org.nebula.service.core.DynamicDataSource.java Source code

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Here is the source code for org.nebula.service.core.DynamicDataSource.java

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/*
 * Copyright 2002-2015 the original author or authors.
 *
 * 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.nebula.service.core;

import org.apache.commons.dbcp.BasicDataSource;
import org.nebula.service.config.DbUrlChangeListener;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;
import org.springframework.stereotype.Service;

import java.sql.SQLException;
import java.util.HashMap;
import java.util.Map;

import javax.annotation.PostConstruct;
import javax.sql.DataSource;

@Service
public class DynamicDataSource extends AbstractRoutingDataSource implements DbUrlChangeListener {

    private final static String LOOKUP_KEY = "NEBULA";
    private Map<Object, Object> datasources = new HashMap<Object, Object>();
    @Value("${jdbc.maxActive}")
    private int jdbcMaxActive;

    @Value("${jdbc.maxIdle}")
    private int jdbcMaxIdle;

    @Value("${jdbc.initialSize}")
    private int jdbcInitialSize;

    @Value("${jdbc.username}")
    private String jdbcUsername;

    @Value("${jdbc.password}")
    private String jdbcPassword;

    public DynamicDataSource() {
        this.setTargetDataSources(datasources);
    }

    @Override
    protected Object determineCurrentLookupKey() {
        return LOOKUP_KEY;
    }

    protected DataSource determineTargetDataSource() {
        Object lookupKey = this.determineCurrentLookupKey();
        DataSource dataSource = (DataSource) this.datasources.get(lookupKey);

        if (dataSource == null) {
            throw new IllegalStateException(
                    "Cannot determine target DataSource for lookup key [" + lookupKey + "]");
        }
        return dataSource;
    }

    public void onChange(String dbUrl) {

        logger.info("Change target dbUrl to: " + dbUrl);

        Object oldDataSource = this.datasources.remove(LOOKUP_KEY);

        if (oldDataSource != null) {
            try {
                ((BasicDataSource) oldDataSource).close();
            } catch (SQLException e) {
                //ignore
            }
        }

        BasicDataSource dataSource = new BasicDataSource();
        dataSource.setDriverClassName("com.mysql.jdbc.Driver");
        dataSource.setMaxActive(jdbcMaxActive);
        dataSource.setMaxIdle(jdbcMaxIdle);
        dataSource.setInitialSize(jdbcInitialSize);
        dataSource.setUrl(dbUrl);
        dataSource.setUsername(jdbcUsername);
        dataSource.setPassword(jdbcPassword);
        dataSource.setTestOnBorrow(true);
        dataSource.setValidationQuery("SELECT 1");

        this.datasources.put(LOOKUP_KEY, dataSource);
    }

}