Open text file and edit it in java

[Gillian Anderson]

Hello,
I connect to file and open it with FileWriter class and write normally, i.e add a line to the file, but now I want to read the file and return a variable ip, a line like ip = 182.15 .. and change the IP. How can I perform this task, if you have any solution or any idea about then please let me know. Thanks in advance.

[GlassFish]

Hello,
Well instead of FileWriter you use a FileReader. Then you use a BufferedReader to read your file line by line (method "readLine ()). Finally, you analyze your line to determine if it interests you or not. If you need more information on the API which are used by java rather the java.io package which you are interested in then you can find then on the sun's official site.

[Vodka]

Hello,
Even I do a same kind of a problem with my java code. I am trying it but nothing is working for me. I actually used FileReader and buffered with the method readline and I can access the line that I want but how can I now edit. I have searched a lot of help on internet but non of them is useful for me, rather it defines a high profile guide or tutorials, which are out of my scope. So, a simple explanation will be appreciated. Thanks in advance.

[HardWeaR]

Hello,
I think you can do the following. If the lines in your file are of the form "key = value", then it would be better to use a property file.
For example:
Here is the code for it

Properties p = new Properties();
d.load(new FileInputStream ("ton_fichier"));
/ / Mails to take the IP address
d.getProperty("IP");
//...

Just try the following code and see if it works.

[InterNetWorKed]

Hello,
You can not edit a file directly like this or else you'll have to use class RandomAccessFile.

With the method I gave you, you need:
- A StringBuilder
- To read each line, you add content to this last (append ())
- Reading the line that you want change, you add the amendment to the StringBuilder
- You add the lines remaining at end of file

Once done, you close your actual buffer reading and you open a write buffer to overwrite the file with the correct content contained in your StringBuilder.