Java 同时使用Camel时，如何使用Spring加载属性？

我有一个HelloWorldJava项目，它使用Camel获取地图，并以JSON格式打印其内容。该映射当前具有硬编码的值，但我确实希望更改代码，以便它使用Spring将嵌套键、值对的sensor.properties文件加载到此映射中

我编写的另一个Java项目只使用Spring，可以将sensor.properties文件加载到Arraylist对象中

但是，当我尝试使用该项目中的代码加载HelloWorld项目中的sensor.properties时，NPE出现以下Camel错误：

Returning Map
3310 [hello.world.request.timer] ERROR org.apache.camel.processor.DefaultErrorHandler      - Failed delivery for exchangeId: 4e984884-df7f-4b82-a977-f5cf4c311814. Exhausted after     delivery attempt: 1 caught: java.lang.NullPointerException
java.lang.NullPointerException
    at sample.SensorGenerator.getSensors(SensorGenerator.java:17)
    at sample.HelloWorld.returnMap(HelloWorld.java:22)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.apache.camel.component.bean.MethodInfo.invoke(MethodInfo.java:231)
    at org.apache.camel.component.bean.MethodInfo$1.proceed(MethodInfo.java:146)
    at org.apache.camel.component.bean.BeanProcessor.process(BeanProcessor.java:138)
org.apache.camel.management.InstrumentationProcessor.process(InstrumentationProcessor.java:67)
    at org.apache.camel.processor.DelegateProcessor.processNext(DelegateProcessor.java:53)
    at org.apache.camel.processor.DelegateProcessor.proceed(DelegateProcessor.java:82)
    at org.apache.camel.processor.interceptor.TraceInterceptor.process(TraceInterceptor.java:97)
    at org.apache.camel.management.InstrumentationProcessor.process(InstrumentationProcessor.java:67)
    at org.apache.camel.processor.RedeliveryErrorHandler.processExchange(RedeliveryErrorHandler.java:185)
 at org.apache.camel.processor.RedeliveryErrorHandler.processErrorHandler(RedeliveryErrorHandler.java:151)
    at     org.apache.camel.processor.RedeliveryErrorHandler.process(RedeliveryErrorHandler.java:89)
    at     org.apache.camel.processor.DefaultErrorHandler.process(DefaultErrorHandler.java:49)
    at org.apache.camel.processor.DefaultChannel.process(DefaultChannel.java:228)
    at org.apache.camel.processor.Pipeline.process(Pipeline.java:75)
    at     org.apache.camel.processor.UnitOfWorkProcessor.processNext(UnitOfWorkProcessor.java:70)
    at org.apache.camel.processor.DelegateProcessor.process(DelegateProcessor.java:48)
    at org.    apache.camel.management.InstrumentationProcessor.process(InstrumentationProcessor.java:67)
    at     org.apache.camel.component.timer.TimerConsumer.sendTimerExchange(TimerConsumer.java:102)
    at org.apache.camel.component.timer.TimerConsumer$1.run(TimerConsumer.java:49)
    at java.util.TimerThread.mainLoop(Timer.java:555)
    at java.util.TimerThread.run(Timer.java:505)

我是否需要在applicationContext.xml中添加一些内容来告诉Camel Spring将加载我的sensor.properties？我是否需要使用在中指定的Spring集成组件

以下是我当前的ApplicationContext.xml：

    <?xml version="1.0" encoding="UTF-8"?>

<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"     xmlns:camel="http://camel.apache.org/schema/spring"
    xmlns:context="http://www.springframework.org/schema/context"
    xmlns:util="http://www.springframework.org/schema/util"
    xsi:schemaLocation="
        http://www.springframework.org/schema/beans     http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
        http://www.springframework.org/schema/util     http://www.springframework.org/schema/util/spring-util-3.0.xsd
        http://camel.apache.org/schema/spring     http://camel.apache.org/schema/spring/camel-spring.xsd
        http://www.springframework.org/schema/context     http://www.springframework.org/schema/context/spring-context.xsd">

<bean
    class="org.springframework.context.annotation.CommonAnnotationBeanPostProcessor" />
<context:component-scan base-package="sample" />
<context:annotation-config />

<camel:camelContext id="HelloWorldContext">

    <!-- Add Jackson library to render Java Map into JSON -->
    <camel:dataFormats>
      <camel:json id="jack" library="Jackson"/>
    </camel:dataFormats>

    <camel:route>
        <!-- sends a request to the hello world JMS queue every 10 seconds -->
        <camel:from
            uri="timer://hello.world.request.timer?fixedRate=true&amp;period=10000" />
        <camel:to uri="log:hello.world.request?level=INFO?showAll=true" />
        <camel:bean ref="helloWorld" />

        <!-- now print out the map in JSON format -->
        <camel:marshal ref ="jack"/>
        <camel:convertBodyTo type="java.lang.String" />
        <camel:log message="${body}"/> 

        <!-- now log the message -->
        <camel:to uri="log:hello.world.response?level=INFO?showAll=true" />

    </camel:route>

</camel:camelContext>

<bean id="jms" class="org.apache.activemq.camel.component.ActiveMQComponent">
    <property name="configuration" ref="jmsConfig" />
</bean>

<bean id="jmsConfig" class="org.apache.camel.component.jms.JmsConfiguration">
    <property name="connectionFactory" ref="jmsConnectionFactory" />
    <property name="transacted" value="false" />
    <property name="concurrentConsumers" value="1" />
</bean>

<bean id="jmsConnectionFactory" class="org.apache.activemq.ActiveMQConnectionFactory">
    <property name="brokerURL" value="vm://localhost" />
    <property name="redeliveryPolicy" ref="redeliveryPolicy" />
    <property name="prefetchPolicy" ref="prefetchPolicy" />
</bean>

<bean id="prefetchPolicy" class="org.apache.activemq.ActiveMQPrefetchPolicy">
    <property name="queuePrefetch" value="5" />
</bean>

<bean id="redeliveryPolicy" class="org.apache.activemq.RedeliveryPolicy">
    <property name="maximumRedeliveries" value="1" />
    <property name="backOffMultiplier" value="2" />
    <property name="initialRedeliveryDelay" value="2000" />
    <property name="useExponentialBackOff" value="true" />
</bean>

<!-- creates a java.util.Properties instance with values loaded from the supplied location -->
<util:properties id="sensorProperties" location="classpath:/sensor.properties"/>
    <bean class="sample.SensorGenerator">
        <property name="sourceProperties" ref="sensorProperties" />
    </bean>

</beans>

HelloWorld.java：

package sample;

import java.util.*;

import org.apache.camel.Handler;
import org.springframework.stereotype.Service;


/**
 * POJO that returns Hello World string
 *
 */
@Service
public class HelloWorld {

    @AutoWired
    SensorGenerator sensorGenerator;

    @Handler
    public Map<?, ?> returnMap(){
        System.out.println();
        System.out.println("Returning Map");
        // get the map of Sensors
        Map<String,String> mySensorMap = sensorGenerator.getSensors();
        // print out the Sensors in the map on the console
        Set keys = mySensorMap.keySet();

        for (Iterator i = keys.iterator(); i.hasNext();) {
            String key = (String) i.next();
            String value = (String) mySensorMap.get(key);
            System.out.println("key= " + key + ", value= " + value);
        }
        return mySensorMap;
    }

}

SensorGenerator.java（在该类中，我当前对属性进行硬编码，但希望让Spring从sensor.properties加载它们。如果我注释掉For循环和引用sourceProperties的任何行，我可以很好地返回带有硬编码值的映射。这就是为什么我怀疑存在某种Spring/Camel集成问题的原因）：

包装样品

import java.util.HashMap;
import java.util.Map;
import java.util.Properties;

public class SensorGenerator {

    private Properties sourceProperties;

    // variable to increment key number for each sensor
    int sensorNumber = 1;

    // method to inject sensor.properties into a Map using Spring
    Map<String, String> getSensors() {
        Map<String, String> sensorMap = new HashMap<String, String>();
        for (Object key : sourceProperties.keySet()) {

            // Separate out each of the key,value pairs as an entry in the
            // values array
            String[] values = sourceProperties.getProperty((String) key).split(
                    ",");
            System.out.println("values array size= " + values.length);

            // define string buffer that appends sensor number for each sensor's
            // keys.  Ex: sensor1 would have s1make, s1makeDataType, etc.
            StringBuffer sensorNumberStringBuffer = new StringBuffer();
            sensorNumberStringBuffer.append("s");
            sensorNumberStringBuffer.append(sensorNumber);

