Develop Reference

How to rewrite one specific line of a text file in java

The image below shows the format of my settings file for a web bot I'm developing. If you look at line 31 in the image you will see it says chromeVersion. This is so the program knows which version of the chromedriver to use. If the user enters an invalid response or leaves the field blank the program will detect that and determine the version itself and save the version it determines to a string called chromeVersion. After this is done I want to replace line 31 of that file with
"(31) chromeVersion(76/77/78), if you don't know this field will be filled automatically upon the first run of the bot): " + chromeVersion
To be clear I do not want to rewrite the whole file I just want to either change the value assigned to chromeVersion in the text file or rewrite that line with the version included.
Any suggestions or ways to do this would be much appreciated.
image

You will need to rewrite the whole file, except the byte length of the file remains the same after your modification. Since this is not guaranteed to be the case or to find out is too cumbersome here is a simple procedure:
import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.List;
public class Lab1 {
public static void main(String[] args) {
String chromVersion = "myChromeVersion";
try {
Path path = Paths.get("C:\\whatever\\path\\toYourFile.txt");
List<String> lines = Files.readAllLines(path, StandardCharsets.UTF_8);
int lineToModify = 31;
lines.set(lineToModify, lines.get(lineToModify)+ chromVersion);
Files.write(path, lines, StandardCharsets.UTF_8);
} catch (IOException ex) {
ex.printStackTrace();
}
}
}
Note that this is not the best way to go for very large files. But for the small file you have it is not an issue.

Java Spanish Encoding in Properties File

So I'm working on a localization example and the normal method of doing it with ResourceBundle and everything doesn't support UTF-8 it seems so I'm moving on to Properties.
I've got it getting the actual properties fine but in the Spanish file, it doesn't like the accents. I have it reading in UTF-8 but it doesn't care, just displays a different symbol than before.
Output:
íHola!
┐C¾mo estßs?
íAdi¾s!
Expected Output:
¡Hola!
¿Cómo estás?
¡Adios!
Properties File:
greetings = ¡Hola!
farewell = ¡Adiós!
inquiry = ¿Cómo estás?
Code:
import java.util.*;
import java.io.*;
public class Test{
public static void main(String[] args) throws IOException {
String language;
String country;
if (args.length != 2) {
language = new String("en");
country = new String("GB");
} else {
language = new String(args[0]);
country = new String(args[1]);
}
String file = String.format("lang_%s_%s.properties",language,country);
InputStream utf8in = Test.class.getClassLoader().getResourceAsStream(file);
Reader reader = new InputStreamReader(utf8in, "UTF-8");
Properties props = new Properties();
props.load(reader);
System.out.println(props.getProperty("greetings"));
System.out.println(props.getProperty("inquiry"));
System.out.println(props.getProperty("farewell"));
}
}
I've just spent about 40 minutes reading everything I could find and they were either the exact same as what I've got now or slightly different and when trying, produced the same results.
Can someone please tell me how I can get my expected output?

In Eclipse, I can be reproduced the problem. Here are steps:
Create Java project and set Text file encoding to CP850.
Create Run/Debug Configurations, set VM arguments to -Dfile.encoding=ISO8859-1.
Confirm Encoding setting in Common tab is CP850;
Run the java program.
When java program print to standard output, those chars become ISO8859-1 bytes.
Those bytes are re-encoded using CP850 and display in Console view.
This is a configuration problem. Make sure the Encoding is the same as the file.encoding of running program.

issue with running a perl script from java

I'm trying to run a Perl script file from java code but it's not working with me. I modified the Perl script and put the arguments in it instead of passing them via java code. The script works fine when running it from the command line but it's not working inside java code, always prints "wrong"!!. I wrote another Perl script (test.pl) and it's working but the desired script doesn't?? I'm working in netbeans7.3.1 (ubuntu).
Here is my code:
package program;
import java.io.*;
//import java.lang.ProcessBuilder;
/**
*
* #author seed
*/
public class Program {
/**
* #param args the command line arguments
*/
public static void main(String[] args) throws IOException,Exception {
File input = new File("//home//seed//Downloads//MADA-3.2//sample");
FileOutputStream out = new FileOutputStream(input);
PrintWriter p = new PrintWriter(out);
String s = "قصدنا في هذا القول ذكر";
p.println(s);
p.close();
Process pro = Runtime.getRuntime().exec("perl /home/seed/Downloads/MADA+TOKAN.pl");
pro.waitFor();
if(pro.exitValue() == 0)
{
System.out.println("Command Successful");
}
else{
System.out.print("wrong");}
// TODO code application logic here
}
}

My guess is that some kind of string/path conversion issue.
I see utf8 strings in your code, maybe the path is converted to something.
The filename (MADA+TOKAN.pl) contain special char, it would be better MADAplusTOKAN.pl.
Also your string in script and in question are not the same: (MADA 3.2 != MADA-3.2)
perl MADA+TOKAN.pl config=/home/seed/Downloads/mada/MADA-3.2/config files/template.madaconfig file=/home/seed/Downloads/mada/MADA 3.2/inputfile
vs
perl MADA+TOKAN.pl config=/home/seed/Downloads/MADA-3.2/config-files/template.madaconfig file=/home/seed/Downloads/MADA-3.2/sample

It sounds like it is finding your perl script and executing it, since test.perl and MADA.perl run OK.
It does sound like the arguments being passed in to the perl script are not what was expected. Can you modify the perl script to echo all its input parameters to a file?

Apache commons Fileutils

I downloaded apache commons FileUtils to perform a copy directory and added them under libraries in eclipse as well. When I say Fileutils.copyDirectory(s,d) as give below eclipse says " Multiple markers at this line -Syntax error on token "(", delete this token
-Syntax error on token ")", delete this token". Can someone help
import org.apache.commons.io.FileUtils;
Public class b {
File s = new file("C://Tom//eso");
File d = new file("C://Tom//pos");
FileUtils.copyDirectory(s,d);
}

Try this:
import org.apache.commons.io.FileUtils;
public class B {
public static void main(String[] args) throws Exception {
File s = new File("C:/Tom/eso");
File d = new File("C:/Tom/pos");
FileUtils.copyDirectory(s,d);
}
}
There are several errors in your code:
Classes start with an uppercase char - it's File, not file. And it's class B, not class b (remember to also rename the file to B.java)
You must not use double / chars, just one
The code must reside inside a method, not at the class level
It's public, not Public
You're not handling exceptions, either throw them or catch them

File s = new file("C://Tom//eso");
File d = new file("C://Tom//pos");
file should be capitalized. It should be new File(....
Side note: Usually for windows the path looks like C:\\Tom\\eso, you have forward-slashes instead of backward.

You're trying to call a method outside of the body of a method...try something more along the lines of;
public class b {
public static void main(String args[]) {
File s = new File("C:/Tom/eso");
File d = new File("C:/Tom/pos");
try {
FileUtils.copyDirectory(s,d);
} catch (IOException exp) {
exp.printStackTrace();
}
}
}
Just to highlight...
Public should be public
file should be File
// should be either / or \\ (most people prefer /)
Execution code must be executed from the context of a method or static init section
I'd also recommend that you take the time to learn the Java naming conventions as well as have a read through the tutorials under the Trails Covering the Basics section

Two errors.
First
File s = new file("C://Tom//eso");
File d = new file("C://Tom//pos");
should be
File s = new File("C://Tom//eso");
File d = new File("C://Tom//pos");
Second
FileUtils.copyDirectory(s,d);
should in main method.

'Un'-externalize strings from Eclipse or Intellij

I have a bunch of strings in a properties file which i want to 'un-externalize', ie inline into my code.
I see that both Eclipse and Intellij have great support to 'externalize' strings from within code, however do any of them support inlining strings from a properties file back into code?
For example if I have code like -
My.java
System.out.println(myResourceBundle.getString("key"));
My.properties
key=a whole bunch of text
I want my java code to be replaced as -
My.java
System.out.println("a whole bunch of text");

