javax.servlet.Filter可以通过Autowired获取bean么

在Spring框架中，`javax.servlet.Filter`并不是Spring直接管理的对象，因为Servlet容器如Tomcat负责处理Filter。然而，如果你将Filter作为Spring应用的一部分并将其配置为Spring Bean，那么你可以利用Spring的@Autowired注解来自动注入依赖的Bean。

例如，你在Filter中声明一个字段，并添加@Autowired注解，Spring会尝试找到并注入相应的Bean。但这通常适用于那些实现了ApplicationContextAware接口的Filter，以便它们能自行设置ApplicationContext。在这种情况下，你需要保证Filter能够在初始化阶段访问到Spring的ApplicationContext。

public class MyFilter implements Filter, ApplicationContextAware {
    private static ApplicationContext context;

    @Autowired
    private SomeService service; // 假设SomeService是你想要注入的Bean

    // ...
}

相关问题

import org.springframework.beans.factory.annotation.Autowired; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; import org.springframework.http.HttpMethod; import org.springframework.security.config.annotation.web.builders.HttpSecurity; import org.springframework.security.config.annotation.web.builders.WebSecurity; import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity; import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter; import org.springframework.security.crypto.bcrypt.BCryptPasswordEncoder; import org.springframework.security.crypto.password.PasswordEncoder; import org.springframework.security.web.authentication.UsernamePasswordAuthenticationFilter; @Configuration @EnableWebSecurity public class SecurityConfig extends WebSecurityConfigurerAdapter { @Bean public JwtTokenProvider jwtTokenProvider() { return new JwtTokenProvider(); } @Autowired private JwtTokenProvider jwtTokenProvider; @Override protected void configure(HttpSecurity http) throws Exception { http.csrf().disable() .addFilterBefore(new JwtTokenFilter(jwtTokenProvider), UsernamePasswordAuthenticationFilter.class) .authorizeRequests() .antMatchers("/api/**").authenticated() .anyRequest().permitAll(); } @Override public void configure(WebSecurity web) throws Exception { web.ignoring().antMatchers(HttpMethod.OPTIONS, "/**"); } @Bean public PasswordEncoder passwordEncoder() { return new BCryptPasswordEncoder(12); } }请根据上述代码构建一个JwtTokenFilter类，让上述代码不报错

可以按照以下方式编写JwtTokenFilter类：

import org.springframework.security.authentication.UsernamePasswordAuthenticationToken;
import org.springframework.security.core.context.SecurityContextHolder;
import org.springframework.security.core.userdetails.UserDetails;
import org.springframework.security.core.userdetails.UserDetailsService;
import org.springframework.web.filter.OncePerRequestFilter;
import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

public class JwtTokenFilter extends OncePerRequestFilter {

    private final JwtTokenProvider jwtTokenProvider;
    private final UserDetailsService userDetailsService;

    public JwtTokenFilter(JwtTokenProvider jwtTokenProvider, UserDetailsService userDetailsService) {
        this.jwtTokenProvider = jwtTokenProvider;
        this.userDetailsService = userDetailsService;
    }

    @Override
    protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain) throws ServletException, IOException {
        String token = jwtTokenProvider.resolveToken(request);
        if (token != null && jwtTokenProvider.validateToken(token)) {
            UserDetails userDetails = userDetailsService.loadUserByUsername(jwtTokenProvider.getUsername(token));
            UsernamePasswordAuthenticationToken auth = new UsernamePasswordAuthenticationToken(userDetails, null, userDetails.getAuthorities());
            SecurityContextHolder.getContext().setAuthentication(auth);
        }
        filterChain.doFilter(request, response);
    }
}

在此JwtTokenFilter类中，我们注入了JwtTokenProvider和UserDetailsService，其中JwtTokenProvider用于解析和验证JWT令牌，UserDetailsService用于获取用户详细信息。在doFilterInternal方法中，我们首先从请求中获取JWT令牌并验证其是否有效。如果令牌有效，我们使用UserDetailsService加载用户详细信息，并创建一个UsernamePasswordAuthenticationToken对象，将其设置为安全上下文的认证对象。最后，我们调用filterChain.doFilter方法继续处理请求。

用idea写 用两种方式整合SSM框架 要求：1.以纯注解的方式整合SSM框架

好的，以下是两种方式整合SSM框架的步骤：

## 1. 整合SSM框架方式一（纯注解方式）

### 1.1 创建Maven项目

在IDEA中创建一个Maven项目，选择Web应用程序类型。

### 1.2 导入SSM框架依赖

在pom.xml文件中添加以下依赖：

<!-- Spring框架 -->
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-context</artifactId>
    <version>5.3.8</version>
</dependency>

<!-- Spring MVC框架 -->
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-webmvc</artifactId>
    <version>5.3.8</version>
</dependency>

<!-- MyBatis框架 -->
<dependency>
    <groupId>org.mybatis</groupId>
    <artifactId>mybatis</artifactId>
    <version>3.5.7</version>
</dependency>

<!-- MyBatis-Spring框架 -->
<dependency>
    <groupId>org.mybatis</groupId>
    <artifactId>mybatis-spring</artifactId>
    <version>2.0.7</version>
</dependency>

<!-- 数据库驱动 -->
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>8.0.25</version>
</dependency>

<!-- Servlet API -->
<dependency>
    <groupId>javax.servlet</groupId>
    <artifactId>javax.servlet-api</artifactId>
    <version>4.0.1</version>
    <scope>provided</scope>
</dependency>

<!-- JSP API -->
<dependency>
    <groupId>javax.servlet.jsp</groupId>
    <artifactId>javax.servlet.jsp-api</artifactId>
    <version>2.3.3</version>
    <scope>provided</scope>
</dependency>

<!-- JSTL标签库 -->
<dependency>
    <groupId>javax.servlet</groupId>
    <artifactId>jstl</artifactId>
    <version>1.2</version>
</dependency>

### 1.3 配置web.xml文件

在src/main/webapp/WEB-INF目录下创建web.xml文件，并添加以下配置：

<!-- 配置DispatcherServlet -->
<servlet>
    <servlet-name>dispatcherServlet</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    <!-- 配置SpringMVC的配置文件 -->
    <init-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>classpath:spring-mvc.xml</param-value>
    </init-param>
    <load-on-startup>1</load-on-startup>
</servlet>

<!-- 配置DispatcherServlet映射 -->
<servlet-mapping>
    <servlet-name>dispatcherServlet</servlet-name>
    <url-pattern>/</url-pattern>
</servlet-mapping>

<!-- 配置字符集过滤器 -->
<filter>
    <filter-name>characterEncodingFilter</filter-name>
    <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
    <init-param>
        <param-name>encoding</param-name>
        <param-value>UTF-8</param-value>
    </init-param>
</filter>
<filter-mapping>
    <filter-name>characterEncodingFilter</filter-name>
    <url-pattern>/*</url-pattern>
</filter-mapping>

### 1.4 配置Spring配置文件

在src/main/resources目录下创建spring-context.xml文件，并添加以下配置：

<!-- 配置数据源 -->
<bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
    <property name="driverClassName" value="com.mysql.cj.jdbc.Driver"/>
    <property name="url" value="jdbc:mysql://localhost:3306/test?serverTimezone=Asia/Shanghai&amp;useUnicode=true&amp;characterEncoding=utf8&amp;useSSL=false"/>
    <property name="username" value="root"/>
    <property name="password" value="123456"/>
</bean>

<!-- 配置MyBatis -->
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
    <property name="dataSource" ref="dataSource"/>
    <property name="typeAliasesPackage" value="com.example.demo.entity"/> <!-- 指定实体类路径 -->
    <property name="mapperLocations" value="classpath:mapper/*.xml"/> <!-- 指定Mapper映射文件路径 -->
</bean>

<!-- 配置Mapper扫描器 -->
<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
    <property name="basePackage" value="com.example.demo.mapper"/> <!-- 指定Mapper接口所在的包 -->
</bean>

### 1.5 配置SpringMVC配置文件

在src/main/resources目录下创建spring-mvc.xml文件，并添加以下配置：

<!-- 配置视图解析器 -->
<bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
    <property name="prefix" value="/WEB-INF/views/"/>
    <property name="suffix" value=".jsp"/>
</bean>

<!-- 配置静态资源映射 -->
<mvc:resources mapping="/static/**" location="/static/"/>

<!-- 配置扫描Controller -->
<context:component-scan base-package="com.example.demo.controller"/>

### 1.6 编写Controller

在src/main/java目录下创建com.example.demo.controller包，并在该包下创建UserController.java文件，编写以下代码：

package com.example.demo.controller;

import com.example.demo.entity.User;
import com.example.demo.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.*;

import java.util.List;

