] {filed. getType ()}); object value = getmethod. invoke (resource, new object [] {}); setmethod. invoke (newobject, new object [] {value}) ;}return newobject ;}}

• Code explanation

Object newobject = classtype. newinstance ();

Equivalent

Constructor <? Extends Object> constructor = classtype. getconstructor (new class [] {});

Object newobject = constructor. newinstance (new object [] {});

Field [] declaredfields = classtype. getdeclaredfields () returns all methods declared by the current class (including private)

Classtype. getfields () returns the total methods of the current class, including

Test code

Package me. andy. practice. reflect; import me. andy. practice. annotation. reflectutils; import Org. JUnit. test; import Java. lang. reflect. constructor; import Java. lang. reflect. field; import Java. lang. reflect. method; import static JUnit. framework. assert. assertequals; public class reflecttest {@ test public void test_copy () throws exception {person = new person ("Andy", 1); person copyperson = (person) reflectutils. copy (person); assertequals ("Andy", copyperson. getname (); assertequals (integer. valueof (1), copyperson. getage ());}}
 

Package me. andy. practice. reflect; public class person {private string name; private integer age; Public Person () {} public person (string name, integer age) {This. name = Name; this. age = age;} Public String getname () {return name;} public void setname (string name) {This. name = Name;} public integer getage () {return age;} public void setage (integer age) {This. age = age ;}}