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Java read json file from another jar

so Im trying to develop a "module/addon" system and I want to read a "module.json" file from all modules/addons loaded in a direcory. So I got the part with looping through the files and stuff. But I dont know how I can access that "module.json" file.
Here is what I tried:
try {
for (File file : this.modulesDir.listFiles()) {
if(file.getName().endsWith(".jar")) {
InputStream stream = new URLClassLoader(new URL[]{file.toURL()}).getResourceAsStream("./module.json");
BufferedReader reader = new BufferedReader(new InputStreamReader(stream));
StringBuilder builder = new StringBuilder();
while((builder.append(reader.readLine())) != null);
reader.close();
stream.close();
System.out.println(builder.toString());
}
}
} catch (IOException e) {
e.printStackTrace();
}

Alright! I fixed it by changeing the path of the file to module.json instead of /module.json
Heres the code:
try {
for (File file : this.modulesDir.listFiles()) {
if(file.getName().endsWith(".jar")) {
InputStream stream = new URLClassLoader(new URL[]{file.toURL()}).getResourceAsStream("module.json");
BufferedReader reader = new BufferedReader(new InputStreamReader(stream));
StringBuilder builder = new StringBuilder();
String line;
while((line = reader.readLine()) != null) {
builder.append(line);
}
System.out.println(builder.toString());
}
}
} catch (IOException e) {
e.printStackTrace();
}

Opening a file from internal storage on Android Studio from a class that doesn't extend AppCompatActivity

Is it possible to read a file from internal storage in a utility class that doesn't extend anything? I have the code below to read a file, but I can't use the openFileInput method because it doesn't exist. Is there something I have to import to read these files?
private String readFromFile(String fileName) {
FileInputStream fis = null;
try {
fis = openFileInput("Links"); // this doesn't compile in a utility class
InputStreamReader isr = new InputStreamReader(fis);
BufferedReader bufferedReader = new BufferedReader(isr);
StringBuilder sb = new StringBuilder();
String line;
while ((line = bufferedReader.readLine()) != null) {
sb.append(line);
}
return String.valueOf(sb);
} catch (IOException e) {
e.printStackTrace();
}
return null;
}

Sonar: visitFile(): How to get the source code file

I'm implementing custom script rule plugin for Sonar.
I want to make a checking rule directly for the source code
and not from checking tokens or nodes of the ASTtree.
Having the follow code:
#Override
public void visitFile() {
BufferedReader br = null;
File file = null;
String line = null;
try {
file = this.getSourceCode().getFile();
br = new BufferedReader(new FileReader(file));
while ((line = br.readLine()) != null) {
...
}
}
br.close();
} catch (IOException e) {
e.printStackTrace();
}
}
My problem is that the :
this.getSourceCode().getFile();
returns back null
how can I get the instance of the file for which was actually the visitFile() called?
How does 'visitFile()' works actually?

String and Text File Match Very basic

So i have recently dove head first into java trying to learn lots of things. Recently i have been studying File Writers and Reader and Buffered Writers and Readers. I have recently came to a haul though every time i turn on the application the text file is modified agian. Is there a way that my text file can update every time i change a string. So basically it will read the file on boot and compare it to the string.
Here is my example of reading a text file and turning it into a string
private void Read() {
try(BufferedReader br = new BufferedReader(new FileReader(version))) {
String sCurrentLine;
while((sCurrentLine = br.readLine()) != null) {
System.out.println(sCurrentLine);
}
} catch(IOException e) {
e.printStackTrace();
}
}
All i need to do is it to compare this string with another. Thank you for your time.
** Update**
So i compared the two threads and now nothing is being written to the text file
private void Update() {
try {
fw= new FileWriter(version.getAbsoluteFile());
bw = new BufferedWriter(fw);
try(BufferedReader br = new BufferedReader(new FileReader(version))) {
String sCurrentLine;
while((sCurrentLine = br.readLine()) != null) {
if(!sCurrentLine.equals(VanoEngine.TITLE)) {
bw.write(VanoEngine.TITLE);
}
}
} catch(IOException e) {
e.printStackTrace();
}
}
catch(IOException e) {
e.printStackTrace();
}
}
** Update**
Closed the stream #JavaNoob and still nothing is being written
private void Update() {
try {
fw= new FileWriter(version.getAbsoluteFile());
bw = new BufferedWriter(fw);
try(BufferedReader br = new BufferedReader(new FileReader(version))) {
String sCurrentLine;
while((sCurrentLine = br.readLine()) != null) {
if(!sCurrentLine.equals(VanoEngine.TITLE)) {
bw.write(VanoEngine.TITLE);
}
}
bw.close();
} catch(IOException e) {
e.printStackTrace();
}
}
catch(IOException e) {
e.printStackTrace();
}
}

if(!sCurrentLine.equals(someInputString))
//write `someInputString` to file, because it differs with the one read from file

you can use sCurrentLine.equals("your string").

Reading different file one after another using BufferedReader in Java

I am using BufferedReader to read file in java.
Following is the code snippet:
String line;
br = new BufferedReader(new FileReader("file1.txt"));
while ((line = br.readLine()) != null) {
System.out.println(line);
}
//Here I want to open file named "file2.txt".
As mentioned in the code snipped above, i want to now open a new file.
What is the best way to do so ?
Should i first close br using br.close, and then again initialise br or what ?
P.S.: I am new to Java.

Creating a method will make your code modular and easy to use. This will lead to re-usability of code and ease of understanding. Here is the sample code:
public static void main(String args[]) {
readFile("C:\\sample.txt");
}
public static void readFile(String filename) {
BufferedReader br = null;
try {
String sCurrentLine;
br = new BufferedReader(new FileReader(filename));
while ((sCurrentLine = br.readLine()) != null) {
System.out.println(sCurrentLine);
}
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
if (br != null)br.close();
} catch (IOException ex) {
ex.printStackTrace();
}
}
}

I would make a method and call it twice
void readFile(String fileName) throws IOException {
try (BufferedReader br = new BufferedReader(new FileReader(fileName))) {
...
}
}
note that BufferedReader instance br will be closed automatically and make sure that you are using JDK 7 for this

File I/O operations internally use Decorator pattern. So, .close() on the outermost object should close all internal I/Os

Yes, close it first, but use this pattern ...
BufferedReader br = null;
String line;
try {
br = new BufferedReader(new FileReader("file1.txt"));
while ((line = br.readLine()) != null) {
System.out.println(line);
}
}
finally {
if (br != null) br.close();
}
//Here I want to open file named "file2.txt".
Or, the try-with-resources approach (semantically equivalent to the above) ...
String line;
try (BufferedReader br = new BufferedReader(new FileReader("file1.txt")) {
while ((line = br.readLine()) != null) {
System.out.println(line);
}
}
//Here I want to open file named "file2.txt".