I've been coding Perl and Python a lot and this time I got an assignment to code in Java instead. So I'm not too familiar with handling data in Java.
My task involves having a input file where I need to check dependencies and then output those with transitive dependencies. Clearer ideas below:
Input File:
A: B C
B: C E
C: G
D: A
Output File:
A: B C E G
B: C E G
C: G
D: A B C E G
So far this is what I've got (separating the first and second token):
import java.util.StringTokenizer;
import java.io.*;
public class TestDependency {
public static void main(String[] args) {
try{
FileInputStream fstream = new FileInputStream("input-file");
BufferedReader br = new BufferedReader(new InputStreamReader(fstream));
String strLine;
while ((strLine = br.readLine()) != null) {
StringTokenizer items = new StringTokenizer(strLine, ":");
System.out.println("I: " + items.nextToken().trim());
StringTokenizer depn = new StringTokenizer(items.nextToken().trim(), " ");
while(depn.hasMoreTokens()) {
System.out.println( "D: " + depn.nextToken().trim() );
}
}
} catch (Exception e){//Catch exception if any
System.err.println("Error: " + e.getMessage());
}
}
}
Any help appreciated. I can imagine Perl or Python to handle this easily. Just need to implement it in Java.
This is not very efficient memory-wise and requires good input but should run fine.
public class NodeParser {
// Map holding references to nodes
private Map<String, List<String>> nodeReferenceMap;
/**
* Parse file and create key/node array pairs
* #param inputFile
* #return
* #throws IOException
*/
public Map<String, List<String>> parseNodes(String inputFile) throws IOException {
// Reset list if reusing same object
nodeReferenceMap = new HashMap<String, List<String>>();
// Read file
FileInputStream fstream = new FileInputStream(inputFile);
BufferedReader br = new BufferedReader(new InputStreamReader(fstream));
String strLine;
// Parse nodes into reference mapping
while((strLine = br.readLine()) != null) {
// Split key from nodes
String[] tokens = strLine.split(":");
String key = tokens[0].trim();
String[] nodes = tokens[1].trim().split(" ");
// Set nodes as an array list for key
nodeReferenceMap.put(key, Arrays.asList(nodes));
}
// Recursively build node mapping
Map<String, Set<String>> parsedNodeMap = new HashMap<String, Set<String>>();
for(Map.Entry<String, List<String>> entry : nodeReferenceMap.entrySet()) {
String key = entry.getKey();
List<String> nodes = entry.getValue();
// Create initial node set
Set<String> outSet = new HashSet<String>();
parsedNodeMap.put(key, outSet);
// Start recursive call
addNode(outSet, nodes);
}
// Sort keys
List<String> sortedKeys = new ArrayList<String>(parsedNodeMap.keySet());
Collections.sort(sortedKeys);
// Sort nodes
Map<String, List<String>> sortedParsedNodeMap = new LinkedHashMap<String, List<String>>();
for(String key : sortedKeys) {
List<String> sortedNodes = new ArrayList<String>(parsedNodeMap.get(key));
Collections.sort(sortedNodes);
sortedParsedNodeMap.put(key, sortedNodes);
}
// Return sorted key/node mapping
return sortedParsedNodeMap;
}
/**
* Recursively add nodes by referencing the previously generated list mapping
* #param outSet
* #param nodes
*/
private void addNode(Set<String> outSet, List<String> nodes) {
// Add each node to the set mapping
for(String node : nodes) {
outSet.add(node);
// Get referenced nodes
List<String> nodeList = nodeReferenceMap.get(node);
if(nodeList != null) {
// Create array list from abstract list for remove support
List<String> referencedNodes = new ArrayList<String>(nodeList);
// Remove already searched nodes to prevent infinite recursion
referencedNodes.removeAll(outSet);
// Recursively search more node paths
if(!referencedNodes.isEmpty()) {
addNode(outSet, referencedNodes);
}
}
}
}
}
Then, you can call this from your program like so:
public static void main(String[] args) {
try {
NodeParser nodeParser = new NodeParser();
Map<String, List<String>> nodeSet = nodeParser.parseNodes("./res/input.txt");
for(Map.Entry<String, List<String>> entry : nodeSet.entrySet()) {
String key = entry.getKey();
List<String> nodes = entry.getValue();
System.out.println(key + ": " + nodes);
}
} catch (IOException e){
System.err.println("Error: " + e.getMessage());
}
}
Also, the output is not sorted but that should be trivial.
String s = "A: B C D";
String i = s.split(":")[0];
String dep[] = s.split(":")[1].trim().split(" ");
System.out.println("i = "+i+", dep = "+Arrays.toString(dep));
Related
I have a relatively inefficent CSVReader code, see below. It takes more than 30 seconds to read 30000+ lines. How to speed up this reading process as fast as possible?
public class DataReader {
private String csvFile;
private List<String> sub = new ArrayList<String>();
private List<List> master = new ArrayList<List>();
public void ReadFromCSV(String csvFile) {
String line = "";
String cvsSplitBy = ",";
try (BufferedReader br = new BufferedReader(new FileReader(csvFile))) {
System.out.println("Header " + br.readLine());
while ((line = br.readLine()) != null) {
// use comma as separator
String[] list = line.split(cvsSplitBy);
// System.out.println("the size is " + country[1]);
for (int i = 0; i < list.length; i++) {
sub.add(list[i]);
}
List<String> temp = (List<String>) ((ArrayList<String>) sub).clone();
// master.add(new ArrayList<String>(sub));
master.add(temp);
sub.removeAll(sub);
}
} catch (IOException e) {
e.printStackTrace();
}
System.out.println(master);
}
public List<List> getMaster() {
return master;
}
}
UPDATE: I have found that my code actually can finish the reading work in less than 1 second if run it separately. As this DataReader is a part used by my simulation model to initialize the relevant properties. And the following part is associated with the use of the data imported, WHICH TAKES 40 SECONDS TO FINISH! Anyone could help by looking at the generic part of the codes?
// add route network
Network<Object> net = (Network<Object>)context.getProjection("IntraCity Network");
IndexedIterable<Object> local_hubs = context.getObjects(LocalHub.class);
for (int i = 0; i <= CSV_reader_route.getMaster().size() - 1; i++) {
String source = (String) CSV_reader_route.getMaster().get(i).get(0);
String target = (String) CSV_reader_route.getMaster().get(i).get(3);
double dist = Double.parseDouble((String) CSV_reader_route.getMaster().get(i).get(6));
double time = Double.parseDouble((String) CSV_reader_route.getMaster().get(i).get(7));
Object source_hub = null;
Object target_hub = null;
Query<Object> source_query = new PropertyEquals<Object>(context, "hub_code", source);
for (Object o : source_query.query()) {
if (o instanceof LocalHub) {
source_hub = (LocalHub) o;
}
if (o instanceof GatewayHub) {
source_hub = (GatewayHub) o;
}
}
Query<Object> target_query = new PropertyEquals<Object>(context, "hub_code", target);
for (Object o : target_query.query()) {
if (o instanceof LocalHub) {
target_hub = (LocalHub) o;
}
if (o instanceof GatewayHub) {
target_hub = (GatewayHub) o;
}
}
// System.out.println(target_hub.getClass() + " " + time);
// Route this_route = (Route) net.addEdge(source_hub, target_hub);
// context.add(this_route);
// System.out.println(net.getEdge(source_hub, target_hub));
if (net.getEdge(source, target) == null) {
Route this_route = (Route) net.addEdge(source, target);
context.add(this_route);
// this_route.setDist(dist);
// this_route.setTime(time); }
}
}
In your code you are doing many write operation to just add the list of values from current row in your master list which is not required. You can replace the existing code with simple one as given below.
