java对ftp操作遇到的一系列的坑
首先让我先讲一下最近项目中遇到的服务器主要使用的ftp服务器构建工具 （IIS 、ser-u、filezilla）
IIS（摘录自百度百科）
- IIS 是widow中IIS是一个World Wide Web server。Gopher server和FTP server全部包容在里面。 IIS意味着你能发布网页，并且有ASP（Active Server Pages）、JAVA、VBscript产生页面，有着一些扩展功能。IIS支持一些有趣的东西，像有编辑环境的界面（FRONTPAGE）、有全文检索功能的（INDEX SERVER）、有多媒体功能的（NET SHOW） 其次,IIS是随Windows NT Server 4.0一起提供的文件和应用程序服务器，是在Windows NT Server上建立Internet服务器的基本组件。它与Windows NT Server完全集成，允许使用Windows NT Server内置的安全性以及NTFS文件系统建立强大灵活的Internet/Intranet站点。IIS（Internet Information Server，互联网信息服务）是一种Web（网页）服务组件，其中包括Web服务器、FTP服务器、NNTP服务器和SMTP服务器，分别用于网页浏览、文件传输、新闻服务和邮件发送等方面，它使得在网络（包括互联网和局域网）上发布信息成了一件很容易的事。
ser-u（摘录自百度百科）
- Serv-U™ - Windows平台的FTP服务器软件Serv-U 是目前众多的FTP 服务器软件之一。通过使用Serv-U，用户能够将任何一台PC 设置成一个FTP 服务器，这样，用户或其他使用者就能够使用FTP 协议，通过在同一网络上的任何一台PC与FTP 服务器连接，进行文件或目录的复制，移动，创建，和删除等。这里提到的FTP 协议是专门被用来规定计算机之间进行文件传输的标准和规则，正是因为有了像FTP 这样的专门协议，才使得人们能够通过不同类型的计算机，使用不同类型的操作系统，对不同类型的文件进行相互传递。
filezilla(摘录百度百科)
- FileZilla是一个免费开源的FTP软件，分为客户端版本和服务器版本，具备所有的FTP软件功能。可控性、有条理的界面和管理多站点的简化方式使得Filezilla客户端版成为一个方便高效的FTP客户端工具，而FileZilla Server则是一个小巧并且可靠的支持FTP&SFTP的FTP服务器软件。
java中操作ftp api-ftpclient
- 相关的的api在下面
http://commons.apache.org/proper/commons-net/apidocs/org/apache/commons/net/ftp/FTPClient.html
开始记录在使用这两个ftp构建工具遇到的一些问题（win7 平台）
- ftp 某些方法 如listFile 等方法无效，卡死
这个问题是两个工具中我都遇到了 ，这个问题是关于主动模和被动模式有关，这里我贴出我在看了相关的博文的总结：
- 主动模式
是可以这样想服务端的端口确定 比如命令端口21端口，还有数据端口20端口 主动链接放在客户端，客户端会开启一个大于1023端口去链接服务器21端口，还有开启N+1端口去链接服务器的数据端口，并监听这两个端口
而客户端又要向服务端开放端口 ，这个是客户端开发由外向内的端口链接（在数据端口上面），，，所以一般会被防火墙拦截 （端口随机）
所以一般会出现可以连接上，但是访问数据会出现异常的现象，就比如今天我用eclipse 的时候出现的问题,调用listFile 会出现卡死在创建socket上面了 - 被动模式
被动方式与主动方式不同的是，先是一样的21端口链接，但是链接成功后，服务器端先开启一个数据端口，告知客户端通过本地的端口来连接自己的这个开放的端口，一般的ftp服务器都允许客户端通过高端口位链接自己。
- 主动模式
卡死,由于ftpclient 操作默认是是通过主动模式 ，可以设置为被动模式（但是自己当时使用eclipse 会出现这个问题 ，使用idea却没有问题 ，跟踪代码是在卡死在了创建socket上面）
ftpClient.enterLocalPassiveMode();
- ftp通过ser-u构建，出现的问题
ftpclient listFile方法无法返回正确的数据，一般返回时null ，使用listNames 返回的也是只有文件名，这个是ftpclient 工具包的一个bug，这个有专门的大神分析了源码，并给出了多种的解决办法，比如我使用了下面这种（分析太多，，有机会仔细看下）
ftpClient.configure(new FTPClientConfig("com.zznode.tnms.ra.c11n.nj.resource.ftp.UnixFTPEntryParser"));
奇怪的是使用IIS 构建的服务器并不会出现这个问题
- 使用ser-u构建 ftp服务器获取文件列表，会获取当前目录和上一级目录
估计是为了兼容linux 和window不同的平台吧 ，，不是吧权限模型也改成了和linux一样的rwx嘛，但是IIS 不会反悔上一级和当前的目录，所以如果是使用ser-u 构建的ftp，那么在进行ftp文件无限层级检索的时候要记得过滤
. ..
