子类共享父类的数据

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


public class TeacherAnswer extends StudentPaper {

	private String teacherAnswer;//老师给的答案

	public String getTeacherAnswer() {
		return teacherAnswer;
	}
	public void setTeacherAnswer(String teacherAnswer) {
		this.teacherAnswer = teacherAnswer;
	}




	public void fatherToChild (Object father,Object child)throws Exception{  
        if(!(child.getClass().getSuperclass()==father.getClass())){  
            throw new Exception("child不是father的子类");  
        }  
        Class fatherClass= father.getClass();  
        Field ff[]= fatherClass.getDeclaredFields();  
        for(int i=0;i<ff.length;i++){  
            Field f=ff[i];//取出每一个属性，如deleteDate  
            Class type=f.getType();  
            Method m=fatherClass.getMethod("get"+upperHeadChar(f.getName()));//方法getDeleteDate  
            Object obj=m.invoke(father);//取出属性值               
            f.set(child,obj);  
        }  
    }  

	private String upperHeadChar(String in){  
        String head=in.substring(0,1);  
        String out=head.toUpperCase()+in.substring(1,in.length());  
        return out;  
    }  



}

public class StudentPaper {
//父类的member 成员变量应该protected 不应该是private
	protected String studentanswer;


	public String getStudentanswer() {
		return studentanswer;
	}

	public void setStudentanswer(String studentanswer) {
		this.studentanswer = studentanswer;
	}


}

public class StudentPaper {

	private String studentanswer;


	public String getStudentanswer() {
		return studentanswer;
	}

	public void setStudentanswer(String studentanswer) {
		this.studentanswer = studentanswer;
	}


}

public static void main(String[] args) throws Exception {
                         StudentPaper s = new StudentPaper();
                         s.setStudentanswer("学员的回答");
							Answer a = new Answer();
							a.fatherToChild(s,a);
							System.out.println(a.toString());

	}