apache-camel - 如何在 Camel 上下文之外访问 Apache camel eh-cache？

Question

我想使用来自网络服务的数据并将其放入 Camel eh-cache 中。后来我想通过 CacheManager 在 Camel 上下文之外使用这个缓存。我没有找到任何方法。

在下面的代码中，我跳过了 Web 服务的使用，并使用了 Map 中的数据并将其提供给 eh-cache，但我无法使用 CacheManager 访问此缓存。

CamelRouter 类

package com.camel;


import java.net.URL;
import java.util.HashMap;
import java.util.Map;

import org.apache.camel.builder.RouteBuilder;
import org.apache.camel.component.ehcache.EhcacheConstants;
import org.apache.camel.main.Main;
import org.ehcache.Cache;
import org.ehcache.CacheManager;
import org.ehcache.config.Configuration;
import org.ehcache.config.builders.CacheManagerBuilder;
import org.ehcache.xml.XmlConfiguration;

public class Test {

    private static Main main;

    public static void main(String[] args) throws Exception {

        main = new Main();
        main.addRouteBuilder(new RouteBuilder() {

            @Override
            public void configure() throws Exception {
                from("timer:foo?period=5s&repeatCount=1")
                .process(exchange ->{
                    Map<String, String> inputMap = new HashMap<>();
                    inputMap.put("name", "murli");
                    inputMap.put("lastname", "hiware");
                    inputMap.put("city", "pune");
                    exchange.getIn().setBody(inputMap);
                    exchange.getIn().setHeader("CamelEhcacheAction", EhcacheConstants.ACTION_PUT_ALL);
                })
                .to("ehcache://testCache?configUri=ehcache.xml&keyType=java.lang.String&valueType=java.lang.String")
                .process(exchange -> {
                    URL myUrl = getClass().getResource("/ehcache.xml"); 
                    Configuration xmlConfig = new XmlConfiguration(myUrl); 
                    CacheManager myCacheManager = CacheManagerBuilder.newCacheManager(xmlConfig); 
                    myCacheManager.init();
                    //here I want to access already created testCache component but it is creating new one.
                    Cache<String, String> cache = myCacheManager.getCache("testCache", String.class, String.class);
                    System.out.println("Cache Element:"+cache.get("name"));
                    System.out.println("Exchange Message:"+exchange.getIn().getBody());

                });
            }
        });

         main.run();
    }

}

ehcache 配置文件

<config
    xmlns:xsi='http://www.w3.org/2001/XMLSchema-instance'
    xmlns='http://www.ehcache.org/v3'
    xsi:schemaLocation="http://www.ehcache.org/v3 http://www.ehcache.org/schema/ehcache-core.xsd">

  <cache alias="testCache"> 
    <key-type>java.lang.String</key-type> 
    <value-type>java.lang.String</value-type> 
    <resources>
      <heap unit="entries">2000</heap> 
      <offheap unit="MB">100</offheap> 
    </resources>
  </cache>

  <cache-template name="myDefaults"> 
    <key-type>java.lang.Long</key-type>
    <value-type>java.lang.String</value-type>
    <heap unit="entries">200</heap>
  </cache-template>

  <cache alias="bar" uses-template="myDefaults"> 
    <key-type>java.lang.Number</key-type>
  </cache>

  <cache alias="simpleCache" uses-template="myDefaults" /> 

</config>

请让我知道我尝试实现的用例是否可以使用 camel eh-cache 实现？

Answer 1

您通常应该能够使用 from("ehcache://...) 检索值。

但是，我假设您确实想要访问缓存或缓存管理器。

这是这样做的方法:

public static void main(String[] args) throws Exception {
    URL url = App.class.getResource("/ehcache.xml");
    Configuration xmlConfig = new XmlConfiguration(url);

    CacheManager cacheManager = CacheManagerBuilder.newCacheManager(xmlConfig);
    cacheManager.init();

    Main main = new Main();
    main.bind("cacheManager", cacheManager);

    main.addRouteBuilder(new RouteBuilder() {

        @Override
        public void configure() throws Exception {
            from("timer:foo?period=5s&repeatCount=1")
                .process(exchange ->{
                    Map<String, String> inputMap = new HashMap<>();
                    inputMap.put("name", "murli");
                    inputMap.put("lastname", "hiware");
                    inputMap.put("city", "pune");
                    exchange.getIn().setBody(inputMap);
                    exchange.getIn().setHeader("CamelEhcacheAction", EhcacheConstants.ACTION_PUT_ALL);
                })
                .to("ehcache://testCache?cacheManager=#cacheManager&keyType=java.lang.String&valueType=java.lang.String")
                .process(exchange -> {
                    //here I want to access already created testCache component but it is creating new one.
                    Cache<String, String> cache = cacheManager.getCache("testCache", String.class, String.class);
                    System.out.println("Cache Element:"+cache.get("name"));
                    System.out.println("Exchange Message:"+exchange.getIn().getBody());

                });
        }
    });

    main.run();
}