语言与可复用性

package com.qinshuq.zk.study;

import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.List;

public class GettingFieldValues {
    
    public static void main(String[] args) {
        printAllNamesAndAges();
        printAllNamesAndAges2();
    }
    
    public static void printAllNamesAndAges() {
        // Get all ages of persons
        List<Person> persons = createPersons();
        List<Integer> ages = new ArrayList<Integer>();
        for (Person p: persons) {
            ages.add(p.getAge());
        }
        System.out.println(ages);
        
        // Get all name of cats
        List<Cat> cats = createCats();
        List<String> names = new ArrayList<String>();
        for (Cat c: cats) {
            names.add(c.getName());
        }
        System.out.println(names);
    }
    
    public static void printAllNamesAndAges2() {
        List<Person> persons = createPersons();
        List<Cat> cats = createCats();
        System.out.println(getAllFieldValues(persons, Person.class, "age"));
        System.out.println(getAllFieldValues(cats, Cat.class, "name"));
    }
    
    private static <T> List<Object> getAllFieldValues(List<T> objList,  Class c, String objFieldName) {
        List<Object> values = new ArrayList<Object>(); 
        try {
            for (Object obj: objList) {
                Field f = null;
                f = c.getDeclaredField(objFieldName);
                f.setAccessible(true);
                values.add(f.get(obj));
                f.setAccessible(false);
            }
            return values;
        } catch (SecurityException e) {
            return new ArrayList<Object>();
        } catch (NoSuchFieldException e) {
            return new ArrayList<Object>();
        } catch (IllegalArgumentException e) {
            return new ArrayList<Object>();
        } catch (IllegalAccessException e) {
            return new ArrayList<Object>();
        }
                
    }

    public static List<Person> createPersons() {
        List<Person> persons = new ArrayList<Person>();
        persons.add(new Person("qin", 30));
        persons.add(new Person("shu",29));
        return persons;
    }
    
    public static List<Cat> createCats() {
        List<Cat> cats = new ArrayList<Cat>();
        cats.add(new Cat("mimi", 2));
        cats.add(new Cat("nini", 1));
        return cats;
    }

}


class Person {
    
    private String name;
    private int    age;
    
    public Person(String name, int age) {
        this.name = name;
        this.age = age;
    }
    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;
    }
    
}

class Cat {
    private String name;
    private int    years;
    
    public Cat(String name, int years) {
        this.name = name;
        this.years = years;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public int getYears() {
        return years;
    }
    public void setYears(int years) {
        this.years = years;
    }
}

#!/usr/bin/env python
# -*- coding: utf-8 -*-
# -------------------------------------------------------------------------------
# Name:     GetSpecFieldValues.py   
# Purpose:  extract all values from specified field of object in a list.    
#            
# Author:   qin.shuq  
#
# Created:  2015-03-12
#-------------------------------------------------------------------------------

def getSpecFieldValues(objlist, fieldName):
    return map(lambda obj: obj.__dict__[fieldName], objlist)

class Person(object):
    def __init__(self, name, age):
        self.name = name
        self.age = age

class Cat(object):
    def __init__(self, name, years):
        self.name = name
        self.years = years

if __name__ == ‘__main__‘:
    
    persons = [Person(‘qin‘, 30), Person(‘shu‘, 29)]
    cats = [Cat(‘mimi‘, 2), Cat(‘nini‘, 1)]
    print  getSpecFieldValues(persons, ‘age‘)
    print  getSpecFieldValues(cats, ‘name‘)