巴中建设银行网站,wordpress访问不了,WordPress免签约支付插件,动漫网站开发 sh框架Java一一一简易图书管理系统
1. 需求分析
功能需求#xff1a; 添加图书删除图书更新图书信息查询图书列出所有图书
2. 设计
实体类#xff1a;Book业务逻辑类#xff1a;LibraryManager
3. 实现
3.1 Book类
public class Book {private String id;private String t…Java一一一简易图书管理系统
1. 需求分析
功能需求 添加图书删除图书更新图书信息查询图书列出所有图书
2. 设计
实体类Book业务逻辑类LibraryManager
3. 实现
3.1 Book类
public class Book {private String id;private String title;private String author;private int year;public Book(String id, String title, String author, int year) {this.id id;this.title title;this.author author;this.year year;}// Getters and Setterspublic String getId() {return id;}public void setId(String id) {this.id id;}public String getTitle() {return title;}public void setTitle(String title) {this.title title;}public String getAuthor() {return author;}public void setAuthor(String author) {this.author author;}public int getYear() {return year;}public void setYear(int year) {this.year year;}Overridepublic String toString() {return Book{ id id \ , title title \ , author author \ , year year };}
}3.2 LibraryManager类
import java.util.ArrayList;
import java.util.List;
import java.util.stream.Collectors;public class LibraryManager {private ListBook books;public LibraryManager() {this.books new ArrayList();}public void addBook(Book book) {books.add(book);}public boolean removeBook(String id) {return books.removeIf(book - book.getId().equals(id));}public void updateBook(String id, Book updatedBook) {Book book books.stream().filter(b - b.getId().equals(id)).findFirst().orElse(null);if (book ! null) {book.setTitle(updatedBook.getTitle());book.setAuthor(updatedBook.getAuthor());book.setYear(updatedBook.getYear());}}public ListBook searchBooksByTitle(String title) {return books.stream().filter(book - book.getTitle().contains(title)).collect(Collectors.toList());}public ListBook getAllBooks() {return new ArrayList(books);}
}4. 测试
public class Main {public static void main(String[] args) {LibraryManager manager new LibraryManager();// 添加图书manager.addBook(new Book(1, Java Basics, John Doe, 2021));manager.addBook(new Book(2, Advanced Java, Jane Doe, 2022));// 列出所有图书System.out.println(All Books:);manager.getAllBooks().forEach(System.out::println);// 更新图书Book updatedBook new Book(1, Java Fundamentals, John Doe, 2021);manager.updateBook(1, updatedBook);// 搜索图书System.out.println(Search Results:);manager.searchBooksByTitle(Java).forEach(System.out::println);// 删除图书manager.removeBook(2);// 再次列出所有图书System.out.println(All Books after removal:);manager.getAllBooks().forEach(System.out::println);}
}5. 总结
这个简易的图书管理系统展示了Java在面向对象编程中的基本应用包括类的定义、方法的实现以及简单的集合操作。通过这个案例初学者可以学习到如何使用Java创建和管理对象集合以及如何实现简单的业务逻辑。
请注意这只是一个基础示例实际应用中可能需要考虑更多的功能和异常处理以及与数据库的交互等。
案例名称基于Spring Boot的RESTful图书管理系统
1. 环境准备
Java 11 或更高版本Spring Boot 2.5.x 或更高版本Maven 或 Gradle 作为构建工具一个文本编辑器或IDE如IntelliJ IDEA或Eclipse
2. 项目结构
src/
|-- main/
| |-- java/
| | -- com.example.bookstore/
| | |-- BookController.java
| | |-- BookService.java
| | -- Book.java
| -- resources/
| -- application.properties3. 实现步骤
3.1 创建Spring Boot项目
使用Spring Initializr来生成项目基础结构。
3.2 添加依赖
在pom.xmlMaven或build.gradleGradle中添加Web和JPA依赖。
pom.xml 示例:
dependenciesdependencygroupIdorg.springframework.boot/groupIdartifactIdspring-boot-starter-web/artifactId/dependencydependencygroupIdorg.springframework.boot/groupIdartifactIdspring-boot-starter-data-jpa/artifactId/dependencydependencygroupIdcom.h2database/groupIdartifactIdh2/artifactIdscoperuntime/scope/dependency
/dependencies3.3 Book实体类
package com.example.bookstore;import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;Entity
