1、FileInputStream（）

              // 構建字節輸入流對象，參數為文件名              FileInputStream fin = new FileInputStream("message");              System.out.
2、RandomaccessFile（）
              String str6="";              ArrayList<String> strs=new ArrayList<String>();              RandomAccessFile file=new RandomAccessFile("message","r");              str6 = file.readLine();              while(str6!=null){                  strs.add(str6);                  str6 = file.readLine();              }              for(int j=0;j<strs.size();j++){                  System.out.println(strs.get(j));              }              file.close();
3、File
              File file2=new File("message");              if(file2.exists()&&file2.isFile()){                  InputStream is=new FileInputStream(file2);                  byte[] buf = new byte[is.available()];                  System.out.println(is.available());                   while(is.read(buf)!=-1){                  //每次讀取打印                      System.out.println(new String(buf));                  }              }
4、避免亂碼
            File file3 = new File("message");            if (file3.exists() && file3.isFile()) {                try {                    InputStream is = new FileInputStream(file3);                    InputStreamReader reader = new InputStreamReader(is,"utf-8");//                    char[] cbuf = new char[is.available()];//字符，字節                                        StringBuffer sb2=new StringBuffer();//2                    while (reader.read(cbuf) != -1) {                        sb2.append(cbuf);                    }                    System.out.println(sb2.toString());                                    } catch (Exception e) {                }            }
5、BufferedReader
            File file = new File("message");            try {                InputStream is = new FileInputStream(file);                if (file.exists() && file.isFile()) {                    BufferedReader br = new BufferedReader(                            new InputStreamReader(is, "utf-8"));                    StringBuffer sb2 = new StringBuffer();                    String line = null;                    while ((line = br.readLine()) != null) {                        sb2.append(line + "/n");                    }                    br.close();                    System.out.println(sb2.toString());                }            } catch (Exception e) {            }