JDK20 + SpringBoot 3.1.0 + JdbcTemplate 使用

通过 JdbcTemplate 直接执行 SQL 语句，结合源码动态编译即可方便实现动态修改代码逻辑的效果

一.测试数据库 Postgres

-- public.tb_rabbit_basic definition-- Drop table-- DROP TABLE public.tb_rabbit_basic;CREATE TABLE public.tb_rabbit_basic (id int4 NULL,animal_name varchar NULL,country varchar NULL
);

二.SpringBoot项目

1.Pom 依赖

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"><modelVersion>4.0.0</modelVersion><groupId>org.example</groupId><artifactId>JdbcTemplateDemo</artifactId><version>1.0-SNAPSHOT</version><build><plugins><plugin><groupId>org.apache.maven.plugins</groupId><artifactId>maven-compiler-plugin</artifactId><configuration><source>18</source><target>18</target></configuration></plugin></plugins></build><properties><maven.compiler.source>20</maven.compiler.source><maven.compiler.target>20</maven.compiler.target><project.build.sourceEncoding>UTF-8</project.build.sourceEncoding><spring-boot.version>3.1.0</spring-boot.version></properties><!--配置阿里云依赖包和插件仓库--><repositories><repository><id>aliyun</id><url>https://maven.aliyun.com/repository/central/</url><releases><enabled>true</enabled></releases><snapshots><enabled>true</enabled></snapshots></repository></repositories><dependencies><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId><version>${spring-boot.version}</version></dependency><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId><version>1.18.26</version></dependency><!--druid--><dependency><groupId>com.alibaba</groupId><artifactId>druid-spring-boot-starter</artifactId><version>1.2.16</version><exclusions><exclusion><groupId>org.springframework.boot</groupId><artifactId>spring-boot-autoconfigure</artifactId></exclusion><exclusion><groupId>org.slf4j</groupId><artifactId>slf4j-api</artifactId></exclusion></exclusions></dependency><!--        mybatis--><dependency><groupId>org.mybatis.spring.boot</groupId><artifactId>mybatis-spring-boot-starter</artifactId><version>3.0.2</version><exclusions><exclusion><groupId>org.springframework.boot</groupId><artifactId>spring-boot-autoconfigure</artifactId></exclusion><exclusion><groupId>org.slf4j</groupId><artifactId>slf4j-api</artifactId></exclusion></exclusions></dependency><!-- pgsql --><dependency><groupId>org.postgresql</groupId><artifactId>postgresql</artifactId><version>42.6.0</version></dependency></dependencies>
</project>

2.配置文件

server:port: 8081spring:datasource:postgres:readTimeout: 259200000 # 3 * 24 * 60 * 60 * 1000druid:username: postgrespassword: 123456url: jdbc:postgresql://127.0.0.1:5432/wiki_animal_dbdriverClassName: org.postgresql.Drivertype: com.alibaba.druid.pool.DruidDataSource# 下面为连接池的补充设置，应用到上面所有数据源中# 初始化大小，最小，最大initial-size: 5min-idle: 5max-active: 20# 配置获取连接等待超时的时间max-wait: 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time-between-eviction-runs-millis: 60000# 配置一个连接在池中最小生存的时间，单位是毫秒min-evictable-idle-time-millis: 300000validation-query: select version()test-while-idle: truetest-on-borrow: falsetest-on-return: false# 打开PSCache，并且指定每个连接上PSCache的大小pool-prepared-statements: true#   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max-pool-prepared-statement-per-connection-size: 20filters: stat,walluse-global-data-source-stat: true# 通过connectProperties属性来打开mergeSql功能；慢SQL记录connect-properties: druid.stat.mergeSql=true;druid.stat.slowSqlMillis=5000

3.启动类

package org.example;import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;/*** @author moon*/
@SpringBootApplication
public class JdbcApp {public static void main(String[] args) {SpringApplication.run(JdbcApp.class, args);}
}

