Modifying MP3 file as below is causing Out of Memory error . is there anyway i can do the below operation more efficiently ( i.e., using lesser memory)
public void BacaMP3(){
String a = System.getProperty("user.dir") + "/src/MP3/21.waltz-cut.mp3";
String bitMP3="";
try {
File song = new File(a);
FileInputStream file = new FileInputStream(song);
int input = 0;
System.out.println("Creating file ...");
while (input != -1) {
input = file.read();
count++;
if (input==-1)bitMP3="#";
else{
bitMP3 = Integer.toBinaryString(input);
while(bitMP3.length()<8){
bitMP3="0"+bitMP3;
}
}
area1.append(bitMP3+"\n");
}
System.out.println(count);
file.close();
System.out.println("Done");
} catch (Exception e) {
System.out.println("Error  " + e.toString());
}
}
As a starter
while(bitMP3.length()<8){
bitMP3="0"+bitMP3; // Here you are creating two string till count is less than 8 move it to string buffer
}
area1.append(bitMP3+"\n"); // Here you are already using string buffer why doing string concatenation then change to area1.append(bitMP3).append("\n");
Related
I'm a noob to Java so may be missing something obvious but I have a function which works for files files in the 200-300k range without issue but once I get to 1.4mb it falls over silently!
Here's the code:
private String readOutputFile(String filename) {
if (filename == null) {
return null;
}
File file = new File(filename);
FileInputStream fis = null;
String fileContent = "";
this.logger.log("Reading " + filename + " from filesystem.");
try {
fis = new FileInputStream(file);
System.out.println("Total file size to read (in bytes) : " + fis.available());
int content;
while ((content = fis.read()) != -1) {
fileContent += (char) content;
}
} catch (IOException e) {
this.logger.log("IO Problem reading ITMS output file\n");
e.printStackTrace();
throw new Error("io-error/itms-output");
} finally {
try {
if (fis != null)
fis.close();
} catch (IOException ex) {
this.logger.log("IO Problem reading and/or closing ITMS output file\n");
ex.printStackTrace();
throw new Error("io-error/finally-block");
}
}
this.logger.log("File content has been read in");
String compressed = this.compress(this.cleanXML(fileContent));
this.logger.log("The compressed file size is :" + compressed.length() + " bytes");
return compressed;
}
When it hits the size threshold which creates it to fail, it seems to stay within the while loop or at least that's my assumption because while it does report to the console the "Total file size to read ..." it never reaches the "File content has been read in" logging.
You are creating many temporary String objects by performing character concatenation in your loop. I would use a StringBuilder. I would also prefer a try-with-resources. And if at all possible, I would prefer to stream from the InputStream to the OutputStream directly (instead of reading this entirely into memory). Anyway, based on what is here,
private String readOutputFile(String filename) {
if (filename == null) {
return null;
}
File file = new File(filename);
StringBuilder sb = new StringBuilder();
this.logger.log("Reading " + filename + " from filesystem.");
try (FileInputStream fis = new FileInputStream(file)) {
System.out.println("Total file size to read (in bytes) : " + fis.available());
int content;
while ((content = fis.read()) != -1) {
sb.append((char) content);
}
} catch (IOException e) {
this.logger.log("IO Problem reading ITMS output file\n");
e.printStackTrace();
throw new Error("io-error/itms-output");
}
this.logger.log("File content has been read in");
String compressed = this.compress(this.cleanXML(sb.toString()));
this.logger.log("The compressed file size is : " + compressed.length() + " bytes");
return compressed;
}
I'm programming a conversion tool that should take a json file as an input. Due to the problem that json input files may be very large I'll perform a split at the beginning. I have to resort the structure of the input file and because I don't want to keep the whole large file in my memory all the time, I'll split it.
I'm proofing the occurences of a json block by counting the { and }. If the counter is 0, a split should be performed. That's where the problem is: if the file is about 40MBs large the JVM throws a StackOverFlowError and I don't know why.
Here's what I do to perform a split:
/*
* Utility-function to read a json file part by part and save the parts to a separate json file.
* #param scanner The scanner which contains the file and which returns the lines from the file.
* #param j The counter of the file. As the file should change whenever the counter changes.
* #return jsonString The content of the jsonString.
*/
public String readPartOfFileAndSave(String filepath, Scanner scanner, int j) {
String jsonString = "";
int i = 0;
++j;
while (scanner.hasNext()) {
String token = scanner.next();
jsonString += token + System.lineSeparator();
if (token.contains("{")) {
i++;
}
if (token.contains("}")) {
i--;
}
if (i == 0) {
// DEBUG
// if (j % 1000 == 0) {
// System.gc();
// System.out.println("Garbage Collector called manually");
// }
saveFile(filepath, "actor", j, jsonString);
readPartOfFileAndSave(filepath, scanner, j);
}
}
return "";
}
/*
* #param filename The name of the target file where the content is saved to.
