经验备忘,仅供参考

1.场景

配置文件的数据库连接的用户名和密码需要改成密文,提高安全性.
加解密使用一个工具类来实现,并非是泛用的加解密过程,不方便用插件.

2.思路

1.找到从配置文件获取用户名和密码的逻辑,或者使用用户名和密码创建数据源的逻辑
2.重写对应逻辑的源码类,增加解密的步骤

3.项目环境

Spring Boot 2.4.2

        <!-- mybatis-plus -->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
        </dependency>

        <!-- 动态数据源 -->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>dynamic-datasource-spring-boot-starter</artifactId>
        </dependency>

        <!-- 阿里数据库连接池 -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid-spring-boot-starter</artifactId>
            <version>${druid.version}</version>
        </dependency>

        <!-- postgresql驱动包 -->
        <dependency>
            <groupId>org.postgresql</groupId>
            <artifactId>postgresql</artifactId>
        </dependency>

项目实际使用了多数据源功能

#默认数据源
spring.datasource.dynamic.datasource.postgresql.url=jdbc:postgresql://0.0.0.0:0/demo?useUnicode=true&characterEncoding=UTF-8&allowMultiQueries=true&serverTimezone=Asia/Shanghai
spring.datasource.dynamic.datasource.postgresql.username=81c5f00b41ee312
spring.datasource.dynamic.datasource.postgresql.password=3bbb7b271bf65ddda9cba27dad0bf20e23e84f85d3f7fb4

spring.datasource.dynamic.datasource.prod_01.url=jdbc:postgresql://0.0.0.0:0/demo?useUnicode=true&characterEncoding=UTF-8&allowMultiQueries=true&serverTimezone=Asia/Shanghai
spring.datasource.dynamic.datasource.prod_01.username=81c5f00b41ee312
spring.datasource.dynamic.datasource.prod_01.password=3bbb7b271bf65ddda9cba27dad0bf20e23e84f85d3f7fb4

spring.datasource.dynamic.datasource.prod_02.url=jdbc:postgresql://10.0.0.0:0/demo?useUnicode=true&characterEncoding=UTF-8&allowMultiQueries=true&serverTimezone=Asia/Shanghai
spring.datasource.dynamic.datasource.prod_02.username=6e4398db9ca4d1d
spring.datasource.dynamic.datasource.prod_02.password=c79d198ea20e940c8d0fcb495cef9ab

4.确认创建数据源逻辑

将数据库连接改成错误的
查看异常报错信息,进入报错的类
报错节点增加断点,debug进入断点,由断点向调用链的上方回溯
在疑似地方继续增加断点,反复debug
最终找到的类是(也可以去改其他类的逻辑):
com.baomidou.dynamic.datasource.creator.DruidDataSourceCreator

*
 * Copyright © 2018 organization baomidou
 *
 * 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 com.baomidou.dynamic.datasource.creator;

import com.alibaba.druid.filter.Filter;
import com.alibaba.druid.filter.logging.Slf4jLogFilter;
import com.alibaba.druid.filter.stat.StatFilter;
import com.alibaba.druid.pool.DruidDataSource;
import com.alibaba.druid.wall.WallConfig;
import com.alibaba.druid.wall.WallFilter;
import com.baomidou.dynamic.datasource.exception.ErrorCreateDataSourceException;
import com.baomidou.dynamic.datasource.spring.boot.autoconfigure.DataSourceProperty;
import com.baomidou.dynamic.datasource.spring.boot.autoconfigure.druid.DruidConfig;
import com.baomidou.dynamic.datasource.spring.boot.autoconfigure.druid.DruidSlf4jConfig;
import com.baomidou.dynamic.datasource.spring.boot.autoconfigure.druid.DruidWallConfigUtil;
import lombok.Data;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.ApplicationContext;
import org.springframework.util.StringUtils;

import javax.sql.DataSource;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
import java.util.Properties;

import static com.baomidou.dynamic.datasource.support.DdConstants.DRUID_DATASOURCE;

/**
 * Druid数据源创建器
 *
 * @author TaoYu
 * @since 2020/1/21
 */
@Data
public class DruidDataSourceCreator implements DataSourceCreator {

    private static Boolean druidExists = false;

    static {
        try {
            Class.forName(DRUID_DATASOURCE);
            druidExists = true;
        } catch (ClassNotFoundException ignored) {
        }
    }

    private DruidConfig gConfig;

    @Autowired(required = false)
    private ApplicationContext applicationContext;

    public DruidDataSourceCreator(DruidConfig gConfig) {
        this.gConfig = gConfig;
    }

    @Override
    public DataSource createDataSource(DataSourceProperty dataSourceProperty) {
        DruidDataSource dataSource = new DruidDataSource();
        dataSource.setUsername(dataSourceProperty.getUsername());
        dataSource.setPassword(dataSourceProperty.getPassword());
        dataSource.setUrl(dataSourceProperty.getUrl());
        dataSource.setName(dataSourceProperty.getPoolName());
        String driverClassName = dataSourceProperty.getDriverClassName();
        if (!StringUtils.isEmpty(driverClassName)) {
            dataSource.setDriverClassName(driverClassName);
        }
        DruidConfig config = dataSourceProperty.getDruid();
        Properties properties = config.toProperties(gConfig);

        List<Filter> proxyFilters = this.initFilters(dataSourceProperty, properties);
        dataSource.setProxyFilters(proxyFilters);

        dataSource.configFromPropety(properties);
        //连接参数单独设置
        dataSource.setConnectProperties(config.getConnectionProperties());
        //设置druid内置properties不支持的的参数
        this.setParam(dataSource, config);

        if (!dataSourceProperty.getLazy()) {
            try {
                dataSource.init();
            } catch (SQLException e) {
                throw new ErrorCreateDataSourceException("druid create error", e);
            }
        }
        return dataSource;
    }

    private List<Filter> initFilters(DataSourceProperty dataSourceProperty, Properties properties) {
        List<Filter> proxyFilters = new ArrayList<>(2);
        String filters = properties.getProperty("druid.filters");
        if (!StringUtils.isEmpty(filters)) {
            if (filters.contains("stat")) {
                StatFilter statFilter = new StatFilter();
                statFilter.configFromProperties(properties);
                proxyFilters.add(statFilter);
            }
            if (filters.contains("wall")) {
                WallConfig wallConfig = DruidWallConfigUtil.toWallConfig(dataSourceProperty.getDruid().getWall(), gConfig.getWall());
                WallFilter wallFilter = new WallFilter();
                wallFilter.setConfig(wallConfig);
                proxyFilters.add(wallFilter);
            }
            if (filters.contains("slf4j")) {
                Slf4jLogFilter slf4jLogFilter = new Slf4jLogFilter();
                // 由于properties上面被用了，LogFilter不能使用configFromProperties方法，这里只能一个个set了。
                DruidSlf4jConfig slf4jConfig = gConfig.getSlf4j();
                slf4jLogFilter.setStatementLogEnabled(slf4jConfig.getEnable());
                slf4jLogFilter.setStatementExecutableSqlLogEnable(slf4jConfig.getStatementExecutableSqlLogEnable());
                proxyFilters.add(slf4jLogFilter);
            }
        }
        if (this.applicationContext != null) {
            for (String filterId : gConfig.getProxyFilters()) {
                proxyFilters.add(this.applicationContext.getBean(filterId, Filter.class));
            }
        }
        return proxyFilters;
    }