            // make and its data type (with sensor number prefix)
            StringBuffer makeStringBuffer = new StringBuffer();
            makeStringBuffer.append(sensorNumberStringBuffer);
            makeStringBuffer.append("make");
            StringBuffer makeDataTypeStringBuffer = new StringBuffer();
            makeDataTypeStringBuffer.append(sensorNumberStringBuffer);
            makeDataTypeStringBuffer.append("makeDataType");

            // model and its data type (with sensor number prefix)
            StringBuffer modelStringBuffer = new StringBuffer();
            modelStringBuffer.append(sensorNumberStringBuffer);
            modelStringBuffer.append("model");
            StringBuffer modelDataTypeStringBuffer = new StringBuffer();
            modelDataTypeStringBuffer.append(sensorNumberStringBuffer);
            modelDataTypeStringBuffer.append("modelDataType");

            // serialNumber and its data type (with sensor number prefix)
            StringBuffer serialNumberStringBuffer = new StringBuffer();
            serialNumberStringBuffer.append(sensorNumberStringBuffer);
            serialNumberStringBuffer.append("serialNumber");
            StringBuffer serialNumberDataTypeStringBuffer = new StringBuffer();
            serialNumberDataTypeStringBuffer.append(sensorNumberStringBuffer);
            serialNumberDataTypeStringBuffer.append("serialNumberDataType");

            // sensorType and its data type (with sensor number prefix)
            StringBuffer sensorTypeStringBuffer = new StringBuffer();
            sensorTypeStringBuffer.append(sensorNumberStringBuffer);
            sensorTypeStringBuffer.append("sensorType");
            StringBuffer sensorTypeDataTypeStringBuffer = new StringBuffer();
            sensorTypeDataTypeStringBuffer.append(sensorNumberStringBuffer);
            sensorTypeDataTypeStringBuffer.append("sensorTypeDataType");

            /*
              put all the key,value pairs for this sensor in the sensorMap
            */

            //TODO: Change all the hard coded values below to be elements
            // from the values array once Spring can load spring.properties

            // make and and its data type
            sensorMap.put(makeStringBuffer.toString(), "DummyMake");
            sensorMap.put(makeDataTypeStringBuffer.toString(), "String");

            // model and and its data type
            sensorMap.put(modelStringBuffer.toString(), "DummyModel");
            sensorMap.put(modelDataTypeStringBuffer.toString(), "String");

            // serialNumber and and its data type
            sensorMap.put(serialNumberStringBuffer.toString(), "1234567890");
            sensorMap.put(serialNumberDataTypeStringBuffer.toString(), "long");

            // sensorType and its data type
            sensorMap.put(sensorTypeStringBuffer.toString(), "DummyType");
            sensorMap.put(sensorTypeDataTypeStringBuffer.toString(), "String");

            // increment for next sensor
            sensorNumber++;
        }
        return sensorMap;
    }

    public void setSourceProperties(Properties properties) {
        this.sourceProperties = properties;
    }

}

下面是一个示例sensor.properties文件：

sensor1=DummySensor1:String,SensorModel1:String,1234567890:long,SensorType1:String
sensor2=DummySensor2:String,SensorModel2:String,8675309123:long,SensorType2:String

---

问题是SensorGenerator不是由spring实例化的，而是由您的代码实例化的，因此永远无法设置属性

@Service
public class HelloWorld {

    @Handler
    public Map<?, ?> returnMap(){
        SensorGenerator sensorGenerator = new SensorGenerator();

@服务
公共类HelloWorld{
@处理者
公共地图returnMap（）{
SensorGenerator SensorGenerator=新的SensorGenerator（）；

---

您应该让sensorGenerator在HelloWorld服务中自动连接。

谢谢Frederic。我觉得这很愚蠢，但在盯着代码看了这么久之后，我需要其他人来查看它。我修改了HelloWorld类以删除您提到的构造函数，并添加了@autowired，现在它可以工作了。：-）我修改了HelloWorld类代码在我的问题中包含@Autowired更正。希望这对将来的人有所帮助。

        for (Object key : sourceProperties.keySet()) {

sensor1=DummySensor1:String,SensorModel1:String,1234567890:long,SensorType1:String
sensor2=DummySensor2:String,SensorModel2:String,8675309123:long,SensorType2:String

@Service
public class HelloWorld {

    @Handler
    public Map<?, ?> returnMap(){
        SensorGenerator sensorGenerator = new SensorGenerator();