如何使用 Spring Boot 和 Apache Camel 创建 RESTful Web 服务？
How to create RESTful Web Service with Spring Boot and Apache Camel?
我正在 Spring 引导项目中学习 Apache Camel，我尝试创建一个 Retful Web 服务，该服务正在启动，但问题是我在调用端点时收到 404。
@Component
@RequiredArgsConstructor
public class RestJavaDsl extends RouteBuilder {
private final WeatherDataProvider weatherDataProvider;
@Override
public void configure() throws Exception {
from("rest:get:javadsl/weather/{city}?produces=application/json")
.outputType(WeatherDto.class)
.process(this::getWeatherData);
}
private void getWeatherData(Exchange exchange) {
String city = exchange.getMessage().getHeader("city", String.class);
WeatherDto currentWeather = weatherDataProvider.getCurrentWeather(city);
Message message = new DefaultMessage(exchange.getContext());
message.setBody(currentWeather);
exchange.setMessage(message);
}
}
我创建这个 class 来硬编码一些数据：
@Component
public class WeatherDataProvider {
private static Map<String, WeatherDto> weatherData = new HashMap<>();
public WeatherDataProvider() {
WeatherDto dto = WeatherDto.builder().city("London").temp("10").unit("C").receivedTime(new Date().toString()).id(1).build();
weatherData.put("LONDON", dto);
}
public WeatherDto getCurrentWeather(String city) {
return weatherData.get(city.toUpperCase());
}
public void setCurrentWeather(WeatherDto dto) {
dto.setReceivedTime(new Date().toString());
weatherData.put(dto.getCity().toUpperCase(), dto);
}
}
@Data
@NoArgsConstructor
@AllArgsConstructor
@Builder
public class WeatherDto implements Serializable {
static int counter = 1;
private int id = counter++;
private String city;
private String temp;
private String unit;
private String receivedTime;
}
application.yml
camel:
component:
servlet:
mapping:
context-path: /services/*
pom.xml
<?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>2.6.3</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.dgs</groupId>
<artifactId>camel-rest-springboot</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>camel-rest-springboot</name>
<description>Demo project for Spring Boot</description>
<properties>
<java.version>11</java.version>
<camel.version>3.14.0</camel.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.apache.camel.springboot</groupId>
<artifactId>camel-spring-boot-starter</artifactId>
<version>${camel.version}</version>
</dependency>
<dependency>
<groupId>org.apache.camel</groupId>
<artifactId>camel-test</artifactId>
<scope>test</scope>
<version>${camel.version}</version>
</dependency>
<dependency>
<groupId>org.apache.camel</groupId>
<artifactId>camel-jackson</artifactId>
<version>${camel.version}</version>
</dependency>
<dependency>
<groupId>org.apache.camel</groupId>
<artifactId>camel-jaxb</artifactId>
<version>${camel.version}</version>
</dependency>
<dependency>
<groupId>org.apache.camel</groupId>
<artifactId>camel-servlet</artifactId>
<version>${camel.version}</version>
</dependency>
<dependency>
<groupId>org.apache.camel.springboot</groupId>
<artifactId>camel-servlet-starter</artifactId>
<version>${camel.version}</version>
</dependency>
<dependency>
<groupId>org.apache.camel.springboot</groupId>
<artifactId>camel-rest-starter</artifactId>
<version>${camel.version}</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>1.18.0</version>
<scope>provided</scope>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
服务正在启动，这是控制台日志：
2022-01-24 20:01:40.353 INFO 15796 --- [ main] c.d.c.CamelRestSpringbootApplication : Starting CamelRestSpringbootApplication using Java 11.0.5 on pc-PC with PID 15796 (D:\Spring Boot\camel-rest-springboot\target\classes started by pc in D:\Spring Boot\camel-rest-springboot)
2022-01-24 20:01:40.357 INFO 15796 --- [ main] c.d.c.CamelRestSpringbootApplication : No active profile set, falling back to default profiles: default
2022-01-24 20:01:43.583 INFO 15796 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat initialized with port(s): 8080 (http)
2022-01-24 20:01:43.604 INFO 15796 --- [ main] o.apache.catalina.core.StandardService : Starting service [Tomcat]
2022-01-24 20:01:43.604 INFO 15796 --- [ main] org.apache.catalina.core.StandardEngine : Starting Servlet engine: [Apache Tomcat/9.0.56]
