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Merge pull request #2 from RanjeetKaur17/develop.0.2.0 

Examples for Reading a file into an arraylist.
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RanjeetKaur 2018-08-12 00:13:58 +04:00 committed by GitHub
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commit 9dc52f5630
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24
core-java-io/src/main/java/com/baeldung/fileparser/BufferedReaderExample.java Normal file
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package com.baeldung.fileparser;
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
public class BufferedReaderExample {
protected static ArrayList<String> generateArrayListFromFile(String filename) throws IOException {
ArrayList<String> result = new ArrayList<>();
try (BufferedReader br = new BufferedReader(new FileReader(filename))) {
while (br.ready()) {
result.add(br.readLine());
}
return result;
}
}
}

31
core-java-io/src/main/java/com/baeldung/fileparser/FileReaderExample.java Normal file
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package com.baeldung.fileparser;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
public class FileReaderExample {
protected static ArrayList<String> generateArrayListFromFile(String filename) throws IOException {
ArrayList<String> result = new ArrayList<>();
try (FileReader f = new FileReader(filename)) {
StringBuffer sb = new StringBuffer();
while (f.ready()) {
char c = (char) f.read();
if (c == '\n') {
result.add(sb.toString());
sb = new StringBuffer();
} else {
sb.append(c);
}
}
if (sb.length() > 0) {
result.add(sb.toString());
}
}
return result;
}
}

18
core-java-io/src/main/java/com/baeldung/fileparser/FilesReadLinesExample.java Normal file
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package com.baeldung.fileparser;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.ArrayList;
import java.util.List;
public class FilesReadLinesExample {
protected static ArrayList<String> generateArrayListFromFile(String filename) throws IOException {
List<String> result = Files.readAllLines(Paths.get(filename));
return (ArrayList<String>) result;
}
}

24
core-java-io/src/main/java/com/baeldung/fileparser/ScannerIntExample.java Normal file
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package com.baeldung.fileparser;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Scanner;
public class ScannerIntExample {
protected static ArrayList<Integer> generateArrayListFromFile(String filename) throws IOException {
ArrayList<Integer> result = new ArrayList<>();
try (Scanner s = new Scanner(new FileReader(filename))) {
while (s.hasNext()) {
result.add(s.nextInt());
}
return result;
}
}
}

24
core-java-io/src/main/java/com/baeldung/fileparser/ScannerStringExample.java Normal file
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package com.baeldung.fileparser;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Scanner;
public class ScannerStringExample {
protected static ArrayList<String> generateArrayListFromFile(String filename) throws IOException {
ArrayList<String> result = new ArrayList<>();
try (Scanner s = new Scanner(new FileReader(filename))) {
while (s.hasNext()) {
result.add(s.nextLine());
}
return result;
}
}
}

19
core-java-io/src/test/java/com/baeldung/fileparser/BufferedReaderUnitTest.java Normal file
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package com.baeldung.fileparser;
import static org.junit.Assert.assertTrue;
import java.io.IOException;
import java.util.List;
import org.junit.Test;
public class BufferedReaderUnitTest {
protected static final String TEXT_FILENAME = "src/test/resources/sampleTextFile.txt";
@Test
public void whenParsingExistingTextFile_thenGetArrayList() throws IOException {
List<String> lines = BufferedReaderExample.generateArrayListFromFile(TEXT_FILENAME);
assertTrue("File does not has 2 lines", lines.size() == 2);
}
}

19
core-java-io/src/test/java/com/baeldung/fileparser/FileReaderUnitTest.java Normal file
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package com.baeldung.fileparser;
import static org.junit.Assert.assertTrue;
import java.io.IOException;
import java.util.List;
import org.junit.Test;
public class FileReaderUnitTest {
protected static final String TEXT_FILENAME = "src/test/resources/sampleTextFile.txt";
@Test
public void whenParsingExistingTextFile_thenGetArrayList() throws IOException {
List<String> lines = FileReaderExample.generateArrayListFromFile(TEXT_FILENAME);
assertTrue("File does not has 2 lines", lines.size() == 2);
}
}

19
core-java-io/src/test/java/com/baeldung/fileparser/FilesReadAllLinesUnitTest.java Normal file
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package com.baeldung.fileparser;
import static org.junit.Assert.assertTrue;
import java.io.IOException;
import java.util.List;
import org.junit.Test;
public class FilesReadAllLinesUnitTest {
protected static final String TEXT_FILENAME = "src/test/resources/sampleTextFile.txt";
@Test
public void whenParsingExistingTextFile_thenGetArrayList() throws IOException {
List<String> lines = FilesReadLinesExample.generateArrayListFromFile(TEXT_FILENAME);
assertTrue("File does not has 2 lines", lines.size() == 2);
}
}

19
core-java-io/src/test/java/com/baeldung/fileparser/ScannerIntUnitTest.java Normal file
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package com.baeldung.fileparser;
import static org.junit.Assert.assertTrue;
import java.io.IOException;
import java.util.List;
import org.junit.Test;
public class ScannerIntUnitTest {
protected static final String NUMBER_FILENAME = "src/test/resources/sampleNumberFile.txt";
@Test
public void whenParsingExistingTextFile_thenGetIntArrayList() throws IOException {
List<Integer> numbers = ScannerIntExample.generateArrayListFromFile(NUMBER_FILENAME);
assertTrue("File does not has 2 lines", numbers.size() == 2);
}
}

19
core-java-io/src/test/java/com/baeldung/fileparser/ScannerStringUnitTest.java Normal file
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package com.baeldung.fileparser;
import static org.junit.Assert.assertTrue;
import java.io.IOException;
import java.util.List;
import org.junit.Test;
public class ScannerStringUnitTest {
protected static final String TEXT_FILENAME = "src/test/resources/sampleTextFile.txt";
@Test
public void whenParsingExistingTextFile_thenGetArrayList() throws IOException {
List<String> lines = ScannerStringExample.generateArrayListFromFile(TEXT_FILENAME);
assertTrue("File does not has 2 lines", lines.size() == 2);
}
}

2
core-java-io/src/test/resources/sampleNumberFile.txt Normal file
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111
222

2
core-java-io/src/test/resources/sampleTextFile.txt Normal file
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Hello
World