差異處
這裏顯示兩個版本的差異處。
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java:apache_camel:aggregator:helloworld [2019/03/17 21:46] tony [AggregatorGroupRouteBuilder] |
java:apache_camel:aggregator:helloworld [2023/06/25 09:48] |
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| - | ====== Camel - Aggregator Hello World ====== | ||
| - | ===== Introduction ===== | ||
| - | Camel Aggregator提供開發人員能夠將大量訊息合成一個的功能。假設你的系統會接受外來通知，並將內容寫進資料庫中；一次連線寫一筆資料會比較快，還是透過一次連線寫入五筆資料快呢? 正常來說，一次連線寫入五筆同屬性資料會是比較快的。它與[[java:apache_camel:throttler:helloworld|Throttler]]的最大區別在於，Throttler限制了client的請求，而Aggreator則是收集起來一次請求。因此，如果使用Aggreator，你的程式必須要有對應的處理方式。\\ | ||
| - | \\ | ||
| - | 我將透過HTTP GET請求/events/{id}做為範例，說明如何使用Aggregator去將單位時間內的請求，以{id}去分組並Aggredate成各別分組訊息。本篇文章中使用到兩個RouteBuilder，分別為RestRouteBuilder與AggregatorGroupRouteBuilder。RestRouteBuilder負責REST核心相關設定，可參考[[java:apache_camel:throttler:helloworld|先前文章]]。接下來直接說明AggregatorGroupRouteBuilder。 | ||
| - | ===== AggregatorGroupRouteBuilder ===== | ||
| - | <code java> | ||
| - | package org.tonylin.practice.camel.aggregator; | ||
| - | import static com.google.common.base.Preconditions.checkState; | ||
| - | |||
| - | import org.apache.camel.builder.RouteBuilder; | ||
| - | import org.apache.camel.processor.aggregate.GroupedExchangeAggregationStrategy; | ||
| - | |||
| - | public class AggregatorGroupRouteBuilder extends RouteBuilder { | ||
| - | |||
| - | private final static String GET_EVENTS = "GET_EVENTS"; | ||
| - | |||
| - | private Object eventHandler; | ||
| - | private int period = 500; | ||
| - | |||
| - | public AggregatorGroupRouteBuilder(Object eventHandler) { | ||
| - | this.eventHandler = eventHandler; | ||
| - | |||
| - | } | ||
| - | |||
| - | public void setPeriod(int period) { | ||
| - | this.period = period; | ||
| - | } | ||
| - | |||
| - | @Override | ||
| - | public void configure() throws Exception { | ||
| - | checkState(eventHandler!=null, "Can't find eventHandler"); | ||
| - | |||
| - | rest("/events/{id}").get().route().id(GET_EVENTS) | ||
| - | .aggregate(new GroupedExchangeAggregationStrategy()) | ||
| - | .header("id") | ||
| - | .completionInterval(period) | ||
| - | .bean(eventHandler).endRest(); | ||
| - | } | ||
| - | } | ||
| - | </code> | ||
| - | 以下是在configure中的幾個重點: | ||
| - | * aggregate(new GroupedExchangeAggregationStrategy()): 使用GroupedExchangeAggregationStrategy去做aggregate，aggregate的內容為Exchange。如果有任何條件限制，要以Exchange去操作。 | ||
| - | * header("id"): 與aggregate一起使用，代表以header id去分組，在這裡就是屬於event的id。 | ||
| - | * completionInterval(period): 做aggregate的單位時間。 | ||
| - | * bean(eventHandler): 請求的處理者，必須要有能力處理aggregate後的訊息。 | ||
| - | Camel Aggregator提供了很多細部操作，你也可以根據自身需求做AggregationStrategy，這部分以後有機會再分享。接下來讓我們透過單元測試展示效果。 | ||
| - | ===== Unit Test ===== | ||
| - | 測試有兩個目標，testGroupedExchange用以確認aggregate group後的結果，另外一個testCompletionInterval則是確認單位時間設定的作用。以下為程式碼主要結構，主要測試程式碼稍後做說明: | ||
| - | <code java> | ||
| - | package org.tonylin.practice.camel.aggregator; | ||
| - | |||
| - | import static com.google.common.base.Preconditions.checkState; | ||
| - | |||
| - | import java.util.Arrays; | ||
| - | import java.util.List; | ||
| - | import java.util.Map; | ||
| - | import java.util.concurrent.ConcurrentHashMap; | ||
| - | import java.util.concurrent.CountDownLatch; | ||
| - | import java.util.concurrent.TimeUnit; | ||
| - | import java.util.stream.Collectors; | ||
| - | |||
| - | import org.apache.camel.Exchange; | ||
| - | import org.apache.camel.Handler; | ||
| - | import org.apache.camel.RoutesBuilder; | ||
| - | import org.apache.camel.test.junit4.CamelTestSupport; | ||
| - | import org.apache.http.HttpResponse; | ||
| - | import org.apache.http.client.HttpClient; | ||
| - | import org.apache.http.client.methods.HttpGet; | ||
| - | import org.apache.http.impl.client.HttpClientBuilder; | ||
| - | import org.junit.Test; | ||
| - | import org.tonylin.practice.camel.rest.RestRouteBuilder; | ||
| - | |||
| - | public class AggregatorGroupRouteBuilderTest extends CamelTestSupport { | ||
| - | |||
| - | private RestHandler hander = new RestHandler(); | ||
| - | |||
| - | private HttpClient client = HttpClientBuilder.create().build(); | ||
| - | |||
| - | @Override | ||
| - | protected RoutesBuilder[] createRouteBuilders() throws Exception { | ||
| - | AggregatorGroupRouteBuilder aggregatorGroupRouteBuilder = new AggregatorGroupRouteBuilder(hander); | ||
| - | aggregatorGroupRouteBuilder.setPeriod(500); | ||
| - | |||
| - | return new RoutesBuilder[] { | ||
| - | new RestRouteBuilder(), | ||
| - | aggregatorGroupRouteBuilder | ||
| - | }; | ||
| - | } | ||
| - | |||
| - | @Test | ||
| - | public void testGroupedExchange() throws Exception { | ||
| - | // skip | ||
| - | } | ||
| - | @Test | ||
| - | public void testCompletionInterval() throws Exception { | ||
| - | // skip | ||
| - | } | ||
| - | } | ||
| - | </code> | ||
| - | |||
| - | |||
| - | |||
| - | |||
| - | ===== Reference ===== | ||
| - | * [[http://camel.apache.org/aggregator.html|Camel - Aggregator]] | ||
| - | |||
| - | ===== ===== | ||
| - | ---- | ||
| - | \\ | ||
| - | ~~DISQUS~~ | ||
