File and I/O Operations

/**
 * Read file content as UTF-8 string
 * @param file the file to read
 * @return file content as string
 * @throws IORuntimeException if reading fails
 */
public static String readUtf8String(File file);

/**
 * Read file content as string with specified charset
 * @param file the file to read
 * @param charset charset to use for reading
 * @return file content as string
 * @throws IORuntimeException if reading fails
 */
public static String readString(File file, Charset charset);

/**
 * Read file content as byte array
 * @param file the file to read
 * @return file content as bytes
 * @throws IORuntimeException if reading fails
 */
public static byte[] readBytes(File file);

/**
 * Read file lines as list
 * @param file the file to read
 * @param charset charset to use for reading
 * @return list of lines
 * @throws IORuntimeException if reading fails
 */
public static List<String> readLines(File file, Charset charset);

/**
 * Read file lines as UTF-8 list
 * @param file the file to read
 * @return list of lines in UTF-8
 * @throws IORuntimeException if reading fails
 */
public static List<String> readUtf8Lines(File file);

import cn.hutool.core.io.FileUtil;
import java.io.File;
import java.nio.charset.StandardCharsets;

File textFile = new File("example.txt");

// Read file content
String content = FileUtil.readUtf8String(textFile);
String gbkContent = FileUtil.readString(textFile, Charset.forName("GBK"));
byte[] bytes = FileUtil.readBytes(textFile);

// Read lines
List<String> lines = FileUtil.readUtf8Lines(textFile);
List<String> gbkLines = FileUtil.readLines(textFile, Charset.forName("GBK"));

/**
 * Write string content to file using UTF-8 encoding
 * @param content content to write
 * @param file target file
 * @return target file
 * @throws IORuntimeException if writing fails
 */
public static File writeUtf8String(String content, File file);

/**
 * Write string content to file using specified charset
 * @param content content to write
 * @param file target file
 * @param charset charset to use for writing
 * @return target file
 * @throws IORuntimeException if writing fails
 */
public static File writeString(String content, File file, Charset charset);

/**
 * Write byte array to file
 * @param data bytes to write
 * @param file target file
 * @return target file
 * @throws IORuntimeException if writing fails
 */
public static File writeBytes(byte[] data, File file);

/**
 * Append string content to file using UTF-8 encoding
 * @param content content to append
 * @param file target file
 * @return target file
 * @throws IORuntimeException if writing fails
 */
public static File appendUtf8String(String content, File file);

/**
 * Write lines to file
 * @param lines lines to write
 * @param file target file
 * @param charset charset to use
 * @return target file
 * @throws IORuntimeException if writing fails
 */
public static File writeLines(Collection<String> lines, File file, Charset charset);

/**
 * Copy file or directory
 * @param src source file or directory
 * @param dest destination file or directory
 * @param isOverride whether to override existing files
 * @return destination file
 * @throws IORuntimeException if copying fails
 */
public static File copy(File src, File dest, boolean isOverride);

/**
 * Copy file content only (not directory structure)
 * @param src source file
 * @param dest destination file
 * @param isOverride whether to override existing file
 * @return destination file
 * @throws IORuntimeException if copying fails
 */
public static File copyContent(File src, File dest, boolean isOverride);

/**
 * Move file or directory
 * @param src source file or directory
 * @param dest destination file or directory
 * @param isOverride whether to override existing files
 * @return destination file
 * @throws IORuntimeException if moving fails
 */
public static File move(File src, File dest, boolean isOverride);

/**
 * Delete file or directory recursively
 * @param file file or directory to delete
 * @return true if deletion successful
 */
public static boolean del(File file);

/**
 * Create directory and parent directories if not exist
 * @param dir directory to create
 * @return created directory
 */
public static File mkdir(File dir);

/**
 * Create file and parent directories if not exist
 * @param file file to create
 * @return created file
 * @throws IORuntimeException if creation fails
 */
public static File touch(File file);

/**
 * Check if file or directory exists
 * @param path file path
 * @return true if exists
 */
public static boolean exist(String path);

/**
 * Check if file or directory exists
 * @param file file object
 * @return true if exists
 */
public static boolean exist(File file);

/**
 * Check if path represents a file (not directory)
 * @param file file object
 * @return true if is file
 */
public static boolean isFile(File file);

/**
 * Check if path represents a directory
 * @param file file object
 * @return true if is directory
 */
public static boolean isDirectory(File file);

/**
 * Get file size in bytes
 * @param file file object
 * @return file size in bytes, -1 if file doesn't exist
 */
public static long size(File file);

/**
 * Get file extension
 * @param file file object
 * @return file extension without dot, null if no extension
 */
public static String extName(File file);

/**
 * Get file name without extension
 * @param file file object
 * @return file name without extension
 */
public static String mainName(File file);

/**
 * Copy data from input stream to output stream
 * @param in input stream
 * @param out output stream
 * @return number of bytes copied
 * @throws IORuntimeException if copying fails
 */
public static long copy(InputStream in, OutputStream out);

