通过blueprint xml设置引用

Question

我试图将一个接口的引用作为一个类中的属性传递(继承另一个类)，我得到一个错误。我在一个不继承任何东西的类中尝试了同样的方法，它工作得很好。我不知道我是不是错过了什么。任何帮助都是非常感谢的。谢谢:)

类：

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.UnsupportedEncodingException;
import java.util.Hashtable;
import java.util.StringTokenizer;
import java.util.Vector;
import java.util.logging.Level;
import java.util.logging.Logger;

import org.apache.camel.Endpoint;
import org.apache.camel.Exchange;
import org.apache.camel.Processor;
import org.apache.camel.impl.ScheduledPollConsumer;

import com.walmart.utils.storeConfig.api.IStoreConfigService;


public class WalPipeConsumer extends ScheduledPollConsumer
{
    final static private String CLASS_NAME = WalPipeConsumer.class.getName();

    final static private Logger logger = Logger.getLogger(CLASS_NAME);

    protected Hashtable pipeBuffers;

    private Vector msgs = new Vector();

    private int arrrayLength = 0, headerLength = 0;

    private final Endpoint endpoint;

    private final String pipe;

    private IStoreConfigService storeConfigService;

public WalPipeConsumer(Endpoint endpoint, Processor processor, String pipe)
        throws Exception
{
    super(endpoint, processor);
    logger.finest("inside the wal pipe consumer constructor");
    this.pipe = pipe;
    this.endpoint = endpoint;
    this.countryCode = countryCode;
    logger.finest("before starting the thread");
    new Thread(new WalPipeInputRunner(), "WalCamel Pipe Consumer[" + pipe
            + "]").start();
    logger.finest("after starting the thread");
}

// There are some more functions 
/**
 * @param storeConfigServicethe storeConfigService to set
 */
public void setStoreConfigService(IStoreConfigService storeConfigService) {
    this.storeConfigService = storeConfigService;
}

Blueprint.xml：

<reference id="storeConfigService"
    interface="com.walmart.utils.storeConfig.api.IStoreConfigService" />

<bean id="storeConfigAdapter" class="com.tgcs.walpipe.endpoint.StoreConfigAdapter" init-method="init">
    <property name="storeConfigService" ref="storeConfigService" />
</bean>

<bean id="WalPipeConsumer" class="com.tgcs.walpipe.endpoint.WalPipeConsumer">
    <property name="storeConfigService" ref="storeConfigService" /> 
</bean>

​

错误：

[2017.09.15-10:34:00.788] [SEVERE] 
[org.apache.aries.blueprint.container.BlueprintContainerImpl] 
[org.apache.aries.blueprint.container.BlueprintContainerImpl.doRun] - Unable 
to start blueprint container for bundle com.tgcs.walpipe.endpoint
org.osgi.service.blueprint.container.ComponentDefinitionException: Unable to 
find a matching constructor on class 
com.tgcs.walpipe.endpoint.WalPipeConsumer for arguments [] when 
instanciating bean WalPipeConsumer 

Answer 1

Blueprint尝试创建WalPipeConsumer的实例。您正在使用属性来设置storeConfigService。因此blueprint将首先调用空构造函数来实例化该类，然后调用设置器来设置storeConfigService。

因为该类没有空的构造器，所以这将失败。

要解决这个问题，要么需要一个空的构造函数，要么使用元素来设置现有构造函数的所有参数。