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.