Existing code:
String[] list = line.split(cvsSplitBy);
// System.out.println("the size is " + country[1]);
for (int i = 0; i < list.length; i++) {
sub.add(list[i]);
}
List<String> temp = (List<String>) ((ArrayList<String>) sub).clone();
// master.add(new ArrayList<String>(sub));
master.add(temp);
sub.removeAll(sub);
Suggested code:
master.add(Arrays.asList(line.split(cvsSplitBy)));
I don't have a CSV that big, but you could try the following:
public static void main(String[] args) throws IOException {
Path csvPath = Paths.get("path/to/file.csv");
List<List<String>> master = Files.lines(csvPath)
.skip(1)
.map(line -> Arrays.asList(line.split(",")))
.collect(Collectors.toList());
}
EDIT: I tried it with a CSV sample with 50k entries and the code runs in less than one second.
With extends to the answer of #Alex R, you can process it in parallel as well like this:
public static void main(String[] args) throws IOException {
Path csvPath = Paths.get("path/to/file.csv");
List<List<String>> master = Files.lines(csvPath)
.skip(1).parallel()
.map(line -> Arrays.asList(line.split(",")))
.collect(Collectors.toList());
}
I made a java program that will check contents of directory and generate for each file a md5 checksum. When the program is done it will save it to a CSV file. So far the lookup of files is working perfectly except that when writing to the CSV i want to make to only add new detected files. I think the issue lies with the md5 string used as key is not correctly found.
Here is an excerpt of the CSV file:
4d1954a6d4e99cacc57beef94c80f994,uiautomationcoreapi.h;E:\Tools\Strawberry-perl-5.24.1.1-64\c\x86_64-w64-mingw32\include\uiautomationcoreapi.h;N/A
56ab7135e96627b90afca89199f2c708,winerror.h;E:\Tools\Strawberry-perl-5.24.1.1-64\c\x86_64-w64-mingw32\include\winerror.h;N/A
146e5c5e51cc51ecf8d5cd5a6fbfc0a1,msimcsdk.h;E:\Tools\Strawberry-perl-5.24.1.1-64\c\x86_64-w64-mingw32\include\msimcsdk.h;N/A
e0c43f92a1e89ddfdc2d1493fe179646,X509.pm;E:\Tools\Strawberry-perl-5.24.1.1-64\perl\vendor\lib\Crypt\OpenSSL\X509.pm;N/A
As you can see first is the MD5 as key and afterwards is a long string containing name, location and score that will be split with the ; character.
and here is the code that should make sure only new ones are added:
private static HashMap<String, String> map = new HashMap<String,String>();
public void UpdateCSV(HashMap<String, String> filemap) {
/*Set set = filemap.entrySet();
Iterator iterator = set.iterator();
while(iterator.hasNext()) {
Map.Entry mentry = (Map.Entry) iterator.next();
String md = map.get(mentry.getKey());
System.out.println("checking key:" + md);
if (md == null) {
String[] line = mentry.getValue().toString().split(";");
System.out.println("Adding new File:" + line[0]);
map.put(mentry.getKey().toString(), mentry.getValue().toString());
}
}*/
for (final String key : filemap.keySet()) {
String md = map.get(key.toCharArray());
if (md == null) {
System.out.println("Key was not found:" + key);
String[] line = filemap.get(key).toString().split(";");
System.out.println("Adding new File:" + line[0]);
map.put(key, filemap.get(key));
}
}
}
As you can see from the commented code i tried in different ways already. hashmap filemap is the current status of the folder structure.
To read the already saved CSV file is use the following code:
private void readCSV() {
System.out.println("Reading CSV file");
BufferedReader br = new BufferedReader(filereader);
String line = null;
try {
while ((line = br.readLine()) != null) {
String str[] = line.split(",");
for (int i = 0; i < str.length; i++) {
String arr[] = str[i].split(":");
map.put(arr[0], arr[1]);
System.out.println("just added to map" + arr[0].toString() + " with value "+ arr[0].toString() );
}
}
}
catch(java.io.IOException e) {
System.out.println("Can't read file");
}
}
So when i run the program it will say that all files are new even tough they are already known in the CSV. So can anyone help to get this key string checked correctly?
