java使用copy in 的方式把数据导入postgres或greenplum

copy in

postgres导入数据的时候可以使用cpoy 命令进行数据导入,如果使用java操作copy命令则需要使用postgres提供的jdbc驱动中的CopyManager来实现

• 封装一下

public class PGCopyInUtils {


/**
 * 将表中的数据导出到本地文件
 *
 * @param connection 连接
 * @param filePath 文件路径
 * @param tableOrQuery 表名 或者查询语句
 * @throws SQLException SQLException
 * @throws IOException IOException
 */
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);
            String copyOut = "COPY " + tableOrQuery + " TO STDOUT DELIMITER AS ','";
final long line = copyManager.copyOut(copyOut, fileOutputStream);
            System.out.println(line);
        } finally {
if (fileOutputStream != null) {
try {
                    fileOutputStream.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }

/**
 * 将文件中的数据导入到数据库中
 *
 * @param connection 连接
 * @param filePath 文件路径
 * @param tableName 表名
 * @throws SQLException SQLException
 * @throws IOException IOException
 * @return long 导入的行数
 */
public static long copyFromFile(Connection connection, String filePath, String tableName)
throws SQLException, IOException {
        FileInputStream fileInputStream = null;
try {
            CopyManager copyManager = new CopyManager((BaseConnection) connection);
            fileInputStream = new FileInputStream(filePath);
            String copyIn = "COPY " + tableName + " FROM STDIN DELIMITER AS ','";
return copyManager.copyIn(copyIn, fileInputStream);
        } finally {
if (fileInputStream != null) {
try {
                    fileInputStream.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }
}

• 使用

1. connection 数据库连接
2. 文件路径
3. 表名
PGCopyInUtils.copyFromFile(connection, Constants.COPY_DEVICE_DATA_FILE_PATH, Constants.TABLE_NAME);

• 注意

以上文件内容的分隔符为"," 标准输入.