/**
 * Copy data with specified buffer size
 * @param in input stream
 * @param out output stream
 * @param bufferSize buffer size for copying
 * @return number of bytes copied
 * @throws IORuntimeException if copying fails
 */
public static long copy(InputStream in, OutputStream out, int bufferSize);

/**
 * Read input stream content as string
 * @param in input stream
 * @param charset charset to use for reading
 * @return content as string
 * @throws IORuntimeException if reading fails
 */
public static String read(InputStream in, Charset charset);

/**
 * Read input stream content as UTF-8 string
 * @param in input stream
 * @return content as UTF-8 string
 * @throws IORuntimeException if reading fails
 */
public static String readUtf8(InputStream in);

/**
 * Read input stream content as byte array
 * @param in input stream
 * @return content as bytes
 * @throws IORuntimeException if reading fails
 */
public static byte[] readBytes(InputStream in);

/**
 * Close closeable resource safely (no exception thrown)
 * @param closeable resource to close
 */
public static void close(Closeable closeable);

/**
 * Close multiple closeable resources safely
 * @param closeables resources to close
 */
public static void close(Closeable... closeables);

import cn.hutool.core.io.FileUtil;
import cn.hutool.core.io.IoUtil;
import java.io.*;

// File operations
File sourceFile = new File("source.txt");
File destFile = new File("destination.txt");

// Writing
FileUtil.writeUtf8String("Hello World", destFile);
FileUtil.appendUtf8String("\nNew line", destFile);

// Copying
FileUtil.copy(sourceFile, destFile, true); // Override if exists

// File properties
boolean exists = FileUtil.exist("example.txt");
long size = FileUtil.size(new File("example.txt"));
String extension = FileUtil.extName(new File("example.txt")); // "txt"

// Stream operations
try (InputStream in = new FileInputStream("input.txt");
     OutputStream out = new FileOutputStream("output.txt")) {
    
    long copied = IoUtil.copy(in, out);
    System.out.println("Copied " + copied + " bytes");
}

// Safe resource closing
FileInputStream fis = null;
try {
    fis = new FileInputStream("file.txt");
    String content = IoUtil.readUtf8(fis);
} finally {
    IoUtil.close(fis); // Safe close, no exception thrown
}

/**
 * Copy file using NIO
 * @param src source file path
 * @param dest destination file path
 * @return destination path
 * @throws IORuntimeException if copying fails
 */
public static Path copy(Path src, Path dest);

/**
 * Move file using NIO
 * @param src source file path
 * @param dest destination file path
 * @return destination path
 * @throws IORuntimeException if moving fails
 */
public static Path move(Path src, Path dest);

/**
 * Delete file or directory using NIO
 * @param path path to delete
 * @return true if deletion successful
 */
public static boolean del(Path path);

/**
 * Read file content using NIO
 * @param path file path
 * @return file content as string
 * @throws IORuntimeException if reading fails
 */
public static String readUtf8(Path path);

/**
 * Write content to file using NIO
 * @param path file path
 * @param content content to write
 * @return file path
 * @throws IORuntimeException if writing fails
 */
public static Path writeUtf8(Path path, String content);

/**
 * Get resource URL from classpath
 * @param resource resource path
 * @return resource URL, null if not found
 */
public static URL getResource(String resource);

/**
 * Get resource as stream from classpath
 * @param resource resource path
 * @return resource stream, null if not found
 */
public static InputStream getResourceAsStream(String resource);

/**
 * Read resource content as UTF-8 string
 * @param resource resource path
 * @return resource content
 * @throws IORuntimeException if reading fails
 */
public static String readUtf8Str(String resource);

/**
 * Read resource content as string with specified charset
 * @param resource resource path
 * @param charset charset to use
 * @return resource content
 * @throws IORuntimeException if reading fails
 */
public static String readStr(String resource, Charset charset);

/**
 * Get file type based on file header
 * @param file file to check
 * @return file type string (e.g., "jpg", "png", "pdf")
 */
public static String getType(File file);

/**
 * Get file type based on input stream header
 * @param in input stream
 * @return file type string
 */
public static String getType(InputStream in);

/**
 * Check if file is of specified type
 * @param file file to check
 * @param type expected file type
 * @return true if file matches type
 */
public static boolean isType(File file, String type);

// Resource operations
String config = ResourceUtil.readUtf8Str("config/application.properties");
InputStream stream = ResourceUtil.getResourceAsStream("data/template.xml");

// File type detection
String fileType = FileTypeUtil.getType(new File("image.jpg")); // "jpg"
boolean isPdf = FileTypeUtil.isType(new File("document.pdf"), "pdf");

// NIO operations
Path source = Paths.get("source.txt");
Path dest = Paths.get("destination.txt");
NioUtil.copy(source, dest);
String content = NioUtil.readUtf8(source);

public class IORuntimeException extends RuntimeException {
    public IORuntimeException(String message);
    public IORuntimeException(String message, Throwable cause);
    public IORuntimeException(Throwable cause);
}