并非所有内容类型都支持 Spring REST 控制器内容/类型

Question

我正在尝试创建一个使用 HTML 的 Web 服务，该 HTML 稍后用于使用 iText 创建 PDF。

我使用 Postman 将请求发送到服务器，但每次我收到以下错误，无论我选择哪种内容类型：

{
    "status": "CONFLICT",
    "code": 40902,
    "message": "Content type 'text/plain' not supported",
    "developerMessage": "null",
    "moreInfoUrl": "class org.springframework.web.HttpMediaTypeNotSupportedException",
    "throwable": null
}

消息根据选择的内容类型而变化：

"message": "Content type 'text/xml' not supported"
"message": "Content type 'text/html' not supported"

这是我的终点：

@RequestMapping(path = "/reports/pdf", method = RequestMethod.POST, consumes = MediaType.TEXT_HTML_VALUE)
public ResponseEntity<byte[]> generatePdfReport(@RequestBody String html) throws Exception {
    byte[] pdfBytes = reportsService.generatePdf(html);
    ResponseEntity<byte[]> response = new ResponseEntity<byte[]>(pdfBytes, HttpStatus.OK);
    return response;
}

我已将consumes 属性更改为：

• MediaType.TEXT_PLAIN_VALUE
• MediaType.TEXT_XML_VALUE

以匹配我在 Postman 上发送的内容。

根据@dnault 注释，将其从RequestMapping 注释中完全删除，结果相同。

我研究过类似的问题：

• Content type 'text/plain;charset=UTF-8' not supported error in spring boot inside RestController class 这是与我的问题最接近的问题，但我已经将请求中的内容类型设置为我期望在端点上的内容类型。
• Error org.springframework.web.HttpMediaTypeNotSupportedException
• Error: org.springframework.web.HttpMediaTypeNotSupportedException: Content type 'text/plain;charset=UTF-8' not supported

但是，以上所有内容以及我检查过的与我的问题不太接近的其他一些内容都没有提供解决此问题的答案。

我尝试发送到服务器的示例 HTML 是：

<table style="border: 1px solid black; font-size: 12px; margin-top: 1px; width: 900px;" id="table_direction">
    <tr>
        <td width="33%" colspan="2">
            <strong>Data1</strong>
        </td>
        <td width="33%" colspan="2">
            <strongData2</strong>
        </td>
        <td width="16%" colspan="1">Foo</td>
        <td width="16%" colspan="1">Bar</td>
    </tr>
    <tr>
        <td colspan="">ID</td>
        <td colspan="">123456</td>
        <td colspan="">Property 1</td>
        <td colspan="">Foo</td>
        <td colspan="">Property 2</td>
        <td colspan="">Bar</td>
    </tr>
</table>

我们的配置是通过Java配置类进行的，如下：

@Configuration
@EnableWebMvc
@ComponentScan(basePackages = "com.company.project")
@PropertySource("classpath:application.properties")

@EnableTransactionManagement // proxyTargetClass = true
@EnableJpaRepositories(basePackages = { "com.company.project.dao", "com.company.project.repository" })

public class HelloWorldConfiguration extends WebMvcConfigurerAdapter {

    @Inject
    Environment env;

    @Value("${jdbc.user}")
    private String userDB;

    @Value("${jdbc.password}")
    private String passDB;

    @Value("${jdbc.url}")
    private String urlDB;

    @Value("${jdbc.driverClassName}")
    private String driverClassName;

    @Bean
    public static PropertySourcesPlaceholderConfigurer propertySourcesPlaceholderConfigurer() {
        return new PropertySourcesPlaceholderConfigurer();
    }

    @Bean
    public CommonsMultipartResolver multipartResolver() {
        return new CommonsMultipartResolver();
    }

    @Bean(name = "dataSource")
    public DriverManagerDataSource dataSource() {
        DriverManagerDataSource driverManagerDataSource = new DriverManagerDataSource();
        driverManagerDataSource.setDriverClassName(driverClassName);
        driverManagerDataSource.setUrl(urlDB);
        driverManagerDataSource.setUsername(userDB);
        driverManagerDataSource.setPassword(passDB);
        return driverManagerDataSource;
    }

    @Bean
    public LocalSessionFactoryBean sessionFactory() {
        LocalSessionFactoryBean sessionFactory = new LocalSessionFactoryBean();
        sessionFactory.setDataSource(dataSource());
        sessionFactory.setPackagesToScan(new String[] { "com.company.project.model" });
        sessionFactory.setHibernateProperties(hibernateProperties());
        return sessionFactory;
    }

    @Bean
    public LocalContainerEntityManagerFactoryBean entityManagerFactory(DataSource dataSource,
            JpaVendorAdapter jpaVendorAdapter) {
        LocalContainerEntityManagerFactoryBean entityManagerFactoryBean = new LocalContainerEntityManagerFactoryBean();
        entityManagerFactoryBean.setDataSource(dataSource);
        entityManagerFactoryBean.setJpaVendorAdapter(jpaVendorAdapter);
        entityManagerFactoryBean.setPackagesToScan("com.company.project.model");
        entityManagerFactoryBean.setJpaProperties(hibernateProperties());
        return entityManagerFactoryBean;
    }

    private Properties hibernateProperties() {
        Properties jpaProperties = new Properties();
        jpaProperties.put("hibernate.hbm2ddl.auto", env.getProperty("hibernate.hbm2ddl.auto"));
        jpaProperties.put("hibernate.show_sql", env.getProperty("hibernate.show_sql"));
        jpaProperties.put("hibernate.dialect", env.getProperty("hibernate.dialect"));
        return jpaProperties;
    }

