java开发之读写txt文件操作的实现

 import java.io.bufferedreader;
 import java.io.file;
 import java.io.fileinputstream;
 import java.io.filenotfoundexception;
 import java.io.fileoutputstream;
 import java.io.filereader;
 import java.io.ioexception;
 import java.io.inputstreamreader;
 import java.io.printwriter;

 /**
  * @author hongten
  *
  * @time 2011-12-12 2011
  */
 public class myfile {
     @suppresswarnings("static-access")
     public static void main(string[] args) {
         myfile myfile = new myfile();
         try {
             for (int i = 0; i < 5; i++) {
                 myfile.creattxtfile("test");
                 myfile.writetxtfile("显示的是追加的信息" + i);
                 string str = myfile.readdate();
                 system.out.println("*********\n" + str);
             }
         } catch (ioexception e) {
             // todo auto-generated catch block
             e.printstacktrace();
         }
     }

     private static string path = "txt/";
     private static string filenametemp;

     /**
      * 创建文件
      *
      * @throws ioexception
      */
     public static boolean creattxtfile(string name) throws ioexception {
         boolean flag = false;
         filenametemp = path + name + ".txt";
         file filename = new file(filenametemp);
         if (!filename.exists()) {
             filename.createnewfile();
             flag = true;
         }
         return flag;
     }

     /**
      * 写文件
      *
      * @param newstr
      *            新内容
      * @throws ioexception
      */
     public static boolean writetxtfile(string newstr) throws ioexception {
         // 先读取原有文件内容，然后进行写入操作
         boolean flag = false;
         string filein = newstr + "\r\n";
         string temp = "";

         fileinputstream fis = null;
         inputstreamreader isr = null;
         bufferedreader br = null;

         fileoutputstream fos = null;
         printwriter pw = null;
         try {
             // 文件路径
             file file = new file(filenametemp);
             // 将文件读入输入流
             fis = new fileinputstream(file);
             isr = new inputstreamreader(fis);
             br = new bufferedreader(isr);
             stringbuffer buf = new stringbuffer();

             // 保存该文件原有的内容
             for (int j = 1; (temp = br.readline()) != null; j++) {
                 buf = buf.append(temp);
                 // system.getproperty("line.separator")
                 // 行与行之间的分隔符 相当于“\n”
                 buf = buf.append(system.getproperty("line.separator"));
             }
             buf.append(filein);

             fos = new fileoutputstream(file);
             pw = new printwriter(fos);
             pw.write(buf.tostring().tochararray());
             pw.flush();
             flag = true;
         } catch (ioexception e1) {
             // todo 自动生成 catch 块
             throw e1;
         } finally {
             if (pw != null) {
                 pw.close();
             }
             if (fos != null) {
                 fos.close();
             }
             if (br != null) {
                 br.close();
             }
             if (isr != null) {
                 isr.close();
             }
             if (fis != null) {
                 fis.close();
             }
         }
         return flag;
     }

     /**
      * 读取数据
      */
     public void readdata1() {
         try {
             filereader read = new filereader(filenametemp);
             bufferedreader br = new bufferedreader(read);
             string row;
             while ((row = br.readline()) != null) {
                 system.out.println(row);
             }
         } catch (filenotfoundexception e) {
             e.printstacktrace();
         } catch (ioexception e) {
             e.printstacktrace();
         }
     }

     public string readdate() {
         // 定义一个待返回的空字符串
         string strs = "";
         try {
             filereader read = new filereader(new file(filenametemp));
             stringbuffer sb = new stringbuffer();
             char ch[] = new char[1024];
             int d = read.read(ch);
             while (d != -1) {
                 string str = new string(ch, 0, d);
                 sb.append(str);
                 d = read.read(ch);
             }
             system.out.print(sb.tostring());
             string a = sb.tostring().replaceall("@@@@@", ",");
             strs = a.substring(0, a.length() - 1);
         } catch (filenotfoundexception e) {
             e.printstacktrace();
         } catch (ioexception e) {
             e.printstacktrace();
         }
         return strs;
     }
 }