In Java, properties file is always used to store the configuration data or settings. In this example we will show you how to read and write to/from a properties file.
1. Example 1
In this example, set the property value and write it into a properties file named “config.properties“. The new saved properties file will be stored at your project root folder.
package com.mkyong.common;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.Properties;
public class App {
public static void main( String[] args )
{
Properties prop = new Properties();
try {
//set the properties value
prop.setProperty("database", "localhost");
prop.setProperty("dbuser", "mkyong");
prop.setProperty("dbpassword", "password");
//save properties to project root folder
prop.store(new FileOutputStream("config.properties"), null);
} catch (IOException ex) {
ex.printStackTrace();
}
}
}
Output – The content of the file “config.properties”
#Mon Jan 11 18:54:40 MYT 2010
dbpassword=password
database=localhost
dbuser=mkyong
2. Example 2
In this 2nd example, load a properties file named “config.properties” and retrieved the saved property value.
package com.mkyong.common;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.Properties;
public class App {
public static void main( String[] args )
{
Properties prop = new Properties();
try {
//load a properties file
prop.load(new FileInputStream("config.properties"));
//get the property value and print it out
System.out.println(prop.getProperty("database"));
System.out.println(prop.getProperty("dbuser"));
System.out.println(prop.getProperty("dbpassword"));
} catch (IOException ex) {
ex.printStackTrace();
}
}
}
Output
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Silence, the way to avoid many problems;
Smile, the way to solve many problems;