操作文件和文件夹

Posted 2020-10-12 冬天不眠

package Test;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.Date;

/**
 * 功能：该类用于操作文件和文件夹
 */
public class FileUtil {
    
    /**
     * 将源文件的数据写入到目标文件中，
     * 不会检查源文件是否存在，
     * 若目标文件存在则直接写入，
     * 否则创建目标文件后再进行写入。
     * @param srcPath
     * @param desPath
     */
    private static void copyFile(String srcPath,String desPath){
        try {
            FileInputStream in = new FileInputStream(srcPath);
            FileOutputStream out = new FileOutputStream(desPath);
            byte[] bt = new byte[1024];
            int count;
            while ((count = in.read(bt)) > 0) {
                out.write(bt, 0, count);
            }
            in.close();
            out.close(); 
        } catch (IOException ex) {
            ex.printStackTrace();
        }        
    }
    
    /**
     * 复制文件，若文件存在则替换该文件。
     * @param srcPath
     * @param desPath
     * @throws Exception
     */
    public static void copyAndReplaceFile(String srcPath,String desPath) throws Exception{
        srcPath = separatorReplace(srcPath);
        desPath = separatorReplace(desPath);
        File srcFile = new File(srcPath);
        if(!srcFile.isFile()){
            throw new Exception("source file not found!");
        }
        copyFile(srcPath,desPath);
    }
    
    /**
     * 复制文件，若文件已存在则不进行替换。
     * @param srcPath
     * @param desPath
     * @throws Exception
     */
    public static void copyAndNotReplaceFile(String srcPath,String desPath) throws Exception{
        srcPath = separatorReplace(srcPath);
        desPath = separatorReplace(desPath);
        File srcFile = new File(srcPath);
        File desFile = new File(desPath);
        if(!srcFile.isFile()){
            throw new Exception("source file not found!");
        }
        if(desFile.isFile()){
            return;
        }
        copyFile(srcPath,desPath);
    }
    
    /**
     * 移动文件，若文件存在则替换该文件。
     * @param srcPath
     * @param desPath
     * @throws Exception
     */
    public static void moveAndReplaceFile(String srcPath,String desPath) throws Exception{
        srcPath = separatorReplace(srcPath);
        desPath = separatorReplace(desPath);
        copyAndReplaceFile(srcPath,desPath);
        deleteFile(srcPath);
    }
    
    /**
     * 移动文件，若文件存在则不进行替换。
     * @param srcPath
     * @param desPath
     * @throws Exception
     */
    public static void moveAndNotReplaceFile(String srcPath,String desPath) throws Exception{
        srcPath = separatorReplace(srcPath);
        desPath = separatorReplace(desPath);
        copyAndNotReplaceFile(srcPath,desPath);
        deleteFile(srcPath);
    }
    
    /**
     * 复制并合并文件夹，
     * 不会替换目标文件夹中已经存在的文件或文件夹。
     * @param srcPath
     * @param desPath
     * @throws Exception 
     */
    public static void copyAndMergerFolder(String srcPath,String desPath) throws Exception{        
        srcPath = separatorReplace(srcPath);
        desPath = separatorReplace(desPath);
        File folder = getFolder(srcPath);
        createFolder(desPath);
        File[] files = folder.listFiles();
        for(File file:files){
            String src = file.getAbsolutePath();
            String des = desPath+File.separator+file.getName();
            if(file.isFile()){
                copyAndNotReplaceFile(src,des);
            }else if(file.isDirectory()){
                copyAndMergerFolder(src,des);
            }
        }
    }
    
    /**
     * 复制并替换文件夹，
     * 将目标文件夹完全替换成源文件夹，
     * 目标文件夹原有的资料会丢失。
     * @param srcPath
     * @param desPath
     * @throws Exception 
     */
    public static void copyAndReplaceFolder(String srcPath,String desPath) throws Exception{   
        srcPath = separatorReplace(srcPath);
        desPath = separatorReplace(desPath);
        File folder = getFolder(srcPath);
        createNewFolder(desPath);
        File[] files = folder.listFiles();
        for(File file:files){
            String src = file.getAbsolutePath();
            String des = desPath+File.separator+file.getName();
            if(file.isFile()){
                copyAndReplaceFile(src,des);
            }else if(file.isDirectory()){
                copyAndReplaceFolder(src,des);
            }
        }
    } 
    
    /**
     * 合并文件夹后，将源文件夹删除。
     * @param srcPath
     * @param desPath
     * @throws Exception 
     */
    public static void moveAndMergerFolder(String srcPath,String desPath) throws Exception{
        srcPath = separatorReplace(srcPath);
        desPath = separatorReplace(desPath);        
        copyAndMergerFolder(srcPath,desPath);
        deleteFolder(srcPath);
    }
    
    /**
     * 替换文件夹后，将源文件夹删除。
     * @param srcPath
     * @param desPath
     * @throws Exception 
     */
    public static void moveAndReplaceFolder(String srcPath,String desPath) throws Exception{
        srcPath = separatorReplace(srcPath);
        desPath = separatorReplace(desPath);
        copyAndReplaceFolder(srcPath,desPath);
        deleteFolder(srcPath);
    }    

    /**
     * 创建文件夹，如果文件夹存在则不进行创建。
     * @param path
     * @throws Exception 
     */
    public static void createFolder(String path) throws Exception{
        path = separatorReplace(path);
        File folder = new File(path);
        if(folder.isDirectory()){
            return;
        }else if(folder.isFile()){
            deleteFile(path);
        }
        folder.mkdirs();
    }
    
    /**
     * 创建一个新的文件夹，如果文件夹存在，则删除后再创建。
     * @param path
     * @throws Exception
     */
    public static void createNewFolder(String path) throws Exception{
        path = separatorReplace(path);
        File folder = new File(path);
        if(folder.isDirectory()){
            deleteFolder(path);
        }else if(folder.isFile()){
            deleteFile(path);
        }
        folder.mkdirs();
    }
    
    /**
     * 创建一个文件，如果文件存在则不进行创建。
     * @param path
     * @throws Exception
     */
    public static File createFile(String path) throws Exception{
        path = separatorReplace(path);
        File file = new File(path);
        if(file.isFile()){
            return file;
        }else if(file.isDirectory()){
            deleteFolder(path);
        }
        return createFile(file);
    }
    
    /**
     * 创建一个新文件，如果存在同名的文件或文件夹将会删除该文件或文件夹，
     * 如果父目录不存在则创建父目录。
     * @param path
     * @throws Exception
     */
    public static File createNewFile(String path) throws Exception{
        path = separatorReplace(path);
        File file = new File(path);
        if(file.isFile()){
            deleteFile(path);
        }else if(file.isDirectory()){
            deleteFolder(path);
        }
        return createFile(file);
    }
    
    /**
     * 分隔符替换
     * window下测试通过
     * @param path
     * @return
     */
    public static String separatorReplace(String path){
        return path.replace("\\","/");
    }
    
    /**
     * 创建文件及其父目录。
     * @param file
     * @throws Exception
     */
    public static File createFile(File file) throws Exception{
        createParentFolder(file);
        if(!file.createNewFile()) {
            throw new Exception("create file failure!");
        }
        return file;
    }
    
    /**
     * 创建父目录
     * @param file
     * @throws Exception
     */
    private static void createParentFolder(File file) throws Exception{
        if(!file.getParentFile().exists()) {
            if(!file.getParentFile().mkdirs()) {
                throw new Exception("create parent directory failure!");
            }
        }
    }
    
    /**
     * 根据文件路径删除文件，如果路径指向的文件不存在或删除失败则抛出异常。
     * @param path
     * @return
     * @throws Exception 
     */
    public static void deleteFile(String path) throws Exception {
        path = separatorReplace(path);
        File file = getFile(path);    
        if(!file.delete()){
            throw new Exception("delete file failure");
        }                      
    }
    
    /**
     * 删除指定目录中指定前缀和后缀的文件。
     * @param dir
     * @param prefix
     * @param suffix
     * @throws Exception 
     */
    public static void deleteFile(String dir,String prefix,String suffix) throws Exception{     
        dir = separatorReplace(dir);
        File directory = getFolder(dir);
        File[] files = directory.listFiles();
        for(File file:files){
            if(file.isFile()){
                String fileName = file.getName();
                if(fileName.startsWith(prefix)&&fileName.endsWith(suffix)){
                    deleteFile(file.getAbsolutePath());
                }
            }
        }    
    }
    