I wrote a simple java program that you can use to do this.
Dexternalize.java
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileWriter;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Map.Entry;
import java.util.Properties;
import java.util.Set;
import java.util.Stack;
import java.util.logging.Level;
import java.util.logging.Logger;
public class Deexternalize {
public static final Logger logger = Logger.getLogger(Deexternalize.class.toString());
public static void main(String[] args) throws IOException {
if(args.length != 2) {
System.out.println("Deexternalize props_file java_file_to_create");
return;
}
Properties defaultProps = new Properties();
FileInputStream in = new FileInputStream(args[0]);
defaultProps.load(in);
in.close();
File javaFile = new File(args[1]);
List<String> data = process(defaultProps,javaFile);
buildFile(javaFile,data);
}
public static List<String> process(Properties propsFile, File javaFile) {
List<String> data = new ArrayList<String>();
Set<Entry<Object,Object>> setOfProps = propsFile.entrySet();
int indexOf = javaFile.getName().indexOf(".");
String javaClassName = javaFile.getName().substring(0,indexOf);
data.add("public class " + javaClassName + " {\n");
StringBuilder sb = null;
// for some reason it's adding them in reverse order so putting htem on a stack
Stack<String> aStack = new Stack<String>();
for(Entry<Object,Object> anEntry : setOfProps) {
sb = new StringBuilder("\tpublic static final String ");
sb.append(anEntry.getKey().toString());
sb.append(" = \"");
sb.append(anEntry.getValue().toString());
sb.append("\";\n");
aStack.push(sb.toString());
}
while(!aStack.empty()) {
data.add(aStack.pop());
}
if(sb != null) {
data.add("}");
}
return data;
}
public static final void buildFile(File fileToBuild, List<String> lines) {
BufferedWriter theWriter = null;
try {
// Check to make sure if the file exists already.
if(!fileToBuild.exists()) {
fileToBuild.createNewFile();
}
theWriter = new BufferedWriter(new FileWriter(fileToBuild));
// Write the lines to the file.
for(String theLine : lines) {
// DO NOT ADD windows carriage return.
if(theLine.endsWith("\r\n")){
theWriter.write(theLine.substring(0, theLine.length()-2));
theWriter.write("\n");
} else if(theLine.endsWith("\n")) {
// This case is UNIX format already since we checked for
// the carriage return already.
theWriter.write(theLine);
} else {
theWriter.write(theLine);
theWriter.write("\n");
}
}
} catch(IOException ex) {
logger.log(Level.SEVERE, null, ex);
} finally {
try {
theWriter.close();
} catch(IOException ex) {
logger.log(Level.SEVERE, null, ex);
}
}
}
}
Basically, all you need to do is call this java program with the location of the property file and the name of the java file you want to create that will contain the properties.
For instance this property file:
test.properties
TEST_1=test test test
TEST_2=test 2456
TEST_3=123456
will become:
java_test.java
public class java_test {
public static final String TEST_1 = "test test test";
public static final String TEST_2 = "test 2456";
public static final String TEST_3 = "123456";
}
Hope this is what you need!
EDIT:
I understand what you requested now. You can use my code to do what you want if you sprinkle a bit of regex magic. Lets say you have the java_test file from above. Copy the inlined properties into the file you want to replace the myResourceBundle code with.
For example,
TestFile.java
public class TestFile {
public static final String TEST_1 = "test test test";
public static final String TEST_2 = "test 2456";
public static final String TEST_3 = "123456";
public static void regexTest() {
System.out.println(myResourceBundle.getString("TEST_1"));
System.out.println(myResourceBundle.getString("TEST_1"));
System.out.println(myResourceBundle.getString("TEST_3"));
}
}
Ok, now if you are using eclipse (any modern IDE should be able to do this) go to the Edit Menu -> Find/Replace. In the window, you should see a "Regular Expressions" checkbox, check that. Now input the following text into the Find text area:
myResourceBundle\.getString\(\"(.+)\"\)
And the back reference
\1
into the replace.
Now click "Replace all" and voila! The code should have been inlined to your needs.
Now TestFile.java will become:
TestFile.java
public class TestFile {
public static final String TEST_1 = "test test test";
public static final String TEST_2 = "test 2456";
public static final String TEST_3 = "123456";
public static void regexTest() {
System.out.println(TEST_1);
System.out.println(TEST_1);
System.out.println(TEST_3);
}
}

You may use Eclipse "Externalize Strings" widget. It can also be used for un-externalization. Select required string(s) and press "Internalize" button. If the string was externalized before, it'll be put back and removed from messages.properties file.

May be if you can explain on how you need to do this, then you could get the correct answer.
The Short answer to your question is no, especially in Intellij (I do not know enough about eclipse). Of course the slightly longer but still not very useful answer is to write a plugin. ( That will take a list of property files and read the key and values in a map and then does a regular expression replace of ResourceBundle.getValue("Key") with the value from Map (for the key). I will write this plugin myself, if you can convince me that, there are more people like you, who have this requirement.)
The more elaborate answer is this.
1_ First I will re-factor all the code that performs property file reading to a single class (or module called PropertyFileReader).
2_ I will create a property file reader module, that iterates across all the keys in property file(s) and then stores those information in a map.
4_ I can either create a static map objects with the populated values or create a constant class out of it. Then I will replace the logic in the property file reader module to use a get on the map or static class rather than the property file reading.
5_ Once I am sure that the application performs ok.(By checking if all my Unit Testing passes), then I will remove my property files.
Note: If you are using spring, then there is a easy way to split out all property key-value pairs from a list of property files. Let me know if you use spring.

I would recommend something else: split externalized strings into localizable and non-localizable properties files. It would be probably easier to move some strings to another file than moving it back to source code (which will hurt maintainability by the way).
Of course you can write simple (to some extent) Perl (or whatever) script which will search for calls to resource bundles and introduce constant in this place...
In other words, I haven't heard about de-externalizing mechanism, you need to do it by hand (or write some automated script yourself).

An awesome oneliner from #potong sed 's|^\([^=]*\)=\(.*\)|s#Messages.getString("\1")#"\2"#g|;s/\\/\\\\/g' messages.properties |
sed -i -f - *.java run this inside your src dir, and see the magic.