public class Book {IdGeneratedValue(strategy GenerationType.IDENTITY)private Long id;private String title;private String author;private int publishYear;// Constructors, getters and setters
}3.4 BookRepository接口
package com.example.bookstore;import org.springframework.data.jpa.repository.JpaRepository;public interface BookRepository extends JpaRepositoryBook, Long {
}3.5 BookService业务逻辑类
package com.example.bookstore;import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import java.util.List;
import java.util.Optional;Service
public class BookService {Autowiredprivate BookRepository bookRepository;public ListBook getAllBooks() {return bookRepository.findAll();}public Book getBookById(Long id) {return bookRepository.findById(id).orElse(null);}public Book addBook(Book book) {return bookRepository.save(book);}public Book updateBook(Long id, Book updatedBook) {OptionalBook bookOptional bookRepository.findById(id);if (bookOptional.isPresent()) {Book book bookOptional.get();book.setTitle(updatedBook.getTitle());book.setAuthor(updatedBook.getAuthor());book.setPublishYear(updatedBook.getPublishYear());return bookRepository.save(book);}return null;}public void deleteBook(Long id) {bookRepository.deleteById(id);}
}3.6 BookController控制器
package com.example.bookstore;import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.*;import java.util.List;RestController
RequestMapping(/api/books)
public class BookController {Autowiredprivate BookService bookService;GetMappingpublic ListBook getAllBooks() {return bookService.getAllBooks();}GetMapping(/{id})public ResponseEntityBook getBookById(PathVariable Long id) {Book book bookService.getBookById(id);return book ! null ? ResponseEntity.ok(book) : ResponseEntity.notFound().build();}PostMappingpublic Book addBook(RequestBody Book book) {return bookService.addBook(book);}PutMapping(/{id})public ResponseEntityBook updateBook(PathVariable Long id, RequestBody Book updatedBook) {Book book bookService.updateBook(id, updatedBook);return book ! null ? ResponseEntity.ok(book) : ResponseEntity.notFound().build();}DeleteMapping(/{id})public ResponseEntityVoid deleteBook(PathVariable Long id) {bookService.deleteBook(id);return ResponseEntity.ok().build();}
}3.7 配置文件application.properties
spring.datasource.urljdbc:h2:mem:testdb
spring.datasource.driverClassNameorg.h2.Driver
spring.datasource.usernamesa
spring.datasource.password
spring.jpa.database-platformorg.hibernate.dialect.H2Dialectspring.h2.console.enabledtrue4. 运行和测试
使用您喜欢的IDE运行main方法或使用Maven/Gradle命令来启动Spring Boot应用。使用Postman或curl命令行工具来测试API。
5. 总结
这个案例展示了如何使用Spring Boot创建一个简单的RESTful API它提供了基本的CRUD操作。通过这个案例您可以学习到Spring Boot的核心概念如依赖注入、服务层、数据访问层以及RESTful API设计。
这个示例使用了内存数据库H2适合开发和测试但在生产环境中您应该使用更健壮的数据库解决方案并考虑安全性、异常处理和日志记录等因素。
接下来我们将在图书管理系统中增加一个新功能用户认证和授权。我们将使用Spring Security来实现这一功能确保只有认证用户可以访问敏感数据和执行特定操作。
带有用户认证和授权的图书管理系统
1. 添加Spring Security依赖
首先需要在项目的pom.xmlMaven或build.gradleGradle文件中添加Spring Security的依赖。
pom.xml 示例:
dependencies!-- ... other dependencies ... --dependencygroupIdorg.springframework.boot/groupIdartifactIdspring-boot-starter-security/artifactId/dependency
/dependencies2. 配置Spring Security
创建一个配置类来配置Spring Security。
package com.example.bookstore;import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.security.config.annotation.web.builders.HttpSecurity;
import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
import org.springframework.security.core.userdetails.User;
import org.springframework.security.core.userdetails.UserDetailsService;
