How Does A Buffer Reader Work
Mar 5, 2014a buffer reader , how does it work and what is the code for it ?
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C Buffer To Java String
Sep 4, 2014Due to compatibility reasons, I need to be able to store a random C buffer inside of a Java String. THis means that the Java String should contain the exact same buffer information (i.e. byte sequence) as the original C buffer. How would I do that?
All the functions I found will always somehow code/decode the C buffer, and modify its content depending on the selected encoding.
I need to do this inside JNI. Following is what I have:
Java Code:
unsigned char* cBuffer=getCBuffer();
// Transfer the C buffer to s:
jstring s=NULL;
if (env->EnsureLocalCapacity(2) >= 0)
{
jbyteArray bytes = env->NewByteArray(signalLength);
if (bytes != NULL)
[Code] ....
Sending XML Records To Sax Parser Using Buffer
Mar 26, 2014i am having a below piece of code in my worker thread. In my output i am getting xml records from the database. I'm sending this output to a input stream & finally to a sax parser.My query is, before sending to the parser i need to store the input stream in buffer. The buffer should store 1000 records. For every 1000 records the parser should be called from buffer.
while (orset.next()) {
output = orset.getString("xmlrecord");
writeCount++;
InputStream in = new ByteArrayInputStream(output.getBytes("UTF-8"));
InputStream inputStream = new ByteArrayInputStream(output.getBytes("UTF-8"));
Reader reader = new InputStreamReader(inputStream,"UTF-8");
[code]....
String Buffer Append Method
Feb 17, 2014I have the following code which always gives me java heap space error because of line number 65 due to string buffer append method in this line, I don't know why?
/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
import samy.*;
import java.util.Scanner;
public class InfixToPostfix {
OrderedList list = new OrderedList();
Scanner input = new Scanner(System.in);
public StringBuffer postfix = new StringBuffer();
[Code] .....
Swing GUI Freezing With Bounded-buffer
Jul 12, 2014I'm writing a simple application, that provides a Swing GUI to a bounded-buffer problem. The application is composed by:
- Main.java: it creates a map of four threads (four instances of the class MyThread). Also it creates a shared database (an instance of the class Database) between the four threads.
- MyThread.java: it's an extension of Thread, and it shows a Swing GUI associated to this thread. Each thread is associated a GUI.
- GUI.java
- Database.java: it's an extension of ArrayList and and it can contain a maximum of five elements. An element is an instance of the class User. Also it implements put() and extract() method consistent with the algorithm of bounded-buffer problem.
- DatabaseException.java: it's a simple message.
- User.java
public class Main {
public static void main(String[] args) {
Database db = new Database();
Map<String, Thread> tdg_m = new HashMap();
for (int i = 1; i <= 4; i++) {
tdg_m.put("T" + i, new MyThread(db));
[Code] .....
The issue is the following. When the database is full, and i try to put an element, the GUI freezes. The same problem occurs when I try to extract an element from the empty database.
Difference Between Stringbuilder And String Buffer
Apr 3, 2014what is the difference between stringbuffer and string builder?
View Replies View RelatedSmoothing Input Using Ring / Circular Buffer?
Aug 11, 2014Normally I would just implement a circular buffer and be happy but there's a fundamental problem with that.OK, so I'm working on a piece of cheap Android hardware that's being used for demo purposes. One of the problems, primarily because it's cheap (imo) is that the screen input is not clean and is interfering with the UI experience. Specifically when gliding your finger, the result is quite non linear.
I know that's not the best drawing but it sort of explains the problem to a degree. In reality, it's probably a bit smoother than that, but there is still noisy data getting in, and the problem is it causes the UI to be jittery at times.
I would like to smooth this using something like a Circular Buffer. Now I figured the best way to do this would be to store the last 4 float inputs and then effectively calculate the next value based on an average, so say our input was this:10, 15, 20, 25 and 35 is the current input.
15 - 10 = 5
20 - 15 = 5
25 - 20 = 5
Then for the next value, 35 - 25 = 10. 10 + (3 * 5) = 25 / 4 = 6.25...Then adding 6.25 to the previous value resulting in this: 10 15 20 25 31.25 which would appear theoretically smoother. However I'm struggling to work out in my head the best way to implement such a function.
Using String Tokenizer And Buffer To Decode A Message?
Apr 15, 2014So I have this file in which has a few sentences on a single line. What I need to be able to do is read the file and then take each word and create a token out of it. Then what it does is it selects the first letter of every 5th word, uppercase it, and then allow me to use append it via a stringbuffer object to create a word out of it.
I know I'll need to use a string tokenizer but I'm not sure how to do so in a way that makes each word separate and how to tell it to only hit the 1st letter of every 5th word.
Here's what I've come up with so far, but I'm currently at a loss at what to do and my textbook/documentation is just not working.
Java Code:
String line; // The line we read from the file.
char letter; // The first letter of each 5th word.
String sw; // The completed string.
public static void main (String [] args)throws IOException {
[Code] ....
Convert Buffered Reader To Joptionpane?
Feb 16, 2015I have to make an application called miles to meters that converts miles to meters that asks for user input through joption pane and the output can be eather system.out.println or joption pane, I found the code i need but it uses buffered reader for input not joption pane. Here is the source code
import java.io.*;
import java.util.*;
class MetersToMiles{
public static void main (String[] args)throws
Exception{
// 1 meters = 0.00062137119 miles;
[Code] ....
Manipulating Data From Buffered Reader
Nov 3, 2014I've got a .csv file with some text and numeric data. I've used BufferedReader to successfully print the data to the console. Now I need to perform mathematical operations on the numerical data. How do I access the data from the BufferedReader in my calculation methods?
This is what my BufferedReader looks like:
ReadCVS obj=new ReadCVS();
obj.run();
}
public void run(){
String csvFile = "myDataSet.csv";
BufferedReader buffread=null;
String row="";
[Code] .....
What I would like to be able to do is create some loops to calculate totals for some of the elements, but I'm not sure how to access the data from other methods (and potentially classes?).
Reading Inputs Using Buffered Reader
Oct 13, 2014I am trying to read the following input (which will be inputted by the user when run) using the BufferedReader approach:
1
*** * * * *** *** *** ***
* * * * * * * * *
* * * *** *** *** *** ***
* * * * * * * * *
*** * * *** *** *** ***
I am reading each line of the input one line at a time and incrementally storing four char positions into an array, so i am able to hold a vertical representation of each column. I.e. column 1 will be stored in array[0].
The problem with my code is that is does not read the last line of the input, it reads all the other inputs before it but just refuses to read the last line and execute the procedure of storing the characters.
Code:
public void defuseBomb(){
try {
BufferedReader reader = new BufferedReader(new InputStreamReader(
System.in));
String asciiLine = reader.readLine()+ " ";
int digit = (asciiLine.length())/4;
[Code] .....
Going To NextLine In Java Buffered Reader
Jul 18, 2014I have a text and I am reading each line in the text with the simple while loop:
BufferedReader br = new BufferedReader(new FileReader(new File(a.txt)));
string line = new String();
while((line = br.readLine())!=null){
if(line.equals("john"))
//skip to next line
else{
//continue something else..
}
}
My question is how do I skip to the next line ? Using apache.commons.io.FileUtils; one could easily have done something like this:
LineIterator it = FileUtils.lineIterator(file, "UTF-8");
String line = it.nextLine(); //this goes to the next line..
How can this be done using BufferedReader ?
Java IO File Reader / Writer
Feb 2, 2015I've been working on a saving system for a game I'm working on using java IO writer and reader. When I tried exporting it (as a executable jar) to test I couldn't get it to work, when it worked before. If I had to guess it's the file location not being able to find the file. Which it just looks like :
FileReader end = new FileReader("Saves.txt");
I don't exactly know how to set it up to read the file. I'd tried giving it a look up but I don't know how to exactly word my problem.
Poker Hand Reader In Java
Oct 29, 2014ive been working on a poker game in java but seem to have got stuck in my 3 of a kind. What I was trying to do was create a loop that would increment a counter every time time is more than 1 instance of a card, but even if the counter increments and I draw a 3 of a kind it still returns false.
private boolean ThreeOfKind(ArrayList<Card> sortedCards) {
Card previousCard = null;
for (Card c : sortedCards){
int kindcount = 0;
[code]....
Buffered Reader Statement Not Working
Mar 12, 2015String name="admin";
String fpass="";
try {
BufferedReader in = new BufferedReader(new FileReader("D:Dairy MangamentNew1 Dairy ManagmentPassword.txt"));
fpass = in.readLine();
in.close();
} catch (Exception e) {e.printStackTrace();}
[Code] ....
Its not comparing the user name and password..
Reading Buffered-reader Character Wise?
Mar 12, 2014what this code means?
public static String readBuffer(Reader reader, int limit) throws IOException {
StringBuilder sb = new StringBuilder();
for (int i = 0; i < limit; i++) {
int c = reader.read();
if (c == -1) {
return ((sb.length() > 0) ? sb.toString() : null);
[Code] ....
I am particularly confused with the below lines -
if (((char) c == '
') || ((char) c == '
')) {
break;
}
This is how I am calling this code from my application -
BufferedReader bf = null;
StringBuffer stringBuff = new StringBuffer();
String ln = null;
while ((ln = readBuffer(bf, 2048)) != null) {
stringBuff.append(ln);
}
Using Buffered Reader And Columns To Read In Two Strings?
Dec 8, 2014I'm making a tree of contacts with people's names as one string and their numbers as another. I need to read that in from a .dat that is set up to have two columns, across from the names are the numbers, so i have to read that in, but I'm not sure how. Here is what I have:
Tree<String, String> tree = new Tree<String, String>();
BufferedReader br = new BufferedReader(new FileReader("/Users/katedess/Desktop/animals.dat"));
String read;
while((read = br.readLine()) != null) {
tree.add(read);
}
br.close();
}
How To Make File Reader Object Move To Next Line If There Is No More Input On Line
Feb 18, 2015How do I make the file reader object move to the next line if there is no more input on the line. Here is my text and output file as you can see that my text file column cuts off on the 2nd line after 70. I want to read that next line which is 100 into my labs variable however its reading it into my final exams variable. I'll also post the code but I didn't think it was necessary.
textfile:
100908095
1008070
10070
output:
Labs Projects Tests Final Exams
100908095
1008070100
70
[import java.util.Scanner;
import java.io.*;
public class MyGrades
{
public static void main (String[] args) throws IOException
{
int lab, project, test;
int finalExam;//Par and Player values
[Code]...
not sure if I code wrapped it correctly
Getting 64 Bit JVM To Work?
Jun 18, 2014The problem is as follows: I've been running java script using git bash and at one point it tells me that I need to increase heap size because apparently it takes more than 1gb to run. However although I manually increase it via control panel>programs>java nothing changes. I've been told that I need to ' figure out how to use 64bit java (and a VM that supports 64bit) in order to increase the maximum memory allocation (heap size) to something north of 2g.'
My laptop has 8GB worth of RAM (Windows 7)so it shouldn't technically have problems running anything above 1G. But there is apparently a 1GB wall But increasing the heap size to above 2G results in an error stating that VM doesn't initialize within git bash, I thought that my java is 32 bit so I downloaded a 64 bit java. Now how and if it is even possible to allocate a program to run under 64 bit java and if I should delete the other java version.
How Does Recursion Work
Dec 13, 2014how does recursion works, I don't understand why it prints al numbers going up again?This is the code
void print2(int n){
if (n<0){
out.printf(" %d",-1);
return;
}
out.printf(" %d", n);
print2(n-1)
out.printf(" %d", n);
}
this should be the output if n is 6: 6 5 4 3 2 1 0 -1 0 1 2 3 4 5 6.
Creating A Chart For Work?
Mar 6, 2015I need to create a chart for work and comes across this sample from mbostock's chord diagram (bl.ocks.org/mbostock/4062006).
I only need to revise the tick label (names, display positions) but I don't know how to do it as I have 0 experience with Java.
My sample data for the var matrix is
[0,100,100,100]
[0,0,99,98]
[0,0,92,84]
[0,99,0,0]
which shows flows between country A, B, C and D.
I would like to revise the tick labels, so that:
1) Instead of showing 0K 5K 10K, I would like to show the country names (A - D), with no number or tick. I figured out this one by just commenting out all the codes relating to ticks.
2) Place the country names in the center of the arch. I don't know how to do this one.
Scrolling In Panel Won't Work
Oct 9, 2014I've got a panel which an arbitrary number of text fields may be added to at run time. I've got it set up so that the window's height, and the height of the panel in which the fields appear will never exceed the height of the screen.What I don't have is a way to make the panel scroll to access the fields that are being visually truncated. I'm setting the autoscrolls on the panel to true, but when I run the program, the fields are simply truncated.
pnlDeclensions.setAutoscrolls(true);
How Inheritance And Exception Work Together
Jun 10, 2014how inheritence and exception work together ?? what are the rules ??
View Replies View RelatedToString Method Won't Work
Oct 4, 2014So I'm working on a project and noticed that my toString() method won't work. This is just an example of the type of code that I have in my real project. THIS IS MY MAIN CLASS
XML Code:
package trialanderror;
import java.util.Scanner;
public class TrialAndError {
public static void main(String[] args) {
Scanner keys = new Scanner(System.in);
String name;
String phonenumber;
[code]....
JSP :: DropDown Menu Does Not Work
Nov 17, 2014I want to create a dropdown menu with contents from a database. You can see my Code in the attachment. It does not work, but why? I have a dropdown-symbol, but no contents.
View Replies View RelatedJava Won't Work With Chrome
Apr 8, 2014I use Chrome rather than IE. Recently I got an error message when I tried to deposit a check online.
It said that I needed up get a newer version of Java than 6.10, so I downloaded 7u51.
When I tried to deposit the check again, Chrome asked if I wanted to run the app, and I said yes, but that took me back to the download link again.
I spent almost an hour with my bank experts, but they were unable to solve the problem.
When we tried it on Internet Explorer, it worked fine.
Later, I discovered that on the Java Control Panel under the Default Browser for Java, it has only IE and Mozilla, with the IE being checked and greyed out.
I'm assuming that's why the problems on Chrome, even though up until a few days ago, I was able to deposit checks using Chrome-Java.