标签：依赖 tobato fastdfs groupName bean command 引入 import com

场景描述

OpenFeign和FastDFS都存在connectionManager这个类，导致spring在加载bean名称冲突。

解决方案

网上的解决方案有很多，都一一尝试过，但是无法解决。

最后解决方案：采用全类名覆盖加载

资料信息：

JVM优先加载项目中的类而不是依赖包里的类，这主要基于Java的类加载机制中的双亲委派模型以及类加载器的工作原理。

双亲委派模型是Java类加载器的工作原则。当一个类加载器收到类加载的请求时，它首先不会自己去尝试加载这个类，而是把这个请求委派给父类加载器去完成。每一个层次的类加载器都是如此，因此所有的加载请求最终都应该传送到顶层的启动类加载器中。只有当父类加载器无法完成这个加载请求（它的搜索范围中没有找到所需的类）时，子加载器才会尝试自己去加载。

整体思路解析

查看FastDFS源码结构

因为我们采用方案是修改connectionManager的bean名，从而避免bean名称冲突问题，所以主要注入了connectionManager的类，都要进行覆盖。

相关代码

除了标注出来的地方，其他都是保持和源码一模一样。

ConnectionManager

关键：

在自己项目中创建com.github.tobato.fastdfs.con包；
修改ConnectionManager的bean名称，如：@Component("FastDFSConnectionManager")

**package com.github.tobato.fastdfs.conn;**

import java.net.InetSocketAddress;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

import com.github.tobato.fastdfs.exception.FdfsException;
import com.github.tobato.fastdfs.proto.FdfsCommand;

/**
 * 连接池管理
 *
 * <pre>
 * 负责借出连接，在连接上执行业务逻辑，然后归还连
 * </pre>
 *
 * @author tobato
 *
 */
**@Component("FastDFSConnectionManager")**
public class ConnectionManager {

    /** 连接池 */
    @Autowired
    private FdfsConnectionPool pool;
    /** 日志 */
    protected static final Logger LOGGER = LoggerFactory.getLogger(ConnectionManager.class);

    /**
     * 构造函数
     */
    public ConnectionManager() {
        super();
    }

    /**
     * 构造函数
     *
     * @param pool
     */
    public ConnectionManager(FdfsConnectionPool pool) {
        super();
        this.pool = pool;
    }

    /**
     * 获取连接并执行交易
     *
     * @param address
     * @param command
     * @return
     */
    public <T> T executeFdfsCmd(InetSocketAddress address, FdfsCommand<T> command) {

        // 获取连接
        Connection conn = getConnection(address);
        // 执行交易
        return execute(address, conn, command);

    }

    /**
     * 执行交易
     *
     * @param conn
     * @param command
     * @return
     */
    protected <T> T execute(InetSocketAddress address, Connection conn, FdfsCommand<T> command) {
        try {
            // 执行交易
            LOGGER.debug("对地址{}发出交易请求{}", address, command.getClass().getSimpleName());
            return command.execute(conn);
        } catch (FdfsException e) {
            throw e;
        } catch (Exception e) {
            LOGGER.error("execute fdfs command error", e);
            throw new RuntimeException("execute fdfs command error", e);
        } finally {
            try {
                if (null != conn) {
                    pool.returnObject(address, conn);
                }
            } catch (Exception e) {
                LOGGER.error("return pooled connection error", e);
            }
        }
    }

    /**
     * 获取连接
     *
     * @param address
     * @return
     */
    protected Connection getConnection(InetSocketAddress address) {
        Connection conn = null;
        try {
            // 获取连接
            conn = pool.borrowObject(address);
        } catch (FdfsException e) {
            throw e;
        } catch (Exception e) {
            LOGGER.error("Unable to borrow buffer from pool", e);
            throw new RuntimeException("Unable to borrow buffer from pool", e);
        }
        return conn;
    }

    public FdfsConnectionPool getPool() {
        return pool;
    }

    public void setPool(FdfsConnectionPool pool) {
        this.pool = pool;
    }

    public void dumpPoolInfo(InetSocketAddress address) {

        LOGGER.debug("==============Dump Pool Info================");
        LOGGER.debug("活动连接{}", pool.getNumActive(address));
        LOGGER.debug("空闲连接{}", pool.getNumIdle(address));
        LOGGER.debug("连接获取总数统计{}", pool.getBorrowedCount());
        LOGGER.debug("连接返回总数统计{}", pool.getReturnedCount());
        LOGGER.debug("连接销毁总数统计{}", pool.getDestroyedCount());

    }

}

DefaultGenerateStorageClient

关键：

在自己项目中创建com.github.tobato.fastdfs.con包；
因为修改了bean名称了，所以需要修改注入bean名称，如：@Resource(name = "FastDFSConnectionManager")

package com.github.tobato.fastdfs.service;

import java.io.InputStream;
import java.util.Set;

import javax.annotation.Resource;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.context.annotation.Primary;
import org.springframework.stereotype.Component;

import com.github.tobato.fastdfs.conn.ConnectionManager;
import com.github.tobato.fastdfs.domain.FileInfo;
import com.github.tobato.fastdfs.domain.MateData;
import com.github.tobato.fastdfs.domain.StorageNode;
import com.github.tobato.fastdfs.domain.StorageNodeInfo;
import com.github.tobato.fastdfs.domain.StorePath;
import com.github.tobato.fastdfs.proto.storage.DownloadCallback;
import com.github.tobato.fastdfs.proto.storage.StorageDeleteFileCommand;
import com.github.tobato.fastdfs.proto.storage.StorageDownloadCommand;
import com.github.tobato.fastdfs.proto.storage.StorageGetMetadataCommand;
import com.github.tobato.fastdfs.proto.storage.StorageQueryFileInfoCommand;
import com.github.tobato.fastdfs.proto.storage.StorageSetMetadataCommand;
import com.github.tobato.fastdfs.proto.storage.StorageUploadFileCommand;
import com.github.tobato.fastdfs.proto.storage.StorageUploadSlaveFileCommand;
import com.github.tobato.fastdfs.proto.storage.enums.StorageMetdataSetType;

