文件操作工具类.md

文件操作工具类

代码

package top.feb13th.deploy.util;

import java.io.Closeable;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.nio.channels.FileChannel;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.Arrays;
import java.util.StringJoiner;

/**
 * 输入输出工具类
 *
 * @author zhoutaotao
 * @date 2019/9/24 16:26
 */
public class IoUtil {

  /**
   * 获取系统临时目录
   *
   * @param dirs 在临时目录后额外增加的文件名称
   * @return 系统临时目录
   */
  public static String getTmpdir(String... dirs) {
    String tmpdir = System.getProperty("java.io.tmpdir");
    StringJoiner joiner = new StringJoiner(File.separator);
    joiner.add(tmpdir);
    for (String dir : dirs) {
      joiner.add(dir);
    }
    return joiner.toString();
  }

  /**
   * 获取应用程序的运行路径
   *
   * @param dirs 子目录
   * @return 应用程序运行目录 + 子目录
   */
  public static String getAppDir(String... dirs) {
    // 获取当前程序的运行路径
    String location = IoUtil.class.getProtectionDomain().getCodeSource().getLocation()
        .getFile();
    if (location.startsWith("file:")) {
      location = location.substring(5);
    }
    if (location.contains(".jar")) {
      location = location.substring(0, location.indexOf(".jar"));
      File file = new File(location);
      location = file.getParent();
    }
    File file = new File(location);
    if (file.isFile()) {
      // 如果当前是执行的jar文件, 获取jar文件的所在目录
      location = file.getParent();
    }
    return appendPath(location, dirs);
  }

  /**
   * 拼接路径
   *
   * @param prefix 前缀
   * @param paths 路径列表
   * @return 路径
   */
  public static String appendPath(String prefix, String... paths) {
    if (StringUtil.isBlank(prefix)) {
      return null;
    }
    StringJoiner joiner = new StringJoiner(File.separator);
    joiner.add(prefix);
    for (String path : paths) {
      joiner.add(path);
    }
    return joiner.toString();
  }

  /**
   * 删除文件
   *
   * @param dirPath 文件路径
   */
  public static void delete(String dirPath) {
    // 文件路径为空时, 直接返回
    if (StringUtil.isBlank(dirPath)) {
      return;
    }
    File dirFile = new File(dirPath);
    String[] list = dirFile.list();
    if (list != null && list.length > 0) {
      for (String filename : list) {
        String newFilePath = dirPath + File.separator + filename;
        File file = new File(newFilePath);
        if (file.isDirectory()) {
          delete(newFilePath);
        }
        file.delete();
      }
    }
    if (dirFile.exists()) {
      dirFile.delete();
    }
  }

  /**
   * 目录内容拷贝，只拷贝文件内部的文件及文件夹
   *
   * @param from 源目录
   * @param to 目标目录
   */
  public static void copyDir(File from, File to) {
    String[] list;
    if (!from.isDirectory() || (list = from.list()) == null) {
      return;
    }
    String fromPath = from.getAbsolutePath();
    String toPath = to.getAbsolutePath();

    for (String filename : list) {
      String fromFilepath = fromPath + File.separator + filename;
      String toFilepath = toPath + File.separator + filename;
      File fromFile = new File(fromFilepath);
      File toFile = new File(toFilepath);
      if (fromFile.isDirectory()) {
        // 如果赋值的是文件夹,则创建该文件夹, 并进入文件夹内部拷贝文件
        toFile.mkdirs();
        copyDir(fromFile, toFile);
      } else {
        // 拷贝文件内容
        copyFile(fromFile, toFile);
      }
    }
  }

  /**
   * 拷贝两个文件的内容
   *
   * @param from 源文件
   * @param to 目标文件
   */
  public static void copyFile(File from, File to) {
    FileInputStream fromIs = null;
    FileOutputStream toOs = null;
    FileChannel fromChannel = null;
    FileChannel toChannel = null;
    try {
      if (!to.exists()) {
        createFile(to);
      }
      fromIs = new FileInputStream(from);
      toOs = new FileOutputStream(to);
      fromChannel = fromIs.getChannel();
      toChannel = toOs.getChannel();
      fromChannel.transferTo(0, fromChannel.size(), toChannel);
    } catch (IOException e) {
      throw new RuntimeException(e);
    } finally {
      close(fromChannel);
      close(fromIs);
      close(toChannel);
      close(toOs);
    }
  }

  public static void close(Closeable closeable) {
    if (closeable != null) {
      try {
        closeable.close();
      } catch (IOException e) {
        throw new RuntimeException(e);
      }
    }
  }

  /**
   * 从指定文件中读取字符串
   *
   * @param filepath 文件路径
   * @return 如果文件不存在则返回null, 否则返回文件字符串内容
   */
  public static String readString(String filepath) {
    Path path = Paths.get(new File(filepath).toURI());
    if (!Files.exists(path)) {
      return null;
    }
    try {
      return Files.readAllLines(path, StandardCharsets.UTF_8).stream().reduce("", String::concat);
    } catch (IOException e) {
      return null;
    }
  }

  /**
   * 向文件中写入content
   *
   * @param filepath 文件路径
   * @param content 文件内容字符串
   */
  public static void writeString(String filepath, String... content) {
    try {
      Path path = Paths.get(new File(filepath).toURI());
      Files.deleteIfExists(path);
      Path parent = path.getParent();
      if (!Files.exists(parent)) {
        Files.createDirectories(parent);
      }
      Files.createFile(path);
      Files.write(path, Arrays.asList(content), StandardCharsets.UTF_8);
    } catch (IOException e) {
      throw new RuntimeException(e);
    }
  }

  /**
   * 创建新文件, 如果存在则删除重新创建
   *
   * @param filepath 文件路径
   */
  public static void createFile(String filepath) {
    if (StringUtil.isBlank(filepath)) {
      throw new NullPointerException("filepath must not empty");
    }
    createFile(new File(filepath));
  }

  /**
   * 创建新文件, 如果存在则删除重新创建
   *
   * @param file 文件
   */
  public static void createFile(File file) {
    if (ObjectUtil.isNull(file)) {
      throw new NullPointerException("core must not null");
    }
    try {
      Path path = Paths.get(file.toURI());
      Files.deleteIfExists(path);
      Path parent = path.getParent();
      if (!Files.exists(parent)) {
        Files.createDirectories(parent);
      }
      Files.createFile(path);
    } catch (IOException e) {
      throw new RuntimeException(e);
    }
  }

  /**
   * 创建目录
   *
   * @param directorPath 目录路径
   */
  public static void createDirector(String directorPath) {
    if (StringUtil.isBlank(directorPath)) {
      throw new NullPointerException("director path must not empty");
    }
    createDirector(new File(directorPath));
  }

  /**
   * 创建目录
   *
   * @param file 目录
   */
  public static void createDirector(File file) {
    if (ObjectUtil.isNull(file)) {
      throw new NullPointerException("director core must not null");
    }
    try {
      Path path = Paths.get(file.toURI());
      if (!Files.exists(path)) {
        Files.createDirectories(path);
      }
    } catch (IOException e) {
      throw new RuntimeException(e);
    }
  }

}