调用Java Servlet的Firebird存储程序

Question

我有一个带有一些存储过程的Firebird数据库，我正在开发Java Web/Database应用程序。我想知道是否可能以及如何从Java类或servlet调用这些存储过程。

示例：

1. 存储过程deletep，用于从数据库中删除一行
2. 我的WebApp JSP/Servlets
3. 我想创建一个执行删除存储过程的链接

Answer 1

要在Java中执行Firebird存储过程，有几种方法。JDBC默认方法将是：

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

如果可以选择Firebird存储的过程(即：包含SUSPEND并可以返回多行(，则需要执行以下操作：

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 ...
        }
    }
}

如果存储过程可执行并且不返回任何值，这就足够了。如果存储过程可执行(多个(返回列，则需要以下内容：

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
}

另外，您可以使用Firebird特定语法EXECUTE PROCEDURE yourProcedure(?, ?, ?)进行可执行的存储过程和SELECT * FROM yourProcedure(?, ?, ?)。

Answer 2

使用jaybird，firebird jdbc驱动程序。

三个步骤：

1. 创建一个dbutil java类来存储查询：

   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. 创建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. 在JSP文件中创建删除链接

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