    @Bean
    public PlatformTransactionManager transactionManager(EntityManagerFactory entityManagerFactory) {
        return new JpaTransactionManager(entityManagerFactory);
    }

    @Bean(name = "transactionManager2")
    @Autowired
    @Named("transactionManager2")
    public HibernateTransactionManager transactionManager2(SessionFactory s) {
        HibernateTransactionManager txManager = new HibernateTransactionManager();
        txManager.setSessionFactory(s);
        return txManager;
    }

    @Bean
    public JpaVendorAdapter jpaVendorAdapter() {
        HibernateJpaVendorAdapter vendorAdapter = new HibernateJpaVendorAdapter();
        vendorAdapter.setGenerateDdl(true);
        return vendorAdapter;
    }

    public MappingJackson2HttpMessageConverter jacksonMessageConverter(){
        MappingJackson2HttpMessageConverter messageConverter = new MappingJackson2HttpMessageConverter();

        ObjectMapper mapper = new ObjectMapper();
        Hibernate5Module module = new Hibernate5Module();
        module.disable(Hibernate5Module.Feature.USE_TRANSIENT_ANNOTATION);

        mapper.registerModule(module);

        messageConverter.setObjectMapper(mapper);
        return messageConverter;

    }

    @Override
    public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
        converters.add(jacksonMessageConverter());
        super.configureMessageConverters(converters);
    }
}

---

@ControllerAdvice
public class GenericRepositoryRestExceptionHandler extends RepositoryRestExceptionHandler {

    @Autowired
    public GenericRepositoryRestExceptionHandler(MessageSource messageSource) {
        super(messageSource);
        // TODO Auto-generated constructor stub
    }

    @ResponseBody
    @ExceptionHandler(Exception.class)
    ResponseEntity<?> handleException(Exception e) {
        //  return response(HttpStatus.CONFLICT, 40902, e.getMessage());
        return response(HttpStatus.CONFLICT, 40902, e.getMessage(), e.getCause() + "", e.getClass() + "");
    }

    private ResponseEntity<RestError> response(HttpStatus status, int code, String msg) {
        return response(status, code, msg, "", "");
    }

    private ResponseEntity<RestError> response(HttpStatus status, int code, String msg, String devMsg, String moreInfo) {
        return new ResponseEntity<>(new RestError(status, code, msg, devMsg, moreInfo, null), status);
    }

}

---

public class CORSFilter implements Filter {

    public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException {
        System.out.println("Filtering on...........................................................");

        SecurityContext ctx = SecurityContextHolder.getContext();
        HttpServletResponse response = (HttpServletResponse) res;
        response.setHeader("Access-Control-Allow-Origin", "*");
        response.setHeader("Access-Control-Allow-Methods", "POST, GET, PUT, OPTIONS, DELETE");
        response.setHeader("Access-Control-Max-Age", "3600");
        response.setHeader("Access-Control-Allow-Headers", "x-requested-with");
        chain.doFilter(req, res);
    }

    public void init(FilterConfig filterConfig) {}

    public void destroy() {}

}

Answer 1

因为这个

@Override
public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
    converters.add(jacksonMessageConverter());
    super.configureMessageConverters(converters);
}

Spring MVC 会跳过它本来会注册的所有默认转换器。 （如果您好奇，可以在WebMvcConfigurationSupport#getMessageConverters(..) 中完成。）

你唯一的HttpMessageConverter，MappingJackson2HttpMessageConverter ，只能读取MediaType.APPLICATION_JSON的内容，即。 application/json。因此，所有其他请求内容类型都将被拒绝。

您可以自己在 configureMessageConverters 覆盖中注册所有常规默认值（或者只是您需要阅读 HTML 表单、XML、纯文本等的那些）。

或者，您可以改写 extendMessageConverters 以查找默认的 MappingJackson2HttpMessageConverter 实例并将其配置为使用您的自定义 ObjectMapper。例如，

public void extendMessageConverters(List<HttpMessageConverter<?>> converters) {
    ObjectMapper mapper = new ObjectMapper();
    // ...initialize...

    for (HttpMessageConverter<?> converter : converters) {
        if (converter instanceof MappingJackson2HttpMessageConverter) {
            MappingJackson2HttpMessageConverter m = (MappingJackson2HttpMessageConverter) converter;
            m.setObjectMapper(mapper);
        }
    } 
}

并且也许放弃关于依赖默认转换器列表的评论。

Answer 2

我意识到 OP'S 问题中提到的案例与我的略有不同，尽管我有同样的错误。 就我而言，它是在我开始使用不同的 ObjectMapper 后出现的。

最初我使用的是

“com.fasterxml.jackson.core.databind”作为我项目中的 ObjectMapper。

我重构了一些代码，并在此过程中切换到 org.codehaus.jackson 作为 ObjectMapper 的源。

那时一切都崩溃了，Spring 将简单地拒绝每个请求，而不管 Content-Type 与 OP 具​​有相同的错误消息。

我花了 3 天时间来解决这个问题，但最后我只是简单地切换回 ObjectMapper 的“数据绑定”。之后一切都神奇地运行了。

我在这里提到这一点，以防它对某人有所帮助。取消我没有触及 MessageConverters 或任何复杂的 OP。