springboot连接多个ftp springboot ftp连接池

最近在写一个FTP上传工具，用到了Apache的FTPClient，但是每个线程频繁的创建和销毁FTPClient对象对服务器的压力很大，因此，此处最好使用一个FTPClient连接池。仔细翻了一下Apache的api，发现它并没有一个FTPClientPool的实现，所以，不得不自己写一个FTPClientPool。下面就大体介绍一下开发连接池的整个过程，供大家参考。

我们可以利用Apache提供的common-pool包来协助我们开发连接池。而开发一个简单的对象池，仅需要实现common-pool 包中的ObjectPool和PoolableObjectFactory两个接口即可。

线程池的意义

为了减少频繁创建、销毁对象带来的性能消耗，我们可以利用对象池的技术来实现对象的复用。对象池提供了一种机制，它可以管理对象池中对象的生命周期，提供了获取和释放对象的方法，可以让客户端很方便的使用对象池中的对象。

pom引入依赖
commons-net
commons-net
3.5
commons-pool
commons-pool
1.6
org.apache.commons
commons-pool2
2.0
创建ftp配置信息
在resources目录下创建ftp.properties配置文件,目录结构如下：
image.png
添加如下的配置信息:########### FTP用户名称 ###########ftp.userName=hrabbit########### FTP用户密码 ###########ftp.passWord=123456########### FTP主机IP ###########ftp.host=127.0.0.1########### FTP主机端口号 ###########ftp.port=21########### 保存根路径 ###########ftp.baseUrl=/
创建FTPProperties.java配置文件
加载配置内容到Spring中,配置信息基本延用我的就可以。/**
* FTP的配置信息
* @Auther: hrabbit
* @Date: 2018-12-03 2:06 PM
* @Description:
*/@Data@Component@PropertySource("classpath:ftp.properties")@ConfigurationProperties(prefix = "ftp")public class FTPProperties {    private String username;    private String password;    private String host;    private Integer port;    private String baseUrl;    private Integer passiveMode = FTP.BINARY_FILE_TYPE;    private String encoding="UTF-8";    private int clientTimeout=120000;    private int bufferSize;    private int transferFileType=FTP.BINARY_FILE_TYPE;    private boolean renameUploaded;    private int retryTime;
}
创建FTPClientPool线程池/**
* 自定义实现ftp连接池
* @Auther: hrabbit
* @Date: 2018-12-03 3:40 PM
* @Description:
*/@Slf4j@SuppressWarnings("all")public class FTPClientPool implements ObjectPool {    private static final int DEFAULT_POOL_SIZE = 10;    public BlockingQueue blockingQueue;    private FTPClientFactory factory;    public FTPClientPool(FTPClientFactory factory) throws Exception {        this(DEFAULT_POOL_SIZE, factory);
}    public FTPClientPool(int poolSize, FTPClientFactory factory) throws Exception {        this.factory = factory;        this.blockingQueue = new ArrayBlockingQueue(poolSize);
initPool(poolSize);
}    /**
* 初始化连接池
* @param maxPoolSize
*                  最大连接数
* @throws Exception
*/
private void initPool(int maxPoolSize) throws Exception {        int count = 0;        while(count 
count++;
}
}    /**
* 从连接池中获取对象
*/
@Override
public FTPClient borrowObject() throws Exception {
FTPClient client = blockingQueue.take();        if(client == null) {
client = factory.makeObject();
} else if(!factory.validateObject(client)) {
invalidateObject(client);
client = factory.makeObject();
}        return client;
}    /**
* 返还一个对象(链接)
*/
@Override
public void returnObject(FTPClient client) throws Exception {        if ((client != null) && !blockingQueue.offer(client,2,TimeUnit.MINUTES)) {            try {
factory.destroyObject(client);
} catch (Exception e) {                throw e;
}
}
}    /**
* 移除无效的对象(FTP客户端)
*/
@Override
public void invalidateObject(FTPClient client) throws Exception {
blockingQueue.remove(client);
}    /**
* 增加一个新的链接，超时失效
*/
@Override
public void addObject() throws Exception {
blockingQueue.offer(factory.makeObject(), 2, TimeUnit.MINUTES);
}    /**
* 重新连接
*/
public FTPClient reconnect() throws Exception {        return factory.makeObject();
}    /**
* 获取空闲链接数(这里暂不实现)
*/
@Override
public int getNumIdle() {        return blockingQueue.size();
}    /**
* 获取正在被使用的链接数
*/
@Override
public int getNumActive() {        return DEFAULT_POOL_SIZE - getNumIdle();
}    @Override
public void clear() throws Exception {
}    /**
* 关闭连接池
*/
@Override
public void close() {        try {            while(blockingQueue.iterator().hasNext()) {
FTPClient client = blockingQueue.take();
factory.destroyObject(client);
}
} catch(Exception e) {
log.error("close ftp client pool failed...{}", e);
}
}    /**
* 增加一个新的链接，超时失效
*/
public void addObject(FTPClient ftpClient) throws Exception {
blockingQueue.put(ftpClient);
}
}
