Summary of issues encountered by Java using CRF

1, libcrfpp.so placed in the idea project resources, hit jar package in the jar.

Jar Package Tool Class

/*
* Class Nativeutils is published under the the The MIT License:
*
* Copyright (c) Adam Heinrich <[email protected]>
*
* Permission is hereby granted, free of charge, to all person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* In the software without restriction, including without limitation the rights
* To use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* Copies of the software, and to permit persons to whom the software are
* Furnished to does so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall is included in all
* Copies or substantial portions of the software.
*
* The software is provided ' as is ', without WARRANTY of any KIND, EXPRESS OR
* implied, including but not LIMITED to the warranties of merchantability,
* FITNESS for A particular PURPOSE and noninfringement. In NO EVENT shall the
* AUTHORS or COPYRIGHT holders be liable for any CLAIM, damages or other
* Liability, WHETHER in a ACTION of contract, TORT OR OTHERWISE, arising from,
* Out of OR in CONNECTION with the software or the use or other dealings in the
* Software.
*/
Package cz.adamh.utils;

Import java.io.*;
 
/**
* A Simple Library class which helps with loading dynamic libraries stored in the
* JAR Archive. These libraries usualy contain implementation of some methods in
* Native code (using Jni-java native Interface).
*
* @see Http://adamheinrich.com/blog/2012/how-to-load-native-jni-library-from-jar
* @see Https://github.com/adamheinrich/native-utils
*
*/
public class Nativeutils {
 
/**
* Private Constructor-this class would never be instanced
*/
Private Nativeutils () {
}
 
/**
* Loads Library from the current JAR archive
*
* The file from JAR is copied to system temporary directory and then loaded. The temporary file is deleted after exiting.
* Method uses String as filename because the pathname is "abstract" and not system-dependent.
*
* @param path The path of file inside JAR as absolute path (beginning with '/'), e.g./package/file.ext
* @throws ioexception If temporary file creation or Read/write operation fails
* @throws illegalargumentexception If source file (param path) does not exist
* @throws IllegalArgumentException If the path is not absolute or If the filename is shorter than three characters (Restri Ction of {@see file#createtempfile (java.lang.String, Java.lang.String)}).
*/
public static void Loadlibraryfromjar (String path) throws IOException {
 
if (!path.startswith ("/")) {
throw new IllegalArgumentException ("The path has been absolute (start with '/').");
}
 
Obtain filename from path
string[] Parts = Path.split ("/");
String filename = (parts.length > 1)? PARTS[PARTS.LENGTH-1]: null;
 
Split filename to prexif and suffix (extension)
String prefix = "";
String suffix = null;
if (filename! = null) {
Parts = filename.split ("\ \", 2);
prefix = parts[0];
suffix = (parts.length > 1)? "." +PARTS[PARTS.LENGTH-1]: null; Thanks, davs! :-)
}
 
Check if the filename is okay
if (filename = = NULL | | prefix.length () < 3) {
throw new IllegalArgumentException ("The filename has to be at least 3 characters long.");
}
 
Prepare Temporary file
File temp = file.createtempfile (prefix, suffix);
Temp.deleteonexit ();
 
if (!temp.exists ()) {
throw new FileNotFoundException ("File" + temp.getabsolutepath () + "does not exist.");
}
 
Prepare Buffer for data copying
byte[] buffer = new byte[1024];
int readbytes;
 
Open and check input stream
InputStream is = NativeUtils.class.getResourceAsStream (path);
if (is = = null) {
throw new FileNotFoundException ("File" + path + "is not found inside JAR.");
}
 
Open output stream and copy data between source file in JAR and the temporary file
OutputStream OS = new FileOutputStream (temp);
try {
while ((readbytes = is.read (buffer))! =-1) {
Os.write (buffer, 0, readbytes);
}
} finally {
If Read/write fails, close streams safely before throwing an exception
Os.close ();
Is.close ();
}
 
Finally, load the library
System.load (Temp.getabsolutepath ());
}
}

2. Need to install CRF related information

There are two ways to find it online:

This occurs because a library file such as libcrfpp.so.0 cannot be found, and the solution is (as if this method is not used by the root user):

1. Modify the/etc/ld.so.conf file
2. Join Include/usr/local/lib
3. Execute/sbin/ldconfig-v, refresh Lib Library

Solution Two is to establish the following symbolic link:

　 ln -s /usr/local/lib/libcrfpp.a /usr/lib/libcrfpp.a　 ln -s /usr/local/lib/libcrfpp.so /usr/lib/libcrfpp.so　 ln -s /usr/local/lib/libcrfpp.so.0 /usr/lib/libcrfpp.so.0
　 连接 https://zxdcs.github.io/post/16/crf_java/
　 python 用户连接 http://midday.me/article/94d6bd4973264e1a801f8445904a810d
　 公司线上环境是docker容器方式不可用，实际用的方式一。

3、再有是连接库使用训练出来的model文件。路径网上均采用相对路劲，实际容器中不可用，采用绝对路径后解决。

caused By:java.lang.RuntimeException:feature_index.cpp (193) [Mmap_.open (Model_filename)] Mmap.h (153) [(FD =:: Open ( FileName, flag | o_binary)) >= 0] Open Failed:model
At Org.chasen.crfpp.CRFPPJNI.new_Tagger (Native Method)
At Org.chasen.crfpp.tagger.<init> (tagger.java:183)
At Com.jd.app.server.loadcrfmodel.<clinit> (loadcrfmodel.java:89)
... More

This error can be solved with 3.

Summary of issues encountered by Java using CRF