Package org.h2.tools

Class Csv

java.lang.Object
org.h2.tools.Csv
All Implemented Interfaces:
SimpleRowSource
public class Csv extends Object implements SimpleRowSource
A facility to read from and write to CSV (comma separated values) files. When reading, the BOM (the byte-order-mark) character 0xfeff at the beginning of the file is ignored.

  • Constructor