Question

如何从文件中一次读取一行并写入不同的文件？

想知道如何一次读取一行并写入不同的文件。谷歌搜索时找不到好的例子：

例如，阅读包含以下内容的文本文件： sent1 sent2 sent3 ....

写 sent1到1.txt， sent2到2.txt， sent3到3.txt

这似乎是一个简单的操作，我的编码有问题，不知道如何修复它。

import java.util.*;
import java.io.*;

public class MyFunction {
public static void main(String args[])
throws IOException, ClassNotFoundException
{


   //variable initialization

  String strLine;
  int i = 0;
 //Read in a file and process one line at a time

   FileReader singleFile = new FileReader("C:\\data);
   BufferedReader reader = new BufferedReader(singleFile);
    for (int j=0; j < 12; j++) {
   FileWriter outFile = new FileWriter("C:\\doc" + i + ".txt");
   BufferedWriter writer = new BufferedWriter(outFile);     

    //Read one line at a time from the input file
   while ((strLine = reader.readLine()) !=null) {
   //process a string which is not empty

   if (strLine.length() > 0) {

   System.out.println("This is strLine: " + strLine);
   writer.write (strLine);

   i=i+1;
   System.out.println("This is i: " + i);

   } //end of if
   }


   singleFile.close();
   writer.close();

   } }}

Answer 1

最简单的方法可能是在一个数组中打开n个FileWriters，每个输出文件一个（我称之为数组“writers”）。设置计数器i = 0.当您迭代输入行时，将当前行写入writers [i]，然后递增i并设置i = i％n。这将使我在0..n-1范围内循环，这意味着你将写入序列0,1，...... n-1,0,1 ...中的文件......我认为这就是你想要的。

Answer 2

在文件完成之前，您一直处于困境中。取出while循环并将其替换为if，如果突然出现for循环。这将只为你提供前12行。之后，将for循环更改为while循环并手动增加j，如果j> = 12，则将j设置为0.

下面的代码循环超过12个文件，这是你想要的吗？

import java.util.*;
import java.io.*;

public class MyFunction {
public static void main(String args[])
throws IOException, ClassNotFoundException
{


   //variable initialization

  String strLine;
  int i = 0;
   //Read in a file and process one line at a time

   FileReader singleFile = new FileReader("C:\\data);
   BufferedReader reader = new BufferedReader(singleFile);
   j = 0;
   while (true) { //loop forever
   FileWriter outFile = new FileWriter("C:\\doc" + j + ".txt");
   BufferedWriter writer = new BufferedWriter(outFile);     

    //Read one line at a time from the input file
   if ((strLine = reader.readLine()) !=null) { break; } // exit loop
   //process a string which is not empty

   if (strLine.length() > 0) {

   System.out.println("This is strLine: " + strLine);
   writer.write (strLine);

   i=i+1;
   j=j+1;
   if (j >= 12) {j=0};
   System.out.println("This is i: " + i);

   } //end of if


   singleFile.close();
   writer.close();

   } }}

Answer 3

它适用于以下代码。因为我知道文档中只有12行 - 想知道如何找出输入文件中的总行数。

   import java.util.*;
   import java.io.*;



  public class MyFunction {
 public static void main(String args[])
 throws IOException, ClassNotFoundException
 {


 //variable initialization

String strLine;

 //Read in a file and process one line at a time

   FileReader singleFile = new FileReader("C:\\data\\data.txt");  
   BufferedReader reader = new BufferedReader(singleFile);

    for (int i=0; i<12; i++) {
    FileWriter outFile = new FileWriter("C:\\sample\\doc" + i + ".txt");
    BufferedWriter writer = new BufferedWriter(outFile);     

    //Read one line at a time from the input file
    if ((strLine = reader.readLine()) !=null) 
    //process a string which is not empty

    if (strLine.length() > 0) {

    System.out.println("This is strLine: " + strLine);
    writer.write (strLine);

    System.out.println("This is i: " + i);

    } //end of if


  singleFile.close();
  writer.close();

    } }}

从文件一次读取一行并写入不同的文件

3 个答案: