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我正在使用带有 REST 支持的 Spring MVC 4.1.5，试图让 Web 服务使用 google 协议缓冲区消息格式。我看到很多帖子都提到了 JSON 格式的这个问题，但没有提到谷歌协议缓冲区格式的问题。此外，我没有看到 Spring 框架文档有用于 protobufs 的 MediaType（更多内容见下文）我的代码发布在github 上

这是我的控制器代码（使用或不使用 products="application-xprotobuf" 没有区别 - 相同的 406 不可接受的错误）

@RestController
@RequestMapping("/ws")
@EnableWebMvc
public class CustomerRestController {
    @Autowired
    private CustomerRepository customerRepository;
    //@RequestMapping(value="/customers/{id}", method = RequestMethod.GET, produces="application/x-protobuf")
    @RequestMapping(value="/customers/{id}", method = RequestMethod.GET)
    public CustomerProtos.Customer customer(@PathVariable Integer id) {
        return this.customerRepository.findById(id);
    }

    @Bean
    ProtobufHttpMessageConverter protobufHttpMessageConverter() {
        return new ProtobufHttpMessageConverter();
    }

    private CustomerProtos.Customer customer(int id, String f, String l, Collection<String> emails) {
        String emailAddressString = "defaultEmail@address.com";
        for (String email : emails) {
            emailAddressString = email;
            break;
        }

        EmailAddress emailAddress = CustomerProtos.Customer.EmailAddress.newBuilder()
                .setType(CustomerProtos.Customer.EmailType.PROFESSIONAL).setEmail(emailAddressString).build();

        return CustomerProtos.Customer.newBuilder().setFirstName(f).setLastName(l).setId(id).addEmail(emailAddress)
                // .addAllEmail(emailAddresses)
                .build();
    }

    @Bean
    CustomerRepository customerRepository() {
        return new CustomerRepositoryImpl(); 
    }
}

这是我的 web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID" version="2.5">
  <display-name>demo</display-name>
  <welcome-file-list>
    <welcome-file>index.html</welcome-file>
    <welcome-file>index.htm</welcome-file>
    <welcome-file>index.jsp</welcome-file>
    <welcome-file>default.html</welcome-file>
    <welcome-file>default.htm</welcome-file>
    <welcome-file>default.jsp</welcome-file>
  </welcome-file-list>


<servlet>
    <servlet-name>rest</servlet-name>
    <servlet-class>
        org.springframework.web.servlet.DispatcherServlet
    </servlet-class>
    <load-on-startup>1</load-on-startup>
</servlet>

<servlet-mapping>
    <servlet-name>rest</servlet-name>
    <url-pattern>/*</url-pattern>
</servlet-mapping>

    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>/WEB-INF/rest-servlet.xml</param-value>
    </context-param>

    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>

</web-app>

这是我的 pom.xml，请注意，我确实在此处添加了 google protobuf 库，它们最终位于已部署的 .war 文件的 WEB-INF/lib 文件夹中。

<?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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>org.test</groupId>
    <artifactId>demo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>war</packaging>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.3.0.RELEASE</version>
    </parent>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <start-class>demo.DemoApplication</start-class>
        <java.version>1.8</java.version>
        <jackson.version>2.5.3</jackson.version>

    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>4.2.0.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-tx</artifactId>
            <version>4.2.0.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
        </dependency>
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
        </dependency>
        <dependency>
            <groupId>com.google.protobuf</groupId>
            <artifactId>protobuf-java</artifactId>
            <version>2.5.0</version>
        </dependency>
        <dependency>
            <groupId>com.googlecode.protobuf-java-format</groupId>
            <artifactId>protobuf-java-format</artifactId>
            <version>1.2</version>
        </dependency>

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

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

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-legacy</artifactId>
            <version>1.0.0.RELEASE</version>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</project>

这是我的测试客户

package demo;

import java.util.Arrays;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.IntegrationTest;
import org.springframework.boot.test.SpringApplicationConfiguration;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.ResponseEntity;
import org.springframework.http.converter.protobuf.ProtobufHttpMessageConverter;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
import org.springframework.web.client.RestTemplate;

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration
public class DemoApplicationTests {

    @Configuration
    public static class RestClientConfiguration {

        @Bean
        RestTemplate restTemplate(ProtobufHttpMessageConverter hmc) {
            return new RestTemplate(Arrays.asList(hmc));
        }

        @Bean
        ProtobufHttpMessageConverter protobufHttpMessageConverter() {
            return new ProtobufHttpMessageConverter();
        }
    }

    @Autowired
    private RestTemplate restTemplate;

    @Test
    public void contextLoaded() {

        ResponseEntity<CustomerProtos.Customer> customer = restTemplate.getForEntity(
                "http://localhost:7001/demo-0.0.1-SNAPSHOT/ws/customers/2", CustomerProtos.Customer.class);

