使用java的输入，输出流将一个文本文件的内容按行读出，每读一行就顺序添加行号，并写入到另一个文件

代码如下：

import java.io.BufferedReader

import java.io.BufferedWriter

import java.io.File

import java.io.FileInputStream

import java.io.FileNotFoundException

import java.io.FileOutputStream

import java.io.IOException

import java.io.InputStreamReader

import java.io.OutputStreamWriter

public class App {

public static void main(String[] args) throws FileNotFoundException, IOException {

try (

FileInputStream inputStream = new FileInputStream(new File("d:\\temp\\abc.txt"))

InputStreamReader streamReader = new InputStreamReader(inputStream)

BufferedReader reader = new BufferedReader(streamReader)

FileOutputStream outputStream = new FileOutputStream(new File("d:\\temp\\output.txt"))

OutputStreamWriter streamWriter = new OutputStreamWriter(outputStream)

BufferedWriter writer = new BufferedWriter(streamWriter)

) {

int count = 1

String line = null

while ((line = reader.readLine()) != null) {

writer.write(count++ + ": " + line)

writer.newLine()

}

}

System.out.println("done.")

}

}

大概就是这样啦，换成你自己的文件名就行了

import java.io.FileNotFoundException

import java.io.IOException

import java.io.RandomAccessFile

import java.util.ArrayList

public class ShowSourceCode {

public static void main(String[] args) throws FileNotFoundException, IOException{

RandomAccessFile file = new RandomAccessFile("Add.java", "r")

String tmp

while((tmp = file.readLine()) != null){

System.out.println(tmp)

}

file.seek(0)

int lineNum = 1

while((tmp = file.readLine()) != null){

System.out.println(lineNum + ": " + tmp)

lineNum++

}

}

}

import java.io.*

import java.util.*

public class Test{

public static void main(String[] args){

List<String>list=new ArrayList<String>()

try {

File f=new File("d:/file/hello.txt ")

Scanner sc=new Scanner(f)

int k=0

while(sc.hasNextLine()){

list.add(++k+" "+sc.nextLine())

}

FileWriter fw=new FileWriter(f)

for(int i=0i<list.size()i++)

fw.write(list.get(i)+"\r\n")

fw.flush()

fw.close()

System.out.println(" *** 作已经成功完成！")

} catch (FileNotFoundException e) {

e.printStackTrace()

} catch (IOException e) {

e.printStackTrace()

}

}

}

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