安全访问私有AWS RDS Postgres数据库的Java应用集成指南

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

public class DatabaseService {

    private static final String DB_URL = "jdbc:postgresql://your-rds-endpoint.us-east-1.rds.amazonaws.com:5432/your_database_name";
    private static final String USER = "your_db_username";
    private static final String PASS = "your_db_password";

    public String fetchDataFromDatabase(String queryParam) throws SQLException {
        Connection conn = null;
        PreparedStatement stmt = null;
        ResultSet rs = null;
        StringBuilder result = new StringBuilder();

        try {
            // 注册JDBC驱动（PostgreSQL驱动通常在类路径中会自动注册）
            // Class.forName("org.postgresql.Driver");

            conn = DriverManager.getConnection(DB_URL, USER, PASS);

            // 示例：执行一个简单的查询
            String sql = "SELECT column1, column2 FROM your_table WHERE some_column = ?";
            stmt = conn.prepareStatement(sql);
            stmt.setString(1, queryParam); // 设置查询参数

            rs = stmt.executeQuery();

            while (rs.next()) {
                result.append("Column1: ").append(rs.getString("column1"))
                      .append(", Column2: ").append(rs.getString("column2"))
                      .append("\n");
            }
        } finally {
            // 关闭资源
            if (rs != null) try { rs.close(); } catch (SQLException ignore) {}
            if (stmt != null) try { stmt.close(); } catch (SQLException ignore) {}
            if (conn != null) try { conn.close(); } catch (SQLException ignore) {}
        }
        return result.toString();
    }

    // 示例：一个简单的API端点（概念性）
    // 假设这是一个通过HTTP暴露的服务
    public String handleApiRequest(String param) {
        try {
            return fetchDataFromDatabase(param);
        } catch (SQLException e) {
            e.printStackTrace();
            return "Error accessing database: " + e.getMessage();
        }
    }
}

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;

public class LocalApiClient {

    private static final String API_ENDPOINT = "http://your-api-loadbalancer-dns.com/api/data?param=value";

    public static void main(String[] args) {
        try {
            URL url = new URL(API_ENDPOINT);
            HttpURLConnection conn = (HttpURLConnection) url.openConnection();
            conn.setRequestMethod("GET");

            BufferedReader in = new BufferedReader(new InputStreamReader(conn.getInputStream()));
            String inputLine;
            StringBuilder content = new StringBuilder();
            while ((inputLine = in.readLine()) != null) {
                content.append(inputLine);
            }
            in.close();
            conn.disconnect();

            System.out.println("API Response: " + content.toString());

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