Question

由于某些原因，CDI似乎无法将字符串注入WebSocket ServerEndpoint。我收到错误Unsatisfied dependencies for type String with qualifiers @HelloMessage。我在下面包含了Producer和ServerEndpoint实现。有任何想法吗？如果我创建一个自定义类（比如Messenger）并生成而不是String，那么注入似乎有效。

限定符实施

import javax.inject.Qualifier;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;

import static java.lang.annotation.ElementType.FIELD;
import static java.lang.annotation.ElementType.METHOD;
import static java.lang.annotation.ElementType.PARAMETER;
import static java.lang.annotation.ElementType.TYPE;
import static java.lang.annotation.RetentionPolicy.RUNTIME;

@Qualifier
@Retention(RUNTIME)
@Target({TYPE, METHOD, FIELD, PARAMETER})
public
@interface HelloMessage
{
}

制片人实施

import java.io.Serializable;

import javax.inject.Named;
import javax.ws.rs.Produces;

public
class StringProducer
implements Serializable
{
    @Produces
    @HelloMessage
    public
    String getMessage()
    {
        return "Hello, from Message!";
    }
}

ServerEndpoint Implementation

import javax.inject.Inject;
import javax.inject.Named;
import javax.websocket.OnMessage;
import javax.websocket.Session;
import javax.websocket.server.ServerEndpoint;

@ServerEndpoint(value = "/test")
public
class TestEndpoint
{
    @OnMessage
    public
    void onMessage(Session session, String unused)
    {
        System.out.println(this.message);
    }

    @Inject @HelloMessage
    private String message;
}

Answer 1

在定义制作人时，我需要导入javax.enterprise.inject.Produces而不是javax.ws.rs.Produces。

制片人实施

import java.io.Serializable;

import javax.inject.Named;
import javax.enterprise.inject.Produces;

public
class StringProducer
implements Serializable
{
    @Produces
    @HelloMessage
    public
    String getMessage()
    {
        return "Hello, from Message!";
    }
}

为什么CDI找不到我的制片人？

1 个答案: