mysql版本:  8.0.11

java版本: 8

maven版本: 3.6.3

 

mave依赖

        <dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><version>8.0.18</version></dependency><dependency><groupId>org.apache.commons</groupId><artifactId>commons-dbcp2</artifactId><version>2.6.0</version></dependency>

java代码

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.dbcp2.BasicDataSource;
import org.apache.commons.dbcp2.BasicDataSourceFactory;
import org.springframework.core.io.ClassPathResource;import java.io.File;
import java.io.FileInputStream;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.URL;
import java.nio.charset.StandardCharsets;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.Statement;
import java.util.*;@AllArgsConstructor
@NoArgsConstructor
@Data
@Slf4j
public class DbcpDataSourceService {private BasicDataSource dataSource;private String propertiesFile;private Properties properties;private String describe;public DbcpDataSourceService(String propertiesFile) {this.propertiesFile = propertiesFile;initDataSource();}public void initDataSource() {try {long currentTimeMillis = System.currentTimeMillis();//获取配置文件，转换成流InputStream in = null;try {// 开发环境URL url = DbcpDataSourceService.class.getClassLoader().getResource(propertiesFile);File file = new File(url.getFile());in = new FileInputStream(file);} catch (Exception e) {}if (in == null) {// 达成jar包部署之后ClassPathResource classPathResource = new ClassPathResource(propertiesFile);in = classPathResource.getInputStream();}//创建properties对象properties = new Properties();//加载流properties.load(new InputStreamReader(in, StandardCharsets.UTF_8));//创建dataSource对象dataSource = BasicDataSourceFactory.createDataSource(properties);describe = new String(this.properties.getProperty("describe").getBytes(), StandardCharsets.UTF_8);log.info("【{}】数据库连接池 初始化成功, 耗时:【{}】毫秒", describe, System.currentTimeMillis() - currentTimeMillis);} catch (Exception e) {e.printStackTrace();}}public void execute(String sql) {if (dataSource == null) {log.warn("数据库连接池实例为空");return;}try (Connection conn = dataSource.getConnection();Statement statement = conn.createStatement();) {long startTime = System.currentTimeMillis();Class.forName(this.properties.getProperty("driverClassName"));statement.execute(sql);log.info("执行sql成功,sql:【{}】, 运行时长:【{}】毫秒", sql, System.currentTimeMillis() - startTime);} catch (Exception e) {log.error("sql执行失败:【{}】", sql, e);}}public List<List<String>> query(String sql) {return query(sql, Boolean.FALSE);}public List<List<String>> query(String sql, Boolean returnColumnName) {if (dataSource == null) {log.warn("数据库连接池实例为空");return null;}long startTime = System.currentTimeMillis();try (Connection conn = dataSource.getConnection();Statement stmt = conn.createStatement();) {ResultSet rs = stmt.executeQuery(sql);ResultSetMetaData resultSetMetaData = rs.getMetaData();int column = resultSetMetaData.getColumnCount();List<List<String>> result = new LinkedList<>();if (returnColumnName) {List<String> title = new ArrayList<>();for (int i = 1; i <= column; i++) {title.add(resultSetMetaData.getColumnName(i));}result.add(title);}while (rs.next()) {List<String> list = new LinkedList<>();for (int i = 1; i <= column; i++) {list.add(rs.getString(i));}result.add(list);}log.info("查询sql:【{}】, 运行时长:【{}】毫秒", sql, System.currentTimeMillis() - startTime);return result;} catch (Exception e) {log.error("sql查询失败:【{}】", sql, e);return null;}}public void print(String sql) {print(query(sql, Boolean.TRUE));}public void print(List<List<String>> res) {Map<Integer, Integer> columnMaxLength = new HashMap<>();for (int i = 0; i < res.size(); i++) {List<String> strings = res.get(i);for (int k = 0; k < strings.size(); k++) {if (!columnMaxLength.containsKey(k)) {columnMaxLength.put(k, 0);}if (strings.get(k) == null) {continue;}int length = strings.get(k).getBytes().length;if (length > columnMaxLength.get(k)) {columnMaxLength.put(k, length);}}}for (int i = 0; i < res.size(); i++) {List<String> strings = res.get(i);for (int k = 0; k < strings.size(); k++) {System.out.format("%-" + (columnMaxLength.get(k) + 5) + "s", strings.get(k));}System.out.println();}}@Overrideprotected void finalize() throws Throwable {close();super.finalize();}public void close() {try {dataSource.close();log.info("【{}】连接池执行关闭", describe);} catch (Exception e) {}}
}

使用

DbcpDataSourceService ddss = new DbcpDataSourceService("test.properties");
ddss.print("show databases");
ddss.print("show tables");
ddss.close();

test.properties

driverClassName=com.mysql.jdbc.Driverurl=jdbc:mysql://127.0.0.1:3360/test?useUnicode=true&useSSL=false&characterEncoding=utf-8&serverTimezone=GMT%2b8&allowMultiQueries=true&allowPublicKeyRetrieval=trueusername=rootpassword=123456initialSize=1maxTotal=3maxIdle=2minIdle=1maxWaitMillis=1000testOnBorrow=truevalidationQuery=select 1describe=测试

说明

initialSize  初始化连接，连接池启动时创建的初始化连接数量（默认值为0）maxActive  最大活动连接，连接池中可同时连接的最大的连接数（默认值为8）minIdle 最小空闲连接，连接池中最小的空闲的连接数，低于这个数量会被创建新的连接（默认为0，该参数越接近maxIdle，性能越好，因为连接的创建和销毁，都是需要消耗资源的；但是不能太大，因为在机器很空闲的时候，也会创建低于minidle个数的连接，类似于jvm参数中的Xmn设置）maxIdle   最大空闲连接，连接池中最大的空闲的连接数，超过的空闲连接将被释放，如果设置为负数表示不限制（默认为8个，maxIdle不能设置太小，因为假如在高负载的情况下，连接的打开时间比关闭的时间快，会引起连接池中idle的个数上升超过maxIdle，而造成频繁的连接销毁和创建，类似于jvm参数中的Xmx设置)maxWait 从池中取连接的最大等待时间，单位ms.当没有可用连接时，连接池等待连接释放的最大时间，超过该时间限制会抛出异常，如果设置-1表示无限等待（默认为无限）validationQuery 验证使用的SQL语句testWhileIdle    指明连接是否被空闲连接回收器(如果有)进行检验.如果检测失败,则连接将被从池中去除.testOnBorrow    借出连接时不要测试，否则很影响性能。一定要配置，因为它的默认值是true。false表示每次从连接池中取出连接时，不需要执行validationQuery = "SELECT 1" 中的SQL进行测试。若配置为true,对性能有非常大的影响，性能会下降7-10倍。timeBetweenEvictionRunsMillis每30秒运行一次空闲连接回收器，配置timeBetweenEvictionRunsMillis = "30000"后，每30秒运行一次空闲连接回收器（独立线程）。并每次检查3个连接，如果连接空闲时间超过30分钟就销毁。销毁连接后，连接数量就少了，如果小于minIdle数量，就新建连接，维护数量不少于minIdle，过行了新老更替。minEvictableIdleTimeMillis池中的连接空闲30分钟后被回收numTestsPerEvictionRun在每次空闲连接回收器线程(如果有)运行时检查的连接数量removeAbandoned连接泄漏回收参数，当可用连接数少于3个时才执行removeAbandonedTimeout连接泄漏回收参数，180秒，泄露的连接可以被删除的超时值