We Keep Coding

Trouble receiving images from an 8 modem server

I have implemented this java app communicating with a remote 8 modem server and when I request for an image from a security camera (error free or not) the outcome is a 1 byte image (basically a small white square). Can you help me find the error?
Here is my code:
import java.io.*;
import java.util.Scanner;
import ithakimodem.Modem;
public class g {
private static Scanner scanner = new Scanner(System.in);
private static String EchoCode = "E3369";
private static String noImageErrorscode = "M2269";
private static String imageErrorsCode = "G6637";
private static String GPS_Code = "P7302";
private static String ACK_Code = "Q2591";
private static String NACK_Code = "R4510";
public static void main(String[] args) throws IOException, InterruptedException {
int timeout = 2000;
int speed = 80000;
Modem modem = new Modem(speed);
modem.setTimeout(timeout);
modem.write("ATD2310ITHAKI\r".getBytes());
getConsole(modem);
modem.write(("test\r").getBytes());
getConsole(modem);
while (true) {
System.out.println("\nChoose one of the options below :");
System.out.print("Option 0: Exit\n" + "Option 1: Echo packages\n" + "Option 2: Image with no errors\n" + "Option 3: Image with errors\n" + "Option 4: Tracks of GPS\n"
+ "Option 5: ARQ\n" );
System.out.print("Insert option : ");
int option = scanner.nextInt();
System.out.println("");
switch (option) {
case 0: {
// Exit
System.out.println("\nExiting...Goodbye stranger");
modem.close();
scanner.close();
return;
}
case 1: {
// Echo
getEcho(modem, EchoCode);
break;
}
case 2: {
// Image with no errors
getImage(modem, noImageErrorscode, "no_error_image.jpg");
break;
}
case 3: {
// Image with errors
getImage(modem, imageErrorsCode, "image_with_errors.jpg");
}
case 4: {
// GPS
getGPS(modem, GPS_Code);
break;
}
case 5: {
// ARQ
getARQ(modem, ACK_Code, NACK_Code);
break;
}
default:
System.out.println("Try again please\n");
}
}
}
public static String getConsole(Modem modem) {
int l;
StringBuilder stringBuilder= new StringBuilder();
String string = null;
while (true) {
try {
l = modem.read();
if (l == -1) {
break;
}
System.out.print((char) l);
stringBuilder.append((char) l);
string = stringBuilder.toString();
} catch (Exception exc) {
break;
}
}
System.out.println("");
return string;
}
private static void getImage(Modem modem, String password, String fileName) throws IOException {
int l;
boolean flag;
FileOutputStream writer = new FileOutputStream(fileName, false);
flag = modem.write((password + "\r").getBytes());
System.out.println("\nReceiving " + fileName + "...");
if (!flag) {
System.out.println("Code error or end of connection");
writer.close();
return;
}
while (true) {
try {
l = modem.read();
writer.write((char) l);
writer.flush();
if (l == -1) {
System.out.println("END");
break;
}
}
catch (Exception exc) {
break;
}
}
writer.close();
}
private static void getGPS(Modem modem, String password) throws IOException {
int rows = 99;
String Rcode = "";
Rcode = password + "R=10200" + rows;
System.out.println("Executing R parameter = " + Rcode + " (XPPPPLL)");
modem.write((Rcode + "\r").getBytes());
String stringConsole = getConsole(modem);
if (stringConsole == null) {
System.out.println("Code error or end of connection");
return;
}
String[] stringRows = stringConsole.split("\r\n");
if (stringRows[0].equals("n.a")) {
System.out.println("Error : Packages not received");
return;
}
System.out.println("**TRACES**\n");
float l1 = 0, l2 = 0;
int difference = 8;
difference *= 100 / 60;
int traceNumber = 7;
String[] traces = new String[traceNumber + 1];
int tracesCounter = 0, flag = 0;
for (int i = 0; i < rows; i++) {
if (stringRows[i].startsWith("$GPGGA")) {
if (flag == 0) {
String str = stringRows[i].split(",")[1];
l1 = Integer.valueOf(str.substring(0, 6)) * 100 / 60;
flag = 1;
}
String str = stringRows[i].split(",")[1];
l2 = Integer.valueOf(str.substring(0, 6)) * 100 / 60;
if (Math.abs(l2 - l1) >= difference) {
traces[tracesCounter] = stringRows[i];
if (tracesCounter == traceNumber)
break;
tracesCounter++;
l1 = l2;
}
}
}
for (int i = 0; i < traceNumber; i++) {
System.out.println(traces[i]);
}
String w = "", T_cd_fnl = password + "T=";
int p = 1;
System.out.println();
for (int i = 0; i < traceNumber; i++) {
String[] strSplit = traces[i].split(",");
System.out.print("T parameter = ");
String str1 = strSplit[4].substring(1, 3);
String str2 = strSplit[4].substring(3, 5);
String str3= String.valueOf(Integer.parseInt(strSplit[4].substring(6, 10)) * 60 / 100).substring(0, 2);
String str4= strSplit[2].substring(0, 2);
String str5= strSplit[2].substring(2, 4);
String str6= String.valueOf(Integer.parseInt(strSplit[2].substring(5, 9)) * 60 / 100).substring(0, 2);
w = str1 + str2 + str3 + str4 + str5 + str6 + "T";
p = p + 5;
System.out.println(w);
T_cd_fnl = T_cd_fnl + w + "=";
}
T_cd_fnl = T_cd_fnl.substring(0, T_cd_fnl.length() - 2);
System.out.println("\nSending code: " + T_cd_fnl);
getImage(modem, T_cd_fnl, "traces GPS.jpg");
}
private static void getEcho(Modem modem, String strl) throws InterruptedException, IOException {
FileOutputStream echo_time_writer = new FileOutputStream("echoTimes.txt", false);
FileOutputStream echo_counter_writer = new FileOutputStream("echoCounter.txt", false);
int h;
int runtime = 5, packetCounter = 0;
String str = "";
System.out.println("\nRuntime (mins) = " + runtime + "\n");
long start_time = System.currentTimeMillis();
long stop_time = start_time + 60 * 1000 * runtime;
long send_time = 0, receiveTime = 0;
String time = "", ClockTime = "";
echo_time_writer.write("Clock Time\tSystem Time\r\n".getBytes());
while (System.currentTimeMillis() <= stop_time) {
packetCounter++;
send_time = System.currentTimeMillis();
modem.write((strl + "\r").getBytes());
while (true) {
try {
h = modem.read();
System.out.print((char) h);
str += (char) h;
if ( h== -1) {
System.out.println("\nCode error or end of connection");
return;
}
if (str.endsWith("PSTOP")) {
receiveTime = System.currentTimeMillis();
ClockTime = str.substring(18, 26) + "\t";
time = String.valueOf((receiveTime - send_time) + "\r\n");
echo_time_writer.write(ClockTime.getBytes());
echo_time_writer.write(time.getBytes());
echo_time_writer.flush();
str = "";
break;
}
} catch (Exception e) {
break;
}
}
System.out.println("");
}