2022-01-24 20:01:43.820 INFO 15796 --- [ main] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring embedded WebApplicationContext
2022-01-24 20:01:43.821 INFO 15796 --- [ main] w.s.c.ServletWebServerApplicationContext : Root WebApplicationContext: initialization completed in 3235 ms
2022-01-24 20:01:45.228 INFO 15796 --- [ main] o.a.c.c.s.CamelHttpTransportServlet : Initialized CamelHttpTransportServlet[name=CamelServlet, contextPath=]
2022-01-24 20:01:45.233 INFO 15796 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat started on port(s): 8080 (http) with context path ''
2022-01-24 20:01:45.592 INFO 15796 --- [ main] o.a.c.impl.engine.AbstractCamelContext : Message DataType is enabled on CamelContext: camel-1
2022-01-24 20:01:45.607 INFO 15796 --- [ main] o.a.c.impl.engine.AbstractCamelContext : Routes startup (total:1 started:1)
2022-01-24 20:01:45.607 INFO 15796 --- [ main] o.a.c.impl.engine.AbstractCamelContext : Started route1 (rest://get:javadsl/weather/%7Bcity%7D)
2022-01-24 20:01:45.607 INFO 15796 --- [ main] o.a.c.impl.engine.AbstractCamelContext : Apache Camel 3.14.0 (camel-1) started in 370ms (build:83ms init:269ms start:18ms)
2022-01-24 20:01:45.617 INFO 15796 --- [ main] c.d.c.CamelRestSpringbootApplication : Started CamelRestSpringbootApplication in 6.569 seconds (JVM running for 8.087)
但是当我尝试调用端点 http://localhost:8080/services/javadsl/weather/london
看起来这个端点不存在，其余的没有创建。我使用了调试器，但未调用方法 getWeatherData()。
而且我认为这个日志不正常：Started route1 (rest://get:javadsl/weather/%7Bcity%7D)，它应该是这样的：route1 started and consuming from servlet:/javadsl/weather /%7B城市%7D
教程来自这里：https://www.youtube.com/watch?v=spDjbC8mZf0&t=433s
提前致谢！
您可以从使用官方 camel-archetype-spring-boot maven 原型创建示例项目开始。您可以使用 IDE 或使用以下 maven 命令从 command-line 基于原型生成项目。
mvn archetype:generate -DarchetypeArtifactId="camel-archetype-spring-boot" -DarchetypeGroupId="org.apache.camel.archetypes" -DarchetypeVersion="3.14.0"
现在在 maven 项目文件中 pom.xml 将以下块添加到依赖项中
<dependency>
<groupId>org.apache.camel.springboot</groupId>
<artifactId>camel-jetty-starter</artifactId>
</dependency>
请注意，不需要指定版本，因为它由 camel-spring-boot-dependencies BOM（物料清单）在 dependencyManagement 部分提供。
之后，您可以创建新文件 ConfigureCamelContext.java，我们可以在其中配置我们的 CamelContext 并为其提供 RestConfiguration。我们可以通过实现 CamelContextConfiguration 和 @Component 注释来做到这一点。
注释告诉 spring-framework 它应该创建 class 的实例并将其注入到根据其 class-type 或接口请求它的对象。 Camel 配置为自动询问 spring-framework 这些 RestConfiguration 实例，它将继续使用配置 CamelContext。
package com.example;
import org.apache.camel.CamelContext;
import org.apache.camel.spi.RestConfiguration;
import org.apache.camel.spring.boot.CamelContextConfiguration;
import org.springframework.stereotype.Component;
@Component
public class ConfigureCamelContext implements CamelContextConfiguration {
@Override
public void beforeApplicationStart(CamelContext camelContext) {
RestConfiguration restConfiguration = new RestConfiguration();
restConfiguration.setApiComponent("jetty");
restConfiguration.setApiHost("localhost");
restConfiguration.setPort(8081);
camelContext.setRestConfiguration(restConfiguration);
}
@Override
public void afterApplicationStart(CamelContext camelContext) {
}
}
这应该适用于 RestDSL and rest-component。
将 MySpringBootRouter.java 编辑为如下内容：
package com.example;
import org.apache.camel.Exchange;
import org.apache.camel.builder.RouteBuilder;
import org.springframework.stereotype.Component;
@Component
public class MySpringBootRouter extends RouteBuilder {
static final String CONTET_TYPE_TEXT = "text/plain";
@Override
public void configure() {
rest()
.get("/hello/")
.route()
.setHeader(Exchange.CONTENT_TYPE, constant(CONTET_TYPE_TEXT))
.setBody().constant("Hello world")
.end()
.endRest()
.get("/hello/{name}")
.route()
.setHeader(Exchange.CONTENT_TYPE, constant(CONTET_TYPE_TEXT))
.setBody().simple("Hello ${headers.name}")
.end()
.endRest();
from("rest:get:test?produces=plain/text")
.setBody().constant("Hello from JavaDSL");
}
}
注释掉 src/test/java/<grouId>/ 下的 class 因为原型提供的示例测试不适用于 MySpringBootRouter 并且会中断构建。
到运行项目可以使用命令
mvn spring-boot:run
