java File文件的增，删，改，查

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.io.RandomAccessFile;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Set;
import java.util.TreeSet;




public class FileOperate {

private static FileOperate instance = null;
public static FileOperate getInstance() {
if (instance == null) {
instance = new FileOperate();
}
return instance;
}

public FileOperate(){
}


/**
     * 新建目录
     * @param folderPath String 如 c:/fqf
     * @return boolean
     */
   public static void newFolder(String folderPath) {
       try {
           String filePath = folderPath;
           filePath = filePath.toString();
           java.io.File myFilePath = new java.io.File(filePath);
           if (!myFilePath.exists()) {
               myFilePath.mkdir();
           }
       }
       catch (Exception e) {
           System.out.println("新建目录操作出错");
           e.printStackTrace();
       }
   }

   /**
     * 新建文件
     * @param filePathAndName String 文件路径及名称 如c:/text.txt
     * @param fileContent String 文件内容
     * @return boolean
     */
   public static void newFile(String filePathAndName, String fileContent) {

       try {
           String filePath = filePathAndName;
           filePath = filePath.toString();
           File myFilePath = new File(filePath);
           if (!myFilePath.exists()) {
               myFilePath.createNewFile();
           }
           FileWriter resultFile = new FileWriter(myFilePath);
           PrintWriter myFile = new PrintWriter(resultFile);
           String strContent = fileContent;
           myFile.println(strContent);
           resultFile.close();

       }
       catch (Exception e) {
           System.out.println("新建目录操作出错");
           e.printStackTrace();

       }

   }

   /**
     * 删除文件
     * @param filePathAndName String 文件路径及名称 如c:/text.txt
     * @param fileContent String
     * @return boolean
     */
   public static void delFile(String filePathAndName) {
       try {
           String filePath = filePathAndName;
           filePath = filePath.toString();
           java.io.File myDelFile = new java.io.File(filePath);
           myDelFile.delete();

       }
       catch (Exception e) {
           System.out.println("删除文件操作出错");
           e.printStackTrace();

       }

   }

   /**
     * 删除文件夹
     * @param filePathAndName String 文件夹路径及名称 如c:/text
     * @param fileContent String
     * @return boolean
     */
   public static void delFolder(String folderPath) {
       try {
           delAllFile(folderPath); //删除完里面所有内容
           String filePath = folderPath;
           filePath = filePath.toString();
           java.io.File myFilePath = new java.io.File(filePath);
           myFilePath.delete(); //删除空文件夹

       }
       catch (Exception e) {
           System.out.println("删除文件夹操作出错");
           e.printStackTrace();

       }

   }

   /**
     * 删除文件夹里面的所有文件
     * @param path String 文件夹路径 如 c:/text
     */
   public static void delAllFile(String path) {
       File file = new File(path);
       if (!file.exists()) {
           return;
       }
       if (!file.isDirectory()) {
           return;
       }
       String[] tempList = file.list();
       File temp = null;
       for (int i = 0; i < tempList.length; i++) {
           if (path.endsWith(File.separator)) {
               temp = new File(path + tempList[i]);
           }
           else {
               temp = new File(path + File.separator + tempList[i]);
           }
           if (temp.isFile()) {
               temp.delete();
           }
           if (temp.isDirectory()) {
               delAllFile(path+"/"+ tempList[i]);//先删除文件夹里面的文件
               delFolder(path+"/"+ tempList[i]);//再删除空文件夹
           }
       }
   }

   /**
     * 复制单个文件
     * @param oldPath String 原文件路径 如：c:/text.txt
     * @param newPath String 复制后路径 如：f:/text.txt
     * @return boolean
     */
   public static void copyFile(String oldPath, String newPath) {
       try {
           int bytesum = 0;
           int byteread = 0;
           File oldfile = new File(oldPath);
           if (oldfile.exists()) { //文件存在时
               InputStream inStream = new FileInputStream(oldPath); //读入原文件
               FileOutputStream fs = new FileOutputStream(newPath);
               byte[] buffer = new byte[1444];
               int length;
               while ( (byteread = inStream.read(buffer)) != -1) {
                   bytesum += byteread; //字节数 文件大小
                   System.out.println(bytesum);
                   fs.write(buffer, 0, byteread);
               }
               inStream.close();
           }
       }
       catch (Exception e) {
           System.out.println("复制单个文件操作出错");
           e.printStackTrace();