    /**
     * 根据路径删除文件夹，如果路径指向的目录不存在则抛出异常，
     * 若存在则先遍历删除子项目后再删除文件夹本身。
     * @param path
     * @throws Exception 
     */
    public static void deleteFolder(String path) throws Exception {
        path = separatorReplace(path);
        File folder = getFolder(path);
        File[] files = folder.listFiles(); 
        for(File file:files) {                
            if(file.isDirectory()){
                deleteFolder(file.getAbsolutePath());
            }else if(file.isFile()){                    
                deleteFile(file.getAbsolutePath());                                    
            }
        }  
        folder.delete(); 
    }
    
    /**
     * 查找目标文件夹下的目标文件
     * @param dir
     * @param fileName
     * @return
     * @throws FileNotFoundException
     */
    public static File searchFile(String dir,String fileName) throws FileNotFoundException{
        dir = separatorReplace(dir);
        File f = null;
        File folder = getFolder(dir);
        File[] files = folder.listFiles(); 
        for(File file:files) {                
            if(file.isDirectory()){
                f =  searchFile(file.getAbsolutePath(),fileName);
                if(f!=null){
                    break;
                }
            }else if(file.isFile()){ 
                if(file.getName().equals(fileName)){
                    f = file;
                    break;
                }                                                            
            }
        }          
        return f;
    }
          
    /**
     * 获得文件类型。
     * @param path：文件路径
     * @return
     * @throws FileNotFoundException 
     */
    public static String getFileType(String path) throws FileNotFoundException {
        path = separatorReplace(path);
        File file = getFile(path);
        String fileName = file.getName();
        String[] strs = fileName.split("\\.");
        if(strs.length<2){
            return "unknownType";
        }
        return strs[strs.length-1];
    }
    
    /**
     * 根据文件路径，获得该路径指向的文件的大小。
     * @param path
     * @return
     * @throws FileNotFoundException
     */
    public static long getFileSize(String path) throws FileNotFoundException{
        path = separatorReplace(path);        
        File file = getFile(path);
        return file.length();
    }
    
    /**
     * 根据文件夹路径，获得该路径指向的文件夹的大小。
     * 遍历该文件夹及其子目录的文件，将这些文件的大小进行累加，得出的就是文件夹的大小。
     * @param path
     * @return
     * @throws FileNotFoundException
     */
    public static long getFolderSize(String path) throws FileNotFoundException{
        path = separatorReplace(path);                
        long size = 0;
        File folder = getFolder(path);
        File[] files = folder.listFiles();
        for(File file:files){
            if(file.isDirectory()){
                size += getFolderSize(file.getAbsolutePath());
            }else if(file.isFile()){
                size += file.length();
            }
        }
        return size;
    }
    
    /**
     * 通过路径获得文件，
     * 若不存在则抛异常，
     * 若存在则返回该文件。
     * @param path
     * @return
     * @throws FileNotFoundException
     */
    public static File getFile(String path) throws FileNotFoundException{
        path = separatorReplace(path);                
        File file = new File(path);
        if(!file.isFile()){
            throw new FileNotFoundException("file not found!");
        }
        return file;
    }
    
    /**
     * 通过路径获得文件夹，
     * 若不存在则抛异常，
     * 若存在则返回该文件夹。
     * @param path
     * @return
     * @throws FileNotFoundException
     */
    public static File getFolder(String path) throws FileNotFoundException{
        path = separatorReplace(path);                
        File folder = new File(path);
        if(!folder.isDirectory()){
            throw new FileNotFoundException("folder not found!");
        }
        return folder;
    }
    
    /**
     * 获得文件最后更改时间。
     * @param path
     * @return
     * @throws FileNotFoundException
     */
    public static Date getFileLastModified(String path) throws FileNotFoundException{
        path = separatorReplace(path);                
        File file = getFile(path);
        return new Date(file.lastModified());
    }
    
    /**
     * 获得文件夹最后更改时间。
     * @param path
     * @return
     * @throws FileNotFoundException
     */
    public static Date getFolderLastModified(String path) throws FileNotFoundException{
        path = separatorReplace(path);        
        File folder = getFolder(path);
        return new Date(folder.lastModified());
    }
}