从Java Servlet调用Firebird存储过程

Question

I have a Firebird Database with some stored procedure, and I am developing a Java web/database application. I want to know if it is possible and how to call those stored procedures from a java Class or a Servlet.

example:

1. Stored procedure deletep , used to delete a row from database
2. my webapp Jsp/servlets
3. I want to create a link that execute my delete stored procedure

Answer 1

To execute a Firebird stored procedure in Java, there are several ways. The JDBC-default method would be something like:

try (CallableStatement cstmt = connection.prepareStatement(
        "{call yourProcedure(?, ?, ?)}")) {
    cstmt.setString(1, "value1");
    cstmt.setString(2, "value2");
    cstmt.setString(3, "value3");
    cstmt.execute();
}

If the Firebird stored procedure was selectable (that is: contains SUSPEND and can return multiple rows), you would need to do something like:

try (CallableStatement cstmt = connection.prepareStatement(
        "{call yourProcedure(?, ?, ?)}")) {
    cstmt.setString(1, "value1");
    cstmt.setString(2, "value2");
    cstmt.setString(3, "value3");
    try (ResultSet rs = cstmt.executeQuery()) {
        while(rs.next()) {
            // do something with result set rows ...
        }
    }
}

This is sufficient if the stored procedure is executable and doesn't return any values. If the stored procedure is executable with (multiple) return columns, you'd need to something like:

try (CallableStatement cstmt = connection.prepareStatement(
        "{call yourProcedure(?, ?, ?, ?, ?)}")) {
    cstmt.setString(1, "value1");
    cstmt.setString(2, "value2");
    cstmt.setString(3, "value3");
    cstmt.registerOutParameter(4, Types.VARCHAR);
    cstmt.registerOutParameter(5, Types.VARCHAR)
    cstmt.execute();

    String out1 = cstmt.getString(4);
    String out2 = cstmt.getString(5);
    // do something with result
}

Alternatively, you could use the Firebird specific syntax EXECUTE PROCEDURE yourProcedure(?, ?, ?) for executable stored procedures and SELECT * FROM yourProcedure(?, ?, ?) .

Answer 2

This is possible using Jaybird, the Firebird JDBC driver.

Three steps:

1. Create a DBUtil java class to stock the query :

    public static void deletePlan(Connection conn, CallableStatement statement, String code, String rev, String mention) throws SQLException { statement.setString(1, code); statement.setString(2, rev); statement.setString(3, mention); statement.execute(); } 

2. Create the delete servlet

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { Connection conn = MyUtils.getStoredConnection(request); String code = request.getParameter("code"); String rev = request.getParameter("revision"); String mention = request.getParameter("mention"); CallableStatement statement = null; try { statement = conn.prepareCall("execute procedure DELETEP(?,?,?)"); } catch (SQLException e1) { // TODO Auto-generated catch block e1.printStackTrace(); } String errorString = null; try { DBUtils.deletePlan(conn, statement, code, rev, mention); } catch (SQLException e) { e.printStackTrace(); errorString = e.getMessage(); } ......... 

3. Create the delete link in the jsp file

    <a href="${pageContext.request.contextPath}/deletePlan code=${plan.code}&revision=${plan.revision}&mention=${plan.mention}">Delete</a>