       }

   }

   /**
     * 复制整个文件夹内容
     * @param oldPath String 原文件路径 如：c:/text
     * @param newPath String 复制后路径 如：f:/text/ff
     * @return boolean
     */
   public static void copyFolder(String oldPath, String newPath) {

       try {
           (new File(newPath)).mkdirs(); //如果文件夹不存在 则建立新文件夹
           File a=new File(oldPath);
           String[] file=a.list();
           File temp=null;
           for (int i = 0; i < file.length; i++) {
               if(oldPath.endsWith(File.separator)){
                   temp=new File(oldPath+file[i]);
               }
               else{
                   temp=new File(oldPath+File.separator+file[i]);
               }

               if(temp.isFile()){
                   FileInputStream input = new FileInputStream(temp);
                   FileOutputStream output = new FileOutputStream(newPath + "/" +
                           (temp.getName()).toString());
                   byte[] b = new byte[1024 * 5];
                   int len;
                   while ( (len = input.read(b)) != -1) {
                       output.write(b, 0, len);
                   }
                   output.flush();
                   output.close();
                   input.close();
               }
               if(temp.isDirectory()){//如果是子文件夹
                   copyFolder(oldPath+"/"+file[i],newPath+"/"+file[i]);
               }
           }
       }
       catch (Exception e) {
           System.out.println("复制整个文件夹内容操作出错");
           e.printStackTrace();

       }

   }

   /**
     * 移动文件到指定目录
     * @param oldPath String 如：c:/text.txt
     * @param newPath String 如：d:/text.txt
     */
   public static void moveFile(String oldPath, String newPath) {
       copyFile(oldPath, newPath);
       delFile(oldPath);

   }

   /**
     * 移动文件夹到指定目录
     * @param oldPath String 如：c:/text.txt
     * @param newPath String 如：d:/text.txt
     */
   public static void moveFolder(String oldPath, String newPath) {
       copyFolder(oldPath, newPath);
       delFolder(oldPath);

   }
  
   /**
    * 删除文件中特定内容（txt）
    * @param filePath String 如：c:/text.txt
    * @param delContent String 如："123456"
    */
   public static void delFileConcent(String filePath,String delContent) {
   try {
   BufferedReader br = new BufferedReader(new FileReader(filePath));
   String rowtxt = null;
           List < String > list = new ArrayList < String > ();
           while ((rowtxt = br.readLine()) != null) {
               if (rowtxt != null && !"".equals(rowtxt) && !"null".equals(rowtxt)) {
               rowtxt=rowtxt.replace(delContent, "");
                   list.add(rowtxt);
               }
           }
           filePath = filePath.toString();
           File myFilePath = new File(filePath);
           if (!myFilePath.exists()) {
           myFilePath.createNewFile();
           }
           FileWriter resultFile = new FileWriter(myFilePath);
           PrintWriter myFile = new PrintWriter(resultFile);
           String strContent = "";
           for(int i = 0;i < list.size(); i++){
           strContent = list.get(i);
           if(!"<<<*>>>".equals(strContent)){
           myFile.println(strContent);          
           }
           }
           resultFile.close();
       }
       catch (Exception e) {
           System.out.println("操作出错");
           e.printStackTrace();

       }
  
   }
  
   /**
    * 修改文件内容
    * @param filePath 文件地址
    * @param oldContent 修改前内容 String
    * @param newContent 修改后内容 String
    */
   public static void updateFileConcent(String filePath,String oldContent,String newContent) {
   try {
   BufferedReader br = new BufferedReader(new FileReader(filePath));
   String rowtxt = null;
           while ((rowtxt = br.readLine()) != null) {
               if (rowtxt != null && !"".equals(rowtxt) && !"null".equals(rowtxt)) {
               rowtxt=rowtxt.replace(oldContent, newContent);
               }
           }
       }
       catch (Exception e) {
           System.out.println("修改操作出错");
           e.printStackTrace();

       }
   }
  
   /**
    * 删除文件夹中文件（txt）
    * @param folderPath String 如：c:/text
    * @param delContent String 如："123456"
    */
   public static void delFolderConcent(String folderPath,String delContent) {
   File file=new File(folderPath);
       if(file!=null){
           if(file.isDirectory()){
               File fi[]=file.listFiles();
               if(fi!=null){
               for(int i=0;i<fi.length;i++){
                   if(fi[i].isDirectory()){
                   delFolderConcent(folderPath, null);
                   }else{
               try {
                   RandomAccessFile  read=new RandomAccessFile(fi[i], "r");
                   String line1=read.readLine();
                     if(line1.indexOf(delContent)==-1){ 
                         fi[i].deleteOnExit();
                     }
                   System.out.println(line1);
                   read.close();
                  
               } catch (Exception e) {
               System.out.println("操作出错");
                   e.printStackTrace();
               }

                   }
               }
               }else{
               System.out.println(file);
               }
          }
       }     
   }
  
   /**
    * 全级搜索文件列表
    * @param Path 文件位置 如：F:\\text\\
* @return
    */
   public static List searchAllFile(String Path){
   Set fileNameSet = FileOperate.searchFolder(Path);
       // 符合条件的文件路径
       List resultFile=new ArrayList();
      
       TreeSet treeSet = new TreeSet(fileNameSet);
       for(Iterator i = treeSet.iterator(); i.hasNext();) {
           String filePath = i.next().toString();
           filePath = filePath.replaceAll("\\\\", "\\\\\\\\");
           resultFile.add(filePath);        
       }
       return resultFile;
   }
  
   /**
    * 单级搜索文件列表
    * @param folderPath 文件位置 如 F:\\text\\
    * @return
    */
   public static HashSet searchFolder(String folderPath){
   File file = new File(folderPath);
   List fileList = listAllFiles(file);
   HashSet fileName = new HashSet(fileList.size());
   for(int i = 0; i < fileList.size();i++){
   File file2 = (File) fileList.get(i);
   boolean add = fileName.add(file2.getAbsolutePath());
   }
   return fileName;
  
   }
  
   /**
    * 搜索文件子方法
    * searchFolder 方法的附属方法
    * @param directory
    * @return
    */
   private static List listAllFiles(File directory) {
       if(directory == null || !directory.isDirectory()) {
           return null;
       }
       List fileList = new ArrayList();
       addSubFileList(directory, fileList);

       return fileList;
   }

   /**
    * 搜索文件子方法
    * searchFolder 方法的附属方法
    * @param file
    * @param fileList
    */
   private static void addSubFileList(File file, List fileList) {
       File[] subFileArray = file.listFiles();
       if(subFileArray == null || subFileArray.length == 0) {
           return;
       }
       for(int i = 0; i < subFileArray.length; i++) {
           File subFile = subFileArray[i];
           if(subFile == null) {
               continue;
           }
           if(subFile.isFile()) {
               fileList.add(subFile);
               continue;
           }else if(subFile.isDirectory()) {
               addSubFileList(subFile, fileList);
           }
       }
   }
  
  
  
  
   /**
    * 全级搜索文件及内容列表p
    * @param Path 文件位置 如：F:\\text\\
* @return
    */
   public static List searchAllFileAndContext(String Path){
       String content = "";// 某个文件的内容   
       String encoding = "utf8";// 设置读取文件内容时的文件编码
   Set fileNameSet = FileOperate.searchFolder(Path);
       // 符合条件的文件路径
       List resultFile=new ArrayList();      
       TreeSet treeSet = new TreeSet(fileNameSet);
       for(Iterator i = treeSet.iterator(); i.hasNext();) {
           String filePath = i.next().toString();
           filePath = filePath.replaceAll("\\\\", "\\\\\\\\");
//           System.out.println(filePath);
           try {
           String lastName = filePath.substring(filePath.lastIndexOf(".")+1);    
           if(lastName.indexOf("txt")!=-1){
           content = SearchStr.readTxt(filePath, encoding);          
//           System.out.println("文件里面的内容:");
//           System.out.println(content);
           }
           if(!"".equals(content)){
           resultFile.add(filePath+"\n文件里面的内容:\n"+content);
           }else{
           resultFile.add(filePath);
           }
           }catch(IOException e) {
               e.printStackTrace();
           }
       }
       return resultFile;
   }
}