import org.springframework.security.crypto.bcrypt.BCryptPasswordEncoder;
import org.springframework.security.crypto.password.PasswordEncoder;
import org.springframework.security.provisioning.InMemoryUserDetailsManager;Configuration
EnableWebSecurity
public class SecurityConfig {Beanpublic PasswordEncoder passwordEncoder() {return new BCryptPasswordEncoder();}Beanpublic UserDetailsService userDetailsService(PasswordEncoder encoder) {InMemoryUserDetailsManager manager new InMemoryUserDetailsManager();manager.createUser(User.withUsername(user).password(encoder.encode(password)).roles(USER).build());return manager;}Beanpublic HttpSecurity httpSecurity(UserDetailsService userDetailsService) throws Exception {return new HttpSecurity(http - http.authorizeRequests().antMatchers(/api/books/**).authenticated().and().httpBasic().and().csrf().disable());}
}3. 保护RESTful API
使用PreAuthorize注解来保护特定的API端点。
package com.example.bookstore;import org.springframework.security.access.prepost.PreAuthorize;
import org.springframework.web.bind.annotation.*;RestController
RequestMapping(/api/books)
public class BookController {// ... existing code ...PreAuthorize(hasRole(USER))DeleteMapping(/{id})public ResponseEntityVoid deleteBook(PathVariable Long id) {bookService.deleteBook(id);return ResponseEntity.ok().build();}
}4. 增加用户注册功能
创建一个用户注册的API端点。
// ... existing imports ...RestController
RequestMapping(/api/auth)
public class AuthController {private final UserService userService;public AuthController(UserService userService) {this.userService userService;}PostMapping(/register)public ResponseEntity? registerUser(RequestBody UserRegistrationDto userRegistrationDto) {userService.registerUser(userRegistrationDto);return ResponseEntity.ok().build();}
}5. 用户注册服务和数据传输对象
创建UserService和UserRegistrationDto来处理用户注册。
package com.example.bookstore;// UserService.java
Service
public class UserService {private final UserRepository userRepository;private final PasswordEncoder passwordEncoder;Autowiredpublic UserService(UserRepository userRepository, PasswordEncoder passwordEncoder) {this.userRepository userRepository;this.passwordEncoder passwordEncoder;}public void registerUser(UserRegistrationDto userRegistrationDto) {User newUser new User(userRegistrationDto.getUsername(),passwordEncoder.encode(userRegistrationDto.getPassword()));userRepository.save(newUser);}
}// UserRegistrationDto.java
public class UserRegistrationDto {private String username;private String password;// Constructors, getters and setters
}6. 更新数据库配置
在application.properties或application.yml中添加用户表的配置。
# application.properties
spring.datasource.urljdbc:h2:mem:testdb;DB_CLOSE_DELAY-1;DB_CLOSE_ON_EXITFALSE
spring.datasource.driverClassNameorg.h2.Driver
spring.datasource.usernamesa
spring.datasource.passwordspring.jpa.database-platformorg.hibernate.dialect.H2Dialect
spring.jpa.hibernate.ddl-autoupdate# H2 console settings
spring.h2.console.enabledtrue
spring.h2.console.path/h2-console7. 测试和验证
启动应用程序并使用Postman或curl测试用户注册和认证保护的API。
8. 总结
通过增加用户认证和授权我们的图书管理系统变得更加安全。Spring Security提供了一套强大的安全工具可以轻松地集成到Spring Boot应用程序中。通过使用EnableWebSecurity注解和配置HttpSecurity我们可以控制对API端点的访问。此外PreAuthorize注解允许我们在方法级别细粒度地控制访问权限。
请注意本案例中的用户存储在内存中仅用于演示目的。在实际应用中您应该使用数据库来持久化用户信息并考虑使用JWT或OAuth2等更先进的认证机制。
接下来我们将在图书管理系统中增加一个新功能基于角色的访问控制RBAC。这将允许我们根据用户的角色限制对某些资源的访问。
基于角色的访问控制的图书管理系统
1. 扩展用户模型
首先我们需要扩展用户模型来包含角色信息。
package com.example.bookstore;import org.springframework.security.core.GrantedAuthority;