echo_counter_writer.write(("\r\nRuntime: " + String.valueOf(runtime)).getBytes());
echo_counter_writer.write(("\r\nPackets Received: " + String.valueOf(packetCounter)).getBytes());
echo_counter_writer.close();
echo_time_writer.close();
}
private static void getARQ(Modem modem, String strl, String nack_code) throws IOException, InterruptedException {
FileOutputStream arq_time_writer = new FileOutputStream("ARQtimes.txt", false);
FileOutputStream arq_counter_writer = new FileOutputStream("ARQcounter.txt", false);
int runtime = 5;
int xor = 1;
int f = 1;
int m;
int packageNumber = 0;
int iterationNumber = 0;
int[] nack_times_counter = new int[15];
int nack_to_package = 0;
String time = "", clock_time = "", s = "";
long start_time = System.currentTimeMillis();
long stop_time = start_time + 60 * 1000 * runtime;
long send_time = 0, receive_time = 0;
System.out.printf("Runtime (mins) = " + runtime + "\n");
arq_time_writer.write("Clock Time\tSystem Time\tPacket Resends\r\n".getBytes());
while (System.currentTimeMillis() <= stop_time) {
if (xor == f) {
packageNumber++;
nack_times_counter[nack_to_package]++;
nack_to_package = 0;
send_time = System.currentTimeMillis();
modem.write((strl + "\r").getBytes());
} else {
iterationNumber++;
nack_to_package++;
modem.write((nack_code + "\r").getBytes());
}
while (true) {
try {
m = modem.read();
System.out.print((char) m);
s += (char) m;
if (m == -1) {
System.out.println("\nCode error or end of connection");
return;
}
if (s.endsWith("PSTOP")) {
receive_time = System.currentTimeMillis();
break;
}
} catch (Exception e) {
break;
}
}
System.out.println("");
String[] string = s.split("<");
string = string[1].split(">");
f = Integer.parseInt(string[1].substring(1, 4));
xor = string[0].charAt(0) ^ string[0].charAt(1);
for (int i = 2; i < 16; i++) {
xor = xor ^ string[0].charAt(i);
}
if (xor == f) {
System.out.println("Packet ok");
receive_time = System.currentTimeMillis();
time = String.valueOf((receive_time - send_time) + "\t");
clock_time = s.substring(18, 26) + "\t";
arq_time_writer.write(clock_time.getBytes());
arq_time_writer.write(time.getBytes());
arq_time_writer.write((String.valueOf(nack_to_package) + "\r\n").getBytes());
arq_time_writer.flush();
} else {
xor = 0;
}
s = "";
}
arq_counter_writer.write(("\r\nRuntime: " + String.valueOf(runtime)).getBytes());
arq_counter_writer.write("\r\nPackets Received (ACK): ".getBytes());
arq_counter_writer.write(String.valueOf(packageNumber).getBytes());
arq_counter_writer.write("\r\nPackets Resent (NACK): ".getBytes());
arq_counter_writer.write(String.valueOf(iterationNumber).getBytes());
arq_counter_writer.write("\r\nNACK Time Details".getBytes());
for (int i = 0; i < nack_times_counter.length; i++) {
arq_counter_writer.write(("\r\n" + i + ":\t" + nack_times_counter[i]).getBytes());
}
arq_counter_writer.close();
arq_counter_writer.close();
System.out.println("Packets Received: " + packageNumber);
System.out.println("Packets Resent: " + iterationNumber);
System.out.println("\n\nFile arqTimes.txt is created.");
System.out.println("File arqCounter.txt is created.");
}
}
I know the problem is most probably in the getImage() function but I haven't figured it out yet.

