java - 运行 HttpServer 时无法创建新的 native 线程

Question

我设置了一个简单的 REST 服务，该服务从另一个服务接收数据并将其放入数据库中。我计划将其作为包含服务和服务器的 jar 文件运行。我的代码是:

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();
        // ...
    }

我的资源

@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 DbConnection 中，构造函数中的 MysqlDataSource ，一旦它获取一个项目，就会将其放入 blockingQueue 中，另一个线程正在监听并处理对数据库的写入。

现在的问题是，每次收到新请求时，都会重新创建 MyResource，调用构造函数，因此再次启动 DbConnection 类及其附带的所有内容。如何避免呢？结果是:

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

将您的资源类注释为@Singleton 另请参阅此答案 When to use @Singleton annotation of Jersey?