* #param j The counter of the file. As the file should change whenever the counter changes.
* #param content The content of the file.
*/
public void saveFile(String filepath, String fileprefix, int j, String content) {
File file = null;
if (this.osValidator.isWindows()) {
file = new File(filepath + "\\" + fileprefix + "" + j + ".json");
} else {
file = new File(filepath + "/" + fileprefix + "" + j + ".json");
}
try {
// if file doesnt exists, then create it
if (!file.exists()) {
file.createNewFile();
}
BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(file.getAbsoluteFile()), "UTF-8"));
bw.write(content);
bw.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
The exception looks like this:
Exception in thread "AWT-EventQueue-0" java.lang.StackOverflowError
at java.util.Hashtable.get(Hashtable.java:363)
at java.util.Properties.getProperty(Properties.java:969)
at java.lang.System.getProperty(System.java:717)
at sun.security.action.GetPropertyAction.run(GetPropertyAction.java:84)
at sun.security.action.GetPropertyAction.run(GetPropertyAction.java:49)
at java.security.AccessController.doPrivileged(Native Method)
at java.io.BufferedWriter.<init>(BufferedWriter.java:109)
at java.io.BufferedWriter.<init>(BufferedWriter.java:88)
at utility.ReadFileAndSave.saveFile(ReadFileAndSave.java:183)
at utility.ReadFileAndSave.readPartOfFileAndSave(ReadFileAndSave.java:158)
at utility.ReadFileAndSave.readPartOfFileAndSave(ReadFileAndSave.java:159)
splitFile() is called in a separate class. But nothing else happens there.
public void splitFile() {
try {
ReadFileAndSave reader = new ReadFileAndSave();
String jsonFilePath = this.converterView.sourceTextField.getText();
File jsonFile = new File(jsonFilePath);
Scanner scanner = new Scanner(new FileInputStream(jsonFile), "UTF-8");
int j = 0;
File newDir = null;
if (this.osValidator.isWindows()) {
newDir = new File(System.getProperty("user.home") + "\\temp\\");
} else {
newDir = new File(System.getProperty("user.home") + "/temp/");
}
if (!newDir.exists()) {
newDir.mkdir();
}
if (this.osValidator.isWindows()) {
reader.readPartOfFileAndSave(System.getProperty("user.home") + "\\temp\\", scanner, j);
} else {
reader.readPartOfFileAndSave(System.getProperty("user.home") + "/temp/", scanner, j);
}
} catch (FileNotFoundException ex) {
Logger.getLogger(FilterController.class.getName()).log(Level.SEVERE, null, ex);
}
}
The input file has about 38.000 blocks in it. About 5.200 will be splitted to separate files. Then the exception is thrown.
The JVM seems to have a problem with the BufferedWriter. Does anyone know how to fix this issue?
My output is reflecting the file that I am needing to process into hex values but my hex values are not being reflected in the output. Why isn't my file being converted into hex values?
public class HexUtilityDump {
public static void main(String[] args) {
FileReader myFileReader = null;
try {
myFileReader = new FileReader("src/hexUtility/test.txt");
} catch(Exception ex) {
System.out.println("Error opening file: " + ex.getLocalizedMessage());
}
BufferedReader b = null;
b = new BufferedReader(myFileReader);
//Loop through all the records in the file and print them on the console
while (true){
String myLine;
try {
myLine = b.readLine();
//check for null returned from readLine() and exit loop if so.
if (myLine ==null){break;}
System.out.println(myLine);
} catch (IOException e) {
e.printStackTrace();
//it is time to exit the while loop
break;
}
}
}
Here is the code to pull the file through the conversion
public static void convertToHex(PrintStream out, File myFileReader) throws IOException {
InputStream is = new FileInputStream(myFileReader);
int bytesCounter =0;
int value = 0;
StringBuilder sbHex = new StringBuilder();
StringBuilder sbText = new StringBuilder();
StringBuilder sbResult = new StringBuilder();
while ((value = is.read()) != -1) {
//convert to hex value with "X" formatter
sbHex.append(String.format("%02X ", value));
//If the character is not convertible, just print a dot symbol "."
if (!Character.isISOControl(value)) {
sbText.append((char)value);
} else {
sbText.append(".");
}
//if 16 bytes are read, reset the counter,
//clear the StringBuilder for formatting purpose only.