创建一个FTPClientFactory工厂类
创建FTPClientFactory实现PoolableObjectFactory的接口，FTPClient工厂类，通过FTPClient工厂提供FTPClient实例的创建和销毁/**
* FTPClient 工厂
* @Auther: hrabbit
* @Date: 2018-12-03 3:41 PM
* @Description:
*/@Slf4j@SuppressWarnings("all")public class FTPClientFactory implements PoolableObjectFactory {    private FTPProperties ftpProperties;    public FTPClientFactory(FTPProperties ftpProperties) {        this.ftpProperties = ftpProperties;
}    @Override
public FTPClient makeObject() throws Exception {
FTPClient ftpClient = new FTPClient();
ftpClient.setControlEncoding(ftpProperties.getEncoding());
ftpClient.setConnectTimeout(ftpProperties.getClientTimeout());        try {
ftpClient.connect(ftpProperties.getHost(), ftpProperties.getPort());            int reply = ftpClient.getReplyCode();            if (!FTPReply.isPositiveCompletion(reply)) {
ftpClient.disconnect();
log.warn("FTPServer refused connection");                return null;
}            boolean result = ftpClient.login(ftpProperties.getUsername(), ftpProperties.getPassword());
ftpClient.setFileType(ftpProperties.getTransferFileType());            if (!result) {
log.warn("ftpClient login failed... username is {}", ftpProperties.getUsername());
}
} catch (Exception e) {
log.error("create ftp connection failed...{}", e);            throw e;
}        return ftpClient;
}    @Override
public void destroyObject(FTPClient ftpClient) throws Exception {        try {            if(ftpClient != null && ftpClient.isConnected()) {
ftpClient.logout();
}
} catch (Exception e) {
log.error("ftp client logout failed...{}", e);            throw e;
} finally {            if(ftpClient != null) {
ftpClient.disconnect();
}
}
}    @Override
public boolean validateObject(FTPClient ftpClient) {        try {            return ftpClient.sendNoOp();
} catch (Exception e) {
log.error("Failed to validate client: {}");
}        return false;
}    @Override
public void activateObject(FTPClient obj) throws Exception {        //Do nothing
}    @Override
public void passivateObject(FTPClient obj) throws Exception {        //Do nothing
}
}
创建FTPUtils.java的工具类
FTPUtils.java中封装了上传、下载等方法，在项目启动的时候，在@PostConstruct注解的作用下通过执行init()的方法，创建FTPClientFactory工厂中，并初始化了FTPClientPool线程池，这样每次调用方法的时候，都直接从FTPClientPool中取出一个FTPClient对象/**
* @Auther: hrabbit
* @Date: 2018-12-03 3:47 PM
* @Description:
*/@Slf4j@Componentpublic class FTPUtils {    /**
* FTP的连接池
*/
@Autowired
public static FTPClientPool ftpClientPool;    /**
* FTPClient对象
*/
public static FTPClient ftpClient;    private static FTPUtils ftpUtils;    @Autowired
private FTPProperties ftpProperties;    /**
* 初始化设置
* @return
*/
@PostConstruct
public boolean init() {
FTPClientFactory factory = new FTPClientFactory(ftpProperties);
ftpUtils = this;        try {
ftpClientPool = new FTPClientPool(factory);
} catch (Exception e) {
e.printStackTrace();            return false;
}        return true;
}    /**
* 获取连接对象
* @return
* @throws Exception
*/
public static FTPClient getFTPClient() throws Exception {        //初始化的时候从队列中取出一个连接
if (ftpClient==null) {            synchronized (ftpClientPool) {
ftpClient = ftpClientPool.borrowObject();
}
}        return ftpClient;
}    /**
* 当前命令执行完成命令完成
* @throws IOException
*/
public void complete() throws IOException {
ftpClient.completePendingCommand();
}    /**
* 当前线程任务处理完成，加入到队列的最后
* @return
*/
public void disconnect() throws Exception {
ftpClientPool.addObject(ftpClient);
}    /**
* Description: 向FTP服务器上传文件
*
* @Version1.0
* @param remoteFile
*            上传到FTP服务器上的文件名
* @param input
*            本地文件流
* @return 成功返回true，否则返回false
*/
public static boolean uploadFile(String remoteFile, InputStream input)  {        boolean result = false;        try {
getFTPClient();
ftpClient.enterLocalPassiveMode();
result = ftpClient.storeFile(remoteFile, input);
input.close();
ftpClient.disconnect();
} catch (Exception e) {
e.printStackTrace();
}        return result;
}    /**
* Description: 向FTP服务器上传文件
*
* @Version1.0
* @param remoteFile
