package com.ourchr.bookstore.dao;

package com.ourchr.bookstore.dao;

import java.io.*;

public class BaseDAO {

/**

* 存入文件信息

* @param obj

* @param filename

*/

public static void saveObjectToFile(Object obj, String filename) {

try {

ObjectOutputStream os = new ObjectOutputStream(

new FileOutputStream(filename));

os.writeObject(obj);

os.flush();

os.close();

} catch (Exception e) {

e.printStackTrace();

System.out.println("出现异常！");

}

}

/**

* 读取文件信息

* @param filename

* @return

*/

public Object loadObjectFromFile(String filename) {

try {

File file = new File(filename);

if(! file.exists()) {

return null;

}

ObjectInputStream os = new ObjectInputStream(

new FileInputStream(filename));

Object obj = os.readObject();

os.close();

return obj;

} catch (Exception e) {

e.printStackTrace();

System.out.println("出现异常！");

}

return null;

}

}

package com.ourchr.bookstore.dao;

import com.ourchr.bookstore.info.Book;

import java.util.*;

public class BookDAO extends BaseDAO {

private static BookDAO book;

private static final String BOOK_FILE = "book.dat";

private Map<String, Book> bookMap;

@SuppressWarnings("unchecked")

private BookDAO() {

Object obj = this.loadObjectFromFile(BOOK_FILE);

if(obj == null) {

bookMap = new HashMap<String, Book>();

} else {

bookMap = (HashMap<String, Book>)obj;

}

}

/**

* 添加图书

* @param book

*/

public void addBook(Book book) {

bookMap.put(book.getCode(), book);

}

/**

* 删除图书

* @param book

*/

public void removeBook(Book book) {

bookMap.remove(book.getCode());

}

/**

* 查找所有图书

* @return 返回Map<String,Book>

*/

public Map<String, Book> findAllBooks() {

return bookMap;

}

/**

* 查找指定图书信息

* @param code

* @return bookMap.get(code)

*/

public Book findBooksByCode(String code) {

return bookMap.get(code);

}

public static BookDAO getUs() {

if(book == null) {

book = new BookDAO();

}

return book;

}

@SuppressWarnings("static-access")

public void saveBookDat() {

this.saveObjectToFile(bookMap, BOOK_FILE);

}

}

package com.ourchr.bookstore.dao;

import java.util.*;

import com.ourchr.bookstore.info.User;

public class userDAO extends BaseDAO {

private static final String USER_FILE = "Jan.dat";

private static userDAO us = null;

private List<User> userList = new LinkedList<User>();

/**

* 构造函数

*/

@SuppressWarnings("unchecked")

private userDAO() {

Object obj = this.loadObjectFromFile(USER_FILE);

if (obj == null) {

User admin = new User();

admin.setCode("admin");

admin.setPassword("pass");

admin.setName("超级管理员");

admin.setType(User.ADMIN_USER);

userList.add(admin);

} else {

userList = (LinkedList<User>) this.loadObjectFromFile(USER_FILE);

}

}

/**

* userDAO最多只能被调用一次

* 

* @return us

*/

public static userDAO getUs() {

if (us == null) {

us = new userDAO();

}

return us;

}

/**

* 添加读者

* 

* @param user

*/

public void addUser(User user) {

userList.add(user);

}

/**

* 删除读者

* 

* @param user

*/

public void removeUser(User user) {

for (int i = 0; i < userList.size(); i++) {

User u = userList.get(i);

if (u.getCode().equals(user.getCode())) {

userList.remove(i);

return;

}

}

}

/**

* 查找读者

* 

* @param code

* @return 找到则返回 user，否则返回null

*/

public User findUserByCode(String code) {

for (int i = 0; i < userList.size(); i++) {

User user = userList.get(i);

if (user.getCode().equals(code)) {

return user;

}

}

return null;

}

/**

* 保存信息

*/

@SuppressWarnings("static-access")

public void saveUserDat() {

this.saveObjectToFile(userList, USER_FILE);

}

}