新手上路问题，java如何进行文件操作？__breader_Exception_String_BufferedReader_new_

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新手上路问题，java如何进行文件操作？

来源: 互联网发布时间：2015-04-10

本文导语: 假设现有一个文件a.txt,现要读出它的所有内容。然后再在它的开始和结尾分别加入"begin"和"end".(请举个例) 请各位大虾帮帮忙！thanks. | import java.io.*; import java.util.zip.*; import java.util.*; public cla...

假设现有一个文件a.txt,现要读出它的所有内容。然后再在它的开始和结尾分别加入"begin"和"end".(请举个例)
请各位大虾帮帮忙！thanks.

import java.io.*;
import java.util.zip.*;
import java.util.*;
public class FileTool
{
   public void appendToFile(String str, String filename) throws Exception
   {
      FileOutputStream stream;//provides file access
      OutputStreamWriter writer;//writes to the file
      try
      {
         stream = new FileOutputStream(filename, true);
         writer = new OutputStreamWriter(stream);
         writer.write(str);
         writer.close();
         stream.close();
      }//try
      catch(Exception e)
      {
         throw e;
      }//catch
   }//appendToFile
   public void prependToFile(String str, String filename) throws Exception
   {
      // Read the file, then prepend str to the file text and write back
      // to the file.
      String newStr;//final string to be written
      try
      {
         newStr = str + readFile(filename);
         writeFile(newStr, filename);
      }//try
      catch(Exception e)
      {
         throw e;
      }//catch
   }//prependToFile
   public String readFile(String filename) throws Exception
   {
      //Read the file into a string buffer, then return as a string.
      StringBuffer buf;//the intermediary, mutable buffer
      BufferedReader breader;//reader for the template files
      try
      {
         breader = new BufferedReader(new FileReader(filename));//header
         buf = new StringBuffer();
         while(breader.ready())
            buf.append((char)breader.read());
         breader.close();
      }//try
      catch(Exception e)
      {
         throw e;
      }//catch
      return buf.toString();
   }//readFile
   public List readFileToList(String filename) throws Exception
   {
      //Read the file into a List, then return.
      BufferedReader breader;//reader for the template files
      List list;//target vector
      String line;//line from file
      list = new ArrayList();
      try
      {
         breader = new BufferedReader(new FileReader(filename));//header
         while((line = breader.readLine()) != null)
            list.add(line);
         breader.close();
      }//try
      catch(Exception e)
      {
         throw e;
      }//catch
      return list;
   }//readFileToVector
   public void writeFile(String str, String filename) throws Exception
   {
      // Open a writer to the file, then write the string.
      BufferedWriter bwriter;//writer to the file
      String fullfilepath;//path for the output file
      try
      {
         bwriter = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(filename)));
         bwriter.write(str);
         bwriter.flush();
         bwriter.close();
      }//try
      catch(Exception e)
      {
         throw e;
      }//catch
   }//writeFile
   public void copyFile(String sourcename, String targetname) throws Exception
   {
      // Open up a reader from sourcename and a writer to targetname.
      // Write each character from sourcename to targetname, then close.
      BufferedReader breader;//reader from source
      BufferedWriter bwriter;//writer to target
      try
      {
         breader = new BufferedReader(new FileReader(sourcename));
         bwriter = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(targetname)));
         while(breader.ready())
            bwriter.write(breader.read());
         breader.close();
         bwriter.close();
      }//try
      catch(Exception e)
      {
         throw e;
      }//catch
   }//copyFile
   public String readZippedFile(String textFilename, String zipFilename) throws Exception
   {
      // Open a stream from the entry in the zip file for the file.
      // Read the file into a string buffer, then return as a string.
      StringBuffer buf;//the intermediary, mutable buffer
      BufferedReader breader;//reader for the template files
      ZipFile zipFile;//zip file
      ZipEntry zipEntry;//entry in zip
      InputStream iStream;//input stream of file
      try
      {
         zipFile = new ZipFile(zipFilename);
         zipEntry = zipFile.getEntry(textFilename);
         iStream = zipFile.getInputStream(zipEntry);
         breader = new BufferedReader(new InputStreamReader(iStream));
         buf = new StringBuffer();
         while(breader.ready())
            buf.append((char)breader.read());
         breader.close();
      }//try
      catch(Exception e)
      {
         throw e;
      }//catch
      return buf.toString();
   }//readZippedFile
   public String readConsole() throws Exception
   {
      // Create a buffered reader with System.in, then
      // read a line from it.
      BufferedReader breader;
      breader = new BufferedReader(new InputStreamReader(System.in));
      return breader.readLine();
   }//readConsole
   public Properties loadProperties(String propsFile) throws Exception
   {
      // Open up an input stream from the file, then read it into
      // a properties hashtable and return.
      FileInputStream instream;//the input stream
      Properties props;//props object
      instream = null;
      props = new Properties();
      try
      {
         instream = new FileInputStream(propsFile);
         props.load(instream);
      }//try
      finally
      {
         try
         {
            instream.close();
         }//try
         catch(Exception e1)
         {
         }
      }//finally
      return props;
   }//loadProperties
//______________________________________________________________
}

import java.io.*;
import java.util.*;
import corejava.*;

public class DataFileTest
{  static void writeData(Employee[] e, PrintWriter out)
      throws IOException
   {  out.println(e.length);
      int i;
      for (i = 0; i