Display the Shortest Path using BFS in java

This is my BFS algorithm code.
I can calculate the shortest path distance, but somehow I am not able to display the shortest path.
Like for example, I calculated the shortest path from source to destination is 2. But i would like to also display the pathway. (PlaceA -> PlaceB -> PlaceC) for example.
May i know how do i display out the shortest path out using Java?
Please do help me! Thank you!
public static void main(String[] args) {
// TODO Auto-generated method stub
chooseNumOfVertices();
chooseNumOfEdges();
generateGraph();
in.close();
}
private static void generateGraph() {
int source = 0;
int destination = 0;
int edge = chooseEdge;
// TODO Auto-generated method stub
ArrayList<LinkedList<Integer>> graph = new ArrayList<LinkedList<Integer>>();
for (int i = 0; i < limit; i++) {
LinkedList<Integer> vertex = new LinkedList<Integer>();
vertex.add(i);
graph.add(vertex);
}
while (chooseEdge > 0) {
// Randomize the value
int value = new Random().nextInt(cityMapping.size());
int value2 = new Random().nextInt(cityMapping.size());
//
if (value != value2 && !graph.get(value).contains(value2) && !graph.get(value2).contains(value)) {
graph.get(value).add(value2);
graph.get(value2).add(value);
chooseEdge--;
}
}
// Printing out the Nodes
for (int i = 0; i < graph.size(); i++) {
// Return each LinkedList nodes
// System.out.println(graph.get(i));
for (int j = 0; j < graph.get(i).size(); j++) {
// Return each individual nodes inside LinkedList
for (Entry<Integer, String> entry : cityMapping.entrySet()) {
if (entry.getKey() == graph.get(i).get(j)) {
//System.out.print(graph.get(i).get(j) + "-> ");
System.out.print(graph.get(i).get(j) + ". " + entry.getValue() + " -> ");
}
}
}
System.out.println();
}
do {
for (
int i = 0; i < limit; i++) {
int[] newArray = new int[limit];
distance.add(newArray);
predecessor.add(newArray);
}
long time = System.nanoTime();
System.out.println("Searching BFS");
System.out.println("--------------------------------------------");
for (int i = 0; i < limit; i++) {
BFS(graph, i);
}
long CPUTime = (System.nanoTime() - time);
System.out.println("CPU Time for BFS for " + limit + "vertices and " + edge + "edges (in ns): " + CPUTime);
System.out.print("Enter -1 to exit! Enter source vertex (between 0 to " + (limit - 1) + ") : ");
source = in.nextInt();
if (source == -1) {
System.out.print("System terminating...");
break;
}
System.out.print("Enter destination vertex (between 0 to " + (limit - 1) + ") : ");
destination = in.nextInt();
System.out.println("Distance from " + source + " to " + destination + " is: " +
getDistance(source, destination));
System.out.println("The Predecessor of the path from " + source + " to " + destination + " is: "
+ getPredecessor(source, destination));
} while (source != -1);
}
private static void BFS(ArrayList<LinkedList<Integer>> graph, int i) {
// TODO Auto-generated method stub
boolean[] mark = new boolean[graph.size()];
Queue<Integer> L = new ArrayBlockingQueue<Integer>(graph.size()); //Queue
L.add(i);
mark[i] = true;
Arrays.fill(predecessor.get(i), -1);
Arrays.fill(distance.get(i), -1);
distance.get(i)[i] = 0;
while (!L.isEmpty()) {
int vertex = L.remove();
for (int i1 = 0; i1 < graph.get(vertex).size(); i1++) {
int v = graph.get(vertex).get(i1);
if (!mark[v]) {
mark[v] = true;
predecessor.get(i)[v] = vertex;
L.add(v);
distance.get(i)[v] = distance.get(i)[predecessor.get(i)[v]] + 1;
}
}
}
}
public static int getDistance(int start, int end) {
return (distance.get(start)[end]);
}
public static int getPredecessor(int start, int end) {
return (predecessor.get(start)[end]);
}
private static void chooseNumOfEdges() {
System.out.println("Please input the number of Edges:");
chooseEdge = in.nextInt();
}
// Number of Vertices
private static void chooseNumOfVertices() {
in = new Scanner(System.in);
System.out.println("Please input the number of Vertices:");
limit = in.nextInt();
// Read CSV
List<String[]> content = readCsvFile();
// Map each number to a city name
cityMapping = new HashMap<>();
for (int i = 0; i < limit; i++) {
cityMapping.put(i, content.get(i)[0]);
}
// System.out.println(cityMapping);
}
// Read CSV file
public static List<String[]> readCsvFile() {
String csvFile = "./Lab 4/country.csv";
BufferedReader br = null;
ArrayList<String> names = new ArrayList<String>();
List<String[]> content = new ArrayList<>();
String cvsSplitBy = ",";
try {
String line = "";
br = new BufferedReader(new FileReader(csvFile));
while ((line = br.readLine()) != null) {
content.add(line.split(cvsSplitBy));
}
} catch (Exception e) {
e.printStackTrace();
}
Random r = new Random();
Collections.shuffle(content);
return content;
}
}

Reading a text file using Java throws IOException

I have compiled my Java with no error , However, when I want to use the java to read the text , it shows the following error :
java countwords Chp_0001.txt <-- this is my action
Exception in thread "main" java.io.IOException: Stream closed
at java.io.BufferedReader.ensureOpen(BufferedReader.java:122)
at java.io.BufferedReader.read(BufferedReader.java:179)
at countwords.readFile_BSB(assignment.java:164)
at countwords.main(assignment.java:53)
The following is my input of Java :
import java.util.*;
import java.io.*;
class countwords {
public static String [] MWTs ={ "Hong Kong","New York",
"United Kingdom","Basic Law","People's Republic of China",
};
public static void bubble_sort_length(String [] strs){
while (true) {
int swaps = 0;
for (int i = 0 ; i<strs.length -1; i++) {
if (strs[i].length() >= strs[i+1].length())
continue ;
String tmp = strs[i];
strs[i] = strs[i+1];
strs [i+1] = tmp;
swaps++;
}
if (swaps ==0) break ;
}
}
public static void main(String[] args) throws IOException {
String txt=readFile_BSB(args [0]);
bubble_sort_length(MWTs);
txt= underscoreMWTs(txt);
for (int i = 0 ; i < MWTs.length;i++)
System.out.println(i + "-->" + MWTs[i]) ;
System.out.print (txt);
String [] words = txt.split("\\s+");
StringBuilder txt_p = new StringBuilder();
for (String w : words){
txt_p.append(sep_punct(w));
}
words = txt_p.toString().split("\\s+");
Arrays.sort (words);
String w ="";
int cnt =0;
StringBuilder all_lines = new StringBuilder();
for(int i = 0;i < words.length;i++){
if (w.equals(words[i])){
cnt++ ;
} else {
if(!w.equals("")) {
if (w.contains("_")) {
String u = de_underscore (w) ;
if(isMWT (u)) w = u ;
}
all_lines.append (addSpaces(cnt) + " " + w + "\r\n");
}
w=words[i];
cnt=1;
}
}
String [] lines = all_lines.toString().split ("\r\n");
Arrays.sort(lines);
for (int i= lines.length-1;i>= 0 ; i--) {
System.out.println(lines[i]);
}
}
public static boolean isPunct(char c){
return ",.':;\"!)?_#(#".contains(""+c);
}
public static String sep_punct( String w ) {
StringBuilder W= new StringBuilder(w);
String init_puncts = "",end_puncts="";
char c;
while (W.length() > 0) {
c =W.charAt(0);
if (!isPunct(c)) break;
W.deleteCharAt(0);
init_puncts +="" + c + " ";
}
while (W.length() > 0) {
c= W.charAt(W.length () -1);
if (!isPunct(c)) break;
W.deleteCharAt (W.length()-1);
end_puncts += "" +c+"";
}
return "" + init_puncts + W.toString() + end_puncts +"";
}
public static String underscoreMWTs(String txt){
StringBuilder TXT = new StringBuilder(txt);
for(String mwt : MWTs ) {
int pos =0 ;
while ((pos =TXT.indexOf(mwt,pos)) !=-1) {
pos += mwt.length();
}
}
return TXT.toString();
}
public static void space2underscore (StringBuilder sb, int pos, int lgth){
for (int p = pos; p < pos+lgth; p++ ){
if (sb.charAt(p) ==' ')
sb.setCharAt(p,'_');
}
}
public static String de_underscore(String w) {
StringBuilder W = new StringBuilder (w);
for (int i= 0 ; i < W.length(); i++ ) {
if ( W.charAt (i) == '_')
W.setCharAt (i ,' ');
}
return W.toString ();
}
public static boolean isMWT (String w) {
for (String t : MWTs) {
if (w.equals(t)) return true;
}
return false;
}
public static String addSpaces (int cnt) {
String s ="" + cnt;
while (s.length () <10 ) {
s=" " + s;
}
return s;
}
public static String readFile_BSB(String fn) throws IOException{
FileReader fr= new FileReader(fn);
BufferedReader r= new BufferedReader (fr);
StringBuilder s= new StringBuilder();
int c;
while ((c = r.read()) != -1) {
s.append ((char)c);
r.close();
}
return s.toString();
}
}
Please help me with the errors as I am quite hopeless at this point .
Thank You so much !

