Exception error everywhere in JSP

Question

          I've wrote a JSP to access SQL Server database in J2SE sucessfully, but when
          I try that on a different server using Java 1.1 I get the same type of
          errors complaining about
          "the method " blah blah blah" can throw the checked exception
          "java/lang/ClassNotFoundException", but its invocation is neither enclosed
          in a try statement that can catch that exception nor in the body of a method
          or constructor that "throws" that exception."
          this is another sample of my errors
          31. Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
          <------------------------------------------->
          *** Error: The method "java.lang.Class forName(java.lang.String $1);" can
          throw the checked exception "java/lang/ClassNotFoundException", but its
          invocation is neither enclosed in a try statement that can catch that
          exception nor in the body of a method or constructor that "throws" that
          exception.
          33. Connection con=DriverManager.getConnection(url, "ema", "ema");
          <-------------------------------------------->
          *** Error: The method "java.sql.Connection getConnection(java.lang.String
          $1, java.lang.String $2, java.lang.String $3);" can throw the checked
          exception "java/sql/SQLException", but its invocation is neither enclosed in
          a try statement that can catch that exception nor in the body of a method or
          constructor that "throws" that exception.
          Am I missing some libraries or calling the method incorrectly because of the
          version of Java was older?
          Here I also attached my code
          <%
          //connection and query
          Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
          String url="jdbc:odbc:DB";
          Connection con=DriverManager.getConnection(url, "sa", "password");
          PreparedStatement query = con.prepareStatement("select Quarter, Month,
          WeekDay, statusCode, Responded, CNT from REQUEST",
          ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_UPDATABLE);
          ResultSet rs = query.executeQuery();
          rs.last();
          int numrows = rs.getRow();
          rs.beforeFirst();
          %>
          Thanks in advanced
          Ku
          

Answer 1

The compiler is telling you that you must handle all possible thrown
          exceptions
          example:
          try
               Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
          catch (ClassNotFoundException anCNFExcp)
               //Error page telling of error
          try
               Connection con=DriverManager.getConnection(url, "ema", "ema");
          catch (java.sql.SQLException anSQLExcp)
               //Error Page Telling Of error
          you must check each method's signiture that you are calling and handle
          the exceptions that it throws, a simpler way would be to handle the
          whole block of code with a generic handler if you don't care what
          piece of that code blows up
          ex.
          try
               Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
               String url="jdbc:odbc:DB";
               Connection con=
                    DriverManager.getConnection(url, "sa","password");
               PreparedStatement query =
                    con.prepareStatement("select Quarter, Month,
               WeekDay, statusCode, Responded, CNT from REQUEST",
               ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_UPDATABLE);
               ResultSet rs = query.executeQuery();
               rs.last();
               int numrows = rs.getRow();
               rs.beforeFirst();
          catch (Exception anEx)
               //Error Page
          or nest the exceptions to find the specific
          catch (ClassNotFoundException aCNFExcp)
               //Display warning that driver could not be loaded
          catch (SQLException anSQLExcp)
               //display warning that SQL statements blew up
          catch (Exception anEx)
               //display warning that another error occured
          Don Stacy
          On 2 Nov 2001 15:24:05 -0800, "ku916" <[email protected]> wrote:
          >
          >I've wrote a JSP to access SQL Server database in J2SE sucessfully, but when
          >I try that on a different server using Java 1.1 I get the same type of
          >errors complaining about
          >
          >"the method " blah blah blah" can throw the checked exception
          >"java/lang/ClassNotFoundException", but its invocation is neither enclosed
          >in a try statement that can catch that exception nor in the body of a method
          >or constructor that "throws" that exception."
          >
          >this is another sample of my errors
          >
          > 31. Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
          > <------------------------------------------->
          >*** Error: The method "java.lang.Class forName(java.lang.String $1);" can
          >throw the checked exception "java/lang/ClassNotFoundException", but its
          >invocation is neither enclosed in a try statement that can catch that
          >exception nor in the body of a method or constructor that "throws" that
          >exception.
          >
          >
          > 33. Connection con=DriverManager.getConnection(url, "ema", "ema");
          > <-------------------------------------------->
          >*** Error: The method "java.sql.Connection getConnection(java.lang.String
          >$1, java.lang.String $2, java.lang.String $3);" can throw the checked
          >exception "java/sql/SQLException", but its invocation is neither enclosed in
          >a try statement that can catch that exception nor in the body of a method or
          >constructor that "throws" that exception.
          >
          >Am I missing some libraries or calling the method incorrectly because of the
          >version of Java was older?
          >
          >Here I also attached my code
          ><%
          >//connection and query
          >Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
          >String url="jdbc:odbc:DB";
          >Connection con=DriverManager.getConnection(url, "sa", "password");
          >
          >PreparedStatement query = con.prepareStatement("select Quarter, Month,
          >WeekDay, statusCode, Responded, CNT from REQUEST",
          >ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_UPDATABLE);
          >ResultSet rs = query.executeQuery();
          >
          >
          >rs.last();
          >int numrows = rs.getRow();
          >rs.beforeFirst();
          >
          >%>
          >
          >Thanks in advanced
          >Ku