跟我学springboot之(三)配置连接池和JPA的应用
内置的连接池
目前Spring Boot中默认支持的连接池有dbcp,dbcp2, tomcat, hikari三种连接池。
数据库连接可以使用DataSource池进行自动配置。
- 由于Tomcat数据源连接池的性能和并发,在tomcat可用时,我们总是优先使用它。
- 如果HikariCP可用,我们将使用它。
- 如果Commons DBCP可用,我们将使用它,但在生产环境不推荐使用它。
- 最后,如果Commons DBCP2可用,我们将使用它。
以上的几种连接池,可以通过在配置application文件中配置。
spring.datasource.url=jdbc:mysql://localhost/test spring.datasource.username=dbuser spring.datasource.password=dbpass spring.datasource.driver-class-name=com.mysql.jdbc.Driver
Spring Boot能够从大多数数据库的url上推断出driver-class-name,你就不需要再指定它了。对于一个将要创建的DataSource连接池,我们需要能够验证Driver是否可用,所以我们会在做任何事情之前检查它。比如,如果你设置spring.datasource.driverClassName=com.mysql.jdbc.Driver,然后这个类就会被加载。
配置Druid连接池
在SpringBoot 的1.5.2版本中不在支持自动配druid,,即无法通过配置项直接支持相应的连接池;这里列出的这些配置项可以通过定制化DataSource来实现。
druid介绍
Druid是一个JDBC组件,它包括三部分:
- DruidDriver 代理Driver,能够提供基于Filter-Chain模式的插件体系。
- DruidDataSource 高效可管理的数据库连接池。
- SQLParser
Druid可以做什么
- 可以监控数据库访问性能,Druid内置提供了一个功能强大的StatFilter插件,能够详细统计SQL的执行性能,这对于线上分析数据库访问性能有帮助。
- 替换DBCP和C3P0。Druid提供了一个高效、功能强大、可扩展性好的数据库连接池。
- 数据库密码加密。直接把数据库密码写在配置文件中,这是不好的行为,容易导致安全问题。DruidDruiver和DruidDataSource都支持PasswordCallback。
- SQL执行日志,Druid提供了不同的LogFilter,能够支持Common-Logging、Log4j和JdkLog,你可以按需要选择相应的LogFilter,监控你应用的数据库访问情况。
- 扩展JDBC,如果你要对JDBC层有编程的需求,可以通过Druid提供的Filter-Chain机制,很方便编写JDBC层的扩展插件。
Spring Boot与Druid的集成
<dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <scope>runtime</scope> </dependency> <dependency> <groupId>com.alibaba</groupId> <artifactId>druid</artifactId> <version>1.0.25</version> </dependency>
application.properties配置信息
# 驱动配置信息 spring.datasource.type=com.alibaba.druid.pool.DruidDataSource spring.datasource.url = jdbc:mysql://127.0.0.1:3306/test?useUnicode=true&characterEncoding=utf-8 spring.datasource.username = root spring.datasource.password = adminter spring.datasource.driverClassName = com.mysql.jdbc.Driver #连接池的配置信息 ## 初始化大小,最小,最大 spring.druid.initialSize=5 spring.druid.minIdle=5 spring.druid.maxActive=20 ## 配置获取连接等待超时的时间 spring.druid.maxWait=60000 # 配置间隔多久才进行一次检测,检测需要关闭的空闲连接,单位是毫秒 spring.druid.timeBetweenEvictionRunsMillis=60000 # 配置一个连接在池中最小生存的时间,单位是毫秒 spring.druid.minEvictableIdleTimeMillis=300000 spring.druid.validationQuery=SELECT 1 FROM DUAL spring.druid.testWhileIdle=true spring.druid.testOnBorrow=false spring.druid.testOnReturn=false spring.druid.poolPreparedStatements=true spring.druid.maxPoolPreparedStatementPerConnectionSize=20 # 配置监控统计拦截的filters,去掉后监控界面sql无法统计,'wall'用于防火墙 spring.druid.filters=stat,wall,log4j # 通过connectProperties属性来打开mergeSql功能;慢SQL记录 spring.druid.connectionProperties=druid.stat.mergeSql=true;druid.stat.slowSqlMillis=5000
DruidSource配置信息的定制
package com.lf.datasource; import com.alibaba.druid.pool.DruidDataSource; import org.springframework.boot.context.properties.ConfigurationProperties; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Primary; import javax.sql.DataSource; import java.sql.SQLException; @ConfigurationProperties(prefix = "spring.druid") public class DruidSource { private String dbUrl; private String username; private String password; private String driverClassName; private int initialSize; private int minIdle; private int maxActive; private int maxWait; private int timeBetweenEvictionRunsMillis; private int minEvictableIdleTimeMillis; private String