org.wte4j.impl.service.SimpleDbViewModelService.java Source code

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Here is the source code for org.wte4j.impl.service.SimpleDbViewModelService.java

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/**
 * Copyright (C) 2015 Born Informatik AG (www.born.ch)
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *         http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.wte4j.impl.service;

import java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import javax.sql.DataSource;

import org.springframework.beans.factory.annotation.Autowired;
import org.wte4j.Template;
import org.wte4j.WteDataModel;
import org.wte4j.WteException;
import org.wte4j.WteModelService;

/**
 * Implementation of WteModelService for a model which is retrieving its data
 * from a database view.<br/>
 * A client using this class must provide the properties VIEW_NAME and
 * PRIMARY_KEY_COLUMN_NAME. The primary key column must be of integral type. To
 * retrieve a row from the view the method <code>createModel(..)</code> is used:
 * parameter <code>input</code> must contain the primary key of the row and must
 * be of type Integer.
 * 
 */
public class SimpleDbViewModelService implements WteModelService {

    public static final String VIEW_NAME = "viewName";
    public static final String PRIMARY_KEY_COLUMN_NAME = "pkColumnName";

    @Autowired
    protected DataSource ds;

    protected SimpleDbViewModelService() {
    }

    public SimpleDbViewModelService(DataSource aDs) {
        ds = aDs;
    }

    @Override
    public Map<String, Class<?>> listModelElements(Class<?> inputClass, Map<String, String> properties) {
        Map<String, Class<?>> elements = new HashMap<String, Class<?>>();
        String viewName = properties.get(VIEW_NAME);
        Connection connection = null;
        ResultSet rs = null;
        try {
            try {
                connection = ds.getConnection();
                DatabaseMetaData metaData = ds.getConnection().getMetaData();
                rs = metaData.getColumns(null, null, viewName, null);

                while (rs.next()) {
                    String columnName = rs.getString("COLUMN_NAME").toLowerCase();
                    Class<?> type = MapperSqlType.map(rs.getInt("DATA_TYPE"));
                    elements.put(columnName, type);
                }

            } finally {
                if (rs != null) {
                    rs.close();
                }
                if (connection != null) {
                    connection.close();
                }
            }
        } catch (SQLException e) {
            throw new WteException("error in view " + viewName, e);
        }
        return elements;
    }

    @Override
    public List<String> listRequiredModelProperties() {
        List<String> list = new ArrayList<String>();
        list.add(VIEW_NAME);
        list.add(PRIMARY_KEY_COLUMN_NAME);
        return list;
    }

    @Override
    public WteDataModel createModel(Template<?> template, Object input) {
        String viewName = template.getProperties().get(VIEW_NAME);
        String pkColumnName = template.getProperties().get(PRIMARY_KEY_COLUMN_NAME);
        Integer pk = (Integer) input;
        Map<String, Object> dataMap = new HashMap<String, Object>(); //TODO PreparedStatement!
        String query = "select * from " + viewName + " where " + pkColumnName + "=" + pk;
        try {
            Connection connection = null;
            Statement statement = null;
            try {
                connection = ds.getConnection();
                statement = connection.createStatement();
                ResultSet rs = statement.executeQuery(query);
                ResultSetMetaData metaData = rs.getMetaData();
                while (rs.next()) {
                    for (int i = 1; i <= metaData.getColumnCount(); i++) {
                        String columnName = metaData.getColumnName(i).toLowerCase();
                        dataMap.put(columnName, rs.getObject(i));
                    }
                }

            } finally {
                if (statement != null) {
                    statement.close();
                }
                if (connection != null) {
                    connection.close();
                }
            }
        } catch (SQLException e) {
            throw new WteException("error in createModel (" + viewName + ", " + pkColumnName + ", " + pk + ")", e);
        }
        return new WteMapModel(dataMap);
    }

}