一起开发一个文件服务器--4、配置中心与postgresql数据库【试验稿】

版权声明：本文为博主原创文章，未经博主允许不得转载。 https://blog.csdn.net/cdnight/article/details/86585882

前言

终于到了数据库、配置中心和spring整合了。
ps：通常有难度和容易错的都会标注草稿—因为不把踩过的坑说出来是。。欸，是不会记得的。

配置中心与配置bean

添加相关依赖以及添加配置文件

根模块添加：

目标子模块添加依赖：

在配置中心后台添加对应的设置信息

最终成品如下：

添加对应配置类

在plugins config文件夹下面添加数据库的配置文件：

注意，这次我们来试一试xxl-conf的第二种属性映射方式：

代码：

package net.w2p.local.plugins.config;


import com.xxl.conf.core.annotation.XxlConf;

/***
 *
 * 数据库配置文件，配置内容有：
 * druid.driverClassName=org.postgresql.Driver
 * druid.jdbcUrl = jdbc:postgresql://localhost:5432/postgres
 * druid.username = postgres
 * druid.password = 123456
 * druid.initialSize=5
 * druid.minIdle=2
 * druid.maxActive=50
 * druid.maxWait=180000
 * druid.timeBetweenEvictionRunsMillis=60000
 * druid.minEvictableIdleTimeMillis=300000
 * druid.validationQuery=SELECT 'x'
 * druid.testWhileIdle=true
 * druid.testOnBorrow=true
 * druid.testOnReturn=false
 * druid.poolPreparedStatements=false
 * druid.maxPoolPreparedStatementPerConnectionSize=20
 * druid.filters=wall,stat
 * druid.removeAbandoned=false
 * #还是加一个连接的租期吧，就是说60s内必须close---前提是运行自动关闭已经设置了
 * druid.removeAbandonedTimeout = 60
 *
 * ***/
public class DbConf {
    
    private static final String conf_prefix ="file-server.db.";
    
    
    @XxlConf(conf_prefix +"driverClassName")
    public String  driverClassName = "org.postgresql.Driver";
    
    @XxlConf(conf_prefix+"jdbcUrl")
    public String  jdbcUrl = "jdbc:postgresql://localhost:5432/postgres";
    
    @XxlConf(conf_prefix+"username")
    public String  username = "postgres";

    @XxlConf(conf_prefix+"password")
    public String  password = "123456";

    @XxlConf(conf_prefix+"initialSize")
    public Integer initialSize = 5;


    @XxlConf(conf_prefix+"minIdle")
    public Integer minIdle = 2;

    @XxlConf(conf_prefix+"maxActive")
    public Integer maxActive = 50;

    @XxlConf(conf_prefix+"maxWait")
    public Integer maxWait = 180000;

    @XxlConf(conf_prefix+"timeBetweenEvictionRunsMillis")
    public Integer timeBetweenEvictionRunsMillis = 60000;

    @XxlConf(conf_prefix+"minEvictableIdleTimeMillis")
    public Integer minEvictableIdleTimeMillis = 300000;

    @XxlConf(conf_prefix+"validationQuery")
    public String  validationQuery = "SELECT 'x'";

    @XxlConf(conf_prefix+"testWhileIdle")
    public Boolean testWhileIdle = true;

    @XxlConf(conf_prefix+"testOnBorrow")
    public Boolean testOnBorrow = false;

    @XxlConf(conf_prefix+"testOnReturn")
    public Boolean testOnReturn = false;

    @XxlConf(conf_prefix+"poolPreparedStatements")
    public Boolean poolPreparedStatements = false;

    @XxlConf(conf_prefix+"maxPoolPreparedStatementPerConnectionSize")
    public Integer maxPoolPreparedStatementPerConnectionSize = 20;

    @XxlConf(conf_prefix+"filters")
    public String  filters = "wall,stat";

    @XxlConf(conf_prefix+"removeAbandoned")
    public Boolean removeAbandoned = false;


    //还是加一个连接的租期吧，就是说60s内必须close---前提是运行自动关闭已经设置了
    @XxlConf(conf_prefix+"removeAbandonedTimeout")
    public Integer removeAbandonedTimeout = 60;

    public String getDriverClassName() {
        return driverClassName;
    }

    public void setDriverClassName(String driverClassName) {
        this.driverClassName = driverClassName;
    }

    public String getJdbcUrl() {
        return jdbcUrl;
    }

    public void setJdbcUrl(String jdbcUrl) {
        this.jdbcUrl = jdbcUrl;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public Integer getInitialSize() {
        return initialSize;
    }

    public void setInitialSize(Integer initialSize) {
        this.initialSize = initialSize;
    }

