/*

* Copyright (c) 2004-2020 Tada AB and other contributors, as listed below.

*

* All rights reserved. This program and the accompanying materials

* are made available under the terms of the The BSD 3-Clause License

* which accompanies this distribution, and is available at

* http://opensource.org/licenses/BSD-3-Clause

*

* Contributors:

* Tada AB

* Filip Hrbek

* Chapman Flack

*/

package org.postgresql.pljava.example;

import java.lang.reflect.InvocationTargetException;

import java.lang.reflect.Method;

import java.sql.Connection;

import java.sql.DatabaseMetaData;

import java.sql.DriverManager;

import java.sql.ResultSet;

import java.sql.SQLException;

import java.util.ArrayList;

import java.util.Arrays;

import java.util.Comparator;

import java.util.logging.Logger;

import org.postgresql.pljava.ResultSetProvider;

/**

* Example returning (varchar,int) rows, one for each int-valued

* attribute in the JDBC {@link DatabaseMetaData}.

* @author Filip Hrbek

*/

public class MetaDataInts implements ResultSetProvider {

public static ResultSetProvider getDatabaseMetaDataInts()

throws SQLException {

try {

return new MetaDataInts();

} catch (SQLException e) {

throw new SQLException("Error reading DatabaseMetaData",

e.getMessage());

}

}

String[] methodNames;

Integer[] methodResults;

public MetaDataInts() throws SQLException {

Logger log = Logger.getAnonymousLogger();

class MethodComparator implements Comparator<Method> {

@Override

public int compare(Method a, Method b) {

return a.getName().compareTo(b.getName());

}

}

Connection conn = DriverManager

.getConnection("jdbc:default:connection");

DatabaseMetaData md = conn.getMetaData();

Method[] m = DatabaseMetaData.class.getMethods();

Arrays.sort(m, new MethodComparator());

Class<?> prototype[];

Class<?> returntype;

Object[] args = new Object[0];

Integer result = null;

ArrayList<String> mn = new ArrayList<>();

ArrayList<Integer> mr = new ArrayList<>();

for (int i = 0; i < m.length; i++) {

prototype = m[i].getParameterTypes();

if (prototype.length > 0)

continue;

returntype = m[i].getReturnType();

if (!returntype.equals(int.class))

continue;

try {

result = (Integer) m[i].invoke(md, args);

} catch (InvocationTargetException e) {

log.info("Method: " + m[i].getName() + " => "

+ e.getTargetException().getMessage());

result = -1;

} catch (Exception e) {

log.info("Method: " + m[i].getName() + " => " + e.getMessage());

result = -1;

}

mn.add(m[i].getName());

mr.add(result);

}

methodNames = mn.toArray(new String[mn.size()]);

methodResults = mr.toArray(new Integer[mr.size()]);

}

@Override

public boolean assignRowValues(ResultSet receiver, int currentRow)

throws SQLException {

if (currentRow < methodNames.length) {

receiver.updateString(1, methodNames[currentRow]);

receiver.updateInt(2, methodResults[currentRow].intValue());

return true;

}

return false;

}

@Override

public void close() {

}

}