java: file

 

 

?

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264

/**  * 版权所有 2022 涂聚文有限公司  * 许可信息查看：  * 描述：  * IDE:IntelliJ IDEA 2021.2.3  * 数据库：MSSQL Server 2019  * OS:windows 10 x64  * 历史版本： JDK 14.02  * 2022-1-12 创建者 geovindu  * 2022-1-15 添加 Lambda  * 2022-1-15 修改：date  * 接口类 mssql-jdbc-9.4.1.jre16.jar.  *  * 2022-1-15 修改者：Geovin Du  * 生成API帮助文档的指令：  *javadoc - -encoding Utf-8 -d apidoc FileHelper.java    * */       package Geovin.Common;   import Geovin.Model.Person;   import java.io.BufferedReader; import java.io.FileInputStream; import java.io.IOException; import java.io.InputStreamReader; import java.io.*; import java.math.BigInteger; import java.security.MessageDigest; import java.text.DecimalFormat; import java.time.LocalDate; import java.time.format.DateTimeFormatter; import java.util.*; import java.util.concurrent.CountDownLatch;     /**  *  *  *  * */ public class FileHelper {       /**      * 读取文件流      * @param fileName 文件      * @return      * */     public BufferedReader bufferreader(String fileName) {         BufferedReader reader = null; //使用缓冲区的方法将数据读入到缓冲区中         try {             reader = new BufferedReader(new InputStreamReader(new FileInputStream(fileName)));         } catch (Exception e) {             e.printStackTrace();         }         return reader;     }     /**      * 读取文件中的某一行数据      * @param reader      * @param lineNumber      * @return  string      * */     public String readfile(BufferedReader reader, int lineNumber) {         String line = null; //定义行数         try {             int num = 0;             while (true) {                 num++;                 line = reader.readLine();                 if (num == lineNumber) {                     break;                 }             }         } catch (Exception e) {             e.printStackTrace();         } finally {             if (reader != null) {                 try {                     reader.close();                 } catch (Exception e) {                     e.printStackTrace();                 }             }             return line;         }       }          /**      *      *      *      * */     public BigInteger getsize(String size){         //System.out.println(size.substring(0,size.length()-1));         int x=Integer.valueOf(size.substring(0,size.length()-1));           BigInteger resultlen=new BigInteger("0");         if(size.endsWith("m")||size.endsWith("M")) {             resultlen = BigInteger.valueOf(x).multiply(BigInteger.valueOf(1024)).multiply(BigInteger.valueOf(1024));         }else if(size.endsWith("g")||size.endsWith("G")){             resultlen = BigInteger.valueOf(x).multiply(BigInteger.valueOf(1024)).multiply(BigInteger.valueOf(1024)).multiply(BigInteger.valueOf(1024));         }else if(size.endsWith("K")||size.endsWith("k")){             resultlen = BigInteger.valueOf(x).multiply(BigInteger.valueOf(1024));         }         return resultlen;     }       public synchronized static int  getuuid()     {         tmp=tmp+1;           return tmp;     }            /**      * 写数据      * @param fw      * @param size      * @param list      * @return      *      * */     public boolean DuWriteFile(FileWriter fw, int size, List<Person> list) {         DecimalFormat count=new DecimalFormat("00000000000");         //经过测试：ufferedOutputStream执行耗时:1,1，1 毫秒         int tmp_len=0;         long begin0 = System.currentTimeMillis();         try {               String uuid=null;             String uuid2=null;             MessageDigest  md =MessageDigest.getInstance("MD5");             LocalDate localdate=LocalDate.now();             DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyyMMdd");             String date=localdate.format(formatter);             Random rd=new Random();             int z=0;               for(int i=0;i<size;i++){                   for(Person person:list) {                     fw.write(person.getLastName()+","+person.toString());                     System.out.println("ok");                 }             }             return true;         } catch (Exception e1) {             e1.printStackTrace();             return false;         } finally{             long end0 = System.currentTimeMillis();             System.out.println("BufferedOutputStream执行耗时:" + (end0 - begin0) + " 毫秒");         }     }                              /**      *复制文件      * @param sourceFile  原文件      * @param newFile  目标新文件      *      * */     public void CopyFile(String sourceFile,String newFile)     {           try(FileInputStream inputStream=new FileInputStream(sourceFile);             FileOutputStream outputStream=new FileOutputStream(newFile))         {             byte[] buffer=new byte[10];             int len=inputStream.read(buffer);             while (len!=-1)             {                 String copyStr=new String(buffer);                 System.out.println(copyStr);                 outputStream.write(buffer,0,len);                 len=inputStream.read(buffer);             }               }         catch (FileNotFoundException exception)         {             exception.printStackTrace();         }         catch (IOException exception)         {             exception.printStackTrace();         }       }     /**      *复制文件      * @param sourceFile  原文件      * @param newFile  目录新文件      *      * */     public  void CopytFileDu(String sourceFile,String newFile)     {           try(FileInputStream inputStream=new FileInputStream(sourceFile);             BufferedInputStream bufferedInputStream=new BufferedInputStream(inputStream);             FileOutputStream outputStream=new FileOutputStream(newFile);             BufferedOutputStream bufferedOutputStream=new BufferedOutputStream(outputStream)             )         {             long startTime=System.nanoTime();             byte[] buffer=new byte[1024];             int len=bufferedInputStream.read(buffer);             while(len!=-1)             {                 bufferedOutputStream.write(buffer,0,len);                 len=bufferedInputStream.read(buffer);             }             long elapsedTime=System.nanoTime()-startTime;             System.out.println("耗时："+(elapsedTime/1000000.0)+" 毫秒");           }         catch (FileNotFoundException exception)         {             exception.printStackTrace();         }         catch (IOException exception)         {             exception.printStackTrace();         }         }       /**      * 删除文件      * @param sroureFile      *      * */     public  void Delete(String sroureFile)     {         try         {             File file=new File(sroureFile);             file.deleteOnExit();           }         catch (Exception exception)         {             exception.printStackTrace();         }           }       }

　　How to Read and Write Text File in Java (codejava.net)

https://www.codejava.net/java-se/file-io/how-to-read-and-write-text-file-in-java

 

?

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43

/**   *http://commons.apache.org/io/   * You could use the Apache Commons IO library, which gives you FileUtils:       * FileUtils.writeStringToFile(file, stringBuilder.toString(), Charset.forName("UTF-8"))   * @param stringBuffer   * @param file   * @return   * */  public boolean DuBuWriteFile(StringBuffer stringBuffer,File file)  {     boolean isok=false;      try {          FileUtils.writeStringToFile(file, stringBuffer.toString(), Charset.forName("UTF-8"));          isok=true;         }      catch (Exception exception)      {          exception.printStackTrace();      }        return  isok;  }  /**   *https://github.com/google/guava   * Files.write(stringBuilder, file, Charsets.UTF_8)   * @param stringBuffer   * @param file   * @return   * */  public boolean DuGoogleWriteFile(StringBuffer stringBuffer,File file)  {      boolean isok=false;      try {         com.google.common.io.Files.write(stringBuffer.toString(),file, Charsets.UTF_8);          isok=true;      }      catch (Exception exception)      {          exception.printStackTrace();      }        return  isok;  }