*            上传到FTP服务器上的文件名
* @param localFile
*            本地文件
* @return 成功返回true，否则返回false
*/
public static boolean uploadFile(String remoteFile, String localFile){
FileInputStream input = null;        try {
input = new FileInputStream(new File(localFile));
} catch (FileNotFoundException e) {
e.printStackTrace();
}        return uploadFile(remoteFile, input);
}    /**
* 拷贝文件
* @param fromFile
* @param toFile
* @return
* @throws Exception
*/
public boolean copyFile(String fromFile, String toFile) throws Exception {
InputStream in=getFileInputStream(fromFile);
getFTPClient();        boolean flag = ftpClient.storeFile(toFile, in);
in.close();        return flag;
}    /**
* 获取文件输入流
* @param fileName
* @return
* @throws IOException
*/
public static InputStream getFileInputStream(String fileName) throws Exception {
ByteArrayOutputStream fos=new ByteArrayOutputStream();
getFTPClient();
ftpClient.retrieveFile(fileName, fos);
ByteArrayInputStream in=new ByteArrayInputStream(fos.toByteArray());
fos.close();        return in;
}    /**
* Description: 从FTP服务器下载文件
*
* @Version1.0
* @return
*/
public static boolean downFile(String remoteFile, String localFile){        boolean result = false;        try {
getFTPClient();
OutputStream os = new FileOutputStream(localFile);
ftpClient.retrieveFile(remoteFile, os);
ftpClient.logout();
ftpClient.disconnect();
result = true;
} catch (Exception e) {
e.printStackTrace();
} finally {            try {
} catch (Exception e) {
e.printStackTrace();
}
}        return result;
}    /**
* 从ftp中获取文件流
* @param filePath
* @return
* @throws Exception
*/
public static InputStream getInputStream(String filePath) throws Exception {
getFTPClient();
InputStream inputStream = ftpClient.retrieveFileStream(filePath);        return inputStream;
}    /**
* ftp中文件重命名
* @param fromFile
* @param toFile
* @return
* @throws Exception
*/
public boolean rename(String fromFile,String toFile) throws Exception {
getFTPClient();        boolean result = ftpClient.rename(fromFile,toFile);        return result;
}    /**
* 获取ftp目录下的所有文件
* @param dir
* @return
*/
public FTPFile[] getFiles(String dir) throws Exception {
getFTPClient();
FTPFile[] files = new FTPFile[0];        try {
files = ftpClient.listFiles(dir);
}catch (Throwable thr){
thr.printStackTrace();
}        return files;
}    /**
* 获取ftp目录下的某种类型的文件
* @param dir
* @param filter
* @return
*/
public FTPFile[] getFiles(String dir, FTPFileFilter filter) throws Exception {
getFTPClient();
FTPFile[] files = new FTPFile[0];        try {
files = ftpClient.listFiles(dir, filter);
}catch (Throwable thr){
thr.printStackTrace();
}        return files;
}    /**
* 创建文件夹
* @param remoteDir
* @return 如果已经有这个文件夹返回false
*/
public boolean makeDirectory(String remoteDir) throws Exception {
getFTPClient();        boolean result = false;        try {
result = ftpClient.makeDirectory(remoteDir);
} catch (IOException e) {
e.printStackTrace();
}        return result;
}    public boolean mkdirs(String dir) throws Exception {        boolean result = false;        if (null == dir) {            return result;
}
getFTPClient();
ftpClient.changeWorkingDirectory("/");
StringTokenizer dirs = new StringTokenizer(dir, "/");
String temp = null;        while (dirs.hasMoreElements()) {
temp = dirs.nextElement().toString();            //创建目录
ftpClient.makeDirectory(temp);            //进入目录
ftpClient.changeWorkingDirectory(temp);
result = true;
}
ftpClient.changeWorkingDirectory("/");        return result;
}
}
创建FtpClientTest.java测试类
上传一张图片到FTP服务器，并将文件重新命名为hrabbit.jpg，代码如下:/**
* FtpClient测试
* @Auther: hrabbit
* @Date: 2018-12-21 9:14 PM
* @Description:
*/@RunWith(SpringRunner.class)@SpringBootTestpublic class FtpClientTest {    /**
* 测试上传
*/
@Test
public void uploadFile(){        boolean flag = FTPUtils.uploadFile("hrabbit.jpg", "/Users/mrotaku/Downloads/klklklkl_4x.jpg");
Assert.assertEquals(true, flag);
}
}

程序完美运行，这时候我们查看我们的FTP服务器，http://localhost:8866/hrabbit.jpg

image.png

作者：hrabbits