validationQuery; private boolean testWhileIdle; private boolean testOnBorrow; private boolean testOnReturn; private boolean poolPreparedStatements; private int maxPoolPreparedStatementPerConnectionSize; private String filters; private String connectionProperties; public String getDbUrl() { return dbUrl; } public void setDbUrl(String dbUrl) { this.dbUrl = dbUrl; } 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 String getDriverClassName() { return driverClassName; } public void setDriverClassName(String driverClassName) { this.driverClassName = driverClassName; } public int getInitialSize() { return initialSize; } public void setInitialSize(int initialSize) { this.initialSize = initialSize; } public int getMinIdle() { return minIdle; } public void setMinIdle(int minIdle) { this.minIdle = minIdle; } public int getMaxActive() { return maxActive; } public void setMaxActive(int maxActive) { this.maxActive = maxActive; } public int getMaxWait() { return maxWait; } public void setMaxWait(int maxWait) { this.maxWait = maxWait; } public int getTimeBetweenEvictionRunsMillis() { return timeBetweenEvictionRunsMillis; } public void setTimeBetweenEvictionRunsMillis(int timeBetweenEvictionRunsMillis) { this.timeBetweenEvictionRunsMillis = timeBetweenEvictionRunsMillis; } public int getMinEvictableIdleTimeMillis() { return minEvictableIdleTimeMillis; } public void setMinEvictableIdleTimeMillis(int minEvictableIdleTimeMillis) { this.minEvictableIdleTimeMillis = minEvictableIdleTimeMillis; } public String getValidationQuery() { return validationQuery; } public void setValidationQuery(String validationQuery) { this.validationQuery = validationQuery; } public boolean isTestWhileIdle() { return testWhileIdle; } public void setTestWhileIdle(boolean testWhileIdle) { this.testWhileIdle = testWhileIdle; } public boolean isTestOnBorrow() { return testOnBorrow; } public void setTestOnBorrow(boolean testOnBorrow) { this.testOnBorrow = testOnBorrow; } public boolean isTestOnReturn() { return testOnReturn; } public void setTestOnReturn(boolean testOnReturn) { this.testOnReturn = testOnReturn; } public boolean isPoolPreparedStatements() { return poolPreparedStatements; } public void setPoolPreparedStatements(boolean poolPreparedStatements) { this.poolPreparedStatements = poolPreparedStatements; } public int getMaxPoolPreparedStatementPerConnectionSize() { return maxPoolPreparedStatementPerConnectionSize; } public void setMaxPoolPreparedStatementPerConnectionSize(int maxPoolPreparedStatementPerConnectionSize) { this.maxPoolPreparedStatementPerConnectionSize = maxPoolPreparedStatementPerConnectionSize; } public String getFilters() { return filters; } public void setFilters(String filters) { this.filters = filters; } public String getConnectionProperties() { return connectionProperties; } public void setConnectionProperties(String connectionProperties) { this.connectionProperties = connectionProperties; } @Bean //声明其为Bean实例 @Primary //在同样的DataSource中,首先使用被标注的DataSource public DruidDataSource dataSource() throws SQLException { DruidDataSource datasource = new DruidDataSource(); datasource.setUrl(this.dbUrl); datasource.setUsername(username); datasource.setPassword(password); datasource.setDriverClassName(driverClassName); //configuration