        System.out.println("customer retrieved: " + customer.toString());

    }

}

当我使用 mvn test 从命令行运行客户端时，出现以下错误

Tests run: 1, Failures: 0, Errors: 1, Skipped: 0, Time elapsed: 0.697 sec <<< FAILURE! - in demo.DemoApplicationTests
contextLoaded(demo.DemoApplicationTests)  Time elapsed: 0.037 sec  <<< ERROR!
org.springframework.web.client.HttpClientErrorException: 406 Not Acceptable
        at org.springframework.web.client.DefaultResponseErrorHandler.handleError(DefaultResponseErrorHandler.java:91)
        at org.springframework.web.client.RestTemplate.handleResponse(RestTemplate.java:641)
        at org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:597)
        at org.springframework.web.client.RestTemplate.execute(RestTemplate.java:557)
        at org.springframework.web.client.RestTemplate.getForEntity(RestTemplate.java:289)
        at demo.DemoApplicationTests.contextLoaded(DemoApplicationTests.java:42)

我看到有人建议使用 contentNegotiationManager

在我的 rest-servlet.xml 我有 mvc:annotation-driven 标签

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:context="http://www.springframework.org/schema/context"
    xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:p="http://www.springframework.org/schema/p"
    xsi:schemaLocation="
        http://www.springframework.org/schema/beans     
        http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
        http://www.springframework.org/schema/context
        http://www.springframework.org/schema/context/spring-context-4.0.xsd
        http://www.springframework.org/schema/mvc
        http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd">
    <context:component-scan base-package="demo" />
    <mvc:annotation-driven />
  </beans>

我还在演示包中放入了 webConfig.java

package demo;

import org.springframework.context.annotation.Configuration;
import org.springframework.http.MediaType;
import org.springframework.web.servlet.config.annotation.ContentNegotiationConfigurer;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;

@Configuration
@EnableWebMvc
public class WebConfig extends WebMvcConfigurerAdapter {

  /**
    *  Total customization - see below for explanation.
    */
  @Override
  public void configureContentNegotiation(ContentNegotiationConfigurer configurer) {
    configurer.favorPathExtension(false).
            favorParameter(true).
            parameterName("mediaType").
            ignoreAcceptHeader(true).
            useJaf(false).
            defaultContentType(MediaType.TEXT_PLAIN).
            mediaType("xml", MediaType.APPLICATION_XML).
            mediaType("json", MediaType.APPLICATION_JSON).
            mediaType("x-protobuf", MediaType.ALL)
            ;
  }
}

无论有没有 webconfig.java（它正在做 contentNegotationManager 的工作），我都会得到 406 not Acceptable 错误。

我无法在 Spring 4.1.3 甚至4.2.3 jars中找到 MediaType.APPLICATION_XPROTOBUF 。

所以我把这个值留给了 MediaType.ALL （我认为这应该有效？）

当我运行测试客户端时，我在实际运行测试之前收到此消息..

09:27:26.198 [main] DEBUG o.s.web.client.RestTemplate - Created GET request for "http://localhost:7001/demo-0.0.1-SNAPSHOT/ws/customers/2"
09:27:26.199 [main] DEBUG o.s.web.client.RestTemplate - Setting request Accept header to [application/x-protobuf, text/plain, application/xml, application/json]
09:27:26.245 [main] DEBUG o.s.web.client.RestTemplate - GET request for "http://localhost:7001/demo-0.0.1-SNAPSHOT/ws/customers/2" resulted in 406 (Not Acceptable); invoking error
handler

它清楚地显示了将接受标头设置为也包含“application-xprotobuf”值。不确定在这种情况下我缺少什么。

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1 回答 1

7

我遇到了与控制器失败相同的问题406: Not Acceptable。经过大量跟踪后，我发现了示例中的语句：

Spring Boot 会自动注册HttpMessageConverterbean，因此我们只需要定义ProtobufHttpMessageConverterbean 并对其进行适当配置。

应该从字面上理解，因为没有 Spring Boot就不会发生转换器注册。bean已实例化，但从未在 HttpMessageConverters 列表中注册。

我已经通过显式注册一个ProtobufHttpMessageConverter实例来解决它：

@Configuration
@EnableWebMvc
@ComponentScan
public class AppConfig extends WebMvcConfigurerAdapter {

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

您不需要为它声明一个单独的 bean（除非您打算显式调用它）。

另请注意，覆盖configureMessageConverters()会禁用所有标准转换器；如果您的意思是扩展库存转换器列表而不是替换它，请extendMessageConverters()改为覆盖。

于 2016-02-09T16:10:26.763 回答