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How to speed up reading in input in Java

I am attempting to read in info from files to implement Dijkstra's algorithm. I believe that the double for loop is causing this to drastically slow down, is there anyway around this?
Edge[] edge = new Edge[127807];
int indexEdge = 0;
String line2 = "";
BufferedReader fileReader2 = new BufferedReader(new FileReader("Road.txt"));
String valueString = null;
String vertex1IDName = null;
String vertex2IDName = null;
String extra = null;
float value = 0;
int vertex1ID = 0;
int vertex2ID = 0;
//Read the file line by line
while ((line2 = fileReader2.readLine()) != null)
{
//Get all tokens available in line
String[] tokens2 = line2.split(DELIMITER);
for(String token1 : tokens2)
{
vertex1IDName = tokens2[0];
vertex2IDName = tokens2[1];
valueString = tokens2[2];
if(tokens2.length - 1 == 3) {
extra = tokens2[tokens2.length - 1];
}
else {
extra = "";
}
vertex1ID = Integer.parseInt(vertex1IDName);
vertex2ID = Integer.parseInt(vertex2IDName);
value = Float.parseFloat(valueString);
}
System.out.println("value: "+ value + " vertex1ID:"+ vertex1ID +" vertex2ID:"+ vertex2ID+ " extra:" + extra);
//if vertex 1 name or vertex 2 name in vertex.getID()
for(int i = 0; i< indexVertex; i++) {
for(int j = 0; j< indexVertex; j++) {
if(vertex1ID == vertex[i].getID() && vertex2ID == vertex[j].getID()) {
vertex[i].addNeighbour(edge[indexEdge] = new Edge(value,vertex[i],vertex[j],extra));
indexEdge++;
}
}
}
}

how can i get this code to choose a random word once from each array to print a sentence?

Here is my code so far, how do I get this to work though as I am struggling to print a sentence at all, let alone randomly.
I need one word from each array to print a sentence using the words in the array
import java.util.Random;
public class MadLibs {
public static void main(String[] args) {
String[] nouns = null;
String[] verbs = null;
String[] adjec = null;
String[] adver = null;
nouns[0] = "Lion";
nouns[1] = "Stewart";
nouns[2] = "Timbaktu";
nouns[3] = "Kilamanjaro";
nouns[4] = "Hawai";
nouns[5] = "Frog";
nouns[6] = "Russia";
nouns[7] = "Dimethyltryptaline";
nouns[8] = "Dog";
nouns[9] = "Badness";
verbs[0] = "hear";
verbs[1] = "achieve";
verbs[2] = "smash";
verbs[3] = "destroy";
verbs[4] = "smoke";
verbs[5] = "burn";
verbs[6] = "rose";
verbs[7] = "speak";
verbs[8] = "type";
verbs[9] = "be";
adjec[0] = "Tangy";
adjec[1] = "Sour";
adjec[2] = "Smooth";
adjec[3] = "Sticky";
adjec[4] = "Soft";
adjec[5] = "Black";
adjec[6] = "Whispering";
adjec[7] = "Resonant";
adjec[8] = "Wide";
adjec[9] = "Long";
adver[0] = "Truthfully";
adver[1] = "Endlessly";
adver[2] = "Painfully";
adver[3] = "Tirelessly";
adver[4] = "Beautifully";
adver[5] = "Uneasily";
adver[6] = "Wickedly";
adver[7] = "Briskly";
adver[8] = "Now";
adver[9] = "Last";
String random = (verbs[new Random().nextInt(verbs.length)]);
System.out.println("Does your" + verbs + " your " + adjec + nouns + adver );
}
}

Here you go :) Hope this is what you want (I wouldn't normally solve a school assignment but sometimes you just feel like it):
public static void main(String[] args) {
String[] nouns = new String[10];
String[] verbs = new String[10];
String[] adjec = new String[10];
String[] adver = new String[10];
nouns[0] = "Lion";
nouns[1] = "Stewart";
nouns[2] = "Timbaktu";
nouns[3] = "Kilamanjaro";
nouns[4] = "Hawai";
nouns[5] = "Frog";
nouns[6] = "Russia";
nouns[7] = "Dimethyltryptaline";
nouns[8] = "Dog";
nouns[9] = "Badness";
verbs[0] = "hear";
verbs[1] = "achieve";
verbs[2] = "smash";
verbs[3] = "destroy";
verbs[4] = "smoke";
verbs[5] = "burn";
verbs[6] = "rose";
verbs[7] = "speak";
verbs[8] = "type";
verbs[9] = "be";
adjec[0] = "Tangy";
adjec[1] = "Sour";
adjec[2] = "Smooth";
adjec[3] = "Sticky";
adjec[4] = "Soft";
adjec[5] = "Black";
adjec[6] = "Whispering";
adjec[7] = "Resonant";
adjec[8] = "Wide";
adjec[9] = "Long";
adver[0] = "Truthfully";
adver[1] = "Endlessly";
adver[2] = "Painfully";
adver[3] = "Tirelessly";
adver[4] = "Beautifully";
adver[5] = "Uneasily";
adver[6] = "Wickedly";
adver[7] = "Briskly";
adver[8] = "Now";
adver[9] = "Last";
String v = (verbs[new Random().nextInt(verbs.length)]);
String a = (adjec[new Random().nextInt(adjec.length)]);
String n = (nouns[new Random().nextInt(nouns.length)]);
String ad = (adver[new Random().nextInt(adver.length)]);
System.out.println("Does your " + v + " your " + a + " " + n + " " + ad );
}
However, the sentences do not make sense. The words should probably come in another order like:
System.out.println("Does your " + a + " " + n + " " + v + " " + ad );

ListView Android with Array database

I'm having one problem in show my ListView correctly
If I declare
String[] cod = {"cod1","cod2", "cod3"};
String[] desc = {"desc1","desc2", "desc3"};
String[] preco = {"1.00","2.00", "3.00"};
My adapter is:
lista = (ListView)findViewById(R.id.list);
lista.setAdapter(new dataListAdapter(cod, desc, preco));
It works perfectly!
But if I get the data from a database, the ListView shows only one row.
results = DbHelper.getItemsDao().queryRaw(sqlGetItems);
/*GET ALL RESULTS FROM DATABASE*/
List<String[]> array = results.getResults();
int count = array.size();
String[] cod = null, desc = null, preco = new String[count];
for(int i = 0; i < count; i++) {
String[] res = array.get(i);
cod = new String[]{res[0]} ;
desc = new String[]{res[1]};
preco = new String[]{res[3]};
}
lista = (ListView) findViewById(R.id.list);
lista.setAdapter(new dataListAdapter(cod, desc, preco));

Try this solution:
for(int i = 0; i < count; i++) {
String[] res = array.get(i);
cod.add(res[0]) ;
desc.add(res[1]);
preco.add(res[3]);
}

Look at the code carefully:
for(int i = 0; i<count; i++){
String[] res = array.get(i);
cod = new String[]{res[0]} ;
desc = new String[]{res[1]};
preco = new String[]{res[3]} ;
}
lista=(ListView)findViewById(R.id.list);
lista.setAdapter(new dataListAdapter(cod, desc, preco));
Here, the varables cod, desc and preco are created every time in the loop. So they are the last one at the end.
You can try like as follows:
String[] cod = new String[count];
String[] desc = new String[count];
String[] preco = new String[count];
for(int i = 0; i<count; i++){
String[] res = array.get(i);
cod[i] = res[0] ;
desc[i] = res[1];
preco[i] = res[3] ;
}