datasource.setInitialSize(initialSize); datasource.setMinIdle(minIdle); datasource.setMaxActive(maxActive); datasource.setMaxWait(maxWait); datasource.setTimeBetweenEvictionRunsMillis(timeBetweenEvictionRunsMillis); datasource.setMinEvictableIdleTimeMillis(minEvictableIdleTimeMillis); datasource.setValidationQuery(validationQuery); datasource.setTestWhileIdle(testWhileIdle); datasource.setTestOnBorrow(testOnBorrow); datasource.setTestOnReturn(testOnReturn); datasource.setPoolPreparedStatements(poolPreparedStatements); datasource.setMaxPoolPreparedStatementPerConnectionSize(maxPoolPreparedStatementPerConnectionSize); datasource.setFilters(filters); return datasource; } }
基于注解的配置StatView的Servlet
Filter的实现类:
package com.lf.config; import com.alibaba.druid.support.http.WebStatFilter; import javax.servlet.annotation.WebFilter; import javax.servlet.annotation.WebInitParam; @WebFilter(filterName = "druidWebStatFilter", urlPatterns = "/*", initParams = { @WebInitParam(name = "exclusions", value = "*.js,*.gif,*.jpg,*.bmp,*.png,*.css,*.ico,/druid/*")//忽略资源 } ) public class DruidStatFilter extends WebStatFilter { }
StatViewServlet:
package com.lf.config; import com.alibaba.druid.support.http.StatViewServlet; import javax.servlet.annotation.WebInitParam; import javax.servlet.annotation.WebServlet; @WebServlet(urlPatterns = "/druid/*", initParams = { @WebInitParam(name = "allow", value = "127.0.0.1,192.168.163.1"),// IP白名单(没有配置或者为空,则允许所有访问) @WebInitParam(name = "deny", value = "192.168.1.73"),// IP黑名单 (存在共同时,deny优先于allow) @WebInitParam(name = "loginUsername", value = "admin"),// 用户名 @WebInitParam(name = "loginPassword", value = "123456"),// 密码 @WebInitParam(name = "resetEnable", value = "false")// 禁用HTML页面上的“Reset All”功能 }) public class DruidStatViewServlet extends StatViewServlet { private static final long serialVersionUID = -2688872071445249539L; }
在启动类上加入@ServletComponentScan注解
基于Java的配置StatView的Servlet
package com.lf.config; import com.alibaba.druid.support.http.StatViewServlet; import com.alibaba.druid.support.http.WebStatFilter; import org.springframework.boot.web.servlet.FilterRegistrationBean; import org.springframework.boot.web.servlet.ServletRegistrationBean; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; @Configuration public class DruidConfig { @Bean public ServletRegistrationBean registrationBean() { ServletRegistrationBean servletRegistrationBean = new ServletRegistrationBean(new StatViewServlet()); //添加初始化参数:initParams servletRegistrationBean.addUrlMappings("/druid/*"); //白名单: servletRegistrationBean.addInitParameter("allow", "127.0.0.1"); //IP黑名单 (存在共同时,deny优先于allow) : 如果满足deny的话提示:Sorry, you are not permitted to view this page. servletRegistrationBean.addInitParameter("deny", "192.168.1.73"); //登录查看信息的账号密码. servletRegistrationBean.addInitParameter("loginUsername", "admin"); servletRegistrationBean.addInitParameter("loginPassword", "123456"); //是否能够重置数据. servletRegistrationBean.addInitParameter("resetEnable", "false"); return servletRegistrationBean; } @Bean public FilterRegistrationBean filterRegistrationBean() { FilterRegistrationBean filterRegistrationBean = new FilterRegistrationBean(new WebStatFilter()); //添加过滤规则. filterRegistrationBean.addUrlPatterns("/*"); //添加不需要忽略的格式信息. filterRegistrationBean.addInitParameter("exclusions", "*.js,*.gif,*.jpg,*.png,*.css,*.ico,/druid/*"); return filterRegistrationBean; } }
访问: http://192.168.163.1:8080/druid/index.html
运行界面以及介绍

账号和密码为在servlet中配置的

附:使用JdbcTemplate操作数据库
(1)数据源配置
在我们访问数据库的时候,需要先配置一个数据源,下面分别介绍一下几种不同的数据库配置方式。
首先,为了连接数据库需要引入jdbc支持,在pom.xml中引入如下配置:
<dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-jdbc</artifactId> </dependency>
(2)嵌入式数据库支持
嵌入式数据库通常用于开发和测试环境,不推荐用于生产环境。Spring Boot提供自动配置的嵌入式数据库有H2、HSQL、Derby,你不需要提供任何连接配置就能使用。
<dependency> <groupId>org.hsqldb</groupId> <artifactId>hsqldb</artifactId> <scope>runtime</scope> </dependency>
(3)连接生产数据源
(4)使用JdbcTemplate操作数据库
Spring的JdbcTemplate是自动配置的,你可以直接使用@Autowired来注入到你自己的bean中来使用。
import org.springframework.beans.factory.annotation.Autowired; import org.springframework.jdbc.core.JdbcTemplate; import org.springframework.stereotype.Component; @Component public class MyBean { private final JdbcTemplate jdbcTemplate; @Autowired public MyBean(JdbcTemplate jdbcTemplate) { this.jdbcTemplate = jdbcTemplate; } // ... }
案例:
package com.forezp.dao.impl; import com.forezp.dao.IAccountDAO; import com.forezp.entity.Account; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.jdbc.core.BeanPropertyRowMapper; import org.springframework.jdbc.core.JdbcTemplate; import org.springframework.stereotype.Repository; import java.util.List; @Repository public class AccountDaoImpl implements IAccountDAO { @Autowired private JdbcTemplate jdbcTemplate; @Override public int add(Account account) { return jdbcTemplate.update("insert into account(name, money) values(?, ?)", account.getName(),account.getMoney()); } @Override public int update(Account account) { return jdbcTemplate.update("UPDATE account SET NAME=? ,money=? WHERE id=?", account.getName(),account.getMoney(),account.getId()); } @Override public int delete(int id) { return jdbcTemplate.update("DELETE from TABLE account where id=?",id); } @Override public Account findAccountById(int id) { List<Account> list = jdbcTemplate.query("select * from account where id = ?", new Object[]{id}, new BeanPropertyRowMapper(Account.class)); if(list!=null && list.size()>0){ Account account = list.get(0); return account; }else{ return null; } } @Override public List<Account> findAccountList() { List<Account> list = jdbcTemplate.query("select * from account", new Object[]{}, new BeanPropertyRowMapper(Account.class)); if(list!=null && list.size()>0){ return list; }else{ return null; } } }
JPA全称Java Persistence API.JPA通过JDK 5.0注解或XML描述对象-关系表的映射关系,并将运行期的实体对象持久化到数据库中。
JPA 的目标之一是制定一个可以由很多供应商实现的API,并且开发人员可以编码来实现该API,而不是使用私有供应商特有的API。
JPA就是Hibernate功能的一个子集。
案例:
spring: datasource: driver-class-name: com.mysql.cj.jdbc.Driver url: jdbc:mysql://mysql3:3306/test?useUnicode=true&characterEncoding=utf8&characterSetResults=utf8 username: root password: root jpa: hibernate: ddl-auto: update # 第一次简表create 后面用update show-sql: true
pom.xml
<dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-data-jpa</artifactId> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>8.0.26</version> </dependency>
dao:
public interface AccountDao extends JpaRepository<Account,Integer> { }
controller:
package com.forezp.web; import com.forezp.dao.AccountDao; import com.forezp.entity.Account; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.web.bind.annotation.*; import java.util.List; /** * 这里省略了service层,实际开发加上; */ @RestController @RequestMapping("/account") public class AccountController { @Autowired AccountDao accountDao; @RequestMapping(value = "/list", method = RequestMethod.GET) public List<Account> getAccounts() { return accountDao.findAll(); } @RequestMapping(value = "/{id}", method = RequestMethod.GET) public Account getAccountById(@PathVariable("id") int id) { return accountDao.findOne(id); } @RequestMapping(value = "/{id}", method = RequestMethod.PUT) public String updateAccount(@PathVariable("id") int id, @RequestParam(value = "name", required = true) String name, @RequestParam(value = "money", required = true) double money) { Account account = new Account(); account.setMoney(money); account.setName(name); account.setId(id); Account account1 = accountDao.saveAndFlush(account); return account1.toString(); } @RequestMapping(value = "", method = RequestMethod.POST) public String postAccount(@RequestParam(value = "name") String name, @RequestParam(value = "money") double money) { Account account = new Account(); account.setMoney(money); account.setName(name); Account account1 = accountDao.save(account); return account1.toString(); } }
外藩:
敏捷开发之beatlsql应用
beetlSql是一个全功能DAO工具, 同时具有Hibernate 优点 & Mybatis优点功能,适用于承认以SQL为中心,同时又需求工具能自动能生成大量常用的SQL的应用。
beatlsql 优点
- 开发效率
- 无需注解,自动使用大量内置SQL,轻易完成增删改查功能,节省50%的开发工作量
- 数据模型支持Pojo,也支持Map/List这种快速模型,也支持混合模型
- SQL 模板基于Beetl实现,更容易写和调试,以及扩展
- 维护性
- SQL 以更简洁的方式,Markdown方式集中管理,同时方便程序开发和数据库SQL调试。
- 可以自动将sql文件映射为dao接口类
- 灵活直观的支持支持一对一,一对多,多对多关系映射而不引入复杂的OR Mapping概念和技术。
- 具备Interceptor功能,可以调试,性能诊断SQL,以及扩展其他功能
- 其他
- 内置支持主从数据库支持的开源工具
- 支持跨数据库平台,开发者所需工作减少到最小,目前跨数据库支持mysql,postgres,oracle,sqlserver,h2,sqllite,DB2.
beatlsql文档:
http://www.ibeetl.com/guide/#/beetlsql
案例:
项目结构:

pom.xml
<!-- beetlsql --> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-devtools</artifactId> <optional>true</optional> </dependency> <dependency> <groupId>com.ibeetl</groupId> <artifactId>beetl</artifactId> <version>2.3.2</version> </dependency> <dependency> <groupId>com.ibeetl</groupId> <artifactId>beetlsql</artifactId> <version>2.3.1</version> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>8.0.26</version> </dependency>
由于springboot没有对 beatlsql的快速启动装配,所以需要我自己导入相关的bean,包括数据源,包扫描,事务管理器等。
package com.forezp; import org.beetl.core.resource.WebAppResourceLoader; import org.beetl.ext.spring.BeetlGroupUtilConfiguration; import org.beetl.ext.spring.BeetlSpringViewResolver; import org.beetl.sql.core.ClasspathLoader; import org.beetl.sql.core.Interceptor; import org.beetl.sql.core.UnderlinedNameConversion; import org.beetl.sql.core.db.MySqlStyle; import org.beetl.sql.ext.DebugInterceptor; import org.beetl.sql.ext.spring4.BeetlSqlDataSource; import org.beetl.sql.ext.spring4.BeetlSqlScannerConfigurer; import org.beetl.sql.ext.spring4.SqlManagerFactoryBean; import org.springframework.beans.factory.annotation.Qualifier; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.boot.jdbc.DataSourceBuilder; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Primary; import org.springframework.core.io.DefaultResourceLoader; import org.springframework.core.io.support.ResourcePatternResolver; import