    public Integer getMinIdle() {
        return minIdle;
    }

    public void setMinIdle(Integer minIdle) {
        this.minIdle = minIdle;
    }

    public Integer getMaxActive() {
        return maxActive;
    }

    public void setMaxActive(Integer maxActive) {
        this.maxActive = maxActive;
    }

    public Integer getMaxWait() {
        return maxWait;
    }

    public void setMaxWait(Integer maxWait) {
        this.maxWait = maxWait;
    }

    public Integer getTimeBetweenEvictionRunsMillis() {
        return timeBetweenEvictionRunsMillis;
    }

    public void setTimeBetweenEvictionRunsMillis(Integer timeBetweenEvictionRunsMillis) {
        this.timeBetweenEvictionRunsMillis = timeBetweenEvictionRunsMillis;
    }

    public Integer getMinEvictableIdleTimeMillis() {
        return minEvictableIdleTimeMillis;
    }

    public void setMinEvictableIdleTimeMillis(Integer minEvictableIdleTimeMillis) {
        this.minEvictableIdleTimeMillis = minEvictableIdleTimeMillis;
    }

    public String getValidationQuery() {
        return validationQuery;
    }

    public void setValidationQuery(String validationQuery) {
        this.validationQuery = validationQuery;
    }

    public Boolean getTestWhileIdle() {
        return testWhileIdle;
    }

    public void setTestWhileIdle(Boolean testWhileIdle) {
        this.testWhileIdle = testWhileIdle;
    }

    public Boolean getTestOnBorrow() {
        return testOnBorrow;
    }

    public void setTestOnBorrow(Boolean testOnBorrow) {
        this.testOnBorrow = testOnBorrow;
    }

    public Boolean getTestOnReturn() {
        return testOnReturn;
    }

    public void setTestOnReturn(Boolean testOnReturn) {
        this.testOnReturn = testOnReturn;
    }

    public Boolean getPoolPreparedStatements() {
        return poolPreparedStatements;
    }

    public void setPoolPreparedStatements(Boolean poolPreparedStatements) {
        this.poolPreparedStatements = poolPreparedStatements;
    }

    public Integer getMaxPoolPreparedStatementPerConnectionSize() {
        return maxPoolPreparedStatementPerConnectionSize;
    }

    public void setMaxPoolPreparedStatementPerConnectionSize(Integer maxPoolPreparedStatementPerConnectionSize) {
        this.maxPoolPreparedStatementPerConnectionSize = maxPoolPreparedStatementPerConnectionSize;
    }

    public String getFilters() {
        return filters;
    }

    public void setFilters(String filters) {
        this.filters = filters;
    }

    public Boolean getRemoveAbandoned() {
        return removeAbandoned;
    }

    public void setRemoveAbandoned(Boolean removeAbandoned) {
        this.removeAbandoned = removeAbandoned;
    }

    public Integer getRemoveAbandonedTimeout() {
        return removeAbandonedTimeout;
    }

    public void setRemoveAbandonedTimeout(Integer removeAbandonedTimeout) {
        this.removeAbandonedTimeout = removeAbandonedTimeout;
    }
}

配置类注册

在applicationContext-XxlConf.xml中配置托管的bean。

代码

	<!-- ********************************* druid&数据库 配置 ********************************* -->
	<bean id="dbConf" class="net.w2p.local.plugins.config.DbConf">
		
	</bean>

测试是否正常运行

然后编写测试程序查看dbconf的获取情况并执行：

代码：

    @Resource
    DbConf dbConf;

    @Test
    public void printDb(){
        System.out.println(JSONObject.toJSONString(dbConf));
    }

可见，执行成功，数据库获取配置成功。

数据源配置

这一小节用到了下面的文章，请适当查阅：

在Spring中使用@Configuration注解加载JavaConfig配置
Spring Boot 自定义数据源 DruidDataSource
spring bean加载顺序解决办法笔记
Druid连接池基本配置
Spring3.1完全基于注解配置@Configuration类中@Autowire无法注入问题解决
spring中bean配置和bean注入

首先在plugins下面添加beanconfig，用java类来做配置：

代码如下：

package net.w2p.local.plugins.BeanConfiguration;

import com.alibaba.druid.pool.DruidDataSource;
import net.w2p.local.plugins.config.DbConf;
import org.springframework.beans.factory.annotation.Autowire;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.DependsOn;

import javax.annotation.Resource;
import javax.sql.DataSource;
import java.sql.SQLException;

/**
 * Druid监控web配置
 *
 * @author jinxiaoxin
 *
 */
/*******/
@DependsOn(value = "dbConf")
@Configuration
public class DruidConfig {


    @Resource
    DbConf dbConf;