As #Ben pointed out, your problem is that you use String as key when putting, but char[] when getting.
It should be something along the lines:
for (final String key : filemap.keySet()) {
map.computeIfAbsent(key, k -> {
System.out.println("Key was not found:" + k);
String[] line = filemap.get(k).toString().split(";");
System.out.println("Adding new File:" + line[0]);
return filemap.get(k);
});
}
Since you need both key as well as value from filemap, you actually better iterate over entrySet. This will save you additional filemap.gets:
for (final Map.Entry<String, String> entry : filemap.entrySet()) {
final String key = entry.getKey();
final String value = entry.getValue();
map.computeIfAbsent(key, k -> {
System.out.println("Key was not found:" + k);
String[] line = value.split(";");
System.out.println("Adding new File:" + line[0]);
return value;
});
}
I know there are other solutions out there but nothing is working for me.
Question: In my main method, I group together IDs by rating and make the rating the key and the rest of the info the value as a List. When I create the hashmap and put in the lists I can accurately print the contents of the hashmap. However, once I pass the map the evaluate method, the values are lost and I cannot iterate in the same way that I did in the main method, even though the logic is the same. I am not experienced with the Map class in java. Can somebody please help me figure out why when I pass the Map to my evaluate method that I can no longer iterate the Map?
import java.io.*;
import java.util.*;
public class Evaluate {
public static double grandTotal;
public static void main(String[] args) throws Exception {
FileInputStream fs = new FileInputStream("testInput.txt");
BufferedReader br = new BufferedReader(new InputStreamReader(fs));
FileInputStream fs2 = new FileInputStream("testTest.txt");
BufferedReader br2 = new BufferedReader(new InputStreamReader(fs2));
String line;
String line2;
String[] bloop;
String bleep;
String flooper;
String splitter;
String[] splitInput;
List<String> oneStarList= new ArrayList<String>();
List<String> twoStarList= new ArrayList<String>();
List<String> threeStarList= new ArrayList<String>();
List<String> fourStarList= new ArrayList<String>();
List<String> fiveStarList= new ArrayList<String>();
List<String> values2 = new ArrayList<String>();
try {
while ((line=br.readLine()) != null) {
bloop = new String[10];
bloop = line.split("\\s+");
bleep = bloop[1].toString();
flooper = (bloop[0]+" "+bloop[2]+" "+bloop[3]+" "+bloop[4]);
if (bleep.equals("1")){
oneStarList.add(flooper);
}
else if (bleep.equals("2")){
twoStarList.add(flooper);
}
else if (bleep.equals("3")){
threeStarList.add(flooper);
}
else if (bleep.equals("4")){
fourStarList.add(flooper);
}
else if (bleep.equals("5")){
fiveStarList.add(flooper);
}
grandTotal+=(Double.parseDouble(bloop[2]));
}
}
catch (Exception e){
}
Map<String,List<String>> hmap = new HashMap<String,List<String>>();
hmap.put("1",oneStarList);
hmap.put("2", twoStarList);
hmap.put("3", threeStarList);
hmap.put("4", fourStarList);
hmap.put("5", fiveStarList);
while ((line2=br2.readLine()) != null) {
splitInput = new String[5];
splitInput = line2.split("\\s+");
evaluate(splitInput[0],splitInput[1],hmap);
}
br.close();
br2.close();
}
public static void evaluate(String movID, String usrID, Map<String,List<String>> hash) throws Exception{
FileWriter fw = new FileWriter("outputTest.txt");