org.springframework.core.io.support.ResourcePatternUtils; import org.springframework.jdbc.datasource.DataSourceTransactionManager; import javax.sql.DataSource; import java.io.IOException; @SpringBootApplication public class SpringbootBeatlsqlApplication { public static void main(String[] args) { SpringApplication.run(SpringbootBeatlsqlApplication.class, args); } //配置文件 @Bean(initMethod = "init", name = "beetlConfig") public BeetlGroupUtilConfiguration getBeetlGroupUtilConfiguration() { BeetlGroupUtilConfiguration beetlGroupUtilConfiguration = new BeetlGroupUtilConfiguration(); ResourcePatternResolver patternResolver = ResourcePatternUtils.getResourcePatternResolver(new DefaultResourceLoader()); try { // WebAppResourceLoader 配置root路径是关键 WebAppResourceLoader webAppResourceLoader = new WebAppResourceLoader(patternResolver.getResource("classpath:/templates").getFile().getPath()); beetlGroupUtilConfiguration.setResourceLoader(webAppResourceLoader); } catch (IOException e) { e.printStackTrace(); } //读取配置文件信息 return beetlGroupUtilConfiguration; } @Bean(name = "beetlViewResolver") public BeetlSpringViewResolver getBeetlSpringViewResolver(@Qualifier("beetlConfig") BeetlGroupUtilConfiguration beetlGroupUtilConfiguration) { BeetlSpringViewResolver beetlSpringViewResolver = new BeetlSpringViewResolver(); beetlSpringViewResolver.setContentType("text/html;charset=UTF-8"); beetlSpringViewResolver.setOrder(0); beetlSpringViewResolver.setConfig(beetlGroupUtilConfiguration); return beetlSpringViewResolver; } //配置包扫描 @Bean(name = "beetlSqlScannerConfigurer") public BeetlSqlScannerConfigurer getBeetlSqlScannerConfigurer() { BeetlSqlScannerConfigurer conf = new BeetlSqlScannerConfigurer(); conf.setBasePackage("com.forezp.dao"); conf.setDaoSuffix("Dao"); conf.setSqlManagerFactoryBeanName("sqlManagerFactoryBean"); return conf; } @Bean(name = "sqlManagerFactoryBean") @Primary public SqlManagerFactoryBean getSqlManagerFactoryBean(@Qualifier("datasource") DataSource datasource) { SqlManagerFactoryBean factory = new SqlManagerFactoryBean(); BeetlSqlDataSource source = new BeetlSqlDataSource(); source.setMasterSource(datasource); factory.setCs(source); factory.setDbStyle(new MySqlStyle()); factory.setInterceptors(new Interceptor[]{new DebugInterceptor()}); factory.setNc(new UnderlinedNameConversion());//开启驼峰 factory.setSqlLoader(new ClasspathLoader("/sql"));//sql文件路径 return factory; } //配置数据库 @Bean(name = "datasource") public DataSource getDataSource() { return DataSourceBuilder.create() .url("jdbc:mysql://mysql3:3306/test?useUnicode=true&characterEncoding=utf8&useSSL=false&serverTimezone=Asia/Shanghai") .username("root") .password("root") .driverClassName("com.mysql.cj.jdbc.Driver") .build(); } //开启事务 @Bean(name = "txManager") public DataSourceTransactionManager getDataSourceTransactionManager(@Qualifier("datasource") DataSource datasource) { DataSourceTransactionManager dsm = new DataSourceTransactionManager(); dsm.setDataSource(datasource); return dsm; } }
在resouces包下,加META_INF文件夹,文件夹中加入spring-devtools.properties:
restart.include.beetl=/beetl-2.3.2.jar
restart.include.beetlsql=/beetlsql-2.3.1.jar
在templates下加一个index.btl文件。
total = ${total}
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