javafilereaderfilewriter
Append a character for last value in a list in JAVA
Given this input
0000027788|001400000000000000000001224627|G1|||G1
0000027789|001400000000000000000001224627|D1|||G1
0000027790|001400000000000000000001224627|D1|||G1
0000027790|001400000000000000000001224627|D1|||G1
0000027791|001400000000000000000001224627|G2|||G2
0000027792|001400000000000000000001224627|D2|||G2
0000027793|001400000000000000000001224627|D2|||G2
0000027794|001400000000000000000001224627|G6|||G6
I need the 3rd column particularly from the file and find which is the last D1 for the group G1 and similarly last D2 for particular G2. After finding the last value, I need something to be appended in the corresponding line like "LL":
I have tried it, but the line is getting appended parallel to each D1 not only to the last D1.
This is my code:
package com.scb.firstreport;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import java.util.StringTokenizer;
public class EDWBatchProcessor {
//static Logger log = Logger.getLogger(EDWBatchProcessor.class.getName());
public static void main(String[] args) throws JRException, NoSuchFieldException, SecurityException, IllegalArgumentException, IllegalAccessException {
//log.debug("Hello this is a debug message");
File fileDir = new File("D:\\EDWFileProcessing\\simple.txt");
String line = null;
String[] split = null;
try {
// FileReader reads text files in the default encoding.
BufferedReader in = new BufferedReader(
new InputStreamReader(
new FileInputStream(fileDir), "UTF-8"));
BufferedWriter bufferedWriter = null;
while((line = in.readLine()) != null) {
//System.out.println(line);
split = line.split("\\|");
List<String> customerList = new ArrayList<String>();
if(!customerList.contains(split[1])){
customerList.add(split[1]);
bufferedWriter =
new BufferedWriter(new OutputStreamWriter(
new FileOutputStream("D:\\EDWFileProcessing\\output\\"+split[1]+".txt",true), "UTF-8"));
bufferedWriter.write(line);
bufferedWriter.newLine();
bufferedWriter.close();
}
else{
bufferedWriter.write(line);
bufferedWriter.close();
}
}
final File folder = new File("D:\\EDWFileProcessing\\output");
listFilesForFolder(folder);
// Always close files.
in.close();
}
catch(FileNotFoundException ex) {
System.out.println(
"Unable to open file '");
}
catch(IOException ex) {
System.out.println(
"Error reading file '"
);
// Or we could just do this:
// ex.printStackTrace();
}
}
private static void listFilesForFolder(File folder) throws NoSuchFieldException, SecurityException, IllegalArgumentException, IllegalAccessException, JRException, IOException {
for (final File fileEntry : folder.listFiles()) {
if (fileEntry.isDirectory()) {
//listFilesForFolder(fileEntry);
} else {
// System.out.println(fileEntry.getName().substring(0, 30));
//System.out.println(fileEntry.getAbsolutePath());
File fileDir = new File(fileEntry.getAbsolutePath());
String line = null;
String lineNew = "000000000000000000000000000000000";
String[] split = null;
// FileReader reads text files in the default encoding.
BufferedReader in = new BufferedReader(
new InputStreamReader(
new FileInputStream(fileDir), "UTF-8"));
BufferedWriter bufferedWriter = null;
List<String> customerList = new ArrayList<String>();
List<String> recTypeList = new ArrayList<String>();
while((line = in.readLine()) != null) {
// System.out.println(line);
split = line.split("\\|");
bufferedWriter =
new BufferedWriter(new OutputStreamWriter(
new FileOutputStream("D:\\EDWFileProcessing\\output\\simple\\"+split[1]+".txt",true), "UTF-8"));
System.out.println("Split2222222222========>>"+split[2]);
System.out.println("Split2222222222========>>"+recTypeList.contains(split[2]));
if(!recTypeList.contains(split[2])){
recTypeList.add(split[2]);
bufferedWriter.newLine();
bufferedWriter.write(line);
}else{
bufferedWriter.newLine();
line = line.concat("|LL");
bufferedWriter.write(line);
System.out.println("line new.....................");
//bufferedWriter.newLine();
//bufferedWriter.write(lineNew);
// bufferedWriter.newLine();
}
//bufferedWriter.newLine();
bufferedWriter.close();
}
in.close();
}
}
}
}
I tried using list, but "LL" is getting appended to the end of G2.
for (ListIterator<String> it = recTypeList.listIterator(); it.hasNext(); i++) {
String s1 = it.next();
if(s1.equals("G2"))
{
int ind=it.previousIndex()-1;
String val=recTypeList.get(ind);
String lastop=val.concat("LL");
bufferedWriter.write(lastop);
System.out.println(lastop);
System.out.println(val);
}
Solution
Here is how you can find the last D# for each G# and append an LL at the end. If we knew more information about how the format behaves it could have been made simpler. I substituted reading the file by putting it as a string and splitting the lines so that lines is what you have after you finish reading all the lines.