现在您应该可以打开 localhost:8081/hello、localhost:8081/hello/<Name> 或 localhost:8081/test 以纯文本形式获得响应。
我正在 Spring 引导项目中学习 Apache Camel，我尝试创建一个 Retful Web 服务，该服务正在启动，但问题是我在调用端点时收到 404。
@Component
@RequiredArgsConstructor
public class RestJavaDsl extends RouteBuilder {
private final WeatherDataProvider weatherDataProvider;
@Override
public void configure() throws Exception {
from("rest:get:javadsl/weather/{city}?produces=application/json")
.outputType(WeatherDto.class)
.process(this::getWeatherData);
}
private void getWeatherData(Exchange exchange) {
String city = exchange.getMessage().getHeader("city", String.class);
WeatherDto currentWeather = weatherDataProvider.getCurrentWeather(city);
Message message = new DefaultMessage(exchange.getContext());
message.setBody(currentWeather);
exchange.setMessage(message);
}
}
我创建这个 class 来硬编码一些数据：
@Component
public class WeatherDataProvider {
private static Map<String, WeatherDto> weatherData = new HashMap<>();
public WeatherDataProvider() {
WeatherDto dto = WeatherDto.builder().city("London").temp("10").unit("C").receivedTime(new Date().toString()).id(1).build();
weatherData.put("LONDON", dto);
}
public WeatherDto getCurrentWeather(String city) {
return weatherData.get(city.toUpperCase());
}
public void setCurrentWeather(WeatherDto dto) {
dto.setReceivedTime(new Date().toString());
weatherData.put(dto.getCity().toUpperCase(), dto);
}
}
@Data
@NoArgsConstructor
@AllArgsConstructor
@Builder
public class WeatherDto implements Serializable {
static int counter = 1;
private int id = counter++;
private String city;
private String temp;
private String unit;
private String receivedTime;
}
application.yml
camel:
component:
servlet:
mapping:
context-path: /services/*
pom.xml
<?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>2.6.3</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.dgs</groupId>
<artifactId>camel-rest-springboot</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>camel-rest-springboot</name>
<description>Demo project for Spring Boot</description>
<properties>
<java.version>11</java.version>
<camel.version>3.14.0</camel.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.apache.camel.springboot</groupId>
<artifactId>camel-spring-boot-starter</artifactId>
<version>${camel.version}</version>
</dependency>
<dependency>
<groupId>org.apache.camel</groupId>
<artifactId>camel-test</artifactId>
<scope>test</scope>
<version>${camel.version}</version>
</dependency>
<dependency>
<groupId>org.apache.camel</groupId>
<artifactId>camel-jackson</artifactId>
<version>${camel.version}</version>
</dependency>
<dependency>
<groupId>org.apache.camel</groupId>
<artifactId>camel-jaxb</artifactId>
<version>${camel.version}</version>
</dependency>
<dependency>
<groupId>org.apache.camel</groupId>
<artifactId>camel-servlet</artifactId>
<version>${camel.version}</version>
</dependency>
<dependency>
<groupId>org.apache.camel.springboot</groupId>
<artifactId>camel-servlet-starter</artifactId>
<version>${camel.version}</version>
</dependency>
<dependency>
<groupId>org.apache.camel.springboot</groupId>
<artifactId>camel-rest-starter</artifactId>
<version>${camel.version}</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>1.18.0</version>
<scope>provided</scope>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
服务正在启动，这是控制台日志：
2022-01-24 20:01:40.353 INFO 15796 --- [ main] c.d.c.CamelRestSpringbootApplication : Starting CamelRestSpringbootApplication using Java 11.0.5 on pc-PC with PID 15796 (D:\Spring Boot\camel-rest-springboot\target\classes started by pc in D:\Spring Boot\camel-rest-springboot)
2022-01-24 20:01:40.357 INFO 15796 --- [ main] c.d.c.CamelRestSpringbootApplication : No active profile set, falling back to default profiles: default
2022-01-24 20:01:43.583 INFO 15796 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat initialized with port(s): 8080 (http)
2022-01-24 20:01:43.604 INFO 15796 --- [ main] o.apache.catalina.core.StandardService : Starting service [Tomcat]
2022-01-24 20:01:43.604 INFO 15796 --- [ main] org.apache.catalina.core.StandardEngine : Starting Servlet engine: [Apache Tomcat/9.0.56]
