I am new to this technology. I have a text file called condition.txt which looks like this
server_state running
health_state ok
heappercent 20%
hoggingthreadcount 10
stuckthreadcount 1
I have a java file, here I want to read those data from the file and want to access those values. like in my java file I have a String variable called server_state. I want to put the value "running" in my String variable. How?
It sounds like you want to read from a file? The Scanner class is very good for that.
You will have to format your text document in a different way, which means if you are programmatically writing the file, you need to split the 2 variables somehow. In my opinion, a comma (,) or a colon (:) are the easiest things to choose.
stuckthreadcount:1
public void getProps() {
String[] cur = new String[2];
Scanner scanner = new Scanner("C:\Path/To/Your/File.txt");
while(scanner.hasNextLine()) {
cur = scanner.nextLine().split(":"); // a colon is simpler.
if(cur[0].equalsIgnoreCase("server_state")) {
server_state = cur[1];
}
if(cur[0].equalsIgnoreCase("health_state")) {
health_state = cur[1];
}
if(cur[0].equalsIgnoreCase("heappercent")) {
heappercent = Double.parseDouble(cur[1]);
}
if(cur[0].equalsIgnoreCase("hoggingthreadcount")) {
hoggingthreadcount = Integer.parseInt(cur[1]);
}
if(cur[0].equalsIgnoreCase("stuckthreadcount")) {
stuckthreadcount = Integer.parseInt(cur[1]);
}
}
scanner.close();
}
I hope this solves your problem!
Jarod.
i did something similar but to read sting and integer from CSV file, the concept exactly the same
public static Countries[] readObjects() throws IOException
{
BufferedReader br = new BufferedReader(new FileReader("d:\\countries.txt"));
String line = "";
Countries[] countriesArray = new Countries[32];
int arrayIndex = 0;
/***
* Read File line by line and parse every line to Countries object and insert it into the array
*/
while ((line = br.readLine()) != null) {
/***
* Create Country object from the line
*/
Countries country = createCountryObect(line);
countriesArray[arrayIndex] = country;
arrayIndex++;
}
br.close();
return countriesArray;
}
/***
* Read string and parse it into an object
* @param line from the file
* @return Countries Object
*/
public static Countries createCountryObect(String line)
{
Countries country = new Countries();
StringTokenizer st = new StringTokenizer(line," ");
while(st.hasMoreElements())
{
country.countryName = st.nextElement().toString();
//convert country population from string to integer
country.countryPopulation = Integer.parseInt(st.nextElement().toString());
}
return country;
}
and the countries class
public class Countries {
public String countryName;
public int countryPopulation;
}
Here is a similar program I needed to write for work:
public class LogReader {
public static void main(String[] args) throws IOException
{
mapper("workId=\"1915900093138425722");
}
public static void mapper(String id) throws IOException
{
String sepText = "";
FileWriter fileWriter;
BufferedReader br = new BufferedReader(new FileReader(new File("Work.txt")));
String line = "";
while ((line = br.readLine()) != null)
{
System.out.print(line);
sepText += line.substring(0, 23) + "\n";
int startAttIdMarker = line.indexOf(id);
int midAttIdMarker = line.indexOf('"', startAttIdMarker + 1);
int endAttIdMarker = line.indexOf('"', midAttIdMarker + 1 );
sepText += "attributeSetId = " + line.substring(midAttIdMarker + 1 , endAttIdMarker) + "\n" + "\n";
sepText += "********************************************" + "\n";
}
br.close();
File newTextFile = new File("worker.txt");
fileWriter = new FileWriter(newTextFile);
fileWriter.write(sepText);
fileWriter.close();
}
}
You feed a string to the function mapper and it searches for all lines with that string. It then writes those lines to a string which is in turn written to a file of it's own.
Best thing to do is play around with some sample code like this and see what happens.
