Spring Security出现java: cannot find symbol错误求助

问题 #

运行Spring Boot应用时抛出java: cannot find symbol错误，核心提示找不到com.project.questapp.services.UserDetailsServiceImpl类，共出现8个错误，其中3个为此类找不到的错误。已检查报错类的路径未发现问题，单独执行pom.xml也正常。附上SecurityConfig代码及pom.xml配置，询问错误原因。

SecurityConfig代码 #

package com.project.questapp.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.HttpMethod;
import org.springframework.security.authentication.AuthenticationManager;
import org.springframework.security.config.annotation.authentication.configuration.AuthenticationConfiguration;
import org.springframework.security.config.annotation.web.builders.HttpSecurity;
import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
import org.springframework.security.config.http.SessionCreationPolicy;
import org.springframework.security.crypto.bcrypt.BCryptPasswordEncoder;
import org.springframework.security.crypto.password.PasswordEncoder;
import org.springframework.security.web.SecurityFilterChain;
import org.springframework.security.web.authentication.UsernamePasswordAuthenticationFilter;
import org.springframework.web.cors.CorsConfiguration;
import org.springframework.web.cors.UrlBasedCorsConfigurationSource;
import org.springframework.web.filter.CorsFilter;

import com.project.questapp.security.JwtAuthenticationEntryPoint; // 引发错误
import com.project.questapp.security.JwtAuthenticationFilter; // 引发错误
import com.project.questapp.services.UserDetailsServiceImpl; // 引发错误

@Configuration
@EnableWebSecurity
public class SecurityConfig{
    private UserDetailsServiceImpl userDetailsService;

    private JwtAuthenticationEntryPoint handler;

    public SecurityConfig(UserDetailsServiceImpl userDetailsService, JwtAuthenticationEntryPoint handler) {
        this.userDetailsService = userDetailsService;
        this.handler = handler;
    }

    @Bean
    public JwtAuthenticationFilter jwtAuthenticationFilter() {
        return new JwtAuthenticationFilter();
    }

    @Bean
    public PasswordEncoder passwordEncoder() {
        return new BCryptPasswordEncoder();
    }

    @Bean
    public AuthenticationManager authenticationManager(AuthenticationConfiguration authenticationConfiguration) throws Exception {
        return authenticationConfiguration.getAuthenticationManager();
    }

    @Bean
    public CorsFilter corsFilter() {
        UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
        CorsConfiguration config = new CorsConfiguration();
        config.setAllowCredentials(true);
        config.addAllowedOrigin("*");
        config.addAllowedHeader("*");
        config.addAllowedMethod("OPTIONS");
        config.addAllowedMethod("HEAD");
        config.addAllowedMethod("GET");
        config.addAllowedMethod("PUT");
        config.addAllowedMethod("POST");
        config.addAllowedMethod("DELETE");
        config.addAllowedMethod("PATCH");
        source.registerCorsConfiguration("/**", config);
        return new CorsFilter(source);
    }

    @Bean
    public SecurityFilterChain filterChain(HttpSecurity httpSecurity) throws Exception {
        httpSecurity
                .cors()
                .and()
                .csrf().disable()
                .exceptionHandling().authenticationEntryPoint(handler).and()
                .sessionManagement().sessionCreationPolicy(SessionCreationPolicy.STATELESS).and()
                .authorizeHttpRequests()
                .requestMatchers(HttpMethod.GET, "/posts")
                .permitAll()
                .requestMatchers(HttpMethod.GET, "/comments")
                .permitAll()
                .requestMatchers("/auth/**")
                .permitAll()
                .anyRequest().authenticated();

        httpSecurity.addFilterBefore(jwtAuthenticationFilter(), UsernamePasswordAuthenticationFilter.class);
        return httpSecurity.build();
    }
}

pom.xml配置 #

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>3.0.4</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.project</groupId>
    <artifactId>questapp</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>questapp</name>
    <description>QuestApp project for Spring Boot</description>
    <properties>
        <java.version>17</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-security</artifactId>
        </dependency>

        <dependency>
            <groupId>io.jsonwebtoken</groupId>
            <artifactId>jjwt</artifactId>
            <version>0.9.1</version>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>com.mysql</groupId>
            <artifactId>mysql-connector-j</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.security</groupId>
            <artifactId>spring-security-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <configuration>
                    <excludes>
                        <exclude>
                            <groupId>org.projectlombok</groupId>
                            <artifactId>lombok</artifactId>
                        </exclude>
                    </excludes>
                </configuration>
            </plugin>
        </plugins>
    </build>

</project>

可能的原因及解决办法 #

• 类未实际创建或路径拼写错误：确认UserDetailsServiceImpl、JwtAuthenticationEntryPoint、JwtAuthenticationFilter这几个类是否真的存在于对应包下，注意Java包名严格区分大小写，比如是否把services写成Services这类拼写失误。
• 编译缓存问题：执行mvn clean compile清理旧编译文件后重新编译，或者用IDE的Rebuild Project功能重新构建，旧缓存的编译结果可能导致类找不到的误报。
• 依赖版本不兼容：你用的Spring Boot 3.0.4基于Jakarta EE规范，但jjwt 0.9.1是适配旧Java EE的版本，两者存在兼容性冲突。建议替换jjwt依赖为兼容版本：

<dependency>
    <groupId>io.jsonwebtoken</groupId>
    <artifactId>jjwt-api</artifactId>
    <version>0.11.5</version>
</dependency>
<dependency>
    <groupId>io.jsonwebtoken</groupId>
    <artifactId>jjwt-impl</artifactId>
    <version>0.11.5</version>
    <scope>runtime</scope>
</dependency>
<dependency>
    <groupId>io.jsonwebtoken</groupId>
    <artifactId>jjwt-jackson</artifactId>
    <version>0.11.5</version>
    <scope>runtime</scope>
</dependency>

• IDE源码目录配置错误：检查IDE的项目结构，确保src/main/java被标记为Sources Root，如果被误标记为普通目录，IDE不会编译该目录下的类，导致找不到符号。
• 类未被Spring管理：确认UserDetailsServiceImpl、JwtAuthenticationEntryPoint这两个类是否添加了@Service、@Component等Spring注解，只有被Spring扫描到的类才能被注入，否则会间接引发编译错误。

内容的提问来源于stack exchange，提问作者GreenEngineer