import org.springframework.security.core.authority.SimpleGrantedAuthority;import javax.persistence.*;
import java.util.Collection;
import java.util.stream.Collectors;Entity
public class User {IdGeneratedValue(strategy GenerationType.IDENTITY)private Long id;private String username;private String password;ManyToMany(fetch FetchType.EAGER)private SetRole roles;// Constructors, getters and setterspublic Collection? extends GrantedAuthority getAuthorities() {return roles.stream().map(role - new SimpleGrantedAuthority(role.getName())).collect(Collectors.toList());}
}2. 角色模型
创建一个角色模型来定义不同的角色。
package com.example.bookstore;Entity
public class Role {IdGeneratedValue(strategy GenerationType.IDENTITY)private Long id;private String name;// Constructors, getters and setters
}3. 用户角色关联
创建一个关联表来定义用户和角色之间的关系。
package com.example.bookstore;import javax.persistence.*;Entity
Table(name user_role)
public class UserRole {IdGeneratedValue(strategy GenerationType.IDENTITY)private Long id;ManyToOneJoinColumn(name user_id)private User user;ManyToOneJoinColumn(name role_id)private Role role;// Constructors, getters and setters
}4. 更新UserRepository
添加方法来查找用户及其角色。
package com.example.bookstore;import org.springframework.data.jpa.repository.JpaRepository;public interface UserRepository extends JpaRepositoryUser, Long {User findByUsername(String username);
}5. 更新Spring Security配置
更新SecurityConfig来使用自定义的UserDetailsService。
package com.example.bookstore;import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.security.core.userdetails.UserDetails;
import org.springframework.security.core.userdetails.UsernameNotFoundException;
import org.springframework.security.provisioning.UserDetailsManager;Configuration
EnableWebSecurity
public class SecurityConfig extends WebSecurityConfigurerAdapter {Autowiredprivate UserRepository userRepository;BeanOverridepublic UserDetailsService userDetailsService() {return new UserDetailsManager() {Overridepublic UserDetails loadUserByUsername(String username) throws UsernameNotFoundException {User user userRepository.findByUsername(username);if (user null) {throw new UsernameNotFoundException(User not found);}return user;}// Other methods are omitted for brevity};}// Other configurations are omitted for brevity
}6. 基于角色的访问控制
使用PreAuthorize或Secured注解来限制访问。
package com.example.bookstore;import org.springframework.security.access.prepost.PreAuthorize;RestController
RequestMapping(/api/books)
public class BookController {// ... existing code ...PreAuthorize(hasRole(ADMIN))PostMappingpublic Book addBook(RequestBody Book book) {return bookService.addBook(book);}PreAuthorize(hasRole(USER))GetMappingpublic ListBook getAllBooks() {return bookService.getAllBooks();}
}7. 用户角色管理
创建API端点来管理用户角色。
package com.example.bookstore;RestController
RequestMapping(/api/users)
public class UserController {private final UserService userService;Autowiredpublic UserController(UserService userService) {this.userService userService;}PostMapping(/{username}/roles)public ResponseEntity? addRoleToUser(PathVariable String username, RequestBody RoleRequestDto roleRequestDto) {userService.addRoleToUser(username, roleRequestDto.getRoleName());return ResponseEntity.ok().build();}
}// RoleRequestDto.java
public class RoleRequestDto {private String roleName;// Constructors, getters and setters
}8. 测试和验证
启动应用程序并使用Postman或curl测试基于角色的访问控制。
9. 总结
通过实现基于角色的访问控制我们的图书管理系统可以更细致地控制用户对资源的访问。这在多用户应用中尤为重要可以确保用户只能访问他们被授权的资源。
这个案例演示了如何在Spring Security中使用自定义的UserDetailsService来加载用户及其角色信息以及如何使用PreAuthorize注解来实现基于角色的访问控制。在实际应用中您可能还需要实现更复杂的用户和角色管理功能以及更细粒度的权限控制策略。