BufferedWriter bwr = new BufferedWriter(fw);
List<String> values = new ArrayList<String>();
List<String> outputList = new ArrayList<String>();
String[] floop;
String fleep;
int movIDtotal=0;
int usrIDtotal=0;
int totalValues=0;
double pmovIDStar=0;
double pusrIDStar=0;
double pmovID=0;
double pusrID=0;
double numID=0;
double keyTotalProb=0;
String keyOutputStr;
String keyHold;
final Set<Map.Entry<String,List<String>>> entries = hash.entrySet();
for (String key : hash.keySet()){
values = hash.get(key);
System.out.println(key + ":");
for (int i=0;i<values.size();i++){
System.out.println(values.get(i));
floop = new String[5];
fleep = values.get(i);
floop = fleep.split("\\s+");
if (movID.equals(floop[0])){
movIDtotal++;
totalValues++;
}
if (usrID.equals(floop[0])){
usrIDtotal++;
totalValues++;
}
}
values.clear();
}
for (Map.Entry<String, List<String>> entry: entries){
values= entry.getValue();
keyHold = entry.getKey();
for (int j=0;j<values.size();j++){
floop = new String[5];
fleep = values.get(j);
floop = fleep.split("\\s+");
if (movID.equals(floop[0])){
pmovIDStar = Double.parseDouble(floop[3]);
numID = Double.parseDouble(floop[1]);
pmovID = (numID/movIDtotal);
}
if (usrID.equals(floop[0])){
pusrIDStar = Double.parseDouble(floop[3]);
numID = Double.parseDouble(floop[1]);
pusrID = (numID/usrIDtotal);
}
}
keyTotalProb = ((totalValues/grandTotal)*(pmovIDStar)*(pusrIDStar))/(pusrID*pmovID);
keyOutputStr = Double.toString(keyTotalProb);
outputList.add(keyHold);
outputList.add(keyOutputStr);
values.clear();
}
double max = Double.MIN_VALUE;
for (int m=0;m<outputList.size();m+=2){
double coolguy = Double.parseDouble(outputList.get(m+1));
int index = 0;
if(coolguy>max){
max = coolguy;
index = m;
}
try {
bwr.write(String.format("%-1s %-1s %-1s%n", movID,usrID,outputList.get(index)));
bwr.close();
fw.close();
}
catch(Exception e) {
}
}
}
}
Backup info: I'm trying to build a java program that essentially performs the final stage of the Naive Bayes algorithm to predict user ratings (1-5) for movies. I have used MapReduce to train data and now I have an input file where each line contains a string containing information in this order without the commas (movie or user id,rating , number of times rating and ID occur together in total, number of times ID occurs in total, probability that ID and rating occur together out of all ratings for ID). Essentially this is the classification stage.
never suppress excetions. especially when you do coding/debugging.
catch (Exception e){ } is very bad practice
When you do:
final Set<Map.Entry<String,List<String>>> entries = hash.entrySet();
it does not copy hash.entrySet to entries. It creates another reference to it.
same is for values= entry.getValue();
then what do you expect after your first loop (and others too)?
when you do:
values.clear();
your values gone from the lists which are in hash and since entries is just a reference to hash.entrySet() you have what you've done - empty lists.
Hi I am parsing xml tags without using any parser just using StringUtils.substring as I need only 2 tags values. after I get these values I am adding it to list and with these 2 lists I am preparing map with values and keys. This Hash map I want to add it to file. If values are already exist then no need to add else add. But I am facing error in adding it to Hashmap and traversing thru hashmap to check if hashmap key/values exist in file reader read line.
