java读写大文件

 1     static String sourceFilePath = "H:\DataSource-ready\question.json" ;
 2     static String distFilePath = "H:\DataSource-ready\separate\" ;
 3     
 4     public static void main( String[] args )
 5     {
 6         SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");//设置日期格式
 7         System.out.println("开始时间" + sdf.format(new Date()));// new Date()为获取当前系统时间
 8 
 9         long timer = System.currentTimeMillis();         
10         try {
11             File file = new File(sourceFilePath);   
12             BufferedInputStream fis = new BufferedInputStream(new FileInputStream(file));    
13             BufferedReader reader = new BufferedReader(new InputStreamReader(fis,"utf-8"),7*1024*1024);// 用7M的缓冲读取文本文件  
14               
15             int count = 1 ;
16             String outputFile = distFilePath + count + ".json" ;
17             FileWriter fw = new FileWriter(outputFile);
18             String line = "";
19             while((line = reader.readLine()) != null){
20                 if ( line.contains("},") ) {
21                     line = line.replace("},", "}") ;
22                     fw.append(line + "
");
23                     fw.flush();
24                     fw.close();
25                     count ++ ;
26                     outputFile = distFilePath + count + ".json" ;
27                     fw = new FileWriter(outputFile);
28                 }
29                 else {
30                     fw.append(line + "
");    
31                 }                            
32             }
33             reader.close();       
34             fw.flush();
35             fw.close();
36         } catch (IOException e) {
37             System.out.println("读写文件失败!");
38             e.printStackTrace();
39         }
40         timer = System.currentTimeMillis() - timer;  
41         System.out.println("处理时间：" + timer + " 毫秒");  
42         System.out.println("结束时间：" + sdf.format(new Date()));
43     }