Develop Reference

How to write into the USB (External storage)

I am trying to copy a file from my computer to USB in java. The problem is, the code creates a file on the Usb but the content of the file is not copied from source to destination(computer to usb). How can i do that?
I want the filename R.java to be copied into the usb as system.txt.
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.nio.channels.FileChannel;
public class R {
private static File to;
public static void main(String[] args) {
// current working dir where there is file u want to replicate
File f = new File("." + "/R.java");
// destination location
File so = new File("/media");
for (File s : so.listFiles()) {
String r = s.getName();
to = new File("/media/" + r + "/system.txt");
if (!to.exists()) {
try {
to.createNewFile();
} catch (IOException e) {
// TODO Auto-generated catch block
System.out
.print(to.getName() + " " + e.getMessage() + "\n");
}
}
if (f.exists()) {
FileChannel is = null;
FileChannel os = null;
try {
is = new FileInputStream(f).getChannel();
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
try {
os = new FileOutputStream(to).getChannel();
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
try {
os.transferFrom(is, 0, is.size());
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}
}
I am on LINUX machine

decompress a .z file in java [duplicate]

Can someone advice (give example) any appropriate and understandable way how to extract file or files with .7z extension basing upon InputStream. I have been examined the XZ for java api, but couldn't succeed. Waiting for any suggestion.

This code might help you.
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.RandomAccessFile;
import java.util.Arrays;
import net.sf.sevenzipjbinding.ExtractOperationResult;
import net.sf.sevenzipjbinding.ISequentialOutStream;
import net.sf.sevenzipjbinding.ISevenZipInArchive;
import net.sf.sevenzipjbinding.SevenZip;
import net.sf.sevenzipjbinding.SevenZipException;
import net.sf.sevenzipjbinding.impl.RandomAccessFileInStream;
import net.sf.sevenzipjbinding.simple.ISimpleInArchive;
import net.sf.sevenzipjbinding.simple.ISimpleInArchiveItem;
public class unzip {
public static void main(String[] args) {
RandomAccessFile randomAccessFile = null;
ISevenZipInArchive inArchive = null;
try {
randomAccessFile = new RandomAccessFile("oclHashcat-plus-0.14.7z", "r");
inArchive = SevenZip.openInArchive(null, // autodetect archive type
new RandomAccessFileInStream(randomAccessFile));
// Getting simple interface of the archive inArchive
ISimpleInArchive simpleInArchive = inArchive.getSimpleInterface();
System.out.println(" Hash | Size | Filename");
System.out.println("----------+------------+---------");
for (final ISimpleInArchiveItem item : simpleInArchive.getArchiveItems()) {
final int[] hash = new int[] { 0 };
if (!item.isFolder()) {
ExtractOperationResult result;
final long[] sizeArray = new long[1];
result = item.extractSlow(new ISequentialOutStream() {
public int write(byte[] data) throws SevenZipException {
//Write to file
FileOutputStream fos;
try {
File file = new File(item.getPath());
file.getParentFile().mkdirs();
fos = new FileOutputStream(file);
fos.write(data);
fos.close();
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
hash[0] ^= Arrays.hashCode(data); // Consume data
sizeArray[0] += data.length;
return data.length; // Return amount of consumed data
}
});
if (result == ExtractOperationResult.OK) {
System.out.println(String.format("%9X | %10s | %s", //
hash[0], sizeArray[0], item.getPath()));
} else {
System.err.println("Error extracting item: " + result);
}
}
}
} catch (Exception e) {
System.err.println("Error occurs: " + e);
System.exit(1);
} finally {
if (inArchive != null) {
try {
inArchive.close();
} catch (SevenZipException e) {
System.err.println("Error closing archive: " + e);
}
}
if (randomAccessFile != null) {
try {
randomAccessFile.close();
} catch (IOException e) {
System.err.println("Error closing file: " + e);
}
}
}
}
}

what is the maximum size can i write into outputstream in java

I have a requirement in my web application,i.e, to download data as csv from db, without creating a physical file in the server.So i've decided to write to outputstreame directly.
So what is the maximum bytes of data can i write to OutputStream.
my code is something like below.
StreamingOutput stream = new StreamingOutput() {
#Override
public void write(OutputStream os) throws IOException, WebApplicationException {
try {
-----------some code------
while(rs.next){
os.write(rs.getString(0).getBytes()+","+rs.getString(1).getBytes());
}
os.close();
} catch (Exception e) {
throw new WebApplicationException(e);
}
}
};

import java.util.*;
import java.io.*;
public class BigFile{
public static void main(String asd[]){
String fileString = "D:/INSAn/error.log";
try {
BigFile bigFile = new BigFile(fileString);
for (String line : bigFile)
System.out.println("line : " + line);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
System.out.println("exception");
}
}
}
Hey you can use the above code , it will read file of any size.I tested it for 1 GB file.

Decompress files with .7z extension in java

Can someone advice (give example) any appropriate and understandable way how to extract file or files with .7z extension basing upon InputStream. I have been examined the XZ for java api, but couldn't succeed. Waiting for any suggestion.