4.数据源配置类

package org.example.config;import com.alibaba.druid.pool.DruidDataSource;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;
import org.springframework.jdbc.core.JdbcTemplate;import java.sql.SQLException;
import java.util.Properties;/*** @author moon* @date 2023-09-12 12:00* @since 1.8*/
@Slf4j
@Configuration
public class PostgresDataSource {/*** Postgres readTimeout 超时 暂定 3D 可能导致存在大量 socket 死链接*/@Value("${spring.datasource.postgres.readTimeout}")private int readTimeout;@Bean(name = "druidProperties")@ConfigurationProperties(prefix = "spring.datasource")public Properties druidProperties(){return new Properties();}/*** @description: 数据源* @params: [properties]* @return: com.alibaba.druid.pool.DruidDataSource* @create: 2023-09-12*/@Primary@Bean(name = "druidDataSource")public DruidDataSource druidDataSource(@Qualifier("druidProperties") Properties properties){DruidDataSource druidDataSource = new DruidDataSource();druidDataSource.configFromPropety(properties);try {druidDataSource.setSocketTimeout(readTimeout);druidDataSource.init();} catch (SQLException e) {log.error("Postgres Datasource Init Exception:",e);}return druidDataSource;}/*** jdbc template* @param druidDataSource* @return*/@Bean(name = "postgresTemplate")public JdbcTemplate postgresTemplate(@Qualifier("druidDataSource") DruidDataSource druidDataSource){return new JdbcTemplate(druidDataSource);}
}

5.实体对象类包装类

用于配置实体对象类，方便解析 JdbcTemplate 查询的返回值

package org.example.config;import lombok.extern.slf4j.Slf4j;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.beans.BeanUtils;
import org.springframework.beans.BeanWrapperImpl;
import org.springframework.beans.NotWritablePropertyException;
import org.springframework.beans.TypeMismatchException;
import org.springframework.dao.DataRetrievalFailureException;
import org.springframework.dao.InvalidDataAccessApiUsageException;
import org.springframework.jdbc.core.RowMapper;
import org.springframework.jdbc.support.JdbcUtils;
import org.springframework.lang.Nullable;
import org.springframework.stereotype.Component;
import org.springframework.util.ClassUtils;
import org.springframework.util.StringUtils;import java.beans.PropertyDescriptor;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.util.*;
import java.util.concurrent.Semaphore;
import java.util.concurrent.TimeUnit;/*** @author moon* @date 2023-09-11 18:08* @since 1.8*/
@Slf4j
@Component
public class ColumnRowMap {private Map<String,MultiColumnRowMapper> map = new HashMap<>(16);Semaphore semaphore = new Semaphore(1);/*** 获取类包装对象* @param clazz* @return*/public MultiColumnRowMapper getColumnRowMap(Class<?> clazz) {while (true){boolean acquire = false;try {acquire = semaphore.tryAcquire(3, TimeUnit.SECONDS);if (acquire){MultiColumnRowMapper mapper = map.get(clazz.getName());if (null == mapper){mapper = new MultiColumnRowMapper<>(clazz);map.put(clazz.getName(),mapper);}//返回return mapper;}} catch (InterruptedException e) {log.error("get column row map exception:",e);} finally {if (acquire){semaphore.release();}}}}static class MultiColumnRowMapper<T> implements RowMapper<T> {/*** 日志*/protected final Log logger = LogFactory.getLog(this.getClass());/*** 转换类型*/@Nullableprivate Class<T> requiredType;/*** 缓存类属性*/@Nullableprivate Map<String, PropertyDescriptor> mappedFields;@Nullableprivate Set<String> mappedProperties;private boolean primitivesDefaultedForNullValue = true;/*** 是否校验属性一致*/private boolean checkFullyPopulated = false;public void setCheckFullyPopulated(boolean checkFullyPopulated) {this.checkFullyPopulated = checkFullyPopulated;}public boolean isCheckFullyPopulated() {return this.checkFullyPopulated;}public void setPrimitivesDefaultedForNullValue(boolean primitivesDefaultedForNullValue) {this.primitivesDefaultedForNullValue = primitivesDefaultedForNullValue;}public boolean isPrimitivesDefaultedForNullValue() {return this.primitivesDefaultedForNullValue;}/*** 构造并解析目标类属性信息* @param requiredType*/public MultiColumnRowMapper(Class<T> requiredType) {this.requiredType = requiredType;init();}/*** 解析属性*/private void init(){PropertyDescriptor[] var2 = BeanUtils.getPropertyDescriptors(requiredType);int var3 = var2.length;this.mappedFields = new HashMap(var3);this.mappedProperties = new HashSet(var3);for(int var4 = 0; var4 < var3; ++var4) {PropertyDescriptor pd = var2[var4];if (pd.getWriteMethod() != null) {String lowerCaseName = this.lowerCaseName(pd.getName());this.mappedFields.put(lowerCaseName, pd);String underscoreName = this.underscoreName(pd.getName());if (!lowerCaseName.equals(underscoreName)) {this.mappedFields.put(underscoreName, pd);}this.mappedProperties.add(pd.getName());}}}/*** 将返回信息转为指定类对象* @param rs* @param rowNumber* @return* @throws SQLException*/@Nullablepublic T mapRow(ResultSet rs, int rowNumber) throws SQLException {ResultSetMetaData rsmd = rs.getMetaData();int columnCount = rsmd.getColumnCount();T mappedObject = BeanUtils.instantiateClass(requiredType);Set<String> populatedProperties = this.isCheckFullyPopulated() ? new HashSet() : null;BeanWrapperImpl bw = new BeanWrapperImpl();bw.setBeanInstance(mappedObject);PropertyDescriptor pd;for(int index = 1; index <= columnCount; ++index) {String column = JdbcUtils.lookupColumnName(rsmd, index);String field = this.lowerCaseName(StringUtils.delete(column, " "));pd = this.mappedFields != null ? this.mappedFields.get(field) : null;if (pd != null) {try {Object value = this.getColumnValue(rs, index, pd);if (rowNumber == 0 && this.logger.isDebugEnabled()) {this.logger.debug("Mapping column '" + column + "' to property '" + pd.getName() + "' of type '" + ClassUtils.getQualifiedName(pd.getPropertyType()) + "'");}try {bw.setPropertyValue(pd.getName(), value);} catch (TypeMismatchException var14) {if (value != null || !this.primitivesDefaultedForNullValue) {throw var14;}if (this.logger.isDebugEnabled()) {this.logger.debug("Intercepted TypeMismatchException for row " + rowNumber + " and column '" + column + "' with null value when setting property '" + pd.getName() + "' of type '" + ClassUtils.getQualifiedName(pd.getPropertyType()) + "' on object: " + mappedObject, var14);}}if (populatedProperties != null) {populatedProperties.add(pd.getName());}} catch (NotWritablePropertyException var15) {throw new DataRetrievalFailureException("Unable to map column '" + column + "' to property '" + pd.getName() + "'", var15);}}}//校验属性一致性if (populatedProperties != null && !populatedProperties.equals(this.mappedProperties)) {throw new InvalidDataAccessApiUsageException("Given ResultSet does not contain all fields necessary to populate object of " + this.requiredType.getName() + ": " + this.mappedProperties);} else {return mappedObject;}}@Nullableprotected Object getColumnValue(ResultSet rs, int index, PropertyDescriptor pd) throws SQLException {return JdbcUtils.getResultSetValue(rs, index, pd.getPropertyType());}protected String lowerCaseName(String name) {return name.toLowerCase(Locale.US);}protected String underscoreName(String name) {if (!StringUtils.hasLength(name)) {return "";} else {StringBuilder result = new StringBuilder();result.append(Character.toLowerCase(name.charAt(0)));for(int i = 1; i < name.length(); ++i) {char c = name.charAt(i);if (Character.isUpperCase(c)) {result.append('_').append(Character.toLowerCase(c));} else {result.append(c);}}return result.toString();}}}}

6.测试用实体对象

1.基类

package org.example.entity;import lombok.Data;/*** @author moon* @date 2023-09-12 10:45* @since 1.8*/
@Data
public class BaseAnimal {private int id;private String animalName;private String country;}

2.扩展类

package org.example.entity;/*** @author moon* @date 2023-09-12 10:48* @since 1.8*/
public class Rabbit extends BaseAnimal{
}