public class CompName {
/**
* #param args
* #throws IOException
*/
public static void main(String[] args) throws IOException {
// TODO Auto-generated method stub
File file = new File("xml/input1.xml");
ArrayList<String> email = new ArrayList<String>();
ArrayList<String> comp = new ArrayList<String>();
Map<ArrayList<String>,ArrayList<String>> compIdmap = new LinkedHashMap<ArrayList<String>,ArrayList<String>>();
try {
BufferedReader br = new BufferedReader(new FileReader(file));
br.readLine();
while(true){
String line =br.readLine();
//System.out.println("line "+line);
if(line == null) break;
if(line.contains("<CompanyName>"))
{
String compName = StringUtils.substringBetween(line, "<CompanyName>", "</CompanyName>"); //str =" middle "
System.out.println(compName);
comp.add(compName);
}
if(line.contains("<CorporateEmailAddress>"))
{
String emailId = StringUtils.substringBetween(line, "<CorporateEmailAddress>", "</CorporateEmailAddress>"); //str =" middle "
if(emailId == null || emailId.equals(""))
emailId = "unknown";
System.out.println(emailId);
email.add(emailId);
}
for(int i=0;i<email.size();i++)
{
compIdmap.put(email, comp);
}
}
System.out.println("mapping :"+compIdmap);
BufferedWriter br1 = new BufferedWriter(new FileWriter("xml/mapping.txt"));
Iterator it = compIdmap.entrySet().iterator();
while (it.hasNext()) {
Map.Entry pair = (Map.Entry)it.next();
System.out.println(pair.getKey() + " = " + pair.getValue());
br1.write(pair.getKey() + " = " + pair.getValue());
it.remove(); // avoids a ConcurrentModificationException
}
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
input xml file to check these tags is as below
<?xml version="1.0" encoding="UTF-8"?>
<!-- Data provided by Bloomberg LP. -->
<FileDump>
<Version>IBXML 1.3</Version>
<CompanyName>STANDARD CHARTERED B</CompanyName>
<EmailAddress>abc#gmail.com</EmailAddress>
<CorporateEmailAddress></CorporateEmailAddress>
<CompanyName>STANDARD CHARTERED B</CompanyName>
<EmailAddress>abc#gmail.com</EmailAddress>
<CorporateEmailAddress></CorporateEmailAddress>
<CompanyName>DBS BANK LIMITED HON</CompanyName>
<EmailAddress>nnn#bbg.com</EmailAddress>
<CorporateEmailAddress>nicholas#123.com</CorporateEmailAddress>
<CompanyName>DBS BANK LIMITED HON</CompanyName>
<EmailAddress>nnn#bbg.com</EmailAddress>
<CorporateEmailAddress>nicholas#123.com</CorporateEmailAddress>
<CompanyName>DBS BANK LIMITED HON</CompanyName>
<EmailAddress>nnn#bbg.com</EmailAddress>
<CorporateEmailAddress>nicholas#123.com</CorporateEmailAddress>
<CompanyName>DBS BANK (HONG KONG)</CompanyName>
<EmailAddress>www#bbg.com</EmailAddress>
<CorporateEmailAddress>WHEEL#123.com</CorporateEmailAddress>
<CompanyName>DBS BANK (HONG KONG)</CompanyName>
<EmailAddress>www#bbg.com</EmailAddress>
<CorporateEmailAddress>WHEEL#123.com</CorporateEmailAddress>
</FileDump>
I am expecting file output mapping.txt should be
unknown STANDARD CHARTERED B
nicholas#123.com DBS BANK LIMITED HON
WHEEL#123.com DBS BANK (HONG KONG)
There are several problems with the code, the first being you defined the key and value to the map as ArrayList. the key simply cannot be an array list - it has no logical meaning and if you wish the values to be distinct, use Set.
note: the way I understand it an email belongs to one company, so whay not map one-to-one??
and why does it have to be LinkedHashMap? do you care about the order of key insertion?
Here is a working solution
public static void main(String[] args) throws IOException
{
File file = new File("xml/input1.xml");
// main data structure
// key - corporate email
// value - set of distinct companies
// (does this make sense? a corporate email belongs to one company, no?
