postgresql数据库服务启动创建数据库

postgresql  sql语句不支持判断数据库是否存在，也不支持数据库连接url后面加createDatabaseIfNotExist=true

yml配置

spring:
  servlet:
    multipart:
      max-request-size: 100MB
      max-file-size: 100MB
  datasource:
    type: com.alibaba.druid.pool.DruidDataSource
    driver-class-name: org.postgresql.Driver
    url: jdbc:postgresql://12.0.0.1/test?useUnicode=true&currentSchema=public&zeroDateTimeBehavior=convertToNull&characterEncoding=UTF-8&allowMultiQueries=true&serverTimezone=Asia/Shanghai
    username: 
    password: 

package com.aaaa.test;

import com.sun.org.apache.xerces.internal.util.URI;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.context.annotation.Configuration;
import org.springframework.beans.factory.annotation.Value;
import javax.annotation.PostConstruct;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;

@Configuration
public class DataSourceHelper {

    private Logger log = LoggerFactory.getLogger(DataSourceHelper.class);

    @Value("${spring.datasource.driver-class-name}")
    private String driver;

    @Value("${spring.datasource.url}")
    private String url;

    @Value("${spring.datasource.username}")
    private String username;

    @Value("${spring.datasource.password}")
    private String password;

    @PostConstruct
    public void init() {
        try {
            Class.forName(driver);
            URI uri = new URI(url.replace("jdbc:", ""));
            String host = uri.getHost();
            int port = uri.getPort();
            String path = uri.getPath();
            Connection connection = DriverManager.getConnection("jdbc:postgresql://" + host + ":" + port+"/postgres", username, password);
            Statement statement = connection.createStatement();
            ResultSet resultSet = statement.executeQuery("SELECT u.datname  FROM pg_catalog.pg_database u where u.datname= '"+path.replace("/", "") +"';");
            boolean flag=resultSet.next();
           if(!flag){
               statement.executeUpdate("CREATE DATABASE " + path.replace("/", "") + ";");
           }
            statement.close();
            connection.close();
        } catch (Exception e) {
            log.error(e.getMessage());
        }
    }
}

​