How to read values from configuration properties file in java

How to read values from configuration properties file in java

For example, I will create 3 files.

1. main.properties file: .properties is a file extension for files mainly used in Java related technologies to store the configurable parameters of an application. Each parameter is stored as a pair of strings, one storing the name of the parameter (called the key/map), and the other storing the value.

2. GetPropertyValues.java: This java file will have implementation to get property values from property file.

3. ReadConfigMain.java: This java file will have main method and will use to call method of GetPropertyValues class.

Step 1: Create main.properties file

1. If you have spring project, create main.properties file under src/main/resources. Else, create Folder “resources” under Java Resources folder if your project doesn’t have it and than create main.properties file under /Java Resources/resources/.

2. Create main.properties file as given below:

main.propertis file content:

queue_name=QUEUE

queue_manager=QM

queue_hostname=localhost

queue_port=1414

Step 2: Create ReadConfigMain java class

package engineernitesh.blogspot.com;

import java.io.IOException;

public class ReadConfigMain {

public static void main(String[] args) throws IOException {

GetPropertyValues properties = new GetPropertyValues();

properties.getPropValues();

}

}

Step 3: Create GetPropertyValues java class

package engineernitesh.blogspot.com;

import java.io.FileNotFoundException;

import java.io.IOException;

import java.io.InputStream;

import java.util.Date;

import java.util.Properties;

public class GetPropertyValues {

String result = "";

InputStream inputStream;

public String getPropValues() throws IOException {

try {

Properties prop = new Properties();

String propFileName = "main.properties";

inputStream = getClass().getClassLoader().getResourceAsStream(propFileName);

if (inputStream != null) {

prop.load(inputStream);

} else {

throw new FileNotFoundException("property file '" + propFileName + "' not found in the classpath");

}

// get the property value and print it out

String queue_name = prop.getProperty("queue_name");

String queue_manager = prop.getProperty("queue_manager");

String queue_hostname = prop.getProperty("queue_hostname");

String queue_port = prop.getProperty("queue_port");

result = queue_hostname+":" + queue_port + "\ " + queue_manager + "\ " + queue_name;

System.out.println("result: "+result);

} catch (Exception e) {

System.out.println("Exception: " + e);

} finally {

inputStream.close();

}

return result;

}

}