SpringBoot整合自定义FTP文件链接池

说明：经过GenericObjectPool实现的FTP链接池，记录一下以供之后使用
环境：
JDK版本1.8
框架 ：springboot2.1
文件服务器： Serv-U
1.引入依赖

<!--ftp文件上传-->
<dependency>
<groupId>commons-net</groupId>
<artifactId>commons-net</artifactId>
<version>3.3</version>
</dependency>
<!--自定义链接池-->
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-pool2</artifactId>
<version>2.4.2</version>
</dependency>

2.建立ftp.properties

ftp.Host=192.168.xx.xx 本机ip
ftp.Port=21
ftp.UserName=root
ftp.PassWord=root
ftp.workDir=/images
ftp.encoding=utf-8
ftp.root=/
ftp.MaxTotal=100
ftp.MinIdel=2
ftp.MaxIdle=5
ftp.MaxWaitMillis=3000

3.建立配置类FtpConfig

package com.hcq.demo.util;

import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.PropertySource;
import org.springframework.stereotype.Component;

import java.util.HashMap;
import java.util.Map;
import java.util.Set;

/**
* fileName:FtpConfig
* description:
* author:hcq
* createTime:2019-03-15 15:04
*/

@Component
@ConfigurationProperties(prefix="ftp")
@PropertySource("classpath:ftp.properties")
public class FtpConfig {
private String Host;
private int Port;
private String UserName;
private String PassWord;
private String workDir;
private String encoding;
private String root;
private int MaxTotal;
private int MinIdel;
private int MaxIdle;
private int MaxWaitMillis;
.......省略get set
}

4.建立FtpClientFactory工厂类

package com.hcq.demo.util;

import org.apache.commons.net.ftp.FTP;
import org.apache.commons.net.ftp.FTPClient;
import org.apache.commons.pool2.PooledObject;
import org.apache.commons.pool2.impl.DefaultPooledObject;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import org.apache.commons.pool2.PooledObjectFactory;

import java.io.IOException;

/**
* fileName:FtpClientFactory
* description:
* author:hcq
* createTime:2019-03-18 19:49
*/
@Component
public class FtpClientFactory implements PooledObjectFactory<FTPClient> {
@Autowired
FtpConfig config;
//建立链接到池中
@Override
public PooledObject<FTPClient> makeObject() {
FTPClient ftpClient = new FTPClient();//建立客户端实例
return new DefaultPooledObject<>(ftpClient);
}
//销毁链接，当链接池空闲数量达到上限时，调用此方法销毁链接
@Override
public void destroyObject(PooledObject<FTPClient> pooledObject) {
FTPClient ftpClient = pooledObject.getObject();
try {
ftpClient.logout();
if (ftpClient.isConnected()) {
ftpClient.disconnect();
}
} catch (IOException e) {
throw new RuntimeException("Could not disconnect from server.", e);
}
}
//连接状态检查
@Override
public boolean validateObject(PooledObject<FTPClient> pooledObject) {
FTPClient ftpClient = pooledObject.getObject();
try {
return ftpClient.sendNoOp();
} catch (IOException e) {
return false;
}
}
//初始化链接
@Override
public void activateObject(PooledObject<FTPClient> pooledObject) throws Exception {
FTPClient ftpClient = pooledObject.getObject();
ftpClient.connect(config.getHost(),config.getPort());
ftpClient.login(config.getUserName(), config.getPassWord());
ftpClient.setControlEncoding(config.getEncoding());
ftpClient.changeWorkingDirectory(config.getWorkDir());
ftpClient.setFileType(FTP.BINARY_FILE_TYPE);//设置上传文件类型为二进制，不然将没法打开文件
}
//钝化链接，使连接变为可用状态
@Override
public void passivateObject(PooledObject<FTPClient> pooledObject) throws Exception {
FTPClient ftpClient = pooledObject.getObject();
try {
ftpClient.changeWorkingDirectory(config.getRoot());
ftpClient.logout();
if (ftpClient.isConnected()) {
ftpClient.disconnect();
}
} catch (IOException e) {
throw new RuntimeException("Could not disconnect from server.", e);
}
}
//用于链接池中获取pool属性
public FtpConfig getConfig() {
return config;
}
}