2022-01-24 20:01:43.820 INFO 15796 --- [ main] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring embedded WebApplicationContext
2022-01-24 20:01:43.821 INFO 15796 --- [ main] w.s.c.ServletWebServerApplicationContext : Root WebApplicationContext: initialization completed in 3235 ms
2022-01-24 20:01:45.228 INFO 15796 --- [ main] o.a.c.c.s.CamelHttpTransportServlet : Initialized CamelHttpTransportServlet[name=CamelServlet, contextPath=]
2022-01-24 20:01:45.233 INFO 15796 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat started on port(s): 8080 (http) with context path ''
2022-01-24 20:01:45.592 INFO 15796 --- [ main] o.a.c.impl.engine.AbstractCamelContext : Message DataType is enabled on CamelContext: camel-1
2022-01-24 20:01:45.607 INFO 15796 --- [ main] o.a.c.impl.engine.AbstractCamelContext : Routes startup (total:1 started:1)
2022-01-24 20:01:45.607 INFO 15796 --- [ main] o.a.c.impl.engine.AbstractCamelContext : Started route1 (rest://get:javadsl/weather/%7Bcity%7D)
2022-01-24 20:01:45.607 INFO 15796 --- [ main] o.a.c.impl.engine.AbstractCamelContext : Apache Camel 3.14.0 (camel-1) started in 370ms (build:83ms init:269ms start:18ms)
2022-01-24 20:01:45.617 INFO 15796 --- [ main] c.d.c.CamelRestSpringbootApplication : Started CamelRestSpringbootApplication in 6.569 seconds (JVM running for 8.087)
但是当我尝试调用端点 http://localhost:8080/services/javadsl/weather/london
看起来这个端点不存在，其余的没有创建。我使用了调试器，但未调用方法 getWeatherData()。 而且我认为这个日志不正常：Started route1 (rest://get:javadsl/weather/%7Bcity%7D)，它应该是这样的：route1 started and consuming from servlet:/javadsl/weather /%7B城市%7D 教程来自这里：https://www.youtube.com/watch?v=spDjbC8mZf0&t=433s 提前致谢！
您可以从使用官方 camel-archetype-spring-boot maven 原型创建示例项目开始。您可以使用 IDE 或使用以下 maven 命令从 command-line 基于原型生成项目。
mvn archetype:generate -DarchetypeArtifactId="camel-archetype-spring-boot" -DarchetypeGroupId="org.apache.camel.archetypes" -DarchetypeVersion="3.14.0"
现在在 maven 项目文件中 pom.xml 将以下块添加到依赖项中
<dependency>
<groupId>org.apache.camel.springboot</groupId>
<artifactId>camel-jetty-starter</artifactId>
</dependency>
请注意，不需要指定版本，因为它由 camel-spring-boot-dependencies BOM（物料清单）在 dependencyManagement 部分提供。
之后，您可以创建新文件 ConfigureCamelContext.java，我们可以在其中配置我们的 CamelContext 并为其提供 RestConfiguration。我们可以通过实现 CamelContextConfiguration 和 @Component 注释来做到这一点。
注释告诉 spring-framework 它应该创建 class 的实例并将其注入到根据其 class-type 或接口请求它的对象。 Camel 配置为自动询问 spring-framework 这些 RestConfiguration 实例，它将继续使用配置 CamelContext。
package com.example;
import org.apache.camel.CamelContext;
import org.apache.camel.spi.RestConfiguration;
import org.apache.camel.spring.boot.CamelContextConfiguration;
import org.springframework.stereotype.Component;
@Component
public class ConfigureCamelContext implements CamelContextConfiguration {
@Override
public void beforeApplicationStart(CamelContext camelContext) {
RestConfiguration restConfiguration = new RestConfiguration();
restConfiguration.setApiComponent("jetty");
restConfiguration.setApiHost("localhost");
restConfiguration.setPort(8081);
camelContext.setRestConfiguration(restConfiguration);
}
@Override
public void afterApplicationStart(CamelContext camelContext) {
}
}
这应该适用于 RestDSL and rest-component。
将 MySpringBootRouter.java 编辑为如下内容：
package com.example;
import org.apache.camel.Exchange;
import org.apache.camel.builder.RouteBuilder;
import org.springframework.stereotype.Component;
@Component
public class MySpringBootRouter extends RouteBuilder {
static final String CONTET_TYPE_TEXT = "text/plain";
@Override
public void configure() {
rest()
.get("/hello/")
.route()
.setHeader(Exchange.CONTENT_TYPE, constant(CONTET_TYPE_TEXT))
.setBody().constant("Hello world")
.end()
.endRest()
.get("/hello/{name}")
.route()
.setHeader(Exchange.CONTENT_TYPE, constant(CONTET_TYPE_TEXT))
.setBody().simple("Hello ${headers.name}")
.end()
.endRest();
from("rest:get:test?produces=plain/text")
.setBody().constant("Hello from JavaDSL");
}
}
注释掉 src/test/java/<grouId>/ 下的 class 因为原型提供的示例测试不适用于 MySpringBootRouter 并且会中断构建。
到运行项目可以使用命令
mvn spring-boot:run
现在您应该可以打开 localhost:8081/hello、localhost:8081/hello/<Name> 或 localhost:8081/test 以纯文本形式获得响应。