This code might help you.
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.RandomAccessFile;
import java.util.Arrays;
import net.sf.sevenzipjbinding.ExtractOperationResult;
import net.sf.sevenzipjbinding.ISequentialOutStream;
import net.sf.sevenzipjbinding.ISevenZipInArchive;
import net.sf.sevenzipjbinding.SevenZip;
import net.sf.sevenzipjbinding.SevenZipException;
import net.sf.sevenzipjbinding.impl.RandomAccessFileInStream;
import net.sf.sevenzipjbinding.simple.ISimpleInArchive;
import net.sf.sevenzipjbinding.simple.ISimpleInArchiveItem;
public class unzip {
public static void main(String[] args) {
RandomAccessFile randomAccessFile = null;
ISevenZipInArchive inArchive = null;
try {
randomAccessFile = new RandomAccessFile("oclHashcat-plus-0.14.7z", "r");
inArchive = SevenZip.openInArchive(null, // autodetect archive type
new RandomAccessFileInStream(randomAccessFile));
// Getting simple interface of the archive inArchive
ISimpleInArchive simpleInArchive = inArchive.getSimpleInterface();
System.out.println(" Hash | Size | Filename");
System.out.println("----------+------------+---------");
for (final ISimpleInArchiveItem item : simpleInArchive.getArchiveItems()) {
final int[] hash = new int[] { 0 };
if (!item.isFolder()) {
ExtractOperationResult result;
final long[] sizeArray = new long[1];
result = item.extractSlow(new ISequentialOutStream() {
public int write(byte[] data) throws SevenZipException {
//Write to file
FileOutputStream fos;
try {
File file = new File(item.getPath());
file.getParentFile().mkdirs();
fos = new FileOutputStream(file);
fos.write(data);
fos.close();
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
hash[0] ^= Arrays.hashCode(data); // Consume data
sizeArray[0] += data.length;
return data.length; // Return amount of consumed data
}
});
if (result == ExtractOperationResult.OK) {
System.out.println(String.format("%9X | %10s | %s", //
hash[0], sizeArray[0], item.getPath()));
} else {
System.err.println("Error extracting item: " + result);
}
}
}
} catch (Exception e) {
System.err.println("Error occurs: " + e);
System.exit(1);
} finally {
if (inArchive != null) {
try {
inArchive.close();
} catch (SevenZipException e) {
System.err.println("Error closing archive: " + e);
}
}
if (randomAccessFile != null) {
try {
randomAccessFile.close();
} catch (IOException e) {
System.err.println("Error closing file: " + e);
}
}
}
}
}

Cannot Start a Method In a Different Class Using a Library

I've just created my first library for an Android app I've built (I have code I need to reuse in the future across different apps) and I need to start a method I have in the main project from the library - however when I attempt to do so using the line:
com.project.sample.datasettings.UpdateActivity.success();
I'm getting a compiler error stating:
com.project.sample.UpdateActivity Cannot Be Resolved To A Type
SOURCE:
package com.project.sample.networktasklibrary;
import java.io.BufferedInputStream;
import java.io.BufferedReader;
import java.io.DataInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.MalformedURLException;
import java.net.SocketTimeoutException;
import java.net.URL;
import java.util.zip.GZIPInputStream;
import javax.net.ssl.HttpsURLConnection;
import javax.net.ssl.SSLException;
import com.project.sample.networktasklibrary.XmlParserHandlerFinal;
import com.project.sample*;
import org.xml.sax.SAXException;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
// this class performs the call to webservice in the background
public class NetworkTask extends AsyncTask<String, String, InputStream> {
private static final String LOG_TAG = "STDataSettings";
private static final String TAG_RESULT = "success";
private static InputStream stream;
#Override
protected InputStream doInBackground(String... params) {
try {
stream = getQueryResults("https://dl.dropboxusercontent.com/u/31771876/GetPhoneSettings-ST-rsp-eng.xml");
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (SAXException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return stream;
}
/*
* Sends a query to server and gets back the parsed results in a bundle
* urlQueryString - URL for calling the webservice
*/
protected static synchronized InputStream getQueryResults(
String urlQueryString) throws IOException, SAXException,
SSLException, SocketTimeoutException, Exception {
Bundle queryResults = new Bundle();
HttpsURLConnection https = null;
String uri = urlQueryString;
URL urlo = new URL(uri);
https = (HttpsURLConnection) urlo.openConnection();
https.setConnectTimeout(50000); // 20 second timeout
https.setRequestProperty("Connection", "Keep-Alive");
try {
https = (HttpsURLConnection) urlo.openConnection();
if ("gzip".equals(https.getContentEncoding())) {
stream = new GZIPInputStream(stream);
} else
stream = https.getInputStream();
} catch (SSLException e) {
Log.e(LOG_TAG, e.toString());
e.printStackTrace();
} catch (SocketTimeoutException e) {
Log.e(LOG_TAG, e.toString());
e.printStackTrace();
} catch (IOException e) {
Log.e(LOG_TAG, e.toString());
e.printStackTrace();
} catch (Exception e) {
Log.e(LOG_TAG, e.toString());
e.printStackTrace();
} finally {
}
String queryResult = null;
queryResults.putString(TAG_RESULT, queryResult);
return stream;
}
public InputStream getInputStream() {
return stream;
}
protected void onPostExecute(InputStream queryResults) {
// TODO Auto-generated method stub
super.onPostExecute(queryResults);
com.project.sample.datasettings.UpdateActivity.success();
}
}
UPDATE ACTIVITY CODE SAMPLE:
public void success() {
// to parse the response
try {
handler.getQueryResponse(stream);
} catch (SAXException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
// to set method to save the ArryaLists from the parser
setArrayList();
Intent i = new Intent(this, ConfigFinalActivity.class);
startActivity(i);
}

Have you ever tried to add the library to the main project?
Right click the Project name -> Property -> Android -> Add. Then choose the library project.