bufferedreader

I am trying to read a very big file using Java. That big file will have data like this, meaning each line will have an user id. 149905320 1165665384 66969324 886633368 1145241312 286585320 1008665352 And in that big file there will be around 30Million user id's. Now I am trying to read all the user id's one by one from that big file only once. Meaning each user id should be selected only once from that big file. For example, if I have 30Million user id's then it should print 30 Million user id only once with the use of Multithreading code. Below is the code I have which is a multithreaded code

I want to optimize this code: InputStream is = rp.getEntity().getContent(); BufferedReader reader = new BufferedReader(new InputStreamReader(is)); String text = ""; String aux = ""; while ((aux = reader.readLine()) != null) { text += aux; } The thing is that i don't know how to read the content of the bufferedreader and copy it in a String faster than what I have above. I need to spend as little time as possible. Thank you Using string concatenation in a loop is the classic performance killer (because Strings are immutable, the entire, increasingly large String is copied for each concatenation

What is the sense of buffer size in the constructor? BufferedReader(Reader in, int size) As i have written the program: import java.io.*; class bufferedReaderEx{ public static void main(String args[]){ InputStreamReader isr = null; BufferedReader br = null; try{ isr = new InputStreamReader(System.in); // System.out.println("Write data: "); // int i = isr.read(); // System.out.println("Data read is: " + i); //Thus the InputStreamReader is useful for reading the character from the stream System.out.println("Enter the data to be read by the bufferedReader: "); //here isr is containing the lnefeed

Currently I have the below code for reading an InputStream . I am storing the whole file into a StringBuilder variable and processing this string afterwards. public static String getContentFromInputStream(InputStream inputStream) // public static String getContentFromInputStream(InputStream inputStream, // int maxLineSize, int maxFileSize) { StringBuilder stringBuilder = new StringBuilder(); BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream)); String lineSeparator = System.getProperty("line.separator"); String fileLine; boolean firstLine = true; try { //

So Im working of reading a file containing appointments that I wrote to earlier in my code. I want to sift through the text file and find appointments on a certain date and add them to an ArrayList but when the BufferedReader goes through it, it skips ever other line... Heres my code public ArrayList<String> read(int checkDay, int checkMonth, int checkYear) { ArrayList<String> events = new ArrayList<String>(); BufferedReader in = null; String read; try { in = new BufferedReader(new FileReader("calendar.txt")); while ((read = in.readLine()) != null) { read = in.readLine(); String[] split = read

I am using a BufferedReader constructor to make a new copy of an existing BufferedReader . BufferedReader buffReader = new BufferedReader(originalBuffReader); The new buffReader is working fine, but when I do originalBuffReader.readLine() it gives me null . Is there any other way I can make a new bufferReader without affecting my original BufferedReader . FYI: I am getting bufferReader as an input to my method; and I do not have a access to the source. Any other way I can make a new bufferReader without affecting my oroginal BufferReader There's no straight forward way of solving it by just

I would like to know what are the mark() and reset() methods of BufferedReader ? How do I use them? I read the Javadoc but as a beginner I was unable to understand it. Boann The mark and reset methods of streams provide a way to jump backwards in the stream and re-read data. When you call mark() on a BufferedReader it will begin keeping data you read from that point forwards in its internal buffer. When you call reset() it will jump back to the marked position of the stream, so the next read() s will be satisfied by the in-memory buffer. When you read past the end of that buffer, then it will