这两个目录 ，不然会死循环~~~
filezilla 出现listfile为空的情况（好像是之前使用ser-u也出现类似的情况）
网上说是解决ftp支持系统中文环境，创建下面两个类文件:package com.xpp.util.filezillapatch; import java.text.ParseException; import java.text.ParsePosition; import java.text.SimpleDateFormat; import java.util.Calendar; import java.util.Date; import org.apache.commons.net.ftp.parser.FTPTimestampParserImpl; public class FTPTimestampParserImplExZH extends FTPTimestampParserImpl { private SimpleDateFormat defaultDateFormat = new SimpleDateFormat("mm d hh:mm"); private SimpleDateFormat recentDateFormat = new SimpleDateFormat("yyyy mm d"); private String formatDate_Zh2En(String timeStrZh) { if (timeStrZh == null) { return ""; } int len = timeStrZh.length(); StringBuffer sb = new StringBuffer(len); char ch = ' '; for (int i = 0; i < len; i++) { ch = timeStrZh.charAt(i); if ((ch >= '0' && ch <= '9') || ch == ' ' || ch == ':') { sb.append(ch); } } return sb.toString(); } /** * Implements the one {@link FTPTimestampParser#parseTimestamp(String) method} in the {@link FTPTimestampParser * FTPTimestampParser} interface according to this algorithm: If the recentDateFormat member has been defined, try * to parse the supplied string with that. If that parse fails, or if the recentDateFormat member has not been * defined, attempt to parse with the defaultDateFormat member. If that fails, throw a ParseException. * * @see org.apache.commons.net.ftp.parser.FTPTimestampParser#parseTimestamp(String) */ public Calendar parseTimestamp(String timestampStr) throws ParseException { timestampStr = formatDate_Zh2En(timestampStr); Calendar now = Calendar.getInstance(); now.setTimeZone(this.getServerTimeZone()); Calendar working = Calendar.getInstance(); working.setTimeZone(this.getServerTimeZone()); ParsePosition pp = new ParsePosition(0); Date parsed = null; if (this.recentDateFormat != null) { parsed = recentDateFormat.parse(timestampStr, pp); } if (parsed != null && pp.getIndex() == timestampStr.length()) { working.setTime(parsed); working.set(Calendar.YEAR, now.get(Calendar.YEAR)); if (working.after(now)) { working.add(Calendar.YEAR, -1); } } else { pp = new ParsePosition(0); parsed = defaultDateFormat.parse(timestampStr, pp); // note, length checks are mandatory for us since // SimpleDateFormat methods will succeed if less than // full string is matched. They will also accept, // despite "leniency" setting, a two-digit number as // a valid year (e.g. 22:04 will parse as 22 A.D.) // so could mistakenly confuse an hour with a year, // if we don't insist on full length parsing. if (parsed != null && pp.getIndex() == timestampStr.length()) { working.setTime(parsed); } else { throw new ParseException("Timestamp could not be parsed with older or recent DateFormat", pp.getIndex()); } } return working; } }
第二个文件
package com.xpp.util.filezillapatch;
/*
* Copyright 2001-2005 The Apache Software Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
import java.text.ParseException;
import java.util.Calendar;
import org.apache.commons.net.ftp.FTPClientConfig;
import org.apache.commons.net.ftp.FTPFile;
import org.apache.commons.net.ftp.parser.ConfigurableFTPFileEntryParserImpl;
import org.apache.log4j.Logger;
/**
* 注：common-net-1.4.1.jar源码，修改对于日期中文格式的支持，从而解决FTPClient.listFiles()返回为空问题
* Implementation FTPFileEntryParser and FTPFileListParser for standard
* Unix Systems.
*
* This class is based on the logic of Daniel Savarese's
* DefaultFTPListParser, but adapted to use regular expressions and to fit the
* new FTPFileEntryParser interface.
* @version $Id: UnixFTPEntryParser.java 161712 2005-04-18 02:57:04Z scohen $
* @see org.apache.commons.net.ftp.FTPFileEntryParser FTPFileEntryParser (for usage instructions)
*/
public class UnixFTPEntryParser extends ConfigurableFTPFileEntryParserImpl
{
private static Logger logger = Logger.getLogger(UnixFTPEntryParser.class);
/**
* months abbreviations looked for by this parser. Also used
* to determine which month is matched by the parser
*/
private static final String DEFAULT_MONTHS =
"(Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec)";
static final String DEFAULT_DATE_FORMAT
= "MMM d yyyy"; //Nov 9 2001
static final String DEFAULT_RECENT_DATE_FORMAT
= "MMM d HH:mm"; //Nov 9 20:06
static final String NUMERIC_DATE_FORMAT
= "yyyy-MM-dd HH:mm"; //2001-11-09 20:06
/**
* Some Linux distributions are now shipping an FTP server which formats
* file listing dates in an all-numeric format:
* "yyyy-MM-dd HH:mm.
* This is a very welcome development, and hopefully it will soon become
* the standard. However, since it is so new, for now, and possibly
* forever, we merely accomodate it, but do not make it the default.
*
* For now end users may specify this format only via
* UnixFTPEntryParser(FTPClientConfig).
* Steve Cohen - 2005-04-17
*/
public static final FTPClientConfig NUMERIC_DATE_CONFIG =
new FTPClientConfig(
FTPClientConfig.SYST_UNIX,
NUMERIC_DATE_FORMAT,
null, null, null, null);
/**
* this is the regular expression used by this parser.
*
* Permissions:
* r the file is readable
* w the file is writable
* x the file is executable
* - the indicated permission is not granted
* L mandatory locking occurs during access (the set-group-ID bit is
* on and the group execution bit is off)
* s the set-user-ID or set-group-ID bit is on, and the corresponding
* user or group execution bit is also on
* S undefined bit-state (the set-user-ID bit is on and the user
* execution bit is off)
* t the 1000 (octal) bit, or sticky bit, is on [see chmod(1)], and
* execution is on
* T the 1000 bit is turned on, and execution is off (undefined bit-
* state)
*/
private static final String REGEX =
"([bcdlfmpSs-])"
+"(((r|-)(w|-)([xsStTL-]))((r|-)(w|-)([xsStTL-]))((r|-)(w|-)([xsStTL-])))\\+?\\s+"
+ "(\\d+)\\s+"
+ "(\\S+)\\s+"
+ "(?:(\\S+)\\s+)?"
+ "(\\d+)\\s+"
/*
numeric or standard format date
*/
//问题出在此处，这个匹配只匹配2中形式：
//(1)2008-08-03
//(2)Jan 9或4月 26
//而出错的hp机器下的显示为 8月20日（没有空格分开）
//故无法匹配而报错
//将下面字符串改为：
+ "((?:\\d+[-/]\\d+[-/]\\d+)|(?:\\S+\\s+\\S+)|(?:\\S+))\\s+"
//+ "((?:\\d+[-/]\\d+[-/]\\d+)|(?:\\S+\\s+\\S+))\\s+"
/*
year (for non-recent standard format)
or time (for numeric or recent standard format
*/
+ "(\\d+(?::\\d+)?)\\s+"
+ "(\\S*)(\\s*.*)";
/**
* The default constructor for a UnixFTPEntryParser object.
*
* @exception IllegalArgumentException
* Thrown if the regular expression is unparseable. Should not be seen
* under normal conditions. It it is seen, this is a sign that
* REGEX is not a valid regular expression.
*/
public UnixFTPEntryParser()
{
this(null);
}
/**
* This constructor allows the creation of a UnixFTPEntryParser object with
* something other than the default configuration.
*
* @param config The {@link FTPClientConfig configuration} object used to
* configure this parser.