Map<String, Set<String>> compIdmap = new HashMap<String, Set<String>>();
// making use of Java 7 try-with-resources to auto close the file after use
try (BufferedReader br = new BufferedReader(new FileReader(file))) {
String line, compName = "", email = "";
while ((line = br.readLine()) != null) {
if (line.contains("<CompanyName>")) {
compName = StringUtils.substringBetween(line, "<CompanyName>", "</CompanyName>");
}
if (line.contains("<CorporateEmailAddress>")) {
email = StringUtils.substringBetween(line, "<CorporateEmailAddress>", "</CorporateEmailAddress>");
if (email == null || email.equals("")) email = "unknown";
Set<String> companiesSet = compIdmap.containsKey(email) ? compIdmap.get(email) : new HashSet<>();
companiesSet.add(compName);
compIdmap.put(email, companiesSet);
}
}
System.out.println("mapping :" + compIdmap);
BufferedWriter br1 = new BufferedWriter(new FileWriter("xml/mapping.txt"));
Iterator it = compIdmap.entrySet().iterator();
while (it.hasNext()) {
Map.Entry pair = (Map.Entry) it.next();
System.out.println(pair.getKey() + " = " + pair.getValue());
br1.write(pair.getKey() + " = " + pair.getValue());
it.remove(); // avoids a ConcurrentModificationException
}
} catch (FileNotFoundException e) {
e.printStackTrace();
}
}
EDIT:
Here is a solution that produces the exact desired output
public static void main(String[] args)
{
File file = new File("xml/input1.xml");
// contains email + " " + company
Set<String> emailAndCompanySet = new HashSet<>();
// making use of Java 7 try-with-resources to auto close the file after use
try (BufferedReader br = new BufferedReader(new FileReader(file))) {
String line, compName = "", email = "";
while ((line = br.readLine()) != null) {
if (line.contains("<CompanyName>")) {
compName = StringUtils.substringBetween(line, "<CompanyName>", "</CompanyName>");
}
if (line.contains("<CorporateEmailAddress>")) {
email = StringUtils.substringBetween(line, "<CorporateEmailAddress>", "</CorporateEmailAddress>");
if (email == null || email.equals(""))
email = "unknown";
emailAndCompanySet.add(email + " " + compName);
}
}
System.out.println("mapping :" + emailAndCompanySet);
BufferedWriter br1 = new BufferedWriter(new FileWriter("xml/mapping.txt"));
for (String emailAndCompany : emailAndCompanySet) {
System.out.println(emailAndCompany);
br1.write(emailAndCompany);
}
} catch (Exception e) {
e.printStackTrace();
}
}
I am currently writing my thesis, and in that context I need to develop a meta-heuristic using java. However I am facing a problem when trying to read and store the data.
My file is a text file, with around 150 lines. An example of the problem is in line 5 where three integer numbers are stated: 30, 38 and 1. I would like to store each of these as an integer called respectively L, T and S, and this goes on for many other of the lines.
Any of you who knows how to do that? If needed I can send you the txt file.
btw: this is what I've tried so far:
Main.java:
import java.io.IOException;
import java.io.FileWriter;
import java.io.BufferedWriter;
public class MAIN {
public static void main(String[] args) throws IOException {
Test.readDoc("TAP_T38L30C4F2S12_03.txt");
}
}
Test.java:
import java.io.*;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;
public class Test {
private static ArrayList<Integer> integerList = new ArrayList<Integer>();
public static Map<String, ArrayList<Integer>> data = new HashMap<String, ArrayList<Integer>>();
public static String aKey;
public static void readDoc(String File) {
try{
FileReader fr = new FileReader("TAP_T38L30C4F2S12_03.txt");
BufferedReader br = new BufferedReader(fr);
while(true) {
String line = br.readLine();
if (line == null)
break;
else if (line.matches("\\#\\s[a-zA-Z]")){
String key = line.split("\\t")[1];
line = br.readLine();
data.put(key, computeLine(line));
}
else if (line.matches("\\\\\\#\\s(\\|[a-zA-Z]\\|,?\\s?)+")){
String[] keys = line.split("\\t");
line = br.readLine();
ArrayList<Integer> results = computeLine(line);
for (int i=0; i<keys.length; i++){
aKey = aKey.replace("|", "");
// data.put(aKey, results.get(i));
data.put(aKey, results);
}
}
System.out.println(data);
}
} catch(Exception ex) {
ex.printStackTrace(); }
}
private static ArrayList<Integer> computeLine (String line){
String[] splitted = line.split("\\t");
for (String s : splitted) {
integerList.add(Integer.parseInt(s));
}
return integerList;
}
}
And example of the data is seen here:
\# TAP instance
\# Note that the sequence of the data is important!