7.测试类

package org.example.controller;import jakarta.annotation.Resource;
import lombok.extern.slf4j.Slf4j;
import org.example.config.ColumnRowMap;
import org.example.entity.Rabbit;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.support.rowset.SqlRowSet;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;import java.util.ArrayList;
import java.util.List;
import java.util.Map;/*** @author moon* @date 2023-09-12 11:52* @since 1.8*/
@Slf4j
@RestController
@RequestMapping("/animal")
public class AnimalController {@Resource(name = "postgresTemplate")private JdbcTemplate postgresTemplate;@Autowiredprivate ColumnRowMap columnRowMap;/*** 插入 通过 ? 参数占位符*/@GetMapping("/insert")public void insert(){postgresTemplate.update("INSERT INTO PUBLIC.TB_RABBIT_BASIC (ID, ANIMAL_NAME, COUNTRY) VALUES (?,?,?)",18,"海棠兔","法国");}/*** 批量插入*/@GetMapping("/batchInsert")public void batchInsert(){List<Object[]> list = new ArrayList<>(3);list.add(new Object[]{19,"海棠兔","法国"});list.add(new Object[]{20,"喜马拉雅兔","中国"});list.add(new Object[]{30,"野兔","比利时"});postgresTemplate.batchUpdate("INSERT INTO PUBLIC.TB_RABBIT_BASIC (ID, ANIMAL_NAME, COUNTRY) VALUES (?,?,?)",list);}/*** 更新*/@GetMapping("/update")public void update(){postgresTemplate.update("UPDATE PUBLIC.TB_RABBIT_BASIC SET COUNTRY = ? WHERE ID = ?","法国+",19);}/*** 更新*/@GetMapping("/batchUpdate")public void batchUpdate(){List<Object[]> list = new ArrayList<>(3);list.add(new Object[]{"法国+++",19});list.add(new Object[]{"中国+++",20});list.add(new Object[]{"比利时+++",30});postgresTemplate.batchUpdate("UPDATE PUBLIC.TB_RABBIT_BASIC SET COUNTRY = ? WHERE ID = ?",list);}/*** 删除*/@GetMapping("/delete")public void delete(){postgresTemplate.update("DELETE FROM PUBLIC.TB_RABBIT_BASIC WHERE ID = ?",19);}/*** 批量删除*/@GetMapping("/batchDelete")public int[] batchDelete(){List<Object[]> list = new ArrayList<>();list.add(new Object[]{19});list.add(new Object[]{20});list.add(new Object[]{30});int[] result = postgresTemplate.batchUpdate("DELETE FROM PUBLIC.TB_RABBIT_BASIC WHERE ID = ?",list);return  result;}/*** 查询 select ** @return*/@GetMapping("/queryForMap")public Map<String, Object> queryForMap(){return postgresTemplate.queryForMap("SELECT * FROM PUBLIC.TB_RABBIT_BASIC WHERE ID = ?",18);}/*** 查询 query for row set* @return*/@GetMapping("/queryForRowSet")public void queryForRowSet(){SqlRowSet rowSet = postgresTemplate.queryForRowSet("SELECT * FROM PUBLIC.TB_RABBIT_BASIC WHERE ID = ?",18);while (rowSet.next()){int rowId = rowSet.getRow();Integer ID = rowSet.getInt("ID");String ANIMAL_NAME = rowSet.getString("ANIMAL_NAME");String COUNTRY = rowSet.getString("COUNTRY");log.info("rowId {} id {} animalName {} country {}",rowId,ID,ANIMAL_NAME,COUNTRY);}}/*** 查询 query for object* @return*/@GetMapping("/queryForObject")public Object queryForObject(){return postgresTemplate.queryForObject("SELECT ID AS id FROM PUBLIC.TB_RABBIT_BASIC WHERE ID = ?", Integer.class,18);}/*** 查询 query for object* @return*/@GetMapping("/queryForObjectMapper")public Object queryForObjectMapper(){return postgresTemplate.queryForObject("SELECT ID AS id, ANIMAL_NAME AS animalName, COUNTRY AS country FROM PUBLIC.TB_RABBIT_BASIC WHERE ID = ?",columnRowMap.getColumnRowMap(Rabbit.class),18);}/*** 查询 query for object* @return*/@GetMapping("/queryForList")public List<Map<String, Object>> queryForList(){return postgresTemplate.queryForList("SELECT ID AS id, ANIMAL_NAME AS animalName, COUNTRY AS country FROM PUBLIC.TB_RABBIT_BASIC");}/*** 查询 query for object class* @return*/@GetMapping("/queryForListClass")public List<Rabbit> queryForListClass(){return postgresTemplate.query("SELECT ID AS id, ANIMAL_NAME AS animalName, COUNTRY AS country FROM PUBLIC.TB_RABBIT_BASIC",columnRowMap.getColumnRowMap(Rabbit.class));}
}

以批量查询为例：http://127.0.0.1:8081/animal/queryForListClass