删除所有空格和空行

Question

如何从txt删除所有空格和空行使用Java SE的文件？

输入：

qwe 
    qweqwe 
    qwe 



qwe 

输出：

qwe 
qweqwe 
qwe 
qwe 

谢谢！

Answer 1

怎么是这样的：

FileReader fr = new FileReader("infile.txt"); 
BufferedReader br = new BufferedReader(fr); 
FileWriter fw = new FileWriter("outfile.txt"); 
String line; 

while((line = br.readLine()) != null) 
{ 
    line = line.trim(); // remove leading and trailing whitespace 
    if (!line.equals("")) // don't write out blank lines 
    { 
     fw.write(line, 0, line.length()); 
    } 
} 
fr.close(); 
fw.close(); 

注意 - 没有经过测试，可能不是完美的语法，但给你一个想法/方法要遵循。

请参见下面的JavaDoc以供参考： http://download.oracle.com/javase/7/docs/api/java/io/FileReader.html http://download.oracle.com/javase/7/docs/api/java/io/FileWriter.html

Answer 2

看一看TRIM（）函数

http://docs.oracle.com/javase/1.5.0/docs/api/java/lang/String.html#trim()

此外，一些代码将是有益的......

Answer 3

... 
Scanner scanner = new Scanner(new File("infile.txt")); 
PrintStream out = new PrintStream(new File("outfile.txt")); 
while(scanner.hasNextLine()){ 
    String line = scanner.nextLine(); 
    line = line.trim(); 
    if(line.length() > 0) 
     out.println(line); 
} 
... 

Answer 4

的每一行中的空格，不考虑空和空行：

String line = buffer.readLine(); 

while (line != null) { 
    line = removeSpaces(line);   
    //ignore empty lines 
    if (line.isEmpty()) return; 

     ....code.... 


    line = buffer.readLine(); 
} 




public String removeSpaces (String arg) 
{ 
    Pattern whitespace = Pattern.compile("\\s"); 
    Matcher matcher = whitespace.matcher(arg); 
    String result = ""; 
    if (matcher.find()) { 
     result = matcher.replaceAll(""); 
    } 
    return result; 
} 

Answer 5

用于去除空行在同一个文件中。

public static void RemoveEmptyLines(String FilePath) throws IOException 
{ 
    File inputFile = new File(FilePath); 
    BufferedReader reader = new BufferedReader(new FileReader(inputFile)); 
    String inputFileReader; 
    ArrayList <String> DataArray = new ArrayList<String>(); 
    while((inputFileReader=reader.readLine())!=null) 
    { 
     if(inputFileReader.length()==0) 
     { 
      continue; 
     } 
     DataArray.add(inputFileReader); 
    } 
    reader.close(); 

    BufferedWriter bw = new BufferedWriter(new FileWriter(FilePath)); 
    for(int i=0;i<DataArray.size();i++) 
    { 
     bw.write(DataArray.get(i)); 
     bw.newLine(); 
     bw.flush(); 
    } 
    bw.close(); 
} 

Answer 6

package com.home.interview; 

import java.io.File; 
import java.io.FileNotFoundException; 
import java.util.Scanner; 

public class RemoveInReadFile { 

    public static void main(String[] args) { 

     try { 
      Scanner scanner = new Scanner(new File("Readme.txt")); 


      while(scanner.hasNext()) 
      { 
       String line = scanner.next(); 

       String lineAfterTrim = line.trim(); 
       System.out.print(lineAfterTrim); 
      } 


     } 

     catch (FileNotFoundException e) { 

      e.printStackTrace(); 
     } 

    } 

}