Can't get Strings compareTo method to work

for some reason I can't get Strings compareTo method to work. I get this error message:
exception in thread main java.lang.NullpointerException
at java.lang.String.compareTo(Unknown Source)
at Sort.main(Sort.java:27)
What can I do to fix this?
(this code demands that the to arrays are allready sorted individually.)
import java.util.*;
class Sort{
public static void main(String[] args){
String[] ord = new String[6];
ord[0] = "astra";
ord[1] = "bilum";
ord[2] = "deliber";
ord[3] = "kaliber";
ord[4] = "suppe";
ord[5] = "vorte";
String[] ordet = new String[6];
ord[0] = "akilles";
ord[1] = "kopper";
ord[2] = "lipton";
ord[3] = "mus";
ord[4] = "orkester";
ord[5] = "toving";
String[] flettet = new String[ord.length + ordet.length];
for(int i = 0; i < ord.length; i++){
int teller = i;
for(int j = 0; j < ordet.length; j++){
if(ord[i].compareTo(ordet[j]) > 0){ //line 27
teller += 1;
}
}
flettet[teller] = ord[i];
}
}
}

Do you mean - it looks like you are setting the wrong array:
String[] ordet = new String[6];
ordet[0] = "akilles";
ordet[1] = "kopper";
ordet[2] = "lipton";
ordet[3] = "mus";
ordet[4] = "orkester";
ordet[5] = "toving";

You never assign any values to ordet. so compareTo is comparing a string to NULL
String[] ord = new String[6];
ord[0] = "astra";
ord[1] = "bilum";
ord[2] = "deliber";
ord[3] = "kaliber";
ord[4] = "suppe";
ord[5] = "vorte";
String[] ordet = new String[6];
ord[0] = "akilles"; //overwriting ord[0]
ord[1] = "kopper"; //overwriting ord[1]
ord[2] = "lipton"; //overwriting ord[2]
ord[3] = "mus"; //overwriting ord[3]
ord[4] = "orkester"; //overwriting ord[4]
ord[5] = "toving"; //overwriting ord[5]

String[] ordet = new String[6];
ord[0] = "akilles";
ord[1] = "kopper";
ord[2] = "lipton";
ord[3] = "mus";
ord[4] = "orkester";
ord[5] = "toving";
You never filled the ordet array, you just over-wrote the ord array.
At this point there is no elements in the ordet array, just nulls.
So...
if(ord[i].compareTo(ordet[j]) > 0){ //line 27
is comparing to an element that doesnt exist, and #compareTo throws a NullPointerException because you passed in a null, not a String

Some error in Hangman program

I have to build a hangman program for java for a class. the problem i'm having is having the letter change once you guess a letter. all it's doing is getting an error when i guess. any help would be appreciated, thank you
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Random;
public class test2 {
public static void main( String[] args ) {
HangmanSession hangmanSession = new HangmanSession();
hangmanSession.play();
}
}
class HangmanSession {
private Player player;
private Words secretWord;
private LetterBox letterBox;
private int triesNumber = 6;
public HangmanSession() {
player = new Player();
player.askName();
secretWord = new Words();
letterBox = new LetterBox();
}
private void printState() {
letterBox.print();
System.out.print( "Hidden word : " );
secretWord.print();
System.out.print( "Tries left: " + triesNumber + "<guess letter:>" );
}
public void play() {
boolean bool = true;
while( true ) {
bool = true;
printState();
char ch = player.takeGuess();
if( letterBox.contains( ch ) ) {
System.out.println( "Try again, you've already used the letter " + ch );
bool = false;
}
if( bool ) {
if( secretWord.guess( ch ) ) {
System.out.println( "You have found the letter " + ch );
}
else {
triesNumber--;
}
if( triesNumber < 1 )
gameOver();
if( secretWord.found() )
congratulations();
}
}
}
public void congratulations() {
System.out.println( "Congratulations " + player + ", you win!" );
System.exit( 0 );
}
public void gameOver() {
System.out.println( "Sorry " + player + ", this time you lose!" );
System.exit( 0 );
}
}
class Words {
private String fv;
private StringBuffer pValue;
private int found = 0;
{
String Words[] = new String[23];
Words[0] = "carbon";
Words[1] = "dictionary";
Words[2] = "restaurant";
Words[3] = "televison";
Words[4] = "responsible";
Words[5] = "technology";
Words[6] = "computer";
Words[7] = "communicate";
Words[8] = "automobile";
Words[9] = "coffee";
Words[10] = "federation";
Words[11] = "exaggerate";
Words[12] = "cappuccino";
Words[13] = "macintosh";
Words[14] = "apple";
Words[15] = "microsoft";
Words[16] = "lighter";
Words[17] = "shark";
Words[18] = "bunker";
Words[19] = "argument";
Words[20] = "playstation";
Words[21] = "parrot";
Words[22] = "canine";
Random random = new Random();
int randomWord = random.nextInt(22);
for (int i = 0; i < Words.length; i++);
String[] displayLetters = new String[Words[randomWord].length()];
for (int i=0; i<displayLetters.length; i++)
{
displayLetters[i] = "_";
}
for (int i=0; i<displayLetters.length; i++)
{
System.out.print(displayLetters[i]+" ");
}
}
{
}
public boolean found() {
System.out.println( "Letters found:" + found + "/" + fv.length() );
return ( found == fv.length() );
}
public boolean guess( char c ) {
int index = fv.indexOf( c );
if( index == -1 )
return false;
else {
found = found + findOccurances( c );
return true;
}
}
private int findOccurances( char c ) {
int idx = fv.indexOf( c );
pValue.setCharAt( idx, fv.charAt( idx ) );
int counter = 1;
while( idx != -1 ) {
int index = fv.indexOf( c, idx + 1 );
idx = index;
if( idx != -1 ) {
counter++;
pValue.setCharAt( idx, fv.charAt( idx ) );
}
}
return counter;
}
public void print() {
System.out.println( pValue );
}
}
class Player {
private String name = "";
public void askName()
{System.out.print( "Player, enter your name:" );
name = receiveInput();
}
public char takeGuess() {
return receiveInput().charAt( 0 );
}
private String receiveInput() {
String str = " ";
BufferedReader br = new BufferedReader( new InputStreamReader( System.in ) );
try {
str = br.readLine();
}
catch( IOException ex ) {
ex.printStackTrace();
}
return str;
}
public String toString() {
return name;
}
}
class LetterBox {
private char[] lbox = new char[24];
private int counter = 0;
public boolean contains( char c ) {
for( int i = 0; i < counter; i++ ) {
if( lbox[i] == c )
return true;
}
lbox[counter] = c;
counter++;
return false;
}
public void print() {
System.out.print( "\nLetterBox:" );
for( int i = 0; i < counter; i++ ) {
System.out.print( lbox[i] );
}
System.out.println( "" );
}
}
Im getting null for the hidden word: and i'm getting these errors when i try to guess a letter
Exception in thread "main" java.lang.NullPointerException
at Words.guess(Hangman2.java:141)
at HangmanSession.play(Hangman2.java:53)
at Hangman2.main(Hangman2.java:11)

Both your fv and pValue are not initialized, change your initialization block to this
fv = Words[randomWord]; // assign the answer to fv
pValue = new StringBuffer(fv.length()); // init the user result
for (int i = 0; i < displayLetters.length; i++)
{
displayLetters[i] = "_";
pValue.append('_'); // Init the user result to ____
}
And, get yourself a decent IDE like eclipse and try to learn how to set break point and catch exception in debugging.

I don't see where you are initializing private String fv;
and the NullPointerException is caused because of that in this line
int index = fv.indexOf(c);
in public boolean guess(char c) of class Words.
Besides that, there is a lot of stuff to be cleaned up
like empty blocks { } and
for (int i = 0; i < Words.length; i++)
;
do nothing and could be removed.