    private void setParam(DruidDataSource dataSource, DruidConfig config) {
        String defaultCatalog = config.getDefaultCatalog() == null ? gConfig.getDefaultCatalog() : config.getDefaultCatalog();
        if (defaultCatalog != null) {
            dataSource.setDefaultCatalog(defaultCatalog);
        }
        Boolean defaultAutoCommit = config.getDefaultAutoCommit() == null ? gConfig.getDefaultAutoCommit() : config.getDefaultAutoCommit();
        if (defaultAutoCommit != null && !defaultAutoCommit) {
            dataSource.setDefaultAutoCommit(false);
        }
        Boolean defaultReadOnly = config.getDefaultReadOnly() == null ? gConfig.getDefaultReadOnly() : config.getDefaultReadOnly();
        if (defaultReadOnly != null) {
            dataSource.setDefaultReadOnly(defaultReadOnly);
        }
        Integer defaultTransactionIsolation = config.getDefaultTransactionIsolation() == null ? gConfig.getDefaultTransactionIsolation() : config.getDefaultTransactionIsolation();
        if (defaultTransactionIsolation != null) {
            dataSource.setDefaultTransactionIsolation(defaultTransactionIsolation);
        }

        Boolean testOnReturn = config.getTestOnReturn() == null ? gConfig.getTestOnReturn() : config.getTestOnReturn();
        if (testOnReturn != null && testOnReturn) {
            dataSource.setTestOnReturn(true);
        }
        Integer validationQueryTimeout =
                config.getValidationQueryTimeout() == null ? gConfig.getValidationQueryTimeout() : config.getValidationQueryTimeout();
        if (validationQueryTimeout != null && !validationQueryTimeout.equals(-1)) {
            dataSource.setValidationQueryTimeout(validationQueryTimeout);
        }

        Boolean sharePreparedStatements =
                config.getSharePreparedStatements() == null ? gConfig.getSharePreparedStatements() : config.getSharePreparedStatements();
        if (sharePreparedStatements != null && sharePreparedStatements) {
            dataSource.setSharePreparedStatements(true);
        }
        Integer connectionErrorRetryAttempts =
                config.getConnectionErrorRetryAttempts() == null ? gConfig.getConnectionErrorRetryAttempts()
                        : config.getConnectionErrorRetryAttempts();
        if (connectionErrorRetryAttempts != null && !connectionErrorRetryAttempts.equals(1)) {
            dataSource.setConnectionErrorRetryAttempts(connectionErrorRetryAttempts);
        }
        Boolean breakAfterAcquireFailure =
                config.getBreakAfterAcquireFailure() == null ? gConfig.getBreakAfterAcquireFailure() : config.getBreakAfterAcquireFailure();
        if (breakAfterAcquireFailure != null && breakAfterAcquireFailure) {
            dataSource.setBreakAfterAcquireFailure(true);
        }

        Integer timeout = config.getRemoveAbandonedTimeoutMillis() == null ? gConfig.getRemoveAbandonedTimeoutMillis()
                : config.getRemoveAbandonedTimeoutMillis();
        if (timeout != null) {
            dataSource.setRemoveAbandonedTimeoutMillis(timeout);
        }

        Boolean abandoned = config.getRemoveAbandoned() == null ? gConfig.getRemoveAbandoned() : config.getRemoveAbandoned();
        if (abandoned != null) {
            dataSource.setRemoveAbandoned(abandoned);
        }

        Boolean logAbandoned = config.getLogAbandoned() == null ? gConfig.getLogAbandoned() : config.getLogAbandoned();
        if (logAbandoned != null) {
            dataSource.setLogAbandoned(logAbandoned);
        }

        Integer queryTimeOut = config.getQueryTimeout() == null ? gConfig.getQueryTimeout() : config.getQueryTimeout();
        if (queryTimeOut != null) {
            dataSource.setQueryTimeout(queryTimeOut);
        }

        Integer transactionQueryTimeout =
                config.getTransactionQueryTimeout() == null ? gConfig.getTransactionQueryTimeout() : config.getTransactionQueryTimeout();
        if (transactionQueryTimeout != null) {
            dataSource.setTransactionQueryTimeout(transactionQueryTimeout);
        }
    }

