5: Create FileContentProvider

src/main/java/com/bartek/esa/file/di/FileModule.java

@@ -1,5 +1,6 @@
 package com.bartek.esa.file.di;
 
+import com.bartek.esa.file.provider.FileContentProvider;
 import com.bartek.esa.file.provider.FileProvider;
 import dagger.Module;
 import dagger.Provides;
@@ -11,4 +12,9 @@ public class FileModule {
     public FileProvider fileProvider() {
         return new FileProvider();
     }
+
+    @Provides
+    public FileContentProvider fileContentProvider() {
+        return new FileContentProvider();
+    }
 }

src/main/java/com/bartek/esa/file/model/FoundLine.java

@@ -0,0 +1,12 @@
+package com.bartek.esa.file.model;
+
+import lombok.Builder;
+import lombok.Data;
+
+@Data
+@Builder
+public class FoundLine {
+    private int number;
+    private String line;
+    private int position;
+}

src/main/java/com/bartek/esa/file/provider/FileContentProvider.java

@@ -0,0 +1,63 @@
+package com.bartek.esa.file.provider;
+
+import com.bartek.esa.error.EsaException;
+import com.bartek.esa.file.model.FoundLine;
+import io.vavr.control.Try;
+
+import javax.inject.Inject;
+import java.io.File;
+import java.io.FileReader;
+import java.io.IOException;
+import java.io.LineNumberReader;
+import java.nio.file.Files;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.regex.Pattern;
+
+public class FileContentProvider {
+
+    @Inject
+    public FileContentProvider() {
+
+    }
+
+    public List<FoundLine> findPhraseByLines(File file, String regex) {
+        try {
+            return tryToFindPhraseByLines(file, regex);
+        } catch (IOException e) {
+            throw new EsaException(e);
+        }
+    }
+
+    private List<FoundLine> tryToFindPhraseByLines(File file, String regex) throws IOException {
+        LineNumberReader lineNumberReader = readForLines(file);
+        List<FoundLine> foundLines = new ArrayList<>();
+
+        String line;
+        Pattern pattern = Pattern.compile(regex);
+        while ((line = lineNumberReader.readLine()) != null) {
+            if (pattern.matcher(line).find()) {
+                foundLines.add(FoundLine.builder()
+                        .line(line)
+                        .number(lineNumberReader.getLineNumber())
+                        .build());
+            }
+        }
+
+        return foundLines;
+    }
+
+    private LineNumberReader readForLines(File file) {
+        return Try.of(() -> new LineNumberReader(new FileReader(file)))
+                .getOrElseThrow(EsaException::new);
+    }
+
+    public String readFile(File file) {
+        StringBuilder content = new StringBuilder();
+        Try.run(() -> Files.lines(file.toPath())
+                .map(line -> line + "\n")
+                .forEach(content::append));
+
+        return content.toString();
+    }
+}

src/main/java/com/bartek/esa/file/provider/FileProvider.java

@@ -24,15 +24,6 @@ public class FileProvider {
                 .toFile();
     }
 
-    public String readFile(File file) {
-        StringBuilder content = new StringBuilder();
-        Try.run(() -> Files.lines(file.toPath())
-                .map(line -> line + "\n")
-                .forEach(content::append));
-
-        return content.toString();
-    }
-
     public Set<File> findFilesRecursively(String path, String globPattern) {
         return findFilesRecursivelyInSubpath(path, "", globPattern);
     }