Java ResultSet案例讲解

import java.io.FileReader;import java.io.IOException;import java.net.URL;import java.sql.*;import java.util.Properties;

/*** @author 林高禄* @create 2020-06-23-11:12*/ public class JdbcUtils {private static String driver;private static String url;private static String userName;private static String pw;

static{try {Properties p = new Properties();ClassLoader classLoader = JdbcUtils.class.getClassLoader();// 这个路径相对于src的路径来说URL resource = classLoader.getResource("com/lingaolu/file/jdbc.properties");String path = resource.getPath();p.load(new FileReader(path));driver = p.getProperty("driver");url = p.getProperty("url");userName = p.getProperty("user");pw = p.getProperty("password");Class.forName(driver);} catch (IOException e) {e.printStackTrace();} catch (ClassNotFoundException e) {e.printStackTrace();}}

public static Connection createConnection() throws SQLException {return DriverManager.getConnection(url, userName, pw);}

public static void close(Statement stmt,Connection con){if(null != stmt){try {stmt.close();} catch (SQLException e) {e.printStackTrace();}}if(null != con){try {con.close();} catch (SQLException e) {e.printStackTrace();}}}

/*** @author 林高禄* @create 2020-06-24-8:28*/ public class Account {private int id;private String name;private double balance;private int myAge;

public int getId() {return id;}

public void setId(int id) {this.id = id;}

public String getName() {return name;}

public void setName(String name) {this.name = name;}

public double getBalance() {return balance;}

public void setBalance(double balance) {this.balance = balance;}

public int getMyAge() {return myAge;}

public void setMyAge(int myAge) {this.myAge = myAge;}

import com.lingaolu.Utils.JdbcUtils;

import java.sql.*;import java.util.ArrayList;import java.util.List;

/*** @author 林高禄* @create 2020-06-23-17:27*/ public class Demo3 {public static void main(String[] args) {String sql = "select * from account";List accounts = fineAccount(sql);accounts.forEach(System.out::println);System.out.println("----------------------------------");sql = "select * from account where name='张三'";accounts = fineAccount(sql);accounts.forEach(System.out::println);}

public static List fineAccount(String sql){Connection con = null;Statement stmt = null;ResultSet resultSet = null;List rerurnList = new ArrayList<>();try {con = JdbcUtils.createConnection();stmt = con.createStatement();resultSet = stmt.executeQuery(sql);Account acc = null;while(resultSet.next()){// 引号里的字段要与表里的一样int id = resultSet.getInt("id");String name = resultSet.getString("name");double balance = resultSet.getDouble("balance");int age = resultSet.getInt("age");

acc = new Account();acc.setId(id);acc.setName(name);acc.setBalance(balance);acc.setMyAge(age);