I'm using DeflaterOutputStream in combination with Buffered input and output streams, trying to just compress a simple file which I should be able to decompress with the second program (it also adds a number at the end of a line but this is irrelevant). However, it's not creating a valid compressed file. When I try to decompress it, it just creates a blank file. I think it might have something to do with flushing. Any thoughts?
public class Program {
static String inputFileName = "inputfile.txt";
static String outputFileName = "outputfile.txt";
public static void main(String[] args) {
try {
FileInputStream fileInputStream = new FileInputStream(inputFileName);
BufferedInputStream inputBuff = new BufferedInputStream(fileInputStream);
FileOutputStream fileOutputStream = new FileOutputStream(outputFileName);
BufferedOutputStream outputBuff = new BufferedOutputStream(fileOutputStream);
DeflaterOutputStream deflater = new DeflaterOutputStream(outputBuff);
int fileByte;
while ((fileByte =inputBuff.read()) != -1)
{
deflater.write(fileByte);
}
deflater.flush();
outputBuff.flush();
fileOutputStream.flush();
} catch (IOException e) {
e.printStackTrace();
}
}
}
public class Program2 {
static String inputFileName = "outputfile.txt";
static String outputFileName = "decoutputfile.txt";
public static void main(String[] args) {
try {
FileInputStream fileInputStream = new FileInputStream(inputFileName);
BufferedInputStream inputBuff = new BufferedInputStream(fileInputStream);
FileOutputStream fileOutputStream = new FileOutputStream(outputFileName);
BufferedOutputStream outputBuff = new BufferedOutputStream(fileOutputStream);
InflaterOutputStream inflater = new InflaterOutputStream(outputBuff);
int fileByte;
int lineCount = 1;
while ((fileByte =inputBuff.read()) != -1)
{
if (fileByte == '\n'){
inflater.write(lineCount);
lineCount++;
}
inflater.write(fileByte);
}
inflater.flush();
outputBuff.flush();
fileOutputStream.flush();
} catch (IOException e) {
e.printStackTrace();
}
}
}
Related
I am zipping the files using , but while unzipping them, I am facing two problems,
when unzipped without buffer its getting back to original form, but when I use buffer its not able to do it correctly.
the size of the unzipped file is more than the original file.
private static void writeFile(FileOutputStream fos, String zipFilePath) throws IOException {
try (FileInputStream fis = new FileInputStream(zipFilePath);
GZIPInputStream inflaterInputStream = new GZIPInputStream(fis)) {
int data;
**while ((data = inflaterInputStream.read()) != -1) {//without buffer**
fos.write(data);
}
}
}
private static void writeFile(FileOutputStream fos, String zipFilePath) throws IOException {
byte[] buffer = new byte[12048];
try (FileInputStream fis = new FileInputStream(zipFilePath);
GZIPInputStream inflaterInputStream = new GZIPInputStream(fis)) {
int data;
**while ((data = inflaterInputStream.read(buffer)) != -1) {//with buffer**
fos.write(data);
}
}
}
You're not writing the buffer, but data which is the length of bytes read...
Corrected:
private static void writeFile(FileOutputStream fos, String zipFilePath) throws IOException {
byte[] buffer = new byte[12048];
try (InputStream fis = new FileInputStream(zipFilePath);
InputStream inflaterInputStream = new GZIPInputStream(fis)) {
int data;
while ((data = inflaterInputStream.read(buffer)) != -1) {//with buffer**
fos.write(buffer, 0, data);
}
}
}
You'd be better off using apache.commons-io
private static void writeFile(FileOutputStream fos, String zipFilePath) throws IOException {
try (InputStream fis = new FileInputStream(zipFilePath);
InputStream inflaterInputStream = new GZIPInputStream(fis)) {
IOUtils.copy(fis, fos);
}
}
I have my code generating two files with rewritable data. I need a code that continues generating the files with recursive file names and should keep all the previous files as well .
In the below code, every time i have to update my file, I have to hard code it and copy it into a new file.
