loading properties file in init() of servlet without using context-param tag in web.xml [duplicate]

Answer 1

Given that fileName is /WEB-INF/classes/myapp.properties, you need to get it as a webapp resource, not as a local disk file system file.

So, replace

String fileName = config.getInitParameter("configFile");
System.out.println(fileName);
File file = new File(fileName);
FileInputStream fis = new FileInputStream(file);
p = new Properties();
p.load(fis);

by

String fileName = config.getInitParameter("configFile");
InputStream input = config.getServletContext().getResourceAsStream(fileName);
p = new Properties();
p.load(input);

A simpler way is to set the fileName to myapp.properties and get it as a classpath resource.

String fileName = config.getInitParameter("configFile");
InputStream input = Thread.currentThread().getContextClassLoader().getResourceAsStream(fileName);
p = new Properties();
p.load(input);

See also:

• getResourceAsStream() vs FileInputStream
• Where to place and how to read configuration resource files in servlet based application?

Answer 2

import java.io.IOException;
import java.io.PrintWriter;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Properties;
import javax.servlet.ServletConfig;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.log4j.Logger;
@WebServlet("/Propertyloader")
public class Propertyloader extends HttpServlet 
{
    private static final long serialVersionUID = 1L;


    public static Logger logger;
    public static Properties props=new Properties();
    public Propertyloader() 
    {
        super();
    }

    public void init(ServletConfig sconfig)
    {   
        try
        {   
            logger = Logger.getLogger(Propertyloader.class.getName());
            props.load(Propertyloader.class.getClassLoader().getResourceAsStream("books.properties"));
}

Answer 3

I don't know how you set your web.xml, it should be ok as this:

<servlet>
    <servlet-name>MyServletName</servlet-name>
    <servlet-class>com.mycompany.MyServlet</servlet-class>

    <init-param>
        <param-name> param1 </param-name>
        <param-value> value1 </param-value>
    </init-param>
    <init-param>
        <param-name> param2 </param-name>
        <param-value> value2 </param-value>
    </init-param>
    ...
</servlet>

and as in your code, you didn't use absolute path, so this file will be found in classes directory, you should make sure this file exist in WEB-INF/classes dir.

Answer 4

Problem is not with init param setting. Problem is how you are accessing the file. Make sure you have a config file in your class path, e.g. under Web-Inf directory; then change your code to access file like

InputStream is = getClass().getResourceAsStream(fileName);        
p = new Properties();                                       
p.load(is);