java读写大文件

java读写2G以上的大文件（推荐使用以下方法）

    static String sourceFilePath = "H:\DataSource-ready\question.json" ;
    static String distFilePath = "H:\DataSource-ready\separate\" ;
    
    public static void main( String[] args )
    {
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");//设置日期格式
        System.out.println("开始时间" + sdf.format(new Date()));// new Date()为获取当前系统时间

        long timer = System.currentTimeMillis();         
        try {
            File file = new File(sourceFilePath);   
            BufferedInputStream fis = new BufferedInputStream(new FileInputStream(file));    
            BufferedReader reader = new BufferedReader(new InputStreamReader(fis,"utf-8"),7*1024*1024);// 用7M的缓冲读取文本文件  
              
            int count = 1 ;
            String outputFile = distFilePath + count + ".json" ;
            FileWriter fw = new FileWriter(outputFile);
            String line = "";
            while((line = reader.readLine()) != null){
                if ( line.contains("},") ) {
                    line = line.replace("},", "}") ;
                    fw.append(line + "
");
                    fw.flush();
                    fw.close();
                    count ++ ;
                    outputFile = distFilePath + count + ".json" ;
                    fw = new FileWriter(outputFile);
                }
                else {
                    fw.append(line + "
");    
                }                            
            }
            reader.close();       
            fw.flush();
            fw.close();
        } catch (IOException e) {
            System.out.println("读写文件失败!");
            e.printStackTrace();
        }
        timer = System.currentTimeMillis() - timer;  
        System.out.println("处理时间：" + timer + " 毫秒");  
        System.out.println("结束时间：" + sdf.format(new Date()));
    }

共同学习，共同进步，若有补充，欢迎指出，谢谢！