How can Java achieve importing files into a database?

2 years ago
Benjamin Taylor
5 minutes

To import a file into a database in Java, you can follow these steps: 1. First, use Java’s file operation related classes (such as FileInputStream, BufferedReader, etc.) to read the file content. 2. Parse the read file content into field values of the database table, you can use methods like string splitting, regex matching, etc. in Java for parsing. 3. Connect to the database using Java’s JDBC related classes (such as Connection, Statement, PreparedStatement, etc.). 4. Create an SQL statement to insert data, and insert the parsed field values into the database table. 5. Use the setXXX() method of JDBC’s PreparedStatement class to set the field values in the SQL statement. 6. Execute the SQL statement to insert data into the database table. The following is a simple example code that demonstrates the process of importing a CSV file into a MySQL database table.

import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.InputStreamReader;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
public class FileImportToDB {
    public static void main(String[] args) {
        String csvFilePath = "path/to/csv/file.csv";
        String dbUrl = "jdbc:mysql://localhost:3306/database_name";
        String dbUser = "username";
        String dbPassword = "password";
        
        try {
            // 读取CSV文件
            BufferedReader reader = new BufferedReader(new InputStreamReader(new FileInputStream(csvFilePath)));
            String line;
            
            // 连接数据库
            Connection conn = DriverManager.getConnection(dbUrl, dbUser, dbPassword);
            
            // 创建插入数据的SQL语句
            String sql = "INSERT INTO table_name (column1, column2, column3) VALUES (?, ?, ?)";
            PreparedStatement stmt = conn.prepareStatement(sql);
            
            // 逐行读取CSV文件内容并插入数据库
            while ((line = reader.readLine()) != null) {
                String[] values = line.split(","); // 根据CSV文件的分隔符进行分割，这里假设是逗号分隔
                
                // 设置SQL语句中的字段值
                stmt.setString(1, values[0]);
                stmt.setString(2, values[1]);
                stmt.setString(3, values[2]);
                
                // 执行插入操作
                stmt.executeUpdate();
            }
            
            // 关闭资源
            stmt.close();
            conn.close();
            reader.close();
            
            System.out.println("文件导入数据库成功！");
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

Please note: the database connection method in the code example above uses JDBC to connect to a MySQL database, requiring the appropriate JDBC driver library to be imported. Additionally, the code assumes that the delimiter of the CSV file is a comma, you can modify the delimiter and corresponding parsing logic according to your actual situation.

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