public class Test {
public static void main(String[] args) {
String input =
"0000027788|001400000000000000000001224627|G1| | |G1\r\n" +
"0000027789|001400000000000000000001224627|D1| | |G1\r\n" +
"0000027790|001400000000000000000001224627|D1| | |G1\r\n" +
"0000027790|001400000000000000000001224627|D1| | |G1\r\n" +
"0000027791|001400000000000000000001224627|G2| | |G2\r\n" +
"0000027792|001400000000000000000001224627|D2| | |G2\r\n" +
"0000027793|001400000000000000000001224627|D2| | |G2\r\n" +
"0000027794|001400000000000000000001224627|G6| | |G6";
String[] lines = input.split("\r\n");
String[][] parts = new String[lines.length][];
for (int i = 0; i < lines.length; i++)
parts[i] = lines[i].split("\\|");
String currG = "G1";
String lastD = "";
for (int i = 1; i < lines.length; i++) {
if (parts[i][2].startsWith("G")) {
System.out.println("Last D for " + currG + " is " + lastD + " at line " + (i-1));
lines[i-1] += " LL";
currG = parts[i][2];
}
else
lastD = parts[i][2];
}
System.out.println();
for (int i = 0; i < lines.length; i++)
System.out.println(lines[i]);
}
}
Output:
Last D for G1 is D1 at line 3
Last D for G2 is D2 at line 6
0000027788|001400000000000000000001224627|G1| | |G1
0000027789|001400000000000000000001224627|D1| | |G1
0000027790|001400000000000000000001224627|D1| | |G1
0000027790|001400000000000000000001224627|D1| | |G1 LL
0000027791|001400000000000000000001224627|G2| | |G2
0000027792|001400000000000000000001224627|D2| | |G2
0000027793|001400000000000000000001224627|D2| | |G2 LL
0000027794|001400000000000000000001224627|G6| | |G6
My assumptions are that the second column has only G# or D# and that in line 0 it is G1.
Edit: If I add to my above assumptions that under each G# there are Ds with only the same # then this is shorter:
public class Test {
public static void main(String[] args) {
String input =
"0000027788|001400000000000000000001224627|G1| | |G1\r\n" +
"0000027789|001400000000000000000001224627|D1| | |G1\r\n" +
"0000027790|001400000000000000000001224627|D1| | |G1\r\n" +
"0000027790|001400000000000000000001224627|D1| | |G1\r\n" +
"0000027791|001400000000000000000001224627|G2| | |G2\r\n" +
"0000027792|001400000000000000000001224627|D2| | |G2\r\n" +
"0000027793|001400000000000000000001224627|D2| | |G2\r\n" +
"0000027794|001400000000000000000001224627|G6| | |G6";
String[] lines = input.split("\r\n");
String[][] parts = new String[lines.length][];
for (int i = 0; i < lines.length; i++)
parts[i] = lines[i].split("\\|");
String currG = "G1";
for (int i = 1; i < lines.length; i++) {
if (parts[i][2].startsWith("G")) {
System.out.println("Last D" + parts[i-1][2].substring(1) + " for " + currG + " is at line " + (i-1));
lines[i-1] += " LL";
currG = parts[i][2];
}
}
System.out.println();
for (int i = 0; i < lines.length; i++)
System.out.println(lines[i]);
}
}
Edit2: with file reading and writing
public class Test {
public static void main(String[] args) {
String input = "path\\to\\input\\text.txt";
String output = "path\\to\\output\\text.txt";
BufferedReader in;
BufferedWriter out;
try {
in = new BufferedReader(new InputStreamReader(new FileInputStream(input), "UTF-8"));
out = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(output, true), "UTF-8"));
String line, lastLine;
lastLine = in.readLine();
while ((line = in.readLine()) != null) {
String[] parts = line.split("\\|");
if (parts[2].startsWith("G")) {
lastLine += " LL";
}
out.write(lastLine);
out.write(System.lineSeparator());
lastLine = line;
}
out.write(lastLine);
in.close();
out.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
Handle the exceptions properly.
Here is how it works:
lastLine keeps the previous line read while line is searched for a new G. If one is found, then lastLine must contain the last D of the previous G. Here are the first iterations:
lastLine: G1 0
line: D1 1
---
lastLine: D1 1
line: D1 2
---
lastLine: D1 2
line: D1 3
---
lastLine: D1 3
line: G2 4
// line starts with G, so append LL to lastLine because it's the last D for G1.
---
lastLine: G2 4
line: D2 5
...
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