在 Java 中调用存储过程的简单方法

Question

When call a stored procedure I use this code:

    connection = getConnection();
    stmt = connection.prepareCall("{call MPLOGIN (?, ?, ?, ?, ?, ?)}");
    stmt.setString("VUSCD", uscd);
    stmt.setString("VPWD", pwd);
    stmt.setString("VPCSQ", pcsq);
    stmt.setString("VHWID", hwid);
    stmt.registerOutParameter("VLOGID", OracleTypes.VARCHAR);
    stmt.registerOutParameter("VKQ", OracleTypes.VARCHAR);
    stmt.execute();
    String vlogid = stmt.getString("VLOGID");
    String vkq = stmt.getString("VKQ");

write this boring wrapper for few procedure is not problem but if there are hundreds of procedure, it is really a nightmare Is there any easier way to call store procedure than this way? Edit: I think a code generator which use the procedure's parameters from DB is the elagant way but I google for nothing in java

Answer 1

You could, maybe create a generic wrapper, something along these lines:

public Map<String, String> SPWrapper(String call, Map<String, String> inParams, Map<String, OracleTypes> outParams)
{
    connection = getConnection();
    try 
    {
        stmt = connection.prepareCall(call);
        for(String inParam : inParams.keys())
        {
            stmt.setString(inParam, inParams.get(inParam));
        }
        for(String outParam : outParams.keys())
        {
            stmt.registerOutParameter(outParam, outParams.get(outParam));
        }

        stmt.execute();

        Map<String,String> results = new HashMap<String, String>();
        for(String outParam : outParams.keys())
        {
            results.put(outParam, stmt.getString(outParam));
        }

        return results;
    }
    catch (Exception e)
    {
        //LOG Exception
        return new HashMap<String, String>();
    }
    finally
    {
        connection.close();   //Do not leave connections open.
    }
}

You would still need to pass in the call and declare the variables, but at least you now have one generic wrapper to handle all your calls.

Answer 2

I like to use the MyBatis data mapper framework for such problems. An extensive example for working with MyBatis and stored procedures can be found at http://loianegroner.com/2011/03/ibatis-mybatis-working-with-stored-procedures/

Answer 3

There isn't any other way. Yes, it is boring, but number of procedures is finite. This procedures are like methods in Java, so you should operate with them in prescribed rules. Only one convenient thing you could do - create special class, which will contain wrapped methods for each procedure. In this case it will be more elegantly to call them in business code, something like this:

String[] result = DAO.MPLOGIN(uscd, pwd, pcsq, hwid);

But inside this method you have to copy code, that you mentioned above.

Answer 4

In database client a stored procedure such as myproc(10,20) is called just by statement select myproc(10,20);

So in your JDBC program you can just do : connection = getConnection(); stmt = connection.createStatement(); stmt.executeQuery("select myproc(10,20)");

If procedure is returning something then put it in a ResultSet

Answer 5

jOOQ includes a code generator that generates stubs for all of your PL/SQL packages, types, procedures, functions . In your case, you could avoid the boring boiler plate code by calling this stub, instead:

Mplogin result = Routines.mplogin(
    configuration, // This contains your JDBC connection
    uscd, pwd, pcsq, hwid
);

String vlogid = result.getVlogid();
String vkq = result.getVkq();

Disclaimer: I work for the company behind jOOQ.