openGauss example: import and export data through local files

import java.sql.Connection;

import java.sql.DriverManager;
import java.io.IOException;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.sql.SQLException;
import org.opengauss.copy.CopyManager;
import org.opengauss.core .BaseConnection;

public class Copy{

public static void main(String[] args)
{
String urls = new String("jdbc:opengauss://10.180.155.74:8000/postgres"); //Database URL
String username = new String ("jack"); //User name
String password = new String("Gauss@123"); //Password
String tablename = new String("migration_table"); //Define table information
String tablename1 = new String("migration_table_1 ");//Define table information
String driver = "org.opengauss.Driver";
Connection conn = null;

try {
Class.forName(driver);
conn = DriverManager.getConnection(urls, username, password);
} catch (ClassNotFoundException e) {
e.printStackTrace(System .out);
} catch (SQLException e) {
e.printStackTrace(System.out);
}

// Export the query result of SELECT * FROM migration_table to the local file d:/data.txt
try {
copyToFile(conn, "d:/ data.txt", "(SELECT * FROM migration_table)");
} catch (SQLException e) {

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

e.printStackTrace();
}
//Import the data in d:/data.txt into migration_table_1.
try {
copyFromFile(conn, "d:/data.txt", tablename1);
} catch (SQLException e) {
e.printStackTrace();
} catch (IOException e) {

e.printStackTrace();
}

// will migrate_table_1 Export the data to the local file d:/data1.txt
try {
copyToFile(conn, "d:/data1.txt", tablename1);
} catch (SQLException e) {

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


e.printStackTrace();
}
}
// Use copyIn to import data from the file into the database,
public static void copyFromFile(Connection connection, String filePath, String tableName)
throws SQLException, IOException {

FileInputStream fileInputStream = null;

try { CopyManager copyManager = new CopyManager
((BaseConnection)connection) ; "COPY " + tableName + " FROM STDIN", fileInputStream); } finally { if (fileInputStream != null) { try { fileInputStream. close(); } catch (IOException e) { e. printStackTrace(); } }










}
}

// Use copyOut to export data from database to file
public static void copyToFile(Connection connection, String filePath, String tableOrQuery)
throws SQLException, IOException {

FileOutputStream fileOutputStream = null;

try {
CopyManager copyManager = new CopyManager((BaseConnection) connection);
fileOutputStream = new FileOutputStream(filePath);
copyManager.copyOut("COPY " + tableOrQuery + " TO STDOUT", fileOutputStream);
} finally {
if (fileOutputStream != null) {
try {
fileOutputStream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
} }
}