Question

我的档案有：

 public class MyC{
    public void MyMethod()
    {
        System.out.println("My method has been accessed");
        System.out.println("hi");
    }
}

以下代码执行以下操作。 1.如果行计数等于num[index]，它将检查该行是否包含来自的字符串 VALUES1[index]。如果为true，则从VALUES[index]中的第一个索引替换该字符串并写入新文件。

2.如果num index不等于num[index]，它只是将该行按原样写入新文件。

问题是，在写入新文件后，原始第1行和第2行仍会出现在新文件中。如何删除。

继承我的代码：

public class MainTest {


    static int i ;

    public static void main(String[] arg)
    {
        try {



             int num[] = {1,2,4}; //Line Numbers

             String[] VALUES = new String[] {"AB","BC","CD"}; //Correct Solutions

             String[] VALUES1 = new String[] {"class","void","System"}; //To Replace


             FileInputStream fs= new FileInputStream("C:\\Users\\Antish\\Desktop\\Test_File.txt");
             BufferedReader br = new BufferedReader(new InputStreamReader(fs));

             FileWriter writer1 = new FileWriter("C:\\Users\\Antish\\Desktop\\Test_File1.txt");

             String line;
             String line1 = null;

             Integer count =0;

             line = br.readLine();
             count++;

             while(line!=null){


                 for(int index =0;index<num.length;index++){
                     if(count == num[index]){

                         if(line.contains(VALUES1[index])){

                             line1= line.replace(VALUES1[index], VALUES[index]);
                              writer1.write(line1+System.getProperty("line.separator"));
                         }


                     }
                 }


                 writer1.write(line+System.getProperty("line.separator"));

                 line = br.readLine();

                 count++;


                 }


        writer1.close();
        }
        catch (Exception e) {
            e.printStackTrace();
        } finally {
        }

     }
}

这是我的结果：

    public AB MyC{
    **public class MyC{ //This still appears.**
    public BC MyMethod()
    **public void MyMethod()//This still appears.**
    {
        CD.out.println("My method has been accessed");
        System.out.println("My method has been accessed");
        System.out.println("hi");
    }
}

Answer 1

你应该添加一个指示符来显示该行是否被替换

而（线！= NULL）{

             boolean exists = false;
             for(int index =0;index<num.length;index++){
                 if(count == num[index]){

                     if(line.contains(VALUES1[index])){
                         exists = true;
                         line1= line.replace(VALUES1[index], VALUES[index]);
                          writer1.write(line1+System.getProperty("line.separator"));
                     }


                 }
             }

             if (!exists)
                 writer1.write(line+System.getProperty("line.separator"));

Answer 2

在代码中注释这一行

writer1.write(line+System.getProperty("line.separator"));

然后尝试

将数组中的字符串替换为文件中的行

2 个答案: