用Java替换文件中的文本

Question

I've been trying to create a simple program, in java, that replaces some words into a file. To change the text into the file I created, I create a String and set it to the file text:

Path path = Paths.get("somePath/someFile.someExtension");
Charset charset = StandardCharsets.UTF_8;
String s = new String(Files.readAllBytes(path), charset);

EDIT: To save to the file with s , I used Files.write(path, s.getBytes(charset)); .

Then I change the String with commands like s.replaceAll("A", "B") . But now, I'm stuck. I want to make a more complicated then just replacing "A" with "B". I'll try to explain has best I can:

I need to find at the file if wall someNumber someNumer someNumber is in there, and if there are three arguments ( someNumber someNumber someNumber ), then get the value of " someNumber " at the center. For example:

If the commands are:

wall 200 500 100
wall 200 500 100

Then I want to get the argument from the center (in the first case 500 and in the second 500), and store it into a variable, then delete it from the String. After that, on the top of these commands (in the example wall 200 500 100 wall 200 500 100 ), I want to write:

usemtl texture
ceil (someNumber that we stored, in the case, 500)

Note that if the arguments wall wall don't have any kind of separation (for example #other wall ), then the someNumber at the center will be equal (500 and 500 are equal). So, the command below will just appear per group (if wall wall wall... isn't separed with #other wall , for example).

Other example, this would be the file before / after:

Before:

wall 100 300 50
wall 100 300 100
wall 100 300 400

After:

usemtl texture
ceil 300

wall 100 50
wall 100 100
wall 100 400

So, how can I make this replace?

Please answer! I have no idea how!

EDIT: question to @Roan, owner of most of this code:

Now, after the answers @Roan code transformed into:

package com.fileConverter.main;

import java.io.BufferedReader;
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.PrintWriter;

import javax.swing.JFileChooser;

public class FileReplace extends JFileChooser {
    private static final long serialVersionUID = -254322941935132675L;

    private static FileReplace chooser = new FileReplace();

    public static void main(String[] args) {
        chooser.showDialog(chooser, "Open");
    }

    public void cancelSelection() {
        System.exit(0);
    }

    public void approveSelection() {
        super.approveSelection();
        System.out.println("starting...");

        // The path were your file is
        String path = chooser.getSelectedFile().getAbsolutePath();
        File file = new File(path);

        // try to create an inputstream from the file
        FileInputStream fis = null;
        try {
            fis = new FileInputStream(file);
        } catch (FileNotFoundException e) {
            // If we are here the file is not found
            e.printStackTrace();
        }

        // make it a buffered reader
        BufferedReader bufferedReader = new BufferedReader(
                new InputStreamReader(fis));

        // to store the current line
        String line;

        // array to store the different words
        String[] words;

        // create a second temporally file that will replace the original file
        File file2 = new File(chooser.getSelectedFile().getParentFile()
                + "$$$$$$$$$$$$$$$.tmp");
        try {
            file.createNewFile();
        } catch (IOException e1) {
            e1.printStackTrace();
        }
        // and create the streams
        FileOutputStream file2Os = null;
        try {
            file2Os = new FileOutputStream(file2);
        } catch (FileNotFoundException e1) {
            e1.printStackTrace();
        }
        PrintWriter writer = new PrintWriter(file2Os);
        try {
            System.out.println("replacing code...");
            writer.println("mtllib textures.mtl");
            // loop through all lines and
            while ((line = bufferedReader.readLine()) != null) {
                line = line
                        .replace("//", "#")
                        .replace("(", "wall")
                        .replace(")", "\n")
                        .replace("{", "")
                        .replace("}", "")
                        .replace("# brush from cube",
                                "room cube" + countWords(line, "cube"))
                        .replace(" NULL 0 0 0 1 1 0 0 0", "")
                        .replace("\"classname\"", "")
                        .replace("\"worldspawn\"", "");

                // get all the diffent terms
                words = line.split(" ");

                // see if there are 4 terms in there: wall x x x
                // and if the first term equals wall28
                // and if the middle number is the number you want to delete
                // if not just copy the line over

                if (words.length == 4 && words[0].contains("wall")) {
                    double doubleVal = Double.parseDouble(words[2]);
                    int val = (int) doubleVal;
                    // now modify the line by removing the middel number
                    String newLine = words[0] + " " + words[1] + " " + words[3];
                    String valInsert = null;

                    if (val >= 0)
                        valInsert = "\n" + "usemtl texture" + "\n" + "ceil "
                                + val;
                    else if (val < 0)
                        valInsert = "\n" + "usemtl texture" + "\n" + "floor "
                                + val;

