JAVA: Can't get context parameters in Filter
I have a filter and parameters in web.xml

web.xml is like this:

    	<filter>
		<description>
		</description>
		<display-name>AllClassFilter</display-name>
		<filter-name>AllClassFilter</filter-name>
		<filter-class>com.datval.homework.AllClassFilter</filter-class>
		<init-param>
			<param-name>DB_URL</param-name>
			<param-value>jdbc:derby:C:/Users/admin/workspace/homework03/homework/databases/StudentsDB;create=true</param-value>
		</init-param>
		<init-param>
			<param-name>DB_DIALECT</param-name>
			<param-value>org.hibernate.dialect.DerbyDialect</param-value>
		</init-param>
		<init-param>
			<param-name>DB_DRIVER</param-name>
			<param-value>org.apache.derby.jdbc.EmbeddedDriver</param-value>
		</init-param>
	</filter>


mapping is working well. 
But I can't get this parameters in my filter.

    	public void init(FilterConfig config) throws ServletException {
		// TODO Auto-generated method stub
		debugMessage = config.getInitParameter("debugMessage");
		ctx = config.getServletContext();
	}
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
		// TODO Auto-generated method stub
		// place your code here

		ctx.log("Start - " + debugMessage);
		String myDbUrl =  ctx.getInitParameter("DB_URL");
		String DB_DIALECT = ctx.getInitParameter("DB_DIALECT");
		String DB_DRIVER = ctx.getInitParameter("DB_DRIVER");

		Map<String,String> pr = new HashMap<String,String>();
		pr.put("hibernate.connection.url", myDbUrl);
		pr.put("hibernate.dialect", DB_DIALECT);
		pr.put("hibernate.connection.driver_class", DB_DRIVER);
		
		EntityManagerFactory emf = Persistence.createEntityManagerFactory("students",pr);
		EntityManager em = emf.createEntityManager();
		request.setAttribute("em", em);
		chain.doFilter(request, response);
		em.close();
		ctx.log("end - " + debugMessage);
	}


I have checked and myDbUrl is null. What I'm doing wrong? Any idea?
Sorry about code, I will change it later :)
JAVA: Can't get context parameters in Filter
===

I have a filter and parameters in web.xml

web.xml is like this:

    	<filter>
		<description>
		</description>
		<display-name>AllClassFilter</display-name>
		<filter-name>AllClassFilter</filter-name>
		<filter-class>com.datval.homework.AllClassFilter</filter-class>
		<init-param>
			<param-name>DB_URL</param-name>
			<param-value>jdbc:derby:C:/Users/admin/workspace/homework03/homework/databases/StudentsDB;create=true</param-value>
		</init-param>
		<init-param>
			<param-name>DB_DIALECT</param-name>
			<param-value>org.hibernate.dialect.DerbyDialect</param-value>
		</init-param>
		<init-param>
			<param-name>DB_DRIVER</param-name>
			<param-value>org.apache.derby.jdbc.EmbeddedDriver</param-value>
		</init-param>
	</filter>


mapping is working well. 
But I can't get this parameters in my filter.

    	public void init(FilterConfig config) throws ServletException {
		// TODO Auto-generated method stub
		debugMessage = config.getInitParameter("debugMessage");
		ctx = config.getServletContext();
	}
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
		// TODO Auto-generated method stub
		// place your code here

		ctx.log("Start - " + debugMessage);
		String myDbUrl =  ctx.getInitParameter("DB_URL");
		String DB_DIALECT = ctx.getInitParameter("DB_DIALECT");
		String DB_DRIVER = ctx.getInitParameter("DB_DRIVER");

		Map<String,String> pr = new HashMap<String,String>();
		pr.put("hibernate.connection.url", myDbUrl);
		pr.put("hibernate.dialect", DB_DIALECT);
		pr.put("hibernate.connection.driver_class", DB_DRIVER);
		
		EntityManagerFactory emf = Persistence.createEntityManagerFactory("students",pr);
		EntityManager em = emf.createEntityManager();
		request.setAttribute("em", em);
		chain.doFilter(request, response);
		em.close();
		ctx.log("end - " + debugMessage);
	}


I have checked and myDbUrl is null. What I'm doing wrong? Any idea?
Sorry about code, I will change it later :)