Check your loop in readFile_BSB():
BAD
while ((c = r.read()) != -1) {
s.append ((char)c);
r.close(); // Close while reading?
}
BETTER
while ((c = r.read()) != -1) {
s.append ((char)c);
}
r.close(); // Close after reading.
Why not good? Reading byte by byte is very slow, in case of Exception your streams are not closed...

Long type output file

I tried to create a file and write the output of my program to it in Java. When I use WriteLong then the file does not contain long value. Please explain how I can create this file.
My program is to print prime numbers between 500000 and 10000000
public class primenumber {
public static void main(String[] args) {
long start = 5000000;
long end = 10000000;
System.out.println("List of prime numbers between " + start + " and " + end);
for (long i = start; i <= end; i++) {
if (isPrime(i)) {
System.out.println(i);
}
}
}
public static boolean isPrime(long i2) {
if (i2 <= 1) {
return false;
}
for (long i = 2; i < Math.sqrt(i2); i++) {
if (i2 % i == 0) {
return false;
}
}
return true;
}
}

I'm assuming you want the program to print human readable ASCII long values. You can use a PrintWriter and something like,
PrintWriter pw = null;
try {
pw = new PrintWriter(filePath);
pw.println("List of prime numbers between " + start + " and " + end);
for (long i = start; i <= end; i++) {
if (isPrime(i)) {
pw.println(i);
}
}
} catch (FileNotFoundException e) {
e.printStackTrace();
} finally {
pw.close();
}
or, using try-with-resources
try (PrintWriter pw = new PrintWriter(filePath)) {
pw.println("List of prime numbers between " + start + " and " + end);
for (long i = start; i <= end; i++) {
if (isPrime(i)) {
pw.println(i);
}
}
} catch (FileNotFoundException e) {
e.printStackTrace();
}
If you wanted to create a binary file you could use a DataOutputStream.

You need to use a PrintWriter, for example:
import java.io.*;
public class primenumber {
public static void main(String[] args) throws IOException {
long start = 5000000;
long end = 10000000;
System.out.println("List of prime numbers between " + start + " and " + end);
PrintWriter pw = new PrintWriter(new FileOutputStream("primes.txt"));
for (long i = start; i <= end; i++) {
if (isPrime(i)) {
pw.println(i);
}
}
pw.close();
}
public static boolean isPrime(long i2) {
if (i2 <= 1) {
return false;
}
for (long i = 2; i < Math.sqrt(i2); i++) {
if (i2 % i == 0) {
return false;
}
}
return true;
}
}

Compile time error on online compilation?