@Controller
@RequestMapping("/user")
public class UserController {

    @Autowired
    private UserService userService;

    @GetMapping("/list")
    public String list(Model model) {
        List<User> userList = userService.findAll();
        model.addAttribute("userList", userList);
        return "user/list";
    }

    @GetMapping("/add")
    public String add() {
        return "user/add";
    }

    @PostMapping("/save")
    public String save(User user) {
        userService.save(user);
        return "redirect:/user/list";
    }

    @GetMapping("/edit/{id}")
    public String edit(@PathVariable("id") Long id, Model model) {
        User user = userService.findById(id);
        model.addAttribute("user", user);
        return "user/edit";
    }

    @PostMapping("/update")
    public String update(User user) {
        userService.update(user);
        return "redirect:/user/list";
    }

    @GetMapping("/delete/{id}")
    public String delete(@PathVariable("id") Long id) {
        userService.delete(id);
        return "redirect:/user/list";
    }
}

### 1.7 编写Service

在src/main/java目录下创建com.example.demo.service包，并在该包下创建UserService.java文件，编写以下代码：

package com.example.demo.service;

import com.example.demo.entity.User;

import java.util.List;

public interface UserService {

    List<User> findAll();

    User findById(Long id);

    void save(User user);

    void update(User user);

    void delete(Long id);
}

在com.example.demo.service包下创建UserServiceImpl.java文件，编写以下代码：

package com.example.demo.service.impl;

import com.example.demo.entity.User;
import com.example.demo.mapper.UserMapper;
import com.example.demo.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

@Service
public class UserServiceImpl implements UserService {

    @Autowired
    private UserMapper userMapper;

    @Override
    public List<User> findAll() {
        return userMapper.findAll();
    }

    @Override
    public User findById(Long id) {
        return userMapper.findById(id);
    }

    @Override
    public void save(User user) {
        userMapper.save(user);
    }

    @Override
    public void update(User user) {
        userMapper.update(user);
    }

    @Override
    public void delete(Long id) {
        userMapper.delete(id);
    }
}

### 1.8 编写Mapper

在src/main/java目录下创建com.example.demo.mapper包，并在该包下创建UserMapper.java文件，编写以下代码：

package com.example.demo.mapper;

import com.example.demo.entity.User;

import java.util.List;

public interface UserMapper {

    List<User> findAll();

    User findById(Long id);

    void save(User user);

    void update(User user);

    void delete(Long id);
}

在com.example.demo.mapper包下创建UserMapper.xml文件，编写以下代码：

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.example.demo.mapper.UserMapper">

    <resultMap id="userMap" type="com.example.demo.entity.User">
        <id column="id" property="id"/>
        <result column="username" property="username"/>
        <result column="password" property="password"/>
        <result column="age" property="age"/>
    </resultMap>

    <select id="findAll" resultMap="userMap">
        SELECT * FROM user
    </select>

    <select id="findById" resultMap="userMap">
        SELECT * FROM user WHERE id = #{id}
    </select>

    <insert id="save">
        INSERT INTO user(username, password, age) VALUES(#{username}, #{password}, #{age})
    </insert>

    <update id="update">
        UPDATE user SET username = #{username}, password = #{password}, age = #{age} WHERE id = #{id}
    </update>

    <delete id="delete">
        DELETE FROM user WHERE id = #{id}
    </delete>

</mapper>

### 1.9 编写JSP页面

在src/main/webapp/WEB-INF/views/user目录下创建list.jsp、add.jsp和edit.jsp文件，编写以下代码：

list.jsp：

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <title>User List</title>
</head>
<body>
<h1>User List</h1>
<table border="1">
    <tr>
        <th>ID</th>
        <th>Username</th>
        <th>Password</th>
        <th>Age</th>
        <th>Actions</th>
    </tr>
    <c:forEach var="user" items="${userList}">
        <tr>
            <td>${user.id}</td>
            <td>${user.username}</td>
            <td>${user.password}</td>
            <td>${user.age}</td>
            <td>
                <a href="/user/edit/${user.id}">Edit</a>
                <a href="/user/delete/${user.id}">Delete</a>
            </td>
        </tr>
    </c:forEach>
</table>
<br>
<a href="/user/add">Add User</a>
</body>
</html>

add.jsp：

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <title>Add User</title>
</head>
<body>
<h1>Add User</h1>
<form action="/user/save" method="post">
    <table>
        <tr>
            <td>Username:</td>
            <td><input type="text" name="username"></td>
        </tr>
        <tr>
            <td>Password:</td>
            <td><input type="password" name="password"></td>
        </tr>
        <tr>
            <td>Age:</td>
            <td><input type="number" name="age"></td>
        </tr>
        <tr>
            <td colspan="2"><input type="submit" value="Save"></td>
        </tr>
    </table>
</form>
</body>
</html>

edit.jsp：

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <title>Edit User</title>
</head>
<body>
<h1>Edit User</h1>
<form action="/user/update" method="post">
    <input type="hidden" name="id" value="${user.id}">
    <table>
        <tr>
            <td>Username:</td>
            <td><input type="text" name="username" value="${user.username}"></td>
        </tr>
        <tr>
            <td>Password:</td>
            <td><input type="password" name="password" value="${user.password}"></td>
        </tr>
        <tr>
            <td>Age:</td>
            <td><input type="number" name="age" value="${user.age}"></td>
        </tr>
        <tr>
            <td colspan="2"><input type="submit" value="Update"></td>
        </tr>
    </table>
</form>
</body>
</html>

### 1.10 启动应用

在IDEA中启动应用，访问http://localhost:8080/user/list即可查看用户列表。

## 2. 整合SSM框架方式二（Java配置方式）

### 2.1 创建Maven项目

在IDEA中创建一个Maven项目，选择Web应用程序类型。

### 2.2 导入SSM框架依赖

详见方式一。

### 2.3 配置WebInitializer

在src/main/java目录下创建com.example.demo.config包，并在该包下创建WebInitializer.java文件，编写以下代码：

package com.example.demo.config;

import org.springframework.web.servlet.support.AbstractAnnotationConfigDispatcherServletInitializer;

public class WebInitializer extends AbstractAnnotationConfigDispatcherServletInitializer {

    @Override
    protected Class<?>[] getRootConfigClasses() {
        return new Class[]{};
    }

    @Override
    protected Class<?>[] getServletConfigClasses() {
        return new Class[]{WebConfig.class};
    }

    @Override
    protected String[] getServletMappings() {
        return new String[]{"/"};
    }
}

### 2.4 配置WebConfig

在src/main/java目录下创建com.example.demo.config包，并在该包下创建WebConfig.java文件，编写以下代码：

package com.example.demo.config;

import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.PropertySource;
import org.springframework.core.env.Environment;
import org.springframework.jdbc.datasource.DriverManagerDataSource;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
import org.springframework.web.servlet.config.annotation.ViewResolverRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;

import javax.sql.DataSource;

@Configuration
@EnableWebMvc
@ComponentScan(basePackages = "com.example.demo.controller")
@MapperScan(basePackages = "com.example.demo.mapper")
@PropertySource("classpath:jdbc.properties")
public class WebConfig implements WebMvcConfigurer {

    @Autowired
    private Environment env;

    @Override
    public void configureViewResolvers(ViewResolverRegistry registry) {
        registry.jsp("/WEB-INF/views/", ".jsp");
    }

    @Override
    public void addResourceHandlers(ResourceHandlerRegistry registry) {
        registry.addResourceHandler("/static/**").addResourceLocations("/static/");
    }

    @Bean
    public DataSource dataSource() {
        DriverManagerDataSource dataSource = new DriverManagerDataSource();
        dataSource.setDriverClassName(env.getProperty("jdbc.driverClassName"));
        dataSource.setUrl(env.getProperty("jdbc.url"));
        dataSource.setUsername(env.getProperty("jdbc.username"));
        dataSource.setPassword(env.getProperty("jdbc.password"));
        return dataSource;
    }

    @Bean
    public SqlSessionFactory sqlSessionFactory() throws Exception {
        SqlSessionFactoryBean sessionFactory = new SqlSessionFactoryBean();
        sessionFactory.setDataSource(dataSource());
        return sessionFactory.getObject();
    }
}

### 2.5 配置jdbc.properties

在src/main/resources目录下创建jdbc.properties文件，编写以下代码：

jdbc.driverClassName=com.mysql.cj.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/test?serverTimezone=Asia/Shanghai&useUnicode=true&characterEncoding=utf8&useSSL=false
jdbc.username=root
jdbc.password=123456

### 2.6 编写Controller

详见方式一。

### 2.7 编写Service

详见方式一。

### 2.8 编写Mapper

详见方式一。

### 2.9 编写JSP页面

详见方式一。

### 2.10 启动应用

详见方式一。