【Java/MySql】使用JDBC访问MySql数据库的Maven工程

下载链接：https://files.cnblogs.com/files/xiandedanteng/FindNotnullColumns20191102-1.rar

pom.xml里写：

<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>com.hy</groupId>
      <artifactId>FindNotnullColumns</artifactId>
      <version>0.0.1-SNAPSHOT</version>
  
      <dependencies>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.38</version>
        </dependency>
    
        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.17</version>
        </dependency>
    </dependencies>
</project>

代码：

package com.hy;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.text.MessageFormat;

import org.apache.log4j.Logger;

public class Test {
    private static Logger log = Logger.getLogger(Test.class);

    private static final String JDBC_DRIVER = "com.mysql.jdbc.Driver";
    private static final String DB_URL = "jdbc:mysql://192.168.161.129:3306/test";
    private static final String USER = "root";
    private static final String PSWD = "12345678";

    public static void main(String[] args) {
        Connection conn = null;
        Statement stmt = null;

        try {
            Class.forName(JDBC_DRIVER).newInstance();
            conn = DriverManager.getConnection(DB_URL, USER, PSWD);

            stmt = conn.createStatement();
            String sql = "select id,name,age,cdate from emp order by id limit 10";
            ResultSet rs = stmt.executeQuery(sql);

            int index = 0;
            while (rs.next()) {
                index++;

                String id = rs.getString("id");
                String name = rs.getString("name");
                String age = rs.getString("age");
                String cdate = rs.getString("cdate");

                String raw = "#{0},{1},{2},{3},{4}";
                Object[] arr = { index, id, name, age, cdate };
                String outStr = MessageFormat.format(raw, arr);
                log.info(outStr);
            }
        } catch (Exception e) {
            System.out.print("DB/SQL ERROR:" + e.getMessage());
        } finally {
            try {
                stmt.close();
                conn.close();
            } catch (SQLException e) {
                System.out.print("Can't close stmt/conn because of " + e.getMessage());
            }
            
        }
    }
}

输出：

 INFO [main] - #1,8035200,E:8035200,0,2018-02-02 00:00:00.0
 INFO [main] - #2,8035201,E:8035201,1,2018-02-02 00:00:01.0
 INFO [main] - #3,8035202,E:8035202,2,2018-02-02 00:00:02.0
 INFO [main] - #4,8035203,E:8035203,3,2018-02-02 00:00:03.0
 INFO [main] - #5,8035204,E:8035204,4,2018-02-02 00:00:04.0
 INFO [main] - #6,8035205,E:8035205,5,2018-02-02 00:00:05.0
 INFO [main] - #7,8035206,E:8035206,6,2018-02-02 00:00:06.0
 INFO [main] - #8,8035207,E:8035207,7,2018-02-02 00:00:07.0
 INFO [main] - #9,8035208,E:8035208,8,2018-02-02 00:00:08.0
 INFO [main] - #10,8035209,E:8035209,9,2018-02-02 00:00:09.0

--END-- 2019年11月2日08:12:09