同時從兩個文件中讀取

假設我們有兩個文件f1 and f2.同時從兩個文件中讀取

另外，假定有一個名爲comparision(File f1,File f2)功能。該函數將獲取兩個文件作爲參數，並從f1中取出第一個字符（word），並將其與f2中的所有字符進行比較，直到結束，然後選取第二個字符，直到第一個字符結束爲止。

我的問題是：我該如何執行此操作？我需要知道EOF嗎？如果是這樣，如何得到它？

假設文件是純文本(.txt)並且每個單詞都在一行中。爲例：

f1: 
I 
am 
new 
to 
java 

f2: 

java 
is 
a 
programing 
language

下面的代碼：

static void comparision(File f, File g) throws Exception 
    { 



     Set<String> text = new LinkedHashSet<String>(); 
BufferedReader br = new BufferedReader(new FileReader(g)); 
for(String line;(line = br.readLine()) != null;) 
    text.add(line.trim().toString()); 
     if(text==null) 
      return; 


     BufferedReader br = new BufferedReader(new FileReader(f)); 
     String keyword = br.readLine(); 

     if (keyword != null) { 

      Pattern p = Pattern.compile(keyword, Pattern.CASE_INSENSITIVE); 
      StringBuffer test = new StringBuffer(text.toString()); 
      matcher = p.matcher(test); 
      if (!matcher.hitEnd()) { 
       total++; 
       if (matcher.find()) { 
        //do sth   
       } 
      } 
     } 
    }

編輯由jcolebrand

一些思考，我們需要看起來像這樣（僞碼）程序流

function(file1,file2) throws exceptions{ 
    ArrayList<string> list1, list2; //somebody said we should use an ArrayList ;-) 
    string readinTempValue = null;  

    br = BufferedReader(file1) //we are already using a BufferredReader 
    readinTempValue = br.ReadLine(); 

    //this is a loop structure 
    while (readinTempValue != null){ //trust me on this one 

    //we need to get the string into the array list.... 
    //how can we ADD the value to list1 
    readinTempValue = br.ReadLine(); //trust me on this one 
    } 


    br = BufferedReader(file2) //we are already using a BufferredReader 
    readinTempValue = br.ReadLine(); 

    //this is a loop structure 
    while (readinTempValue != null){ //trust me on this one 

    //we need to get the string into the array list.... 
    //how can we ADD the value to list2 
    readinTempValue = br.ReadLine(); //trust me on this one 
    } 

    foreach(value in list1){ 
    foreach(value in list2){ 
     compare value from list 1 to value from list 2 
    } 
    } 
}

來源

2011-12-15 lonesome

看起來這可能是別人的啓發性的問題...但它需要澄清。剛發佈了一些編輯...你能添加預期的輸出嗎？ – jayunit100 2011-12-15 03:39:17

@ user1064929到目前爲止你做得很好。但是您需要將其分解爲兩個任務：將兩個文件都讀入，將文件1中的每個單詞與文件2中的每個單詞相比較。看起來你正在將兩者混合在一起。 – jcolebrand 2011-12-15 03:49:57

簡單的基本算法（可以根據你爲什麼w螞蟻比較）

Read the second file and create a HashSet "hs" 
for each word "w" in file 1 
    if(hs.contains(w)) 
    { 
    w is present in the second file 
    } 
    else 
    { 
    w is not present in the second file 
    }

修改OP代碼

static int comparision(File f, File g) throws Exception 
    { 
     int occurences = -1; 

     Set<String> text = new HashSet<String>(); 

     BufferedReader br = new BufferedReader(new FileReader(g)); 
     String line = br.readLine(); 

     while (line != null) 
     { 
      String trimmedLine = line.trim(); 
      if (trimmedLine.length() > 0) 
      { 
       text.add(trimmedLine.toString()); 
      } 
      line = br.readLine(); 
     } 

     if (text.isEmpty()) 
     { 
      // file 1 doesn't contain any useful data 
      return -1; 
     } 

     br = new BufferedReader(new FileReader(f)); 
     String keyword = br.readLine(); 

     if (keyword != null) 
     { 
      String trimmedKeyword = keyword.trim(); 
      if (trimmedKeyword.length() > 0) 
      { 
       if (text.contains(trimmedKeyword)) 
       { 
        occurences++; 
       } 
      } 
      line = br.readLine(); 
     } 
     return occurences; 
    }

來源

2011-12-15 03:41:56

同時從兩個文件中讀取

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