MyBatis + Spring映射，接口上的nullpointerexception

Question

I am trying to integrate mybatis into my spring application. I added the mapping configuration, the interface for the mapping and also the xml which has the sql queries.

Here is my config:

Spring xml config:

    <context:annotation-config transaction-manager="transactionManager"/>
    <annotation-driven />

... some other sql datasource configuration here ...

<!-- Mybatis Spring setup -->
        <beans:bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
           <beans:property name="driverClassName" value="com.mysql.jdbc.Driver"/>
           <beans:property name="url" value="jdbc:mysql://localhost/appdb"/>
           <beans:property name="username" value="root"/>
           <beans:property name="password" value=""/>
        </beans:bean>
        <beans:bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
            <beans:property name="dataSource" ref="dataSource" />
        </beans:bean>
        <beans:bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
          <beans:property name="dataSource" ref="dataSource" />
          <beans:property name="configLocation" value="WEB-INF/mybatis/sqlmap-config.xml" />
        </beans:bean>

        <!-- scan for mappers and let them be autowired -->
        <beans:bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
            <beans:property name="basePackage" value="com.project.persistence" />
        </beans:bean>

sqlmap-config.xml:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE configuration
PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-config.dtd">

<configuration>
    <settings>
        <!-- changes from the defaults -->
       <setting name="lazyLoadingEnabled" value="false" />
    </settings>
    <typeAliases>
        <typeAlias type="com.project.domain.User" alias="user"/>
    </typeAliases>
</configuration>

User class:

package com.project.domain;

import java.io.Serializable;

public class User implements Serializable {
    private static final long serialVersionUID = 3647233284813657927L;

    private String id;
    private String name = null;

    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    @Override
    public String toString() {
        return "User [name=" + name + "]";
    }
}

I am using a custom authentication provider where I would like to use the sql query which gives me back that simple user:

    @Component
    public class CustomAuthenticationProvider implements AuthenticationProvider  {

        @Override
        public Authentication authenticate(Authentication authentication) {
            String name = authentication.getName();
            String password = authentication.getCredentials().toString();

            UserService us = new UserService(); // HERE IS THE PROBLEM ! its always null, maybe not autowired?
            User user = us.getUser(name);
            System.out.println("User: " + user);

            boolean isAuthenticated = false;

            //... do the rest of the authentication
   }
}

Here is the UserMapper.xml:

<?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.project.persistence.UserMapper">

    <resultMap id="result" type="user">
        <result property="id" column="id"/>
        <result property="name" column="name"/>
    </resultMap>

    <select id="getUser" parameterType="String" resultType="User">
        SELECT id, name
        FROM bm_users
        WHERE name=#{username};
    </select>

    <select id="getAllUser" parameterType="int" resultMap="result">
        SELECT id,name
        FROM bm_users;
    </select>

    <insert id="saveUser" parameterType="user">
        INSERT INTO bm_users (id,name)
        VALUE (#{id},#{name})
    </insert>

    <update id="updateUser" parameterType="user">
        UPDATE bm_users
        SET
        name = #{name},
        where id = #{id}
    </update>

    <delete id="deleteUser" parameterType="int">
        DELETE FROM bm_users
        WHERE id = #{id}
    </delete>
</mapper>

And here is the UserService.java:

@Service
public class UserService {

    @Autowired
    private UserMapper usermapper;

    public User getUser(String name) {
        return usermapper.getUser(name);
    }
}

So I got a nullpointerexception when the code reaches "User user = us.getUser(name);" in my CustomAuthenticationProvider:

java.lang.NullPointerException
    com.project.service.UserService.getUser(UserService.java:16)
    com.project.authentication.CustomAuthenticationProvider.authenticate(CustomAuthenticationProvider.java:27)
    org.springframework.security.authentication.ProviderManager.authenticate(ProviderManager.java:156)
    org.springframework.security.authentication.ProviderManager.authenticate(ProviderManager.java:177)
    org.springframework.security.web.authentication.UsernamePasswordAuthenticationFilter.attemptAuthentication(UsernamePasswordAuthenticationFilter.java:94)
    org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter.doFilter(AbstractAuthenticationProcessingFilter.java:211)
    org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
    org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:110)
    org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
    org.springframework.security.web.csrf.CsrfFilter.doFilterInternal(CsrfFilter.java:105)
    org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
    org.springframework.security.web.context.request.async.WebAsyncManagerIntegrationFilter.doFilterInternal(WebAsyncManagerIntegrationFilter.java:50)
    org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
    org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:87)
    org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
    org.springframework.security.web.FilterChainProxy.doFilterInternal(FilterChainProxy.java:192)
    org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:160)
    org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:344)
    org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:261)

So it seems to me somehow its not getting autowired.

Any suggestion what should I try?

Thanks

Answer 1

OK, so I could almost solve this. I had to modify my code a little bit. It seems the problem was with my service implementation.

I followed this one to solve it: http://www.javacodegeeks.com/2014/02/building-java-web-application-using-mybatis-with-spring.html

In the tutorial they are using "private StudentService studentService;" in the controller but I had to use StudentServiceImpl to get it work.

However, other interesting thing. This only works from a @Controller class, and not working from my @Component CustomAuthenticationProvider. Is it how it should work? How can I make it work inside my AuthenticationProvider?