I want a recursive function that saves the file, named numerically in an order(Ascending), while keeping the data in my previous file as well, everytime i run the code.
public static void main(String[] args) throws IOException
{
createFileUsingFileClass();
copyFileVersion();
fileChecker();
String data_2 = "This is the new data written in your file";
writeUsingFileWriter(data_2);
copyFileInCode(data_2);
}
private static void createFileUsingFileClass() throws IOException
{
File file = new File("C:\\Users\\esunrsa\\Documents\\file.txt");
//Create the file
if (file.createNewFile()){
System.out.println("File is created!");
}else{
System.out.println("File already exists.");
}
//Write Content
FileWriter writer = new FileWriter(file);
String data_1 = " Initial data";
writer.write(data_1);
writer.close();
}
private static void copyFileVersion() {
FileInputStream ins = null;
FileOutputStream outs = null;
try {
File infile =new File("C:\\Users\\esunrsa\\Documents\\file.txt");
File outfile =new File("C:\\Users\\esunrsa\\Documents\\file_01.txt");
ins = new FileInputStream(infile);
outs = new FileOutputStream(outfile);
byte[] buffer = new byte[1024];
int length;
while ((length = ins.read(buffer)) > 0) {
outs.write(buffer, 0, length);
}
ins.close();
outs.close();
System.out.println("File created successfully!!");
} catch(IOException ioe) {
ioe.printStackTrace();
}
}
private static void fileChecker() {
File f = new File("C:\\Users\\esunrsa\\Documents\\sunrita.txt");
if(f.exists()){
System.out.println("File existed");
}else{
System.out.println("File doesnt exist");
System.exit(0);
//System.out.println("File not found!");
}
}
private static void writeUsingFileWriter(String data_2) {
File file = new File("C:\\Users\\esunrsa\\Documents\\file.txt");
FileWriter fr = null;
try {
fr = new FileWriter(file);
fr.write(data_2);
} catch (IOException e) {
e.printStackTrace();
}finally{
//close resources
try {
fr.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
private static void copyFileInCode(String filename) {
FileInputStream ins = null;
FileOutputStream outs = null;
try {
File infile =new File("C:\\Users\\esunrsa\\Documents\\file.txt");
File outfile =new File("C:\\Users\\esunrsa\\Documents\\file_02.txt");
ins = new FileInputStream(infile);
outs = new FileOutputStream(outfile);
byte[] buffer = new byte[1024];
int length;
while ((length = ins.read(buffer)) > 0) {
outs.write(buffer, 0, length);
}
ins.close();
outs.close();
System.out.println("File created successfully!!");
} catch(IOException ioe) {
ioe.printStackTrace();
}
}
}
I have searched in stack and web a lot, for parsing a CSV file.
But I won't get what I want.
I have this table in CSV format,
what I want is, if I give the "ID"(which is 0,1,2,3... ) it should return me the value right to it i.e., if i give
"2" it should return me "hello how are you ?".
"4" it should return me "What do you prefer over tea ?"
How to achieve this?
Right now I kept my CSV file in the raw folder.
Any help will be apppreciated
You can save data in CSV as:-
ArrayList<TableData> arrayList=new ArrayList<>();
arrayList.add(new TableData(1,"Hello"));
arrayList.add(new TableData(2,"How are u"));
arrayList.add(new TableData(3,"I am fine"));
arrayList.add(new TableData(4,"Thank You"));
File file;
File root = Environment.getExternalStorageDirectory();
if (root.canWrite()){
File dir = new File (root.getAbsolutePath() + "/PersonData");
dir.mkdirs();
file = new File(dir, "Data.csv");
FileOutputStream out = null;
try {
// write to byte array
ByteArrayOutputStream baos = new ByteArrayOutputStream();
DataOutputStream dos = new DataOutputStream(baos);
for (TableData element : arrayList) {
dos.writeUTF(String.valueOf(element.id));
dos.writeUTF(String.valueOf(element.name));
}
byte[] bytes = baos.toByteArray();
out = new FileOutputStream(file);
out.write(bytes);
out.close();
}catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
And Retrive it as:-
File file;
File root = Environment.getExternalStorageDirectory();
File dir = new File (root.getAbsolutePath() + "/PersonData");
dir.mkdirs();
file = new File(dir, "Data.csv");
Uri u1 = null;
u1 = Uri.fromFile(file);
try {
FileInputStream inputStream=new FileInputStream(file);
String input="2";
String previousValue="";
ByteArrayInputStream bais = new ByteArrayInputStream(readFully(inputStream));
DataInputStream in = new DataInputStream(bais);
while (in.available() > 0) {
String element = in.readUTF();
if(previousValue.equalsIgnoreCase(input)){
textView.setText(element);
}
previousValue=element;
}
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
Method to convert inputStream to byte[]:-
public static byte[] readFully(InputStream input) throws IOException
{
byte[] buffer = new byte[8192];
int bytesRead;
ByteArrayOutputStream output = new ByteArrayOutputStream();
while ((bytesRead = input.read(buffer)) != -1)
{
output.write(buffer, 0, bytesRead);
}
return output.toByteArray();
}
Create a separate class for reading CSV file as:-
public class CSVFile {
InputStream inputStream;
public CSVFile(InputStream inputStream){
this.inputStream = inputStream;
}
public List read(){
List resultList = new ArrayList();
BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));
try {
String csvLine;
while ((csvLine = reader.readLine()) != null) {
String[] row = csvLine.split(",");
resultList.add(row);
}
}
catch (IOException ex) {
throw new RuntimeException("Error in reading CSV file: "+ex);
}
finally {
try {
inputStream.close();
}
catch (IOException e) {
throw new RuntimeException("Error while closing input stream: "+e);
}
}
return resultList;
}
}
Now call this in your activity:-
String input="2";
InputStream inputStream = getResources().openRawResource(R.raw.sample);
CSVFile csvFile = new CSVFile(inputStream);
List scoreList = csvFile.read();
for(int i=0;i<scoreList.size();i++){
Object data_list=scoreList.get(i);
String a[]= (String[]) data_list;
String id=a[0];
String value=a[1];
if(input.equalsIgnoreCase(id)){
Log.d("TAG", "Value Found "+value);
}
}
I've tried to write a server and a client in java, to transfer a file. but the received file is weird and look like it's filled with strange bytes and it won't open with any application, however its size is exactly same as the source file.
