Added utility for files

utilities/files/FileUtility.java

@@ -0,0 +1,158 @@
+package utilities.files;
+
+import java.io.*;
+import java.util.LinkedList;
+import java.util.List;
+
+public class FileUtility {
+
+	public static boolean deleteFile(String fileName) {
+		return (new File(fileName)).delete();
+	}
+
+	public static String readFile(InputStream inputStream) throws IOException {
+		StringBuilder stringBuilder = new StringBuilder();
+		int ch;
+		try {
+			while ((ch = inputStream.read()) != -1) {
+				stringBuilder.append((char) ch);
+			}
+		} finally {
+			close(inputStream);
+		}
+		return stringBuilder.toString();
+	}
+
+    public static String readFile(File file) throws IOException {
+        return readFile(new FileInputStream(file));
+    }
+
+	public static String readFile(String fileName) throws IOException {
+	    return readFile(new FileInputStream(fileName));
+	}
+
+    public static void writeToFile(FileWriter fileWriter, String content) throws IOException {
+        BufferedWriter bufferedWriter = null;
+	    try {
+            bufferedWriter = new BufferedWriter(fileWriter);
+            bufferedWriter.write(content);
+            bufferedWriter.flush();
+        } finally {
+            close(bufferedWriter);
+            close(fileWriter);
+        }
+    }
+
+    public static void writeToFile(File file, String content) throws IOException {
+        if (!file.exists()) {
+            file.createNewFile();
+        }
+        writeToFile(new FileWriter(file, true), content);
+    }
+
+    public static void writeToFile(String fileName, String content) throws IOException {
+        File file = new File(fileName);
+        if (!file.exists()) {
+            file.createNewFile();
+        }
+        writeToFile(new FileWriter(fileName, true), content);
+    }
+
+    public static void copyFile(FileInputStream fileInputStream, FileOutputStream fileOutputStream) throws IOException {
+        try {
+            byte[] buf = new byte[1024];
+            int i;
+            while ((i = fileInputStream.read(buf)) != -1)
+                fileOutputStream.write(buf, 0 , i);
+        } finally {
+            close(fileInputStream);
+            close(fileOutputStream);
+        }
+    }
+
+    public static void copyFile(File input, File output) throws IOException {
+        if (!input.exists())
+            return;
+        if (!output.exists())
+            output.createNewFile();
+        copyFile(new FileInputStream(input), new FileOutputStream(output));
+    }
+
+    public static void copyFile(String inputFileName, String outputFileName) throws IOException {
+	    copyFile(new FileInputStream(inputFileName), new FileOutputStream(outputFileName));
+    }
+
+    public static void close(Closeable closeable) {
+        if (null != closeable) {
+            try {
+                closeable.close();
+            } catch (IOException e) {
+                e.printStackTrace();
+            }
+        }
+    }
+
+    public static List<String> readFileLines(InputStream inputStream) throws IOException {
+		List<String> lines = new LinkedList<>();
+		StringBuilder stringBuilder = new StringBuilder();
+		int ch;
+		try {
+			while ((ch = inputStream.read()) != -1) {
+				if (ch == '\n') {
+					lines.add(stringBuilder.toString());
+					stringBuilder = new StringBuilder();
+				} else {
+					stringBuilder.append((char) ch);
+				}
+			}
+		} finally {
+			close(inputStream);
+		}
+		return lines;
+	}
+
+    public static List<String> readFileLines(File file) throws IOException {
+        return readFileLines(new FileInputStream(file));
+    }
+
+	public static List<String> readFileLines(String fileName) throws IOException {
+	    return readFileLines(new FileInputStream(fileName));
+	}
+
+	public static Integer[][] readNumberInLines(InputStream inputStream) throws IOException {
+		List<Integer[]> lines = new LinkedList<>();
+		StringBuilder stringBuilder = new StringBuilder();
+		String[] line;
+		Integer[] n;
+		int ch;
+		try {
+			while ((ch = inputStream.read()) != -1) {
+				if (ch == '\n') {
+					line = stringBuilder.toString().trim().split("\\s*(=>|,|\\s)\\s*");
+					n = new Integer[line.length];
+					for (int i = 0; i < line.length; ++i) {
+						n[i] = Integer.parseInt(line[i]);
+					}
+					lines.add(n);
+					stringBuilder = new StringBuilder();
+				} else {
+					stringBuilder.append((char) ch);
+				}
+			}
+		} finally {
+			close(inputStream);
+		}
+
+		Integer[][] res = {};
+
+		return lines.toArray(res);
+	}
+
+    public static Integer[][] readNumberInLines(File file) throws IOException {
+        return readNumberInLines(new FileInputStream(file));
+    }
+
+	public static Integer[][] readNumberInLines(String fileName) throws IOException {
+	    return readNumberInLines(new FileInputStream(fileName));
+	}
+}