5.建立FtpPool链接池

package com.hcq.demo.util;

import org.apache.commons.net.ftp.FTPClient;
import org.apache.commons.pool2.impl.GenericObjectPool;
import org.apache.commons.pool2.impl.GenericObjectPoolConfig;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

/**
* fileName:ftpPool
* description:FTP链接池
* 1.能够获取池中空闲连接
* 2.能够将连接归还到池中
* 3.当池中空闲连接不足时，能够建立连接
* author:hcq
* createTime:2019-03-16 9:59
*/
@Component
public class FtpPool {
FtpClientFactory factory;
private final GenericObjectPool<FTPClient> internalPool;
//初始化链接池
public FtpPool(@Autowired FtpClientFactory factory){
this.factory=factory;
FtpConfig config = factory.getConfig();
GenericObjectPoolConfig poolConfig = new GenericObjectPoolConfig();
poolConfig.setMaxTotal(config.getMaxTotal());
poolConfig.setMinIdle(config.getMinIdel());
poolConfig.setMaxIdle(config.getMaxIdle());
poolConfig.setMaxWaitMillis(config.getMaxWaitMillis());
this.internalPool = new GenericObjectPool<FTPClient>(factory,poolConfig);
}
//从链接池中取链接
public FTPClient getFTPClient() {
try {
return internalPool.borrowObject();
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
//将连接归还到链接池
public void returnFTPClient(FTPClient ftpClient) {
try {
internalPool.returnObject(ftpClient);
} catch (Exception e) {
e.printStackTrace();
}
}
/**
* 销毁池子
*/
public void destroy() {
try {
internalPool.close();
} catch (Exception e) {
e.printStackTrace();
}
}
}

6.建立FtpUtil类

package com.hcq.demo.util;

import org.apache.commons.net.ftp.FTPClient;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.core.io.ResourceLoader;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Component;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.http.HttpServletResponse;
import java.io.*;
import java.util.UUID;

/** * fileName:FTP工具类 * description:提供文件上传和下载 * author:hcq * createTime:2019-03-16 8:55 */@Componentpublic class FtpUtil { @Autowired FtpConfig config; @Autowired private ResourceLoader resourceLoader; @Autowired FtpPool pool; /** * Description: 向FTP服务器上传文件 * * @Version2.0 * @param file * 上传到FTP服务器上的文件 * @return * 成功返回文件名，不然返回null */ public String upload(MultipartFile file) throws Exception { FTPClient ftpClient = pool.getFTPClient(); //开始进行文件上传 String fileName=UUID.randomUUID()+file.getOriginalFilename().substring(file.getOriginalFilename().lastIndexOf(".")); InputStream input=file.getInputStream(); try { boolean result=ftpClient.storeFile(fileName,input);//执行文件传输 if(!result){//上传失败 throw new RuntimeException("上传失败"); } }catch(Exception e){ e.printStackTrace(); return null; }finally {//关闭资源 input.close(); System.out.println("开始归还链接"); pool.returnFTPClient(ftpClient);//归还资源 } return fileName; } /** * Description: 从FTP服务器下载文件 * * @Version1.0 * @param fileName * FTP服务器中的文件名 * @param resp * 响应客户的响应体 */ public void downLoad(String fileName,HttpServletResponse resp) throws IOException { FTPClient ftpClient = pool.getFTPClient(); resp.setContentType("application/force-download");// 设置强制下载不打开 MIME resp.addHeader("Content-Disposition", "attachment;fileName="+fileName);// 设置文件名 //将文件直接读取到响应体中 OutputStream out = resp.getOutputStream(); ftpClient.retrieveFile(config.getWorkDir()+"/"+fileName, out); out.flush(); out.close(); pool.returnFTPClient(ftpClient); } /** * Description: 从FTP服务器读取图片 * * @Version1.0 * @param fileName * 须要读取的文件名 * @return * 返回文件对应的Entity */ public ResponseEntity show(String fileName){ String username=config.getUserName(); String password=config.getPassWord(); String host=config.getHost(); String work=config.getWorkDir(); //ftp://root:root@192.168.xx.xx/+fileName return ResponseEntity.ok(resourceLoader.getResource("ftp://"+username+":"+password+"@"+host+work+"/"+fileName)); }