運行HttpServer時無法創建新的本地線程

Question

我有一個簡單的REST服務設置，它接收來自另一個服務的數據並將其放入數據庫。我計劃將它作爲包含服務和服務器的jar文件運行。代碼我已經是：

public class Main { 
    public static void main(String[] args) throws IOException { 
     ResourceConfig config = new DefaultResourceConfig(MyResource.class); 
     HttpServer server = HttpServerFactory.create("http://localhost:8080/", config); 
     server.start(); 
     // ... 
    } 

MyResource

@Path("/rest") 
public class MyResource { 

    public MyResource(){ 
     dbConnection = new DbConnection(); 
    } 

    private final DbConnection dbConnection; 

    @POST 
    @Path("/post") 
    @Consumes(MediaType.APPLICATION_XML) 
    public Response addItem(MyItem dao){ 
     dbConnection.addItem(dao); 
     return Response.status(200).build(); 
    } 

在的DbConnection，在構造函數中MysqlDataSource，一旦它得到一個項目，它把的它變成blockingQueue，另一個線程監聽並處理寫入到數據庫。

現在的問題是，每次接收到新的請求時，都會重新創建MyResource，調用構造函數，因此會再次啓動DbConnection類以及所有隨附的類。如何避免它？它導致：

com.sun.jersey.api.container.MappableContainerException: java.lang.OutOfMemoryError: unable to create new native thread 
     at com.sun.jersey.server.impl.resource.PerRequestFactory$PerRequest._getInstance(PerRequestFactory.java:189) 
     at com.sun.jersey.server.impl.resource.PerRequestFactory$AbstractPerRequest.getInstance(PerRequestFactory.java:144) 
     at com.sun.jersey.server.impl.application.WebApplicationContext.getResource(WebApplicationContext.java:239) 
     at com.sun.jersey.server.impl.uri.rules.ResourceClassRule.accept(ResourceClassRule.java:83) 
     at com.sun.jersey.server.impl.uri.rules.RightHandPathRule.accept(RightHandPathRule.java:147) 
     at com.sun.jersey.server.impl.uri.rules.RootResourceClassesRule.accept(RootResourceClassesRule.java:84) 
     at com.sun.jersey.server.impl.application.WebApplicationImpl._handleRequest(WebApplicationImpl.java:1542) 
Caused by: java.lang.OutOfMemoryError: unable to create new native thread 
     at java.lang.Thread.start0(Native Method) 
     at java.lang.Thread.start(Thread.java:714) 
     at myPackage.Db.DbConnection.<init>(DbConnection.java:61) 
     at myPackage.MyResource.<init>(MyResource.java:21) 
     at sun.reflect.GeneratedConstructorAccessor19.newInstance(Unknown Source) 
Exception in thread "Thread-2" java.lang.OutOfMemoryError: unable to create new native thread 
     at java.lang.Thread.start0(Native Method) 
     at java.lang.Thread.start(Thread.java:714) 
     at java.util.concurrent.ThreadPoolExecutor.addWorker(ThreadPoolExecutor.java:949) 
     at java.util.concurrent.ThreadPoolExecutor.execute(ThreadPoolExecutor.java:1371) 
     at sun.net.httpserver.ServerImpl$Dispatcher.handle(ServerImpl.java:433) 
     at sun.net.httpserver.ServerImpl$Dispatcher.run(ServerImpl.java:398) 
     at java.lang.Thread.run(Thread.java:745) 

Answer 1

標註您的資源類作爲@Singleton 另見這個答案When to use @Singleton annotation of Jersey?