                    // write this to the new file
                    writer.println(valInsert);
                    writer.println(newLine);
                } else {
                    // copy the old line
                    writer.println(line);
                }
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
        // close our resources
        writer.close();
        try {
            bufferedReader.close();
        } catch (IOException e) {
            e.printStackTrace();
        }

        // now we rename the temp file and replace the old file
        // with the new file with the new content
        file.delete();
        file2.renameTo(file);

        System.out.println("done!");
    }

    public int countWords(String string, String word) {
        int lastIndex = 0;
        int count = 0;

        while (lastIndex != -1) {

            lastIndex = string.indexOf(word, lastIndex);

            if (lastIndex != -1) {
                count++;
                lastIndex += word.length();
            }
        }
        return count;
    }
}

The problem is that this part doesn't make any replaces:

if (words.length == 4 && words[0].contains("wall")) {
    double doubleVal = Double.parseDouble(words[2]);
    int val = (int) doubleVal;
    // now modify the line by removing the middel number
    String newLine = words[0] + " " + words[1] + " " + words[3];
    String valInsert = null;

    if (val >= 0)
        valInsert = "\n" + "usemtl texture" + "\n" + "ceil "
                + val;
    else if (val < 0)
        valInsert = "\n" + "usemtl texture" + "\n" + "floor "
                + val;

    // write this to the new file
    writer.println(valInsert);
    writer.println(newLine);
}

How can I fix it? Other thing, this part is suppose to create a number that grows after checking how many times cube is wrote, but it doesn't works too :(

.replace("# brush from cube", "room cube" + countWords(line, "cube"))

The countWords method:

public int countWords(String string, String word) {
    int lastIndex = 0;
    int count = 0;

    while (lastIndex != -1) {

        lastIndex = string.indexOf(word, lastIndex);

        if (lastIndex != -1) {
            count++;
            lastIndex += word.length();
        }
    }
    return count;
}

Many Thanks

Answer 1

To analyse a string and see if it matches ("wall" number number number), you can use a REGEX expression: see the doc here .

To use the regex expression, just apply .matches() on your String variable and it'll return true or false depending on if the format is verified.

If the format is verified, then just use the SubString function, specify the start and end index so you get the middle number. To take it out, you could do the opposite. SubString the start (everything until middle number), then SubString the end (everything after the middle number), and then create a new string using those 2.

Answer 2

A simple solution without using (explicitly) regex is to split the String using token (in your case it's a white space.

line = "wall 100 300 50";
String[] words = line.split("\\s+");

You can then get the words[2] convert to an int etc. Then you can write back to a new file (or the same if you have read all file contents).

Regex are more powerful but to me a bit more intimidating so you can pick whatever matches your needs.

Answer 3

Ok I'm very unsure if I understood this correctly.
This is my interpretation of wat your question is:
You have a file with lines that say: wall [number] [number] [number]
Now you want to check if there there are 3 numbers and then delete the middle number if it's the number you're searching for.

So I would do this like this:
Befor you run the programm you'll need a folder on your C: drive with the name "text" and inside that folder you'll need a file called text.txt with you format in it so: for example:
wall 123 300 320
If you change the value of number you can specify wich number the middle number has to be in oder for it to be deleted.

public class FileReplace {

public static void main(String[] args){
    //The path were your file is
    String path = "C:\\text\\text.txt";
    File file = new File(path);

    //The number you want to delete
    int number = 300;

    //try to create an inputstream from the file
    FileInputStream fis = null;
    try {
        fis = new FileInputStream(file);
    } catch (FileNotFoundException e) {
        //If we are here the file is not found
        e.printStackTrace();
    }

    //make it a buffered reader
    BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(fis));

    //to store the current line
    String line;

    //array to store the different words
    String[] words;

    //create a second temporally file that will replace the original file
    File file2 = new File("C:\\text\\$$$$$$$$$$.tmp");
    try {
        file.createNewFile();
    } catch (IOException e1) {
        e1.printStackTrace();
    }
    //and create the streams
    FileOutputStream fos = null;
    try {
        fos = new FileOutputStream(file2);
    } catch (FileNotFoundException e1) {
        e1.printStackTrace();
    }
    PrintWriter writer = new PrintWriter(fos);
    try {
        //loop through all lines and 
        while((line = bufferedReader.readLine()) != null){
            //get all the diffent terms
            words = line.split(" ");

            //see if there are 4 terms in there: wall x x x
            //and if the first term equals wall
            //and if the middle number is the number you want to delete
            //if not just copy the line over
            if(words.length == 4 && words[0].equals("wall") && words[2].equals(String.valueOf(number))){
                //now modify the line by removing the middel number
                String newLine = words[0] + " " + words[1] + " " + words[3];

                //write this to the new file
                writer.println(newLine);
            }else{
                //copy the old line
                writer.println(line);
            }
        }
    } catch (IOException e) {
        e.printStackTrace();
    }
    //close our resources
    writer.close();
    try {
        bufferedReader.close();
    } catch (IOException e) {
        e.printStackTrace();
    }

    //now we rename the temp file and replace the old file
    //with the new file with the new content
    file.delete();
    file2.renameTo(file);
}

}
If you have ay questions about this code feel free to ask them.
Oh and also you might need to run this with administrator right as it uses files.

Hope this helps.

Answer 4

You could use this to count the number of occurances of a word in a string:
Try 1:

public static int countWords(String string, String word) {
    //get all individual words
    String[] terms = string.split(" ");
    //this variable counts how many times word occurs
    int count = 0;
    //a count variable for the loop
    int counter = 0;
    //loop through all the words and if we see a word that equals word we add one to the count variable
    while(counter < terms.length){
        //check if the term equals the word
        if(terms[counter].equals(word)){
            //the term matched add one to the count variable
            count++;
        }
        counter++;
    }
    //return the number of occurrences
    return count;
}

Try 2:

public static String countWords(String string, String word) {
    //get all individual words
    String[] terms = string.split(" ");
    //this variable counts how many times word occurs
    int count = 0;
    //a count variable for the loop
    int counter = 0;

    StringBuffer sb = new StringBuffer();
    sb.append("1");
    //loop trough all the words and if we see a word that equals word we add one to the count variable
    while(counter < terms.length){
        //check if the term equals the word
        if(terms[counter].equals(word)){
            //the term matched add one to the count variable
            count++;
            sb.append(" " + word + (count + 1));
        }
        counter++;
    }
    //return the number of occurrences
    return sb.toString();
}<br><br>

Try 3: you need to have a static variable in your code called lastVar:

static int lastVar = 0;
public static String countWords(String string, String word) {
    //get all individual words
    String[] terms = string.split(" ");
    //this variable counts how many times word occurs
    int count = 0;
    //a count variable for the loop
    int counter = 0;

    StringBuffer sb = new StringBuffer();
    sb.append("1");
    //loop trough all the words and if we see a word that equals word we add one to the count variable
    while(counter < terms.length){
        //check if the term equals the word
        if(terms[counter].equals(word)){
            //the term matched add one to the count variable
            count++;
            sb.append(" " + word + (count + 1 + lastVar));
        }
        counter++;
    }
    lastVar += count + 1;
    //return the number of occurrences
    return sb.toString();
}

That should work.

Hope this helps :D.

Answer 5

To reformat your cube lines you could use:
Try 1:

// loop through all lines and
        while ((line = bufferedReader.readLine()) != null) {
            if(line.contains("// brush from cube")){
                line = line.replace("// brush from cube ", "").replace("(", "").replace(")", "");
                String[] arguments = line.split("\\s+");
                line = "cube" + Cube + " usemtl texture ceil " + arguments[2] + " wall " + arguments[1] + " " + arguments[3] + " usemtl texture floor " + arguments[5] + " wall " + arguments[4] + " " + arguments[6];
                Cube++;
            }
            line = line
                    .replace("//", "#")
                    .replace("(", "wall")
                    .replace(")", "\n")
                    .replace("{", "")
                    .replace("}", "")
                    .replace(" NULL 0 0 0 1 1 0 0 0", "")
                    .replace("\"classname\"", "")
                    .replace("\"worldspawn\"", "");

try 2:

// loop through all lines and
        while ((line = bufferedReader.readLine()) != null) {
            if(line.contains("// brush from cube")){
                line = line + bufferedReader.readLine() + " " + bufferedReader.readLine();
                line = line.replace("// brush from cube ", "").replace("(", "").replace(")", "");
                String[] arguments = line.split("\\s+");
                line = "cube" + Cube + " usemtl texture ceil " + arguments[2] + " wall " + arguments[1] + " " + arguments[3] + " usemtl texture floor " + arguments[5] + " wall " + arguments[4] + " " + arguments[6];
                Cube++;
            }
            line = line
                    .replace("//", "#")
                    .replace("(", "wall")
                    .replace(")", "\n")
                    .replace("{", "")
                    .replace("}", "")
                    .replace(" NULL 0 0 0 1 1 0 0 0", "")
                    .replace("\"classname\"", "")
                    .replace("\"worldspawn\"", "");

PS I've only posted the important part. You should be able to see where in the code this goes. Also you need to have a static int called cube somewhere in you code like:

static int Cube = 1;

That should be it if it doesn't work let me know! :D