基于Mahout的电影推荐系统，数据预处理程序源码，程序处理rating.dat文件.zip

package com; import java.io.BufferedReader; import java.io.File; import java.io.FileReader; import java.io.FileWriter; import java.io.IOException; import java.io.RandomAccessFile; public class Preprocess { public static void appendMethodA(String fileName, String content){ try { // 打开一个随机访问文件流，按读写方式 RandomAccessFile randomFile = new RandomAccessFile(fileName, "rw"); // 文件长度，字节数 long fileLength = randomFile.length(); //将写文件指针移到文件尾。 randomFile.seek(fileLength); randomFile.writeBytes(content); randomFile.close(); } catch (IOException e){ e.printStackTrace(); } } public static void readFileByLines(String fileName){ File file = new File(fileName); BufferedReader reader = null; try { System.out.println("以行为单位读取文件内容，一次读一整行："); reader = new BufferedReader(new FileReader(file)); String tempString = null; int line = 1; //一次读入一行，直到读入null为文件结束 while ((tempString = reader.readLine()) != null){ //显示行号 //System.out.println("line " + line + ": " + tempString); //line++; //写入到文件中 String filename = "out.txt"; String[] strarr = tempString.split("::"); String deststr = strarr[0]+","+strarr[1]+","+strarr[2]+"\n"; appendMethodA(filename,deststr); } reader.close(); } catch (IOException e) { e.printStackTrace(); } finally { if (reader != null){ try { reader.close(); } catch (IOException e1) { } } } } public static void main(String[] args) throws Exception{ //FileReader fr = new FileReader("ratings.dat"); readFileByLines("ratings.dat"); } }