Unreported exception java.sql.SQLException; must be caught or declared to be thrown?

Question

I got this error while trying to compile the below code. I would like to know what is I have done wrong.

unreported exception java.sql.SQLException; must be caught or declared to be thrown
 Class.forName(myDriver);

               ^

private void setupInfo() {

    Driver driver = new org.gjt.mm.mysql.Driver();
    String url = "jdbc:mysql://localhost:3306/test";
    String username = "root";
    String password = "123456";

    String problemFeatureSpecTableName = "ProblemFeatureSpec";
    String solutionFeatureSpectTableName = "SolutionFeatureSpec";
    String classTableName = "Class";
    String extraDataTableName = "ExtraData";
    String casebaseTablename = "CaseBase";
    String problemTableName = "Problem";
    String solutionTableName = "Solution";
    String inactiveContextsTableName = "InactiveContext";
    String constantsTableName = "Constants";
    dbInfo = new DBInfo(new JDBCDriverInfo(driverName, url, username, password),constantsTableName);
    problemSpecInfo = new FeatureSpecRDBInfo(problemFeatureSpecTableName, classTableName, extraDataTableName);
    solutionSpecInfo = new FeatureSpecRDBInfo(solutionFeatureSpectTableName, classTableName, extraDataTableName);
    rdbCasebaseInfo = new RDBCaseBaseInfo(casebaseTablename, solutionTableName, problemTableName, inactiveContextsTableName);
}

You're reading outdated MySQL JDBC tutorials/examples. The [MM driver](http://mmmysql.sourceforge.net/old-index.html) has been taken over by MySQL over 8 years ago and is since then known as [Connector/J](http://dev.mysql.com/downloads/connector/j/) with `com.mysql.jdbc.Driver`. The MM driver classname is only retained for backwards compatibility, but you should really be using `com.mysql.jdbc.Driver`. Your compilation error does by the way not match with the posted source code. You aren't using `Class#forName()` anywhere in the source. Even more, it doesn't throw `SQLException` at all. — BalusC, Dec 16 '10 at 04:23

score 13 · Accepted Answer · answered Dec 16 '10 at 04:13

13

You either need to catch the exception in your method:

public void setupInfo()
{
    try
    {
        // call methods that might throw SQLException
    }
    catch (SQLException e)
    {
        // do something appropriate with the exception, *at least*:
        e.printStackTrace();
    }
}

Or declare the method to throw SQLException:

private void setupInfo() throws SQLException
{
    // call methods that might throw SQLException
}

answered Dec 16 '10 at 04:13

Matt Ball

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Could you add an short explanation of what those do? – Anubian Noob Jun 14 '14 at 20:33
@AnubianNoob it's pretty fundamental Java. http://docs.oracle.com/javase/tutorial/essential/exceptions/catchOrDeclare.html – Matt Ball Jun 14 '14 at 20:35
I know how it works, but it would make the answer clearer. EDIT: Oh, I didn't realize this was from 2010, sorry... – Anubian Noob Jun 14 '14 at 20:36

score 2 · Answer 2 · edited Dec 16 '10 at 04:34

2

Catch the exception or throw it. Better use an IDE (Eclipse or Netbeans), which will tell you the error the moment you press enter.

edited Dec 16 '10 at 04:34

BalusC

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answered Dec 16 '10 at 04:20

Pakka Techie

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score 1 · Answer 3 · answered Dec 16 '10 at 04:14

This line of code throws an uncaught exception:

Driver driver = new org.gjt.mm.mysql.Driver();

try this:

try {
   Driver driver = new org.gjt.mm.mysql.Driver();
}
catch (java.sql.SQLException e) {
  // you may want to do something useful here
 // maybe even throw new RuntimException();
}

score 0 · Answer 4 · answered Dec 16 '10 at 04:21

0

Always try to get help from your IDE. IDEs can often fix the error automatically. Press alt+enter in IntelliJ IDEA or ctrl+1 in Eclipse and choose to fix the error.

answered Dec 16 '10 at 04:21

Nowaker

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Unfortunately (IMO) the typical correction for this error is to catch the exception, print a stacktrace to stderr and continue as if nothing had happened. It is generally not the right thing to do. – Stephen C Dec 16 '10 at 05:32
Usually there are two options - catch or throws. – Nowaker Dec 16 '10 at 13:43

Unreported exception java.sql.SQLException; must be caught or declared to be thrown?

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