I don't know where the problem is! is it about encoding?
Server-side:
import java.net.*;
import java.io.*;
public class MyServer {
public static void main(String[] args) {
char sp = File.separatorChar;
String home = System.getProperty("user.home");
try {
ServerSocket server = new ServerSocket(5776);
while (true){
Socket connection = server.accept();
try {
String FileName=home+sp+"33.jpg";
File inputFile = new File(FileName);
FileInputStream Fin = new FileInputStream(inputFile);
long fileLength = inputFile.length();
byte[] bt= new byte[(int) fileLength];
DataOutputStream Oout = new DataOutputStream(connection.getOutputStream());
Oout.writeLong(fileLength);
Oout.write(bt);
Oout.flush();
Oout.close();
connection.close();
} catch (IOException ex) {}
finally {
try {
if(connection!= null) connection.close();
} catch (IOException e) {}
}
}
} catch (IOException e) {
System.err.println("There is a server on port 5776");
}
}
}
Client-side:
import java.net.*;
import java.io.*;
public class Client {
public static void main(String[] args) {
byte[] IP={(byte)192,(byte)168,1,7};
char sp = File.separatorChar;
String home = System.getProperty("user.home");
String SharingPathString = home+sp+"File Sharing";
String FileName = SharingPathString+sp+"file.jpg";
try {
InetAddress add = InetAddress.getByAddress(IP);
Socket theSocket= new Socket("Shayan-8",5776);
DataInputStream in= new DataInputStream(theSocket.getInputStream());
final long FileLength = in.readLong();
System.out.println("FileLength: "+FileLength);
File SharingPath = new File(SharingPathString);
if(!SharingPath.exists())
SharingPath.mkdir();
File outputFile = new File(FileName);
if(outputFile.exists())
outputFile.delete();
//outputFile.createNewFile();
FileOutputStream Fos = new FileOutputStream(FileName);
DataOutputStream dos = new DataOutputStream(Fos);
byte[] buffer = new byte[100];
int count=0;
long current=0;
while(current < FileLength && (count=in.read(buffer,0,(int)Math.min(FileLength-current, buffer.length)))!=-1)
{Fos.write(buffer, 0, count);
current+=count;
}
// while((count=in.read())!=-1)
// dos.write(count);
dos.close();
Fos.close();
} catch (UnknownHostException uhe) {
System.err.println(uhe);
} catch (IOException e) {
System.err.println(e);
}
}
}
You haven't read anything into bt[]. So you are writing the correct number of null bytes.
I have a requirement to change the encoding of a file from ANSI(windows-1252) to UTF8. I wrote below program to do it through java. This program converts the characters to UTF8, but when I opened the file in notepad++ the encoding type was displayed as ANSI as UTF8. This gives me error when I import this file in access db. A file with UTF8 encoding only is desired. Also the requirement is to convert the file without opening it in any editor.