if(bytesCounter==15) {
sbResult.append(sbHex).append(" ").append(sbText).append("\n");
sbHex.setLength(0);
sbText.setLength(0);
bytesCounter=0;
}else{
bytesCounter++;
}
}
//if still got content
if(bytesCounter!=0){
//add spaces more formatting purpose only
for(; bytesCounter<16; bytesCounter++){
//1 character 3 spaces
sbHex.append(" ");
}
sbResult.append(sbHex).append(" ").append(sbText).append("\n");
}
out.print(sbResult);
is.close();
}
You never call convertToHex, remove the file reading from your main() method. It appears you wanted to do something like,
File f = new File("src/hexUtility/test.txt");
convertToHex(System.out, f);
I have a Method that calls a second method, the second method will:
Create any missing directories
Create a file
Decode a 2D String[] to a String (Not working)
Write content
Write the decoded String to the file with a header (Not working)
First method
public static boolean store(Exception exception, String[][] flags){
return storePrivate(exception, location, flags);
}
Second Method (Not all code just relevant code)
private static boolean storePrivate(Exception exception, String dir, String[][] flags){
String flag = "";
for(int i = 0; i >= flags.length; i++){
flag = flag + "" + flags[i][0] + ": " + flags[i][1] + "\n";
}
try {
File directory = new File(dir);
File file = new File(dir + id + ".txt");
if (!directory.exists()) {
directory.mkdirs();
}
file.createNewFile();
FileWriter filewriter = new FileWriter(file.getAbsoluteFile());
BufferedWriter writer = new BufferedWriter(filewriter);
if(flag != ""){
writer.write("Flags by Developer: ");
writer.write(flag);
}
writer.flush();
writer.close();
return true;
} catch (IOException e) {
return false;
}
}
Call to the first method
public static void main(String[] args) {
try {
test();
} catch (Exception e) {
// TODO Auto-generated catch block
ExceptionAPI.store(e, new String[][]{{"flag1", "Should be part of flag1"}, {"flag2", "this should be flag 2 contence"}});
}
}
public static void test() throws IOException{
throw new IOException();
}
I cant find why this won't work. I think it has to do with the second method, particularly
if(flag != ""){
writer.write("Flags by Developer: ");
writer.write(flag);
}
Thanks if anyone can help me.
Curlip
Try this if you want to just convert an array of strings into a single string:
String[] stringTwoD = //... I think this is a 1D array, and Sting[][] is a 2D, anyway
String stringOneD = "";
for (String s : stringTwoD)
stringOneD += s;//add the string with the format you want
BTW, your loop condition seems wrong and ,so you may change it to :
for(int i = 0; i < flags.length; i++){
flag += flags[i][0] + ": " + flags[i][1] + "\n";
}
I'm trying to create a file that maps every possible binary combination of some part of speech tags, and for some reason the java program I've written just stops after 8192 bytes. I assume that this is the maximum buffer size or something? How can I change that?
My code:
try {
Scanner in = new Scanner(new FileInputStream(file.getPath()));
PrintWriter out = new PrintWriter(new FileOutputStream("S2.gr"));
createS2(in, out);
} catch (Exception e) {
System.out.println("There was an error trying to open the files: " + e.getMessage());
}
private static void createS2(Scanner in, PrintWriter out) {
String[] pos = in.useDelimiter("\\A").next().split("\\n");
out.println("1\tS2");
for (String x : pos) {
out.println("1\tS2\t_" + x);
}
for (String x : pos) {
String temp = ("1\t_" + x + "\t" + x);
out.println(temp);
for (String y : pos) {
out.println(temp + " _" + y);
}
}
for (String x : pos) {
System.out.println(x);
}
}
Try this...
Scanner in = null;
PrintWriter out = null;
try {
in = new Scanner(new FileInputStream(file.getPath()));
out = new PrintWriter(new FileOutputStream("S2.gr"));
createS2(in, out);
} catch (Exception e) {
System.out.println("There was an error trying to open the files: " + e.getMessage());
}
finally {
if(in != null) in.close();
if(out != null) out.close();
}
Note: if you're using Java 7, there's a new feature to make this easier. e.g.
try (Scanner in = new Scanner(new FileInputStream(file.getPath()));
PrintWriter out = new PrintWriter(new FileOutputStream("S2.gr")))
{
createS2(in, out);
} catch (Exception e) {
System.out.println("There was an error trying to open the files: " + e.getMessage());
}
Note: I don't have a JDK 7 available to me at the moment, so the second example might not be 100% correct, but the idea is that the new language feature can manage closing resources for you.