Java implementation file Segmentation and merging

is the IO stream-------------------------------------------------------

Instance class:

1. Abstract class

Import Java.io.File;
Import java.io.IOException;


Public abstract class Partitionfile {

/**
* Number of bytes in a single file set
*/
public static long max_byte = 1024*1024*1000;


/**
* Get the number of files that can be split
*
* @param FilePath
* @param max_byte
* @return
*/
public int Getpartitionfilenum (long filebyte, String FilePath) {
if (Max_byte < Filebyte) {
if (filebyte% Max_byte = = 0) {
return (int) (filebyte/max_byte);
} else {
return (int) (filebyte/max_byte) + 1;
}
}
return 1;
}

/**
* Get file length
*
* @param file
* @return
* @throws IOException
*/
Public abstract long getfilelength (file file) throws IOException;


/**
* Split byte file
*
* @param file
* @throws IOException
* @throws IOException
*/
Public abstract string[] Partitionfile (File outpath,file srcfile, int partitionfilenum) throws IOException;


/**
* Merge Files
* @param files
* @param newFile
* @throws IOException
*/
public abstract void Unitefile (string[] files, String newFile) throws IOException;

}

2. Implementation class

Import Java.io.BufferedReader;
Import Java.io.BufferedWriter;
Import Java.io.File;
Import Java.io.FileInputStream;
Import java.io.FileNotFoundException;
Import Java.io.FileReader;
Import Java.io.FileWriter;
Import java.io.IOException;
Import Java.io.InputStreamReader;


public class Splitbigtextfile extends partitionfile{

public static void Main (string[] args) throws Exception {

/* Large File Split */
String srcfile = "h:\\prodata\\datahktw3\\hk\\b_account_audit.csv";//file to be split
String Outpath = "e:\\111111111111111111111111111\\";//File output location after split
File File = new file (srcfile);
File OPath = new file (Outpath);
Splitbigtextfile partitiontextfile = new Splitbigtextfile ();
int count = Partitiontextfile.getpartitionfilenum (File.length (), srcfile);
String str[] = Partitiontextfile.partitionfile (Opath,file, Count);
System.out.println (str.length);
}

@SuppressWarnings ("finally")
@Override
Public long getfilelength (file file) throws IOException {

FileReader FR = null;
BufferedReader br = null;
Long fileSize = 0;
try {
FR = new FileReader (file);
br = new BufferedReader (FR);
String line = Br.readline ();
while (line! = null) {
FileSize + = Line.length ();
line = Br.readline ();
}
} catch (FileNotFoundException ex) {
Ex.printstacktrace ();
} catch (IOException ex) {
Ex.printstacktrace ();
} finally {
if (br! = null) {
Br.close ();
}
if (fr! = null)
Fr.close ();
return fileSize;
}
}

@Override
Public string[] Partitionfile (File outpath,file srcfile, int partitionfilenum) throws IOException {

if (partitionfilenum <= 0) {
return null;
}
FileReader FR = null;
BufferedReader br = null;
Long readnum = 0;
string[] partitions = new String[partitionfilenum];
try {
FR = new FileReader (srcfile);
br = new BufferedReader (new InputStreamReader (New FileInputStream (Srcfile), "gb2312"));
int i = 1;
while (Partitionfilenum > i) {
String name = "";
String fileType = "";
if (Srcfile.getname (). IndexOf (".")! =-1) {
Name = Srcfile.getname (). substring (0,srcfile.getname (). IndexOf ("."));
FileType = Srcfile.getname (). substring (Srcfile.getname (). LastIndexOf (".") +1,srcfile.getname (). Length ());
} else {
Name = Srcfile.getname ();
}

Windows file segmentation??
if (Outpath.getabsolutepath (). Contains ("\ \")) {
Partitions[i] = outpath.getparent () + "\ \" + name + "\ \" +name+ "_" + i+ ". txt";

Partitions[i] = Partitions[i].touppercase ();
}else{
Linux file segmentation??
Partitions[i] = outpath.getparent () + "/" + name + "/" +name+ "_" + i+ "." +filetype;
}

System.out.println (Partitions[i]);

File Wfile = new file (Partitions[i]);

if (!wfile.exists ()) {
Wfile.getparentfile (). Mkdirs ();
Wfile.createnewfile ();
}


FileWriter FW = new FileWriter (wfile,false);
BufferedWriter bw = new BufferedWriter (FW);


String line = Br.readline ();
int flush=0;
String []tem = null;
StringBuffer SB = null;

while (line! = null) {

SB = new StringBuffer ();

if (Line.trim (). Length () = = 0) {
line = Br.readline ();
Continue
}

TEM = Line.split ("-");
for (int n=0;n<tem.length;n++) {
Sb.append (tem[n]+ ",");
}

Readnum + = sb.tostring (). Length ();

if (i + 1 = = Partitionfilenum) {
Bw.write (line);
Bw.newline ();


} else {
if (readnum >= max_byte) {
Bw.write (Sb.tostring ());
Bw.newline ();
Break
} else {
if (Sb.length () >0) {
Bw.write (Sb.tostring ());
Bw.newline ();
}
}


}
line = Br.readline ();
if (flush%1000==0) {
Bw.flush ();
}
}

Bw.flush ();
Fw.flush ();
Bw.close ();
Fw.close ();


if (Sb!=null && sb.length () ==0) {
Wfile.delete ();
}



Readnum = 0;
i++;
}
} finally {
try {
if (br! = null) {
Br.close ();
}
if (fr! = null) {
Fr.close ();
}
} catch (IOException e) {
E.printstacktrace ();
} finally {
br = NULL;
FR = null;
}
}
return partitions;
}

@Override
public void Unitefile (string[] files, String newFile) throws IOException {
File Wfile = new file (newFile);
FileWriter writer = null;
BufferedWriter bufferedwriter = null;
try {
writer = new FileWriter (wfile,false);
BufferedWriter = new BufferedWriter (writer);
for (int i = 0; i < files.length; i++) {
File Rfile = new file (Files[i]);
FileReader reader = new FileReader (rfile);
BufferedReader BufferedReader = new BufferedReader (reader);
String line = Bufferedreader.readline ();
while (line! = null) {
if (Line.trim (). Length () = = 0) {
line = Bufferedreader.readline ();
Continue
}
Bufferedwriter.write (line);
Bufferedwriter.newline ();
line = Bufferedreader.readline ();
}
Bufferedwriter.flush ();
Writer.flush ();
}
} finally {
if (bufferedwriter! = null) {
Bufferedwriter.close ();
BufferedWriter = null;
}
if (writer! = null) {
Writer.close ();
}
writer = null;
}
}
}

Java implementation file Segmentation and merging