java - 如何使用带有“java/eclipse”的 lambda 函数将 csv 文件加载到 postgres 数据库

Question

我必须在 java 代码的帮助下使用 AWS lambda 函数将我的 CSV 文件加载到 PostgreSQL 数据库中。我尝试过同样的 java 代码，不知道如何使用 lambda 函数。

下面是我使用的java代码 -

package net.codejava;
 
import java.io.*;
import java.sql.*;
 
public class SimpleCsv2DbInserter {
 
    public static void main(String[] args) {
        String jdbcURL = "jdbc:mysql://localhost:3306/sales";
        String username = "user";
        String password = "password";
 
        String csvFilePath = "Reviews-simple.csv";
 
        int batchSize = 20;
 
        Connection connection = null;
 
        try {
 
            connection = DriverManager.getConnection(jdbcURL, username, password);
            connection.setAutoCommit(false);
 
            String sql = "INSERT INTO review (course_name, student_name, timestamp, rating, comment) VALUES (?, ?, ?, ?, ?)";
            PreparedStatement statement = connection.prepareStatement(sql);
 
            BufferedReader lineReader = new BufferedReader(new FileReader(csvFilePath));
            String lineText = null;
 
            int count = 0;
 
            lineReader.readLine(); // skip header line
 
            while ((lineText = lineReader.readLine()) != null) {
                String[] data = lineText.split(",");
                String courseName = data[0];
                String studentName = data[1];
                String timestamp = data[2];
                String rating = data[3];
                String comment = data.length == 5 ? data[4] : "";
 
                statement.setString(1, courseName);
                statement.setString(2, studentName);
 
                Timestamp sqlTimestamp = Timestamp.valueOf(timestamp);
                statement.setTimestamp(3, sqlTimestamp);
 
                Float fRating = Float.parseFloat(rating);
                statement.setFloat(4, fRating);
 
                statement.setString(5, comment);
 
                statement.addBatch();
 
                if (count % batchSize == 0) {
                    statement.executeBatch();
                }
            }
 
            lineReader.close();
 
            // execute the remaining queries
            statement.executeBatch();
 
            connection.commit();
            connection.close();
 
        } catch (IOException ex) {
            System.err.println(ex);
        } catch (SQLException ex) {
            ex.printStackTrace();
 
            try {
                connection.rollback();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
 
    }
}

标签： javapostgresql-10