你正在从相同的语句中访问结果集。这行不通。您可以创建Statements语句1、2和3的多个示例。然后相应地从每个示例访问结果集。最后，关闭所有连接、结果集和语句.

重新执行Statement关闭上一个ResultSet

你说：
java.sql.SQLException:关闭的结果集
一个Statement一次只能产生一个打开的ResultSet。再次执行该语句会自动关闭前一个ResultSet，同时生成后续的ResultSet。
引用Javadoc for ResultSet（强调我的）：
当生成ResultSet对象的Statement对象关闭、重新执行或用于从多个结果序列中检索下一个结果时，ResultSet对象将自动关闭。
请注意引用中的 re-executed 部分。

修改代码

下面是一个使用H2 Database Engine的完整示例应用程序。
使用集合进行软编码，而不是针对3个输入进行硬编码。
请注意我们是如何将报告与数据库查询分离的。通常最好保持这样的separation of concerns。这使我们能够避免您试图同时处理所有结果集的问题。在下面的代码中，我们将每个ResultSet与put的结果收集到我们的Map中。我们将完整的Map返回给调用代码。然后调用代码将该Map传递给一个专门用于报告（或发送电子邮件，如您的问题中所示）的方法。
顺便说一下，我建议养成使用DataSource来包含数据库登录凭证的习惯。此接口使您的部署更加灵活，可以选择将此信息外部化到代码库之外。
请注意我们如何使用try-with-resources到automatically close，分别为Connection、Statement、PreparedStatement和ResultSet。

package work.basil.example.db;

import org.h2.jdbcx.JdbcDataSource;

import javax.sql.DataSource;
import java.sql.*;
import java.time.OffsetDateTime;
import java.time.ZoneOffset;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ThreadLocalRandom;

public class ExH2 {
    public static void main ( String[] args ) {

        ExH2 app = new ExH2 ( );
        DataSource dataSource = app.obtainDataSource ( );

        app.prepareDatabase ( dataSource );
        List < String > users = List.of ( "Alice" , "Bob" , "Carol" , "Davis" );
        app.populateDatabase ( dataSource , users );
        // app.dumpToConsole ( dataSource );
        Map < String, Integer > countPerUserForCurrentWeek = app.countPerUserForCurrentWeek ( dataSource , users );
        app.report ( countPerUserForCurrentWeek );
    }

    private DataSource obtainDataSource ( ) {
        org.h2.jdbcx.JdbcDataSource ds = new JdbcDataSource ( );  // An implementation of `javax.sql.DataSource` bundled with H2.
        ds.setURL ( "jdbc:h2:mem:history_db;DB_CLOSE_DELAY=-1" );
        ds.setUser ( "scott" );
        ds.setPassword ( "tiger" );
        ds.setDescription ( "An example database showing multiple result sets." );
        return ds;
    }

    private void prepareDatabase ( final DataSource dataSource ) {
        String sql =
                """
                        CREATE TABLE IF NOT EXISTS history_
                        (
                            user_ TEXT NOT NULL ,
                            when_ TIMESTAMP WITH TIME ZONE NOT NULL ,
                            id_ UUID NOT NULL DEFAULT RANDOM_UUID() ,
                            CONSTRAINT history_pkey_ PRIMARY KEY ( id_ )
                        )
                        ;
                        """;
        try (
                Connection conn = dataSource.getConnection ( ) ;
                Statement stmt = conn.createStatement ( ) ;
        ) {
            System.out.println ( "INFO - Running `prepareDatabase` method." );
            stmt.executeUpdate ( sql );
        } catch ( SQLException e ) {
            e.printStackTrace ( );
        }
    }

    private void populateDatabase ( final DataSource dataSource , List < String > users ) {
        String sql = """
                INSERT INTO history_ ( user_ , when_ )
                VALUES ( ? , ?)
                ;
                """;
        try
                (
                        Connection conn = dataSource.getConnection ( ) ;
                        PreparedStatement preparedStatement = conn.prepareStatement ( sql ) ;
                ) {
            for ( String user : users ) {
                int limit = ThreadLocalRandom.current ( ).nextInt ( 7 , 42 );
                System.out.println ( "user = " + user + " | limit = " + limit );
                for ( int i = 0 ; i < limit ; i++ ) {
                    preparedStatement.setString ( 1 , user );
                    preparedStatement.setObject ( 2 , OffsetDateTime.now ( ZoneOffset.UTC ) );
                    preparedStatement.executeUpdate ( );
                }
            }

        } catch ( SQLException e ) {
            e.printStackTrace ( );
        }
    }

    private void dumpToConsole ( DataSource dataSource ) {
        String sql = """
                SELECT *
                FROM history_
                ;
                """;
        try (
                Connection conn = dataSource.getConnection ( ) ;
                PreparedStatement preparedStatement = conn.prepareStatement ( sql ) ;
        ) {
//            preparedStatement.setString ( 1, "Carol" );
            try (
                    ResultSet resultSet = preparedStatement.executeQuery ( )
            ) {
                while ( resultSet.next ( ) ) {  // We expect a single row in each result set, for the count.
                    System.out.println (
                            resultSet.getString ( 1 ) + " | " +
                                    resultSet.getString ( 2 ) + " | " +
                                    resultSet.getString ( 3 ) + " | "
                    );
                }
            }
        } catch ( SQLException e ) {
            throw new RuntimeException ( e );
        }
    }

    private Map < String, Integer > countPerUserForCurrentWeek ( final DataSource dataSource , List < String > users ) {
        Map < String, Integer > map = new HashMap <> ( );
        String sql = """
                SELECT COUNT(*) 
                FROM history_
                WHERE user_ = ?
                AND when_ >= ? 
                AND when_ < ?
                ;
                """;
        try
                (
                        Connection conn = dataSource.getConnection ( ) ;
                        PreparedStatement preparedStatement = conn.prepareStatement ( sql ) ;
                ) {
            OffsetDateTime now = OffsetDateTime.now ( ZoneOffset.UTC );
            OffsetDateTime weekAgo = now.minusDays ( 7 );
            preparedStatement.setObject ( 2 , weekAgo );
            preparedStatement.setObject ( 3 , now );
            for ( String user : users ) {
                preparedStatement.setString ( 1 , user );
                try ( ResultSet resultSet = preparedStatement.executeQuery ( ) ) {
                    if ( resultSet.next ( ) ) {  // We expect a single row in each result set, for the count.
                        int count = resultSet.getInt ( 1 );
                        map.put ( user , count );
                    }
                }
            }
        } catch ( SQLException e ) {
            e.printStackTrace ( );
        }
        return Map.copyOf ( map );
    }

    private void report ( Map < String, Integer > countPerUserForCurrentWeek ) {
        System.out.println ( "countPerUserForCurrentWeek = " + countPerUserForCurrentWeek );
    }
}

运行时：

user = Alice | limit = 32
user = Bob | limit = 7
user = Carol | limit = 13
user = Davis | limit = 24
countPerUserForCurrentWeek = {Carol=13, Alice=32, Bob=7, Davis=24}