Why would a constructor catch an exception in one class and not the other?

Question

Like I said guys, just need to know why it would catch the exception. Calling SQLUtil in the java servlet below causes the exception, but it doesn't happen in any other class I test with.

I'm working on a school project and trying to get an SQL table into a servlet that outputs html (odd, I know. I don't have much of a choice in the matter.) So to do this I used a DAO object to import and translate the information into a list. However, importing that object only seems to work in my standard java classes, not the servlet, which catches an exception. Here's all the code, sorry for any ridiculousness

The DAO, SQLUtil

package sqlUtil;
import java.sql.*;
import java.util.*;
import java.io.*;

import sqlUtil.VideoRecording;

public class SQLUtil {
private Connection myConn;
public SQLUtil() throws Exception
{
    // get db properties
            Properties props = new Properties();
            props.load(new FileInputStream("proj.properties"));

            String user = props.getProperty("user");
            String password = props.getProperty("password");
            String dburl = props.getProperty("dburl");

            // connect to database
            myConn = DriverManager.getConnection(dburl, user, password);
}
public List<VideoRecording> getAllVideos() throws Exception 
{
    List<VideoRecording> list = new ArrayList<>();
    Statement myStmt = null;
    ResultSet myRs = null;  
    try
    {
        myStmt = myConn.createStatement();
        myRs = myStmt.executeQuery("select * from Video_Recordings");
        while(myRs.next())
        {
            VideoRecording tempRecording = convertRowToVideoRecording(myRs);
            list.add(tempRecording);
        }
        return list;
    }
    finally{
        close(myStmt,myRs);
    }
}



private VideoRecording convertRowToVideoRecording(ResultSet myRs) throws SQLException
{
    int recording_id = myRs.getInt("recording_id");
    String director = myRs.getString("director");
    String title = myRs.getString("title");
    String category = myRs.getString("category");
    String image_name = myRs.getString("image_name");
    int duration = myRs.getInt("duration");
    String rating = myRs.getString("rating");
    int year_released = myRs.getInt("year_released");
    double price = myRs.getDouble("price");
    int stock_count = myRs.getInt("stock_count");
    VideoRecording tempVideo = new VideoRecording(recording_id, director, title, category, image_name, duration, rating, year_released, price, stock_count);
    return tempVideo;
}

private static void close(Connection myConn, Statement myStmt, ResultSet myRs)
        throws SQLException {

    if (myRs != null) {
        myRs.close();
    }

    if (myStmt != null) {

    }

    if (myConn != null) {
        myConn.close();
    }
}
private void close(Statement myStmt, ResultSet myRs) throws SQLException {
    close(null, myStmt, myRs);      
}

}

And the class it works in:

 package sqlUtil;
 import java.util.*;
 public class TestUtil {

/**
 * @param args
 */
public static void main(String[] args) 
{
    try{
        VideoRecording test = new VideoRecording(1, "directordave", "titletest","categorytest","imagenametest",12,"Ratingtest",1995,21.2,21);   
        System.out.println(test.getCategory());
        SQLUtil util = new SQLUtil();
        List<VideoRecording> testList = util.getAllVideos();
        System.out.println(testList.size());
        System.out.println(testList.get(0).getId());
    }
    catch(Exception exc)
    {
        System.out.println("failure");
    }

}
}

And the servlet class it doesn't work in:

@WebServlet("/videos")
public class VideoListing extends HttpServlet {
private static final long serialVersionUID = 1L;


public VideoListing() 
{
}

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    response.setContentType("text/html");  
    response.setBufferSize(1024);  
    PrintWriter out = response.getWriter();  
    try {
        SQLUtil util = new SQLUtil();
        List<VideoRecording> testList = util.getAllVideos();
        System.out.println(testList.size());
        System.out.println(testList.get(0).getId());
        out.println("<html><body>");
        out.println( "<table border='1' style='width=100%'><tr>");  
        out.println("<td>Recording ID</td>");
        out.println("<td>Director</td>");
        out.println("<td>Title</td>");
        out.println("<td>Category</td>");
        out.println("<td>Duration</td>");
        out.println("<td>Rating</td>");
        out.println("<td>Year Released</td>");
        out.println("<td>Price</td>");
        out.println("<td>Stock Count</td>");

    //For (every employee in list) print each of those as a data object in the table
        out.println("<tr>");
        //for(int i=0; i<testList.size(); i++)
        //{
        //  out.println("<td>"+testList.get(i).getId()+"</td>");
        //}
        out.println("</tr>");
        out.println("</tr></table>");
        out.println( "</body></html>"); 
    }
    catch (Exception exc)
    {
        out.println("complete failure");
    }

}

}

Thanks for any help ahead of time.

I think this is the stacktrace. It's saying the file isn't found for the properties file, but why would that only happen in the servlet, not the java class? They're all in the same project, and the properties file IS there.

java.io.FileNotFoundException: proj.properties (No such file or directory)
at java.io.FileInputStream.open(Native Method)
at java.io.FileInputStream.<init>(FileInputStream.java:146)
at java.io.FileInputStream.<init>(FileInputStream.java:101)
at sqlUtil.SQLUtil.<init>(SQLUtil.java:14)
at servlets.VideoListing.doGet(VideoListing.java:34)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:621)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
at       org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:99)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:936)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1004)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:589)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:310)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:744)

You're gonna have to elaborate on that @Tom, I have no idea what you mean by that — user3092589, Dec 18 '14 at 00:19
You wrote that you have an exception in one of your constructors. So, post that stacktrace please. — Tom, Dec 18 '14 at 00:20
Calling the constructor SQLUtil in the servlet causes the exception. In my other java classes it does not. How would I find the stacktrace in eclipse @Tom — user3092589, Dec 18 '14 at 00:22
@user3092589 In your `catch(Exception exc)` block, add `exc.printStackTrace();`. This will then print out the stack trace. — Jason, Dec 18 '14 at 00:24
`FileNotFoundException: proj.properties (No such file or directory)` .. now what do you think this means? [Read this](http://stackoverflow.com/questions/20389255/java-reading-a-resource-file-from-within-jar/20389418#20389418). — Tom, Dec 18 '14 at 00:30
Please format your source code properly. In the current form it’s hard to read and looks like a mess. — Roland Illig, Dec 18 '14 at 00:31
java.io.FileNotFoundException: proj.properties (No such file or directory) - the answer is quite clear. YOU can find the .properties file, but the class loader cannot. — duffymo, Dec 18 '14 at 00:32
@Tom I understand what that exception means, but the file is ABLE TO be found on my other class. What would the difference be? — user3092589, Dec 18 '14 at 00:33

score 2 · Answer 1 · answered Dec 18 '14 at 00:34

The answer is quite clear. YOU can find the .properties file, but the class loader cannot.

java.io.FileNotFoundException: proj.properties (No such file or directory)

You should not be loading this using a FileInputStream. You should put it in your WEB-INF/classes directory, which is in the CLASSPATH, and load it using the servlet context.

How to load property file from classpath?

score 0 · Accepted Answer · answered Dec 18 '14 at 00:32

0

When you run the program in your IDE, the code can locate the proj.properties file (because it is local), but when you run the program in your servlet container, proj.properties is either not there or not in the path or otherwise cannot be found.

answered Dec 18 '14 at 00:32

Jason

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Why would a constructor catch an exception in one class and not the other?

2 Answers2