Java reflection Technology and class use example _java

Copy Code code as follows:

Package com.java.db;
Import Java.lang.reflect.Constructor;
Import Java.lang.reflect.Field;
Import java.lang.reflect.InvocationTargetException;
Import Java.lang.reflect.Method;
Import java.util.ArrayList;
Import Java.util.Arrays;
Import Java.util.Iterator;
Import java.util.List;
Import Java.util.Map;

Import com.java.entity.BookShelf;
Import Com.java.util.GetMetaDataCloumName;
public class Getnewinstances<t> {
 class[] cl = {};
 object[] ob = {};
 /**
  * Set to empty after each run is not cumulative
  */
 public void Setnulltoarrays () {
   this.cl = new class[]{};
  this.ob = new object[]{};
 }
 /**
  * Copy object array
  *
  * @param obj
  *     & The actual value required in the nbsp;      construction method
  * @return
  */
 public object[] Getobjectarrays (Object obj) {
   ob = arrays.copyof (ob,ob.length + 1);
   ob[ob.length-1] = obj;
   return ob;
 }

/**
* Copy Class array
*
* @param CLA
* The class to add
*
* @return
*/
@SuppressWarnings ("Unchecked")
Public class[] Getclassarrays (class<?> CLA) {
if (CLA!= null) {
CL = arrays.copyof (cl,cl.length + 1);
CL[CL.LENGTH-1] = CLA;
return CL;
}else{
return CL;
}
}

/**
* Get an instance of the class
*
* @param clazz
* The class to instantiate
* @return the class after instantiation
* @throws instantiationexception
* @throws illegalaccessexception
* @throws IllegalArgumentException
* @throws SecurityException
* @throws InvocationTargetException
* @throws nosuchmethodexception
*/
@SuppressWarnings ("Unchecked")
Public Object getclassnewinstance (class<?> clazz)
Throws Instantiationexception, Illegalaccessexception,
IllegalArgumentException, SecurityException,
InvocationTargetException, Nosuchmethodexception {
Object OJ = null;
Constructor[] cons = Clazz.getdeclaredconstructors ()//Get constructor
class[] cla = Cons[1].getparametertypes ();
System.out.println ("Prompts the user to add the size of the field constructor parameter:" +cla.length);
for (int i = 0; i < cla.length; i++) {
String classstr = cla[i].tostring ();
System.out.println ("type of parameter:" +CLASSSTR);
if (Classstr.equals ("Class java.lang.String")) {
Getclassarrays (String.class);
else if (classstr.equals ("int")) {
Getclassarrays (Int.class);
else if (classstr.equals ("double")) {
Getclassarrays (Double.class);
else if (Classstr.equals ("boolean")) {
Getclassarrays (Boolean.class);
else if (classstr.equals ("float")) {
Getclassarrays (Float.class);
else if (classstr.equals ("Class Java.lang.Integer")) {
Getclassarrays (Integer.class);
}else if (classstr.equals ("Class Java.lang.Float")) {
Getclassarrays (Float.class);
}
}
OJ = Clazz.newinstance ()//Returns the current object the concrete instantiation constructs in Bdoperater
return OJ;
}
/**
* Get concrete instance class by constructor
* @param clazz
* @return
* @throws IllegalArgumentException
* @throws SecurityException
* @throws instantiationexception
* @throws illegalaccessexception
* @throws InvocationTargetException
* @throws nosuchmethodexception
*/
Public Object Getobjcon (class<?> clazz) throws IllegalArgumentException, SecurityException, Instantiationexception, Illegalaccessexception, InvocationTargetException, nosuchmethodexception{
Object Obj=null;
obj = This.getclassnewinstance (clazz);
return obj;
}
/**
* Get an instance of the object
* @param clazz
* @return
* @throws instantiationexception
* @throws illegalaccessexception
*/
Public Object getnewinstance (Class clazz) throws Instantiationexception, illegalaccessexception{
Object obj = null;
obj = Clazz.newinstance ();
return obj;
}
/**
* All properties in the class based on reflection
* @param clazz The class that requires the property to be fetched
* @return Property Collection
* @throws SecurityException
* @throws IllegalArgumentException
* @throws instantiationexception
* @throws illegalaccessexception
* @throws InvocationTargetException
* @throws nosuchmethodexception
*/
Public field[] Getfielsdarray (class<object> clazz) throws SecurityException, IllegalArgumentException, Instantiationexception, Illegalaccessexception, InvocationTargetException, nosuchmethodexception{
field[] fields = NULL;
Fields = Clazz.getdeclaredfields ();
return fields;
}
/**
* Get setter Format properties based on string
* @param the attributes that STR needs to be formatted
* @return
*/
public string Getsetterstr (String str) {
String info = null;
String strvalue = str.substring (0,1). toUpperCase ();
info = "Set" +strvalue+str.substring (1,str.length ());
return info;
}
/**
* Restore the SETXX to XX
* @param str
* @return
*/
public string Setsetstr (String str) {
String info = null;
String strvalue = str.substring (3,str.length ());
String lower = strvalue.substring (0). toLowerCase (). substring (0,1);
info = lower+str.substring (4,str.length ());
return info;
}
/**
* Get the method in the class
* @param clazz needed to get the method of the class
* @return
*/
Public method[] Getmethodsarray (Class clazz) {
Method[] methods = Clazz.getmethods ();
return methods;
}
/**
* Instantiate constructors based on list<map>
* @param listmap
* @param clazz
* @param tablename Database name
* @return
* @throws nosuchmethodexception
* @throws InvocationTargetException
* @throws SecurityException
* @throws IllegalArgumentException
* @throws illegalaccessexception
* @throws instantiationexception
*/
@SuppressWarnings ({"Unchecked"})
Public list<object> Getlistbymap (list<map<string,object>> listmap,class clazz,String tableName) Throws Instantiationexception, Illegalaccessexception, IllegalArgumentException, SecurityException, InvocationTargetException, nosuchmethodexception{
list<object> listlast = new arraylist<object> ();
list<string> Metalist = getmetadatacloumname.getcloumnamelist (tablename);
Iterator<map<string,object>> it = Listmap.iterator ();
while (It.hasnext ()) {
map<string,object> map = It.next ();
iterator<string> Iitt = Metalist.iterator ();
while (Iitt.hasnext ()) {
String info = Iitt.next ();
This.getobjectarrays (Map.get (info));
}
System.out.println ("Call Reflection:" +this.cl.length+ "" +this.ob.length);
Object tobj = this.getclassnewinstance (clazz). GetClass (). GetConstructor (this.cl). newinstance (THIS.OB);
Listlast.add (Tobj);
This.setnulltoarrays ();
}
return listlast;
}
public static void Main (string[] args) {
Getnewinstances ge = new Getnewinstances ();
System.out.println (Ge.getsetterstr ("nameSpace") = = "Setnamespace");
System.out.println ("1a" = "1a");
System.out.println (Ge.setsetstr ("Setnamespace"));
}
}