\#
\# |L|, |T|, |S|
30 38 1
\#
\# v
8213 9319 10187 12144 8206 ...
\#
\# w
7027 9652 9956 13973 6661 14751 ...
\#
\# b
1 1 1 1 1 ...
\#
\# c
1399 1563 1303 1303 2019 ...
\#
\# continues
The following code is working with the sample data you gave.
In short :
Create a field to store your data, I chose a TreeMap so you can map a letter to a certain number of Integers but you can use another Collection.
Read the file line by line using BufferedReader#readLine()
Then process each bunch of lines depending on your data. Here I use regular expressions to match a given line and then to remove everything that is not data. See String#split(), String#matches()
But before all start by reading some good beginners books about java and Object Oriented Design.
public class ReadAndParse {
public Map<String, ArrayList<Integer>> data = new TreeMap<String, ArrayList<Integer>>();
public ReadAndParse() {
try {
FileReader fr = new FileReader("test.txt");
BufferedReader br = new BufferedReader(fr);
while(true) {
String line = br.readLine();
if (line == null) break;
else if (line.matches("\\\\#\\s[a-zA-Z]")){
String key = line.split("\\s")[1];
line = br.readLine();
ArrayList<Integer> value= computeLine(line);
System.out.println("putting key : " + key + " value : " + value);
data.put(key, value);
}
else if (line.matches("\\\\\\#\\s(\\|[a-zA-Z]\\|,?\\s?)+")){
String[] keys = line.split("\\s");
line = br.readLine();
ArrayList<Integer> results = computeLine(line);
for (int i=1; i<keys.length; i++){
keys[i] = keys[i].replace("|", "");
keys[i] = keys[i].replace(",", "");
System.out.println("putting key : " + keys[i] + " value : " + results.get(i-1));
ArrayList<Integer> value= new ArrayList<Integer>();
value.add(results.get(i-1));
data.put(keys[i],value);
}
}
}
}
catch (IOException e) {
e.printStackTrace();
}
// print the data
for (Entry<String, ArrayList<Integer>> entry : data.entrySet()){
System.out.println("variable : " + entry.getKey()+" value : "+ entry.getValue() );
}
}
// the compute line function
private ArrayList<Integer> computeLine(String line){
ArrayList<Integer> integerList = new ArrayList<>();
String[] splitted = line.split("\\s+");
for (String s : splitted) {
System.out.println("Compute Line : "+s);
integerList.add(Integer.parseInt(s));
}
return integerList;
}
// and the main function to call it all
public static void main(String[] args) {
new ReadAndParse();
}
}
Some sample output of what I got after parsing your file :
variable : L value : [30]
variable : S value : [1]
variable : T value : [38]
variable : b value : [1, 1, 1, 1, 1]
variable : c value : [1399, 1563, 1303, 1303, 2019]
variable : v value : [8213, 9319, 10187, 12144, 8206]
variable : w value : [7027, 9652, 9956, 13973, 6661, 14751]
I think I've got something.
EDIT:
I've changed my approach
You'll need to import;
import java.io.BufferedReader;
Then
BufferedReader reader = new BufferedReader
int[] arr = new int[3];
int L;
int T;
int S;
for (int i = 0 ;i<5; i++){ //brings you to fifth line
line = reader.readLine();
}
L = line.split(" ")[0]trim();
T = line.split(" ")[1]trim();
S = line.split(" ")[2]trim();
arr[0] = (L);
arr[1] = (T);
arr[2] = (S);