r2dbc ReactiveCrudRepository 不断崩溃

Question

我的 pom.xml 有以下依赖：

<dependency>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-starter-data-r2dbc</artifactId>
  <version>2.3.3.RELEASE</version><!--$NO-MVN-MAN-VER$-->
</dependency>       

<dependency>
            <groupId>io.r2dbc</groupId>
            <artifactId>r2dbc-mssql</artifactId>
            <scope>runtime</scope>
</dependency>

我的属性如下：

spring.r2dbc.url=r2dbc:mssql://localhost:1433/Admin
spring.r2dbc.username=xxx
spring.r2dbc.password=xxx

回购看起来像：

@Repository
public interface UserRepository extends ReactiveCrudRepository<MyUser, String> {
    @Query("SELECT u.Username AS username, u.Password as password FROM Users u INNER JOIN Roles r ON u.RoleId=r.Roleid WHERE u.Username=@username") 
    public Mono<UserDetails> findByUsername(String username);
}

我的用户看起来像：

@SuppressWarnings("serial")
public class MyUser implements UserDetails {

    @Id
    private String username;
    private String password;

    public MyUser(String username, String password) {
        this.username = username;
        this.password = password;
    }
    @Override
    public Collection<? extends GrantedAuthority> getAuthorities() {
        return null;
    }

    @Override
    public String getPassword() {
        return password;
    }

    @Override
    public String getUsername() {
        return username;
    }

    @Override
    public boolean isAccountNonExpired() {
        return false;
    }

    @Override
    public boolean isAccountNonLocked() {
        return false;
    }

    @Override
    public boolean isCredentialsNonExpired() {
        return false;
    }

    @Override
    public boolean isEnabled() {
        return true;
    }

我打开了 SQL 分析器并捕获了进来的查询，它是 100% 正确并返回正确的数据，但它似乎在反序列化时崩溃了。我设置了一个断点，它从不调用 MyUser 构造函数。如果我使用 Mono.just() 手动创建一个，该应用程序将按预期运行。

我收到以下异常：

java.lang.NullPointerException: null
    at org.springframework.data.r2dbc.core.DefaultDatabaseClient$DefaultTypedExecuteSpec.lambda$new$0(DefaultDatabaseClient.java:590) ~[spring-data-r2dbc-1.1.3.RELEASE.jar:1.1.3.RELEASE]
    Suppressed: reactor.core.publisher.FluxOnAssembly$OnAssemblyException: 
Error has been observed at the following site(s):
    |_ checkpoint ⇢ org.springframework.security.web.server.authentication.AuthenticationWebFilter [DefaultWebFilterChain]
    |_ checkpoint ⇢ org.springframework.security.web.server.authentication.AuthenticationWebFilter [DefaultWebFilterChain]
    |_ checkpoint ⇢ org.springframework.security.web.server.context.ReactorContextWebFilter [DefaultWebFilterChain]
    |_ checkpoint ⇢ org.springframework.security.web.server.header.HttpHeaderWriterWebFilter [DefaultWebFilterChain]
    |_ checkpoint ⇢ org.springframework.security.config.web.server.ServerHttpSecurity$ServerWebExchangeReactorContextWebFilter [DefaultWebFilterChain]
    |_ checkpoint ⇢ org.springframework.security.web.server.WebFilterChainProxy [DefaultWebFilterChain]
    |_ checkpoint ⇢ org.springframework.boot.actuate.metrics.web.reactive.server.MetricsWebFilter [DefaultWebFilterChain]
    |_ checkpoint ⇢ HTTP POST "/login?error" [ExceptionHandlingWebHandler]
Stack trace:
        at org.springframework.data.r2dbc.core.DefaultDatabaseClient$DefaultTypedExecuteSpec.lambda$new$0(DefaultDatabaseClient.java:590) ~[spring-data-r2dbc-1.1.3.RELEASE.jar:1.1.3.RELEASE]
        at java.base/java.util.function.BiFunction.lambda$andThen$0(BiFunction.java:70) ~[na:na]
        at io.r2dbc.mssql.MssqlResult.lambda$map$2(MssqlResult.java:169) ~[r2dbc-mssql-0.8.4.RELEASE.jar:0.8.4.RELEASE]

关于问题是什么的任何想法？这段代码例外：

    if (typeToRead.isInterface()) {
        this.mappingFunction = ColumnMapRowMapper.INSTANCE
                .andThen(map -> projectionFactory.createProjection(typeToRead, map));
    } else {
        this.mappingFunction = dataAccessStrategy.getRowMapper(typeToRead);
    }

Answer 1

1. 如果您使用的是存储库，则在您的代码中，MyUser 不会使用@Table 进行注释，例如here

2. 如果您不使用 Spring Data R2dbc 中提供的 OR Mapping，您可以尝试使用 DatabaseClient 手动处理查询，如果您坚持编写自定义 SQL 脚本，它会更加灵活。例如。 here.

Answer 2

尝试将默认构造函数（没有参数的构造函数）添加到您的 MyUser 类。