* @exception IllegalArgumentException
* Thrown if the regular expression is unparseable. Should not be seen
* under normal conditions. It it is seen, this is a sign that
* REGEX is not a valid regular expression.
* @since 1.4
*/
public UnixFTPEntryParser(FTPClientConfig config)
{
super(REGEX);
configure(config);
}
/**
* Parses a line of a unix (standard) FTP server file listing and converts
* it into a usable format in the form of an FTPFile
* instance. If the file listing line doesn't describe a file,
* null is returned, otherwise a FTPFile
* instance representing the files in the directory is returned.
*
* @param entry A line of text from the file listing
* @return An FTPFile instance corresponding to the supplied entry
*/
public FTPFile parseFTPEntry(String entry) {
FTPFile file = new FTPFile();
file.setRawListing(entry);
int type;
boolean isDevice = false;
if (matches(entry))
{
String typeStr = group(1);
String hardLinkCount = group(15);
String usr = group(16);
String grp = group(17);
String filesize = group(18);
String datestr = group(19) + " " + group(20);
String name = group(21);
String endtoken = group(22);
try
{
//file.setTimestamp(super.parseTimestamp(datestr));
FTPTimestampParserImplExZH Zh2En = new FTPTimestampParserImplExZH();
file.setTimestamp(Zh2En.parseTimestamp(datestr));
}
catch (ParseException e)
{
//logger.error(e, e);
//return null; // this is a parsing failure too.
//logger.info(entry+":修改日期重置为当前时间");
file.setTimestamp(Calendar.getInstance());
}
// bcdlfmpSs-
switch (typeStr.charAt(0))
{
case 'd':
type = FTPFile.DIRECTORY_TYPE;
break;
case 'l':
type = FTPFile.SYMBOLIC_LINK_TYPE;
break;
case 'b':
case 'c':
isDevice = true;
// break; - fall through
case 'f':
case '-':
type = FTPFile.FILE_TYPE;
break;
default:
type = FTPFile.UNKNOWN_TYPE;
}
file.setType(type);
int g = 4;
for (int access = 0; access < 3; access++, g += 4)
{
// Use != '-' to avoid having to check for suid and sticky bits
file.setPermission(access, FTPFile.READ_PERMISSION,
(!group(g).equals("-")));
file.setPermission(access, FTPFile.WRITE_PERMISSION,
(!group(g + 1).equals("-")));
String execPerm = group(g + 2);
if (!execPerm.equals("-") && !Character.isUpperCase(execPerm.charAt(0)))
{
file.setPermission(access, FTPFile.EXECUTE_PERMISSION, true);
}
else
{
file.setPermission(access, FTPFile.EXECUTE_PERMISSION, false);
}
}
if (!isDevice)
{
try
{
file.setHardLinkCount(Integer.parseInt(hardLinkCount));
}
catch (NumberFormatException e)
{
// intentionally do nothing
}
}
file.setUser(usr);
file.setGroup(grp);
try
{
file.setSize(Long.parseLong(filesize));
}
catch (NumberFormatException e)
{
// intentionally do nothing
}
if (null == endtoken)
{
file.setName(name);
}
else
{
// oddball cases like symbolic links, file names
// with spaces in them.
name += endtoken;
if (type == FTPFile.SYMBOLIC_LINK_TYPE)
{
int end = name.indexOf(" -> ");
// Give up if no link indicator is present
if (end == -1)
{
file.setName(name);
}
else
{
file.setName(name.substring(0, end));
file.setLink(name.substring(end + 4));
}
}
else
{
file.setName(name);
}
}
return file;
} else {
logger.info("matches(entry) failure:"+entry);
}
return null;
}
/**
* Defines a default configuration to be used when this class is
* instantiated without a {@link FTPClientConfig FTPClientConfig}
* parameter being specified.
* @return the default configuration for this parser.
*/
protected FTPClientConfig getDefaultConfiguration() {
return new FTPClientConfig(
FTPClientConfig.SYST_UNIX,
DEFAULT_DATE_FORMAT,
DEFAULT_RECENT_DATE_FORMAT,
null, null, null);
}
}
然后在你连接ftp的地方加上
ftp.configure(new FTPClientConfig("com.xpp.util.filezillapatch.UnixFTPEntryParser"));这样就能返回正常的数据了