/**
 * 基本存储客户端操作实现
 *
 * @author tobato
 *
 */
@Component
@Primary
public class DefaultGenerateStorageClient implements GenerateStorageClient {

    /** trackerClient */
    @Resource
    protected TrackerClient trackerClient;

    /** connectManager */
    **@Resource(name = "FastDFSConnectionManager")**
    protected ConnectionManager connectionManager;

    /** 日志 */
    protected static Logger LOGGER = LoggerFactory.getLogger(DefaultGenerateStorageClient.class);

    /**
     * 上传不支持断点续传的文件
     */
    @Override
    public StorePath uploadFile(String groupName, InputStream inputStream, long fileSize, String fileExtName) {
        StorageNode client = trackerClient.getStoreStorage(groupName);
        StorageUploadFileCommand command = new StorageUploadFileCommand(client.getStoreIndex(), inputStream,
                fileExtName, fileSize, false);
        return connectionManager.executeFdfsCmd(client.getInetSocketAddress(), command);
    }

    /**
     * 上传从文件
     */
    @Override
    public StorePath uploadSlaveFile(String groupName, String masterFilename, InputStream inputStream, long fileSize,
                                     String prefixName, String fileExtName) {
        StorageNodeInfo client = trackerClient.getUpdateStorage(groupName, masterFilename);
        StorageUploadSlaveFileCommand command = new StorageUploadSlaveFileCommand(inputStream, fileSize, masterFilename,
                prefixName, fileExtName);
        return connectionManager.executeFdfsCmd(client.getInetSocketAddress(), command);
    }

    /**
     * 获取metadata
     */
    @Override
    public Set<MateData> getMetadata(String groupName, String path) {
        StorageNodeInfo client = trackerClient.getFetchStorage(groupName, path);
        StorageGetMetadataCommand command = new StorageGetMetadataCommand(groupName, path);
        return connectionManager.executeFdfsCmd(client.getInetSocketAddress(), command);
    }

    /**
     * 覆盖metadata
     */
    @Override
    public void overwriteMetadata(String groupName, String path, Set<MateData> metaDataSet) {
        StorageNodeInfo client = trackerClient.getUpdateStorage(groupName, path);
        StorageSetMetadataCommand command = new StorageSetMetadataCommand(groupName, path, metaDataSet,
                StorageMetdataSetType.STORAGE_SET_METADATA_FLAG_OVERWRITE);
        connectionManager.executeFdfsCmd(client.getInetSocketAddress(), command);
    }

    /**
     * 合并metadata
     */
    @Override
    public void mergeMetadata(String groupName, String path, Set<MateData> metaDataSet) {
        StorageNodeInfo client = trackerClient.getUpdateStorage(groupName, path);
        StorageSetMetadataCommand command = new StorageSetMetadataCommand(groupName, path, metaDataSet,
                StorageMetdataSetType.STORAGE_SET_METADATA_FLAG_MERGE);
        connectionManager.executeFdfsCmd(client.getInetSocketAddress(), command);
    }

    /**
     * 查询文件信息
     */
    @Override
    public FileInfo queryFileInfo(String groupName, String path) {
        StorageNodeInfo client = trackerClient.getFetchStorage(groupName, path);
        StorageQueryFileInfoCommand command = new StorageQueryFileInfoCommand(groupName, path);
        return connectionManager.executeFdfsCmd(client.getInetSocketAddress(), command);
    }

    /**
     * 删除文件
     */
    @Override
    public void deleteFile(String groupName, String path) {
        StorageNodeInfo client = trackerClient.getUpdateStorage(groupName, path);
        StorageDeleteFileCommand command = new StorageDeleteFileCommand(groupName, path);
        connectionManager.executeFdfsCmd(client.getInetSocketAddress(), command);
    }

    /**
     * 下载整个文件
     */
    @Override
    public <T> T downloadFile(String groupName, String path, DownloadCallback<T> callback) {
        long fileOffset = 0;
        long fileSize = 0;
        return downloadFile(groupName, path, fileOffset, fileSize, callback);
    }

    /**
     * 下载文件片段
     */
    @Override
    public <T> T downloadFile(String groupName, String path, long fileOffset, long fileSize,
                              DownloadCallback<T> callback) {
        StorageNodeInfo client = trackerClient.getFetchStorage(groupName, path);
        StorageDownloadCommand<T> command = new StorageDownloadCommand<T>(groupName, path, 0, 0, callback);
        return connectionManager.executeFdfsCmd(client.getInetSocketAddress(), command);
    }

    public void setTrackerClientService(TrackerClient trackerClientService) {
        this.trackerClient = trackerClientService;
    }

    public void setConnectionManager(ConnectionManager connectionManager) {
        this.connectionManager = connectionManager;
    }

}

标签：依赖,tobato,fastdfs,groupName,bean,command,引入,import,com
From： https://www.cnblogs.com/chenliugou/p/18113183

引入两个依赖，存在相同bean，导致启动失败