    @Bean(autowire= Autowire.BY_TYPE)
    public DataSource druidDataSource() {
        if(dbConf==null){
            System.out.println("欸???数据库配置没有读取成功！！！！");
        }
        DruidDataSource druidDataSource = new DruidDataSource();
        druidDataSource.setDriverClassName(dbConf.getDriverClassName());
        druidDataSource.setUrl(dbConf.getJdbcUrl());
        druidDataSource.setUsername(dbConf.getUsername());
        druidDataSource.setPassword(dbConf.getPassword());
        druidDataSource.setInitialSize(dbConf.getInitialSize());
        druidDataSource.setMaxActive(dbConf.getMaxActive());
        druidDataSource.setMaxWait(dbConf.getMaxWait());
        druidDataSource
                .setTimeBetweenEvictionRunsMillis(dbConf.getTimeBetweenEvictionRunsMillis());
        druidDataSource
                .setMinEvictableIdleTimeMillis(dbConf.getMinEvictableIdleTimeMillis());
        druidDataSource.setValidationQuery(dbConf.getValidationQuery());
        druidDataSource.setTestWhileIdle(dbConf.getTestWhileIdle());
        druidDataSource.setTestOnBorrow(dbConf.getTestOnBorrow());
        druidDataSource.setTestOnReturn(dbConf.getTestOnReturn());
        druidDataSource.setPoolPreparedStatements(dbConf.getPoolPreparedStatements());
        druidDataSource
                .setMaxPoolPreparedStatementPerConnectionSize(dbConf.
                        getMaxPoolPreparedStatementPerConnectionSize());
        druidDataSource.setConnectionProperties("");
        try {
            druidDataSource.setFilters(dbConf.getFilters());
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return druidDataSource;
    }
}

然后在applicationContext.xml里面的componentScan要加上这个路径：

代码如下：

    <!--

    net.w2p.local.plugins.utils  =》 redis,数据库连接池等插件所在
    net.w2p.local.Shared.mybatis.TypeHandlers =》 自定义mybatis数据类型转换，譬如，数组类型，布尔值类型等。

    net.w2p.local.plugins.BeanConfiguration=》自定义的java类作为configuration的方法，包含了数据库datasource源
    -->
    <context:component-scan
            base-package="
            net.w2p.local.plugins.utils,
            net.w2p.Shared.mybatis.TypeHandlers,
            net.w2p.local.plugins.BeanConfiguration
"/>

好了，编写测试用例来看看是不是能够正常运行：

代码：

    @Resource
    DataSource dataSource;

    @Test
    public void tryTestDataSourceConfig() throws  Exception {
        Connection cnn=dataSource.getConnection();
        cnn.close();

    }

好了，现在运行一下：

出错了，问题是：

Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'druidDataSource' defined in net.w2p.local.plugins.BeanConfiguration.DruidConfig: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [javax.sql.DataSource]: Factory method 'druidDataSource' threw exception; nested exception is java.lang.NullPointerException

好了，跟我一步一步调试一下程序吧。。
本人有点怀疑是dbConf没有注入，any way，开始调试：
1、

查看dbConf的内容，欸，已经有数据了，那么dbConf无问题。那没办法了，全部都丧心病狂打断点，哪里断了就哪里有问题。

2、

经过反复比较，发现：

每次运行到setMaxActive以后就跳出来了，一看，maxActive是null，这一步就错了。。。
好了，核查原因。
结果发现配置中心里面没有配置：

疏忽了。
加上配置：

然后执行，

好，datasource成功加载了。

配置JdbcTemplate等数据连接对象

一般来说，网上大部分教程都是用xml进行配置的，譬如：

但我们反其道而行之，就是喜欢写代码，用代码来配置，在DruidConfig文件里面进行配置，例如：

代码：

    /***分别生成jdbcTemplate以及NamedParameterJdbcTemplate两个不同的数据库连接对象***/
    /***注意，这里要有参数表示注入的是我们之前初始化的datasource***/
    @Bean(name="jdbcTemplate")
    @Autowired
    public JdbcTemplate jdbcTemplate(@Qualifier("dataSource")DataSource dataSource){
        return new JdbcTemplate(dataSource);
    }

    @Bean(name="namedParameterJdbcTemplate")
    @Autowired
    public NamedParameterJdbcTemplate namedParameterJdbcTemplate(@Qualifier("dataSource")DataSource dataSource){
        return new NamedParameterJdbcTemplate(dataSource);
    }

测试

编写测试代码：

    @Autowired
    JdbcTemplate jdbcTemplate;
    @Autowired
    NamedParameterJdbcTemplate template;

    @Test
    public void testJdbcTemplate(){
        List objs=jdbcTemplate.queryForList("select 1");
        System.out.println(JSONObject.toJSONString(objs));
        List objs2=template.queryForList("select now()",new HashMap<>());
        System.out.println(JSONObject.toJSONString(objs2));
    }

进行测试：

好了，测试成功，成功配置数据源以及数据访问对象。