list列表中添加多个【只修改了一个属性的对象】

要添加一个objectBean对象到list中，不能使用对象A=对象B，这样的话完全使对象A的指针指向了B，他们表示的是一个区域了。添加到list中是以最后一个为准。下面是正确的代码。红色标记的是需要特别注意的地方。

package TestListObject;

import java.util.Date;

public class ObjectBean {
private String name;
private String sex;
private Date birthday;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getSex() {
return sex;
}
public void setSex(String sex) {
this.sex = sex;
}
public Date getBirthday() {
return birthday;
}
public void setBirthday(Date birthday) {
this.birthday = birthday;
}

}

package TestListObject;

import java.util.ArrayList;
import java.util.Date;
import java.util.List;

public class TestList {
public static void main(String[] args) {
ObjectBean ob = new ObjectBean();
ob.setName("liu");
ob.setSex("女");
ob.setBirthday(new Date());

List<ObjectBean> beanlist = new ArrayList<ObjectBean>();
beanlist.add(ob);
for (int i = 0; i < 3; i++) {
ObjectBean bean = new ObjectBean();
bean.setBirthday(new Date(ob.getBirthday().getTime()+2*i*3600*1000));
bean.setName(ob.getName());
bean.setSex(ob.getSex()+i);
beanlist.add(bean);
}
for (ObjectBean objectBean : beanlist) {
System.out.println(objectBean.getBirthday()+objectBean.getSex());
}
}
}

package TestListObject;

import java.util.ArrayList;
import java.util.Date;
import java.util.List;

public class TestList {
public static void main(String[] args) {
ObjectBean ob = new ObjectBean();
ob.setName("liu");
ob.setSex("女");
ob.setBirthday(new Date());
System.out.println(ob.getBirthday());
ObjectBean bean = new ObjectBean();
bean = ob;
List<ObjectBean> beanlist = new ArrayList<ObjectBean>();
for (int i = 0; i < 3; i++) {
bean.getBirthday().setHours(ob.getBirthday().getHours()+2);
System.out.println(bean.getBirthday());
ObjectBean bean2 = new ObjectBean();
bean2 = bean;
beanlist.add(bean2);
}
}
}