com.acgist.snail.net.ftp.FtpMessageHandler Maven / Gradle / Ivy
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基于Java开发的下载工具，支持下载协议：BT（BitTorrent、磁力链接、种子文件）、HLS（M3U8）、FTP、HTTP。
package com.acgist.snail.net.ftp;
import java.io.IOException;
import java.io.InputStream;
import java.net.Socket;
import java.nio.ByteBuffer;
import java.time.Duration;
import java.util.StringTokenizer;
import java.util.concurrent.atomic.AtomicBoolean;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.acgist.snail.net.TcpMessageHandler;
import com.acgist.snail.system.config.SystemConfig;
import com.acgist.snail.system.exception.NetException;
import com.acgist.snail.utils.IoUtils;
import com.acgist.snail.utils.StringUtils;
import com.acgist.snail.utils.ThreadUtils;
/**
* FTP消息
*
* @author acgist
* @since 1.0.0
*/
public class FtpMessageHandler extends TcpMessageHandler {
private static final Logger LOGGER = LoggerFactory.getLogger(FtpMessageHandler.class);
public static final String SPLIT = "\r\n"; // 处理粘包分隔符
private boolean range = false; // 断点续传
private String failMessage; // 错误信息
private Socket socket; // Socket
private InputStream inputStream; // 输入流
private String charset = SystemConfig.CHARSET_GBK; // 编码：默认GBK
private final AtomicBoolean commandLock = new AtomicBoolean(false); // 命令等待锁
/**
* 支持UTF8命令
*/
private static final String COMMAND_UTF8 = "UTF8";
/**
* 命令结束正则表达式
*/
private static final String COMMAND_END_REGEX = "\\d{3} .*";
public FtpMessageHandler() {
super(SPLIT);
}
@Override
public void onMessage(ByteBuffer attachment) throws NetException {
String tmp;
StringBuffer command = new StringBuffer();
String content = IoUtils.readContent(attachment, charset);
if(content.contains(SPLIT)) {
int index = content.indexOf(SPLIT);
while(index >= 0) {
tmp = content.substring(0, index);
if(tmp.matches(COMMAND_END_REGEX)) {
command.append(tmp);
oneMessage(command.toString());
command.setLength(0);
} else {
command.append(tmp).append(SPLIT);
}
content = content.substring(index + SPLIT.length());
index = content.indexOf(SPLIT);
}
}
}
/**
* 处理单条消息
*/
private void oneMessage(String message) throws NetException {
LOGGER.debug("收到FTP响应：{}", message);
if(StringUtils.startsWith(message, "530 ")) { // 登陆失败
this.failMessage = "服务器需要登陆授权";
this.close();
this.unlockCommand();
} else if(StringUtils.startsWith(message, "550 ")) { // 文件不存在
this.failMessage = "文件不存在";
this.close();
this.unlockCommand();
} else if(StringUtils.startsWith(message, "421 ")) { // Socket打开失败
this.failMessage = "打开连接失败";
this.close();
this.unlockCommand();
} else if(StringUtils.startsWith(message, "350 ")) { // 端点续传
this.range = true;
} else if(StringUtils.startsWith(message, "220 ")) { // 退出系统
} else if(StringUtils.startsWith(message, "226 ")) { // 下载完成
} else if(StringUtils.startsWith(message, "502 ")) { // 不支持命令：FEAT
this.unlockCommand();
} else if(StringUtils.startsWith(message, "211-")) { // 服务器状态：扩展命令编码查询
if(message.toUpperCase().contains(COMMAND_UTF8)) {
this.charset = SystemConfig.CHARSET_UTF8;
LOGGER.debug("FTP设置编码：{}", this.charset);
}
this.unlockCommand();
} else if(StringUtils.startsWith(message, "227 ")) { // 进入被动模式：获取下载Socket的IP和端口
release(); // 释放旧的资源
final int opening = message.indexOf('(');
final int closing = message.indexOf(')', opening + 1);
if (closing > 0) {
// 创建远程Socket
final String data = message.substring(opening + 1, closing);
final StringTokenizer tokenizer = new StringTokenizer(data, ",");
final String host = tokenizer.nextToken() + "." + tokenizer.nextToken() + "." + tokenizer.nextToken() + "." + tokenizer.nextToken();
// final int port = Integer.parseInt(tokenizer.nextToken()) * 256 + Integer.parseInt(tokenizer.nextToken());
final int port = (Integer.parseInt(tokenizer.nextToken()) << 8) + Integer.parseInt(tokenizer.nextToken());
try {
this.socket = new Socket(host, port);
} catch (IOException e) {
LOGGER.error("打开FTP远程Socket异常", e);
}
}
} else if(StringUtils.startsWith(message, "150 ")) { // 下载完成
if(this.socket == null) {
throw new NetException("请切换到被动模式");
}
try {
this.inputStream = this.socket.getInputStream();
this.unlockCommand();
} catch (IOException e) {
LOGGER.error("打开FTP远程输入流异常", e);
}
}
}
/**
* 是否支持断点续传
*/
public boolean range() {
return this.range;
}
/**
* 字符编码
*/
public String charset() {
this.lockCommand();
return this.charset;
}
/**
* 获取输入流，阻塞线程
*/
public InputStream inputStream() {
this.lockCommand();
if(this.inputStream == null && this.failMessage == null) {
this.failMessage = "下载失败";
}
return this.inputStream;
}
/**
* 获取错误信息
*/
public String failMessage() {
return this.failMessage;
}
/**
* 重置锁
*/
public void resetLock() {
this.commandLock.set(false);
}
@Override
public void close() {
this.release();
super.close();
}
/**
* 释放资源：注意释放FTP下载连接资源（文件流、socket），不关闭命令通道。
*/
private void release() {
IoUtils.close(this.inputStream);
IoUtils.close(this.socket);
}
/**
* 锁定命令
*/
private void lockCommand() {
if(!this.commandLock.get()) {
synchronized (this.commandLock) {
if(!this.commandLock.get()) {
ThreadUtils.wait(this.commandLock, Duration.ofSeconds(5));
}
}
}
}
/**
* 解锁命令
*/
private void unlockCommand() {
synchronized (this.commandLock) {
this.commandLock.set(true);
this.commandLock.notifyAll();
}
}
}