    @Override
    public boolean support(DataSourceProperty dataSourceProperty) {
        Class<? extends DataSource> type = dataSourceProperty.getType();
        return (type == null && druidExists) || (type != null && DRUID_DATASOURCE.equals(type.getName()));
    }
}

要修改的地方在createDataSource方法

5.重写源码

在项目下新建一个包com.baomidou.dynamic.datasource.creator(与DruidDataSourceCreator的所在包一致)
包下新建一个类DruidDataSourceCreator
将源码的内容原封不动的复制到新建的类
对createDataSource方法进行修改
修改后:

 @Override
    public DataSource createDataSource(DataSourceProperty dataSourceProperty) {
        String username=dataSourceProperty.getUsername();
        String password=dataSourceProperty.getPassword();
        try {
            DesCode des = new DesCode("这是密钥");
            username= des.decrypt(username);
            password= des.decrypt(password);
        }catch (Exception e){
            e.printStackTrace();
        }
        DruidDataSource dataSource = new DruidDataSource();
        dataSource.setUsername(username);
        dataSource.setPassword(password);
        dataSource.setUrl(dataSourceProperty.getUrl());
        dataSource.setName(dataSourceProperty.getPoolName());

        String driverClassName = dataSourceProperty.getDriverClassName();
        if (!StringUtils.isEmpty(driverClassName)) {
            dataSource.setDriverClassName(driverClassName);
        }
        DruidConfig config = dataSourceProperty.getDruid();
        Properties properties = config.toProperties(gConfig);

        List<Filter> proxyFilters = this.initFilters(dataSourceProperty, properties);
        dataSource.setProxyFilters(proxyFilters);

        dataSource.configFromPropety(properties);
        //连接参数单独设置
        dataSource.setConnectProperties(config.getConnectionProperties());
        //设置druid内置properties不支持的的参数
        this.setParam(dataSource, config);

        if (!dataSourceProperty.getLazy()) {
            try {
                dataSource.init();
            } catch (SQLException e) {
                throw new ErrorCreateDataSourceException("druid create error", e);
            }
        }
        return dataSource;
    }

6.完成测试

在maven先执行clean再执行install,让重写的代码编译,替换原有的代码
启动项目,测试验证功能.

7.其他

使用的IDEA自带的反编译进行的源码查看
建议进行源码下载,这样可以看到作者的注释,变量名也会更准确
非多数据源的加密:

/*
 * Copyright (C) 2013, 2014 Brett Wooldridge
 *
 * 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 com.zaxxer.hikari.util;

import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.Driver;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.SQLFeatureNotSupportedException;
import java.util.Enumeration;
import java.util.Map.Entry;
import java.util.Properties;

import javax.sql.DataSource;

import com.xxl.job.admin.util.DesCode;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public final class DriverDataSource implements DataSource
{
    private static final Logger LOGGER = LoggerFactory.getLogger(DriverDataSource.class);
    private static final String PASSWORD = "password";
    private static final String USER = "user";

    private final String jdbcUrl;
    private final Properties driverProperties;
    private Driver driver;

    public DriverDataSource(String jdbcUrl, String driverClassName, Properties properties, String username, String password)
    {
        this.jdbcUrl = jdbcUrl;
        this.driverProperties = new Properties();

        for (Entry<Object, Object> entry : properties.entrySet()) {
            driverProperties.setProperty(entry.getKey().toString(), entry.getValue().toString());
        }

        if (username != null) {
            driverProperties.put(USER, driverProperties.getProperty("user", username));
        }
        if (password != null) {
            driverProperties.put(PASSWORD, driverProperties.getProperty("password", password));
        }

        if (driverClassName != null) {
            Enumeration<Driver> drivers = DriverManager.getDrivers();
            while (drivers.hasMoreElements()) {
                Driver d = drivers.nextElement();
                if (d.getClass().getName().equals(driverClassName)) {
                    driver = d;
                    break;
                }
            }

            if (driver == null) {
                LOGGER.warn("Registered driver with driverClassName={} was not found, trying direct instantiation.", driverClassName);
                Class<?> driverClass = null;
                ClassLoader threadContextClassLoader = Thread.currentThread().getContextClassLoader();
                try {
                    if (threadContextClassLoader != null) {
                        try {
                            driverClass = threadContextClassLoader.loadClass(driverClassName);
                            LOGGER.debug("Driver class {} found in Thread context class loader {}", driverClassName, threadContextClassLoader);
                        }
                        catch (ClassNotFoundException e) {
                            LOGGER.debug("Driver class {} not found in Thread context class loader {}, trying classloader {}",
                                    driverClassName, threadContextClassLoader, this.getClass().getClassLoader());
                        }
                    }

                    if (driverClass == null) {
                        driverClass = this.getClass().getClassLoader().loadClass(driverClassName);
                        LOGGER.debug("Driver class {} found in the HikariConfig class classloader {}", driverClassName, this.getClass().getClassLoader());
                    }
                } catch (ClassNotFoundException e) {
                    LOGGER.debug("Failed to load driver class {} from HikariConfig class classloader {}", driverClassName, this.getClass().getClassLoader());
                }

                if (driverClass != null) {
                    try {
                        driver = (Driver) driverClass.newInstance();
                    } catch (Exception e) {
                        LOGGER.warn("Failed to create instance of driver class {}, trying jdbcUrl resolution", driverClassName, e);
                    }
                }
            }
        }

        final String sanitizedUrl = jdbcUrl.replaceAll("([?&;]password=)[^&#;]*(.*)", "$1<masked>$2");
        try {
            if (driver == null) {
                driver = DriverManager.getDriver(jdbcUrl);
                LOGGER.debug("Loaded driver with class name {} for jdbcUrl={}", driver.getClass().getName(), sanitizedUrl);
            }
            else if (!driver.acceptsURL(jdbcUrl)) {
                throw new RuntimeException("Driver " + driverClassName + " claims to not accept jdbcUrl, " + sanitizedUrl);
            }
        }
        catch (SQLException e) {
            throw new RuntimeException("Failed to get driver instance for jdbcUrl=" + sanitizedUrl, e);
        }
    }

    @Override
    public Connection getConnection() throws SQLException
    {
        return driver.connect(jdbcUrl, driverProperties);
    }

    @Override
    public Connection getConnection(final String username, final String password) throws SQLException
    {
        String u=username;
        String p=password;
        try {
            DesCode des = new DesCode("这是密钥");
            u= des.decrypt(username);
            p= des.decrypt(password);
        }catch (Exception e){
            e.printStackTrace();
        }

        final Properties cloned = (Properties) driverProperties.clone();
        if (username != null) {
            cloned.put("user", u);
            if (cloned.containsKey("username")) {
                cloned.put("username", u);
            }
        }
        if (password != null) {
            cloned.put("password", p);
        }

        return driver.connect(jdbcUrl, cloned);
    }

    @Override
    public PrintWriter getLogWriter() throws SQLException
    {
        throw new SQLFeatureNotSupportedException();
    }

    @Override
    public void setLogWriter(PrintWriter logWriter) throws SQLException
    {
        throw new SQLFeatureNotSupportedException();
    }

    @Override
    public void setLoginTimeout(int seconds) throws SQLException
    {
        DriverManager.setLoginTimeout(seconds);
    }

    @Override
    public int getLoginTimeout() throws SQLException
    {
        return DriverManager.getLoginTimeout();
    }

    @Override
    public java.util.logging.Logger getParentLogger() throws SQLFeatureNotSupportedException
    {
        return driver.getParentLogger();
    }

    @Override
    public <T> T unwrap(Class<T> iface) throws SQLException
    {
        throw new SQLFeatureNotSupportedException();
    }

    @Override
    public boolean isWrapperFor(Class<?> iface) throws SQLException
    {
        return false;
    }
}