java反射技术与类使用示例

复制代码 代码如下:
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 {
 Class[] cl = {};
 Object[] ob = {};
 
 public void setNullToArrays(){
  this.cl = new Class[]{};
  this.ob = new Object[]{};
 }
 
 public Object[] getObjectArrays(Object obj) {
   ob = Arrays.copyOf(ob,ob.length + 1);
   ob[ob.length - 1] = obj;
   return ob;
 }

 
 @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;
  }
 }

 
 @SuppressWarnings("unchecked")
 public Object getClassNewInstance(Class clazz)
   throws InstantiationException, IllegalAccessException,
   IllegalArgumentException, SecurityException,
   InvocationTargetException, NoSuchMethodException {
  Object oj = null;
  Constructor[] cons = clazz.getDeclaredConstructors();// 得到构造函数
  Class[] cla = cons[1].getParameterTypes();
     System.out.println("提示用户是否需要添加字段   构造函数参数的大小:"+cla.length);
  for (int i = 0; i < cla.length; i++) {
   String classStr = cla[i].toString();
   // System.out.println("参数的类型："+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();//返回当前对象 具体的实例化构造在BDOperater
  return oj;
 }
 
 public Object getObjCon(Class clazz) throws IllegalArgumentException, SecurityException, InstantiationException, IllegalAccessException, InvocationTargetException, NoSuchMethodException{
  Object obj=null;
   obj = this.getClassNewInstance(clazz);
  return obj;
 }
 
 public Object getNewinstance(Class clazz) throws InstantiationException, IllegalAccessException{
  Object obj = null;
  obj =  clazz.newInstance();
  return obj;
 }
 
 public Field[] getFielsdArray(Class