对象复制

1.JAVA中无论生成一个类的多少个对象，这些对象都会对应同一个Class对象.
2.获取某个类或对象所对应的Class对象的常用的3种方式：
   a.使用Class类的静态方法forName,Class.forName("java.lang.String");
   b.使用.class语法：String.class;
   c.使用对象的getClass()方法: String s = "aa"; Class clazz = s.getClass();
3.若想通过类的不带参数的构造方法来生成对象，我们有两种方式：
   a.先将获得Class对象，然后通过该Class对象的newInstance()方法直接生成即可：Class classType = String.class;Object obj = classType.newInstance();
   b.先获得Class对象，然后通过该对象获得对应的Constructor对象，
在通过该Constructor对象的newInstance()方法生成

package com.jelly.reflect;

import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

/**
 * JAVA反射技术
 *
 * @author Jelly QQ:136179492
 *
 */
public class ReflectTester {
    /**
     * 通过一个对象利用反射技术将其复制
     *
     * @param 参数object
     * @return 复制的Object对象
     * @throws Exception
     */
    public Object copy(Object object) throws Exception {
        Class classType = object.getClass();
        Object obj = classType.getConstructor(new Class[] {}).newInstance(
                new Object[] {});
        Field[] fields = classType.getDeclaredFields();
        for (Field field : fields) {
            String name = field.getName();
            String firstLetter = name.substring(0, 1).toUpperCase();
            String getMethodName = "get" + firstLetter + name.substring(1);
            String setMethodName = "set" + firstLetter + name.substring(1);
            Method getMethod = classType.getMethod(getMethodName,
                    new Class[] {});
            Method setMethod = classType.getMethod(setMethodName,
                    new Class[] { field.getType() });
            Object value = getMethod.invoke(object, new Object[] {});
            System.out.println(value);
            setMethod.invoke(obj, new Object[] { value });
        }
        return obj;
    }

    public static void main(String[] args) throws Exception,
            InvocationTargetException {
        ReflectTester test = new ReflectTester();
        Customer customer = new Customer("jelly", 23);
        Customer obj = (Customer) test.copy(customer);
        System.out.println(obj.getName() + obj.getAge());
    }
}

class Customer {
    public Customer() {

    }

    public Customer(String name, int age) {
        this.name = name;
        this.age = age;
    }

    private long id;
    private String name;
    private int age;

    public long getId() {
        return id;
    }

    public void setId(long id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }
}

package com.jelly.reflect; import java.lang.reflect.Field; import java.lang.reflect.InvocationTargetException; import java.lang.reflect.Method; /** * JAVA反射技术 * * @author Jelly QQ:136179492 * */ public class ReflectTester { /** * 通过一个对象利用反射技术将其复制 * * @param 参数object * @return 复制的Object对象 * @throws Exception */ public Object copy(Object object) throws Exception { Class classType = object.getClass(); Object obj = classType.getConstructor(new Class[] {}).newInstance( new Object[] {}); Field[] fields = classType.getDeclaredFields(); for (Field field : fields) { String name = field.getName(); String firstLetter = name.substring(0, 1).toUpperCase(); String getMethodName = "get" + firstLetter + name.substring(1); String setMethodName = "set" + firstLetter + name.substring(1); Method getMethod = classType.getMethod(getMethodName, new Class[] {}); Method setMethod = classType.getMethod(setMethodName, new Class[] { field.getType() }); Object value = getMethod.invoke(object, new Object[] {}); System.out.println(value); setMethod.invoke(obj, new Object[] { value }); } return obj; } public static void main(String[] args) throws Exception, InvocationTargetException { ReflectTester test = new ReflectTester(); Customer customer = new Customer("jelly", 23); Customer obj = (Customer) test.copy(customer); System.out.println(obj.getName() + obj.getAge()); } } class Customer { public Customer() { } public Customer(String name, int age) { this.name = name; this.age = age; } private long id; private String name; private int age; public long getId() { return id; } public void setId(long id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public int getAge() { return age; } public void setAge(int age) { this.age = age; } }