public class ConvertFromAnsiToUtf8 {
private static final char BYTE_ORDER_MARK = '\uFEFF';
private static final String ANSI_CODE = "windows-1252";
private static final String UTF_CODE = "UTF8";
private static final Charset ANSI_CHARSET = Charset.forName(ANSI_CODE);
public static void main(String[] args) {
List<File> fileList;
File inputFolder = new File(args[0]);
if (!inputFolder.isDirectory()) {
return;
}
File parentDir = new File(inputFolder.getParent() + "\\"
+ inputFolder.getName() + "_converted");
if (parentDir.exists()) {
return;
}
if (parentDir.mkdir()) {
} else {
return;
}
fileList = new ArrayList<File>();
for (final File fileEntry : inputFolder.listFiles()) {
fileList.add(fileEntry);
}
InputStream in;
Reader reader = null;
Writer writer = null;
try {
for (File file : fileList) {
in = new FileInputStream(file.getAbsoluteFile());
reader = new InputStreamReader(in, ANSI_CHARSET);
OutputStream out = new FileOutputStream(
parentDir.getAbsoluteFile() + "\\"
+ file.getName());
writer = new OutputStreamWriter(out, UTF_CODE);
writer.write(BYTE_ORDER_MARK);
char[] buffer = new char[10];
int read;
while ((read = reader.read(buffer)) != -1) {
System.out.println(read);
writer.write(buffer, 0, read);
}
}
reader.close();
writer.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
}
Any pointers will be helpful.
Thanks,
Ashish
The posted code correctly transcodes from windows-1252 to UTF-8.
The Notepad++ message is confusing because "ANSI as UTF-8" has no obvious meaning; it appears to be an open defect in Notepad++. I believe Notepad++ means UTF-8 without BOM (see the encoding menu.)
Microsoft Access, being a Windows program, probably expects UTF-8 files to start with a byte-order-mark (BOM).
You can inject a BOM into the document by writing the code point U+FEFF at the start of the file:
import java.io.*;
import java.nio.charset.*;
public class Ansi1252ToUtf8 {
private static final char BYTE_ORDER_MARK = '\uFEFF';
public static void main(String[] args) throws IOException {
Charset windows1252 = Charset.forName("windows-1252");
try (InputStream in = new FileInputStream(args[0]);
Reader reader = new InputStreamReader(in, windows1252);
OutputStream out = new FileOutputStream(args[1]);
Writer writer = new OutputStreamWriter(out, StandardCharsets.UTF_8)) {
writer.write(BYTE_ORDER_MARK);
char[] buffer = new char[1024];
int read;
while ((read = reader.read(buffer)) != -1) {
writer.write(buffer, 0, read);
}
}
}
}
On Windows 7 (64-Bit), running Java 8, I had to close every file. Otherwise, files get truncated to multiples of 4 kB. It is not enough to close the last set of files, I had to close every file to get the desired result. Posting my adapted version that adds error messages:
import java.io.*;
import java.nio.charset.*;
import java.util.ArrayList;
public class ConvertFromAnsiToUtf8 {
private static final char BYTE_ORDER_MARK = '\uFEFF';
private static final String ANSI_CODE = "windows-1252";
private static final String UTF_CODE = "UTF8";
private static final Charset ANSI_CHARSET = Charset.forName(ANSI_CODE);
private static final String PATH_SEP = "\\";
private static final boolean WRITE_BOM = false;
public static void main(String[] args)
{
if (args.length != 2) {
System.out.println("Please name a source and a target directory");
return;
}
File inputFolder = new File(args[0]);
if (!inputFolder.isDirectory()) {
System.out.println("Input folder " + inputFolder + " does not exist");
return;
}
File outputFolder = new File(args[1]);
if (outputFolder.exists()) {
System.out.println("Folder " + outputFolder + " exists - aborting");
return;
}
if (outputFolder.mkdir()) {
System.out.println("Placing converted files in " + outputFolder);
} else {
System.out.println("Output folder " + outputFolder + " exists - aborting");
return;
}
ArrayList<File> fileList = new ArrayList<File>();
for (final File fileEntry : inputFolder.listFiles()) {
fileList.add(fileEntry);
}
InputStream in;
Reader reader = null;
Writer writer = null;
int converted = 0;
try {
for (File file : fileList) {
try {
in = new FileInputStream(file.getAbsoluteFile());
reader = new InputStreamReader(in, ANSI_CHARSET);
OutputStream out = new FileOutputStream(outputFolder.getAbsoluteFile() + PATH_SEP + file.getName());
writer = new OutputStreamWriter(out, UTF_CODE);
if (WRITE_BOM)
writer.write(BYTE_ORDER_MARK);
char[] buffer = new char[1024];
int read;
while ((read = reader.read(buffer)) != -1) {
writer.write(buffer, 0, read);
}
++converted;
} finally {
reader.close();
writer.close();
}
}
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
System.out.println(converted + " files converted");
}
}