JDK20 + SpringBoot 3.1.0 + JdbcTemplate 使用案例详解
作者：猪悟道
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，这篇文章主要介绍了JDK20 + SpringBoot 3.1.0 + JdbcTemplate 使用,需要的朋友可以参考下
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: 8081
spring:
datasource:
postgres:
readTimeout: 259200000 # 3 * 24 * 60 * 60 * 1000
druid:
username: postgres
password: 123456
url: jdbc:postgresql://127.0.0.1:5432/wiki_animal_db
driverClassName: org.postgresql.Driver
type: 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: 5
min-idle: 5
max-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: 300000
validation-query: select version()
test-while-idle: true
test-on-borrow: false
test-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: 20
filters: stat,wall
use-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=50003.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
*/
@Nullable
private Class<T> requiredType;
/**
* 缓存类属性
*/
@Nullable
private Map<String, PropertyDescriptor> mappedFields;
@Nullable
private 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
*/
@Nullable
public 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;
}
}
@Nullable
protected 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;
@Autowired
private 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
三.SpringBoot 封装的工具类演示
import org.example.entity.Rabbit;
import org.springframework.beans.BeanUtils;
import org.springframework.beans.BeanWrapperImpl;
/**
* @author moon
* @date 2023-09-13 20:38
* @since 1.8
*/
public class Test {
public static void main(String[] args) {
Object t = BeanUtils.instantiateClass(Rabbit.class);
BeanWrapperImpl bean = new BeanWrapperImpl(t);
bean.setPropertyValue("id",1);
System.out.println(t);
}
}
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