import java.io.BufferedReader;
import java.io.File;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Scanner;
import java.io.FileNotFoundException;
import java.util.Collections;
import java.util.Comparator;
import java.util.Iterator;
import java.util.List;
import java.util.ArrayList;
import java.util.StringTokenizer;
public class database {
String fileName;
Scanner input;
String[][] data;
List<String> useful_list;
List<String> records;
ArrayList<Object> handles;
public database(String fileName) {
this.fileName = fileName;
}
public void openFile() {
try {
input = new Scanner(new File(fileName));
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
return;
}
}
public void readRecords() {
// Read all lines (records) from the file into an ArrayList
records = new ArrayList<String>();
try {
while (input.hasNext())
records.add(input.nextLine());
} catch (Exception e) {
// TODO: handle exception
}
}
public void parseFields() {
String delimiter = ",\n";
// Create two-dimensional array to hold data (see Deitel, p 313-315)
int rows = records.size(); // #rows for array = #lines in file
data = new String[rows][]; // create the rows for the array
int row = 0;
for (String record : records) {
StringTokenizer tokens = new StringTokenizer(record, delimiter);
int cols = tokens.countTokens();
data[row] = new String[cols]; // create columns for current row
int col = 0;
while (tokens.hasMoreTokens()) {
data[row][col] = tokens.nextToken().trim();
col++;
}
row++;
}
}
public static void main(String[] args) {
String filename = null;
String[] values = new String[4];
String input = null;
BufferedReader reader = new BufferedReader(new InputStreamReader(
System.in));
try {
filename = reader.readLine();
input = reader.readLine();
values = input.split(",");
} catch (IOException e) {
// TODO Auto-generated catch block
System.out.println("Invalid Input");
return;
}
int[] input1;
input1 = new int[4];
try {
for (int j = 0; j < values.length; j++) {
input1[j] = Integer.parseInt(values[j]);
}
} catch (Exception e) {
// TODO Auto-generated catch block
System.out.println("Invalid Input");
return;
}
if (input1[0] >= 4 || input1[0] <= 0) {
System.out.println("Invalid Input");
return;
}
database file1 = new database(filename);
file1.openFile();
file1.readRecords();
file1.parseFields();
file1.search(input1[1]);
if (file1.useful_list.size() == 0) {
System.out.println("Data Unavailable");
return;
}
file1.sortarray(input1[0] - 1);
int width = input1[2];
int skip = (input1[3] - 1) * width;
Iterator<Object> it = file1.handles.iterator();
for (int i = 1; i <= skip; i++) {
if (it.hasNext()) {
it.next();
} else {
System.out.println("Data Unavailable");
return;
}
}
for (int j = 1; j <= width && it.hasNext(); j++) {
String[] a = (String[]) it.next();
for (int i = 0; i < a.length; i++)
if(i<a.length-1)
System.out.print(a[i] + ",");
else
System.out.print(a[i]);
System.out.println();
}
}
void sortarray(final int index) {
handles = new ArrayList<Object>();
for (int i = 0; i < data.length; i++)
handles.add(data[i]);
Collections.sort(handles, new Comparator<Object>() {
public int compare(Object o1, Object o2) {
String[] a = (String[]) o1;
String[] b = (String[]) o2;
if (index == 1 || index == 0) {
int left = Integer.parseInt(a[index]);
int right = Integer.parseInt(b[index]);
return Integer.compare(left, right); //Line 165
} else {
if (a.length == 0 && b.length == 0)
return 0;
if (a.length == 0 && b.length != 0)
return 1;
if (a.length != 0 && b.length == 0)
return -1;
return a[index].compareTo(b[index]);
}
}
public boolean equals(Object o) {
return this == o;
}
});
}
void search(int searchs) {
useful_list = new ArrayList<String>();
for (int row = 0; row < data.length; row++) {
if (Integer.parseInt(data[row][0]) == searchs) {
// store in array list
useful_list.add(data[row][0] + "," + data[row][1] + ","
+ data[row][2] + "," + data[row][3]);
}
}
if (useful_list.size() == 0) {
return;
}
String delimiter = ",\n";
// Create two-dimensional array to hold data (see Deitel, p 313-315)
int rows = useful_list.size(); // #rows for array = #lines in file
data = new String[rows][]; // create the rows for the array
int row1 = 0;
for (String record : useful_list) {
StringTokenizer tokens = new StringTokenizer(record, delimiter);
int cols = tokens.countTokens();
data[row1] = new String[cols]; // create columns for current row
int col1 = 0;
while (tokens.hasMoreTokens()) {
data[row1][col1] = tokens.nextToken().trim();
col1++;
}
row1++;
}
}
}
this code is working fine on eclipse .
but if i submit it for my online compilation ..
it shows compile time error.
error message
*database.java 163 cannotfindsymbolsymbol methodcompare int int location class java.lang.Integer return Integer.compare left right ;^1error*

Integer.compare was introduced to Java in version 1.7. Chances are that the online compiler has an earlier version of the compiler

Integer.compare(int,int) was introduced in Java 1.7. I expect you are seeing that error because Java 6 or earlier is used to compile the code. The docs. themselves (linked above) show how to do it for earlier Java (you should consult them at times like this).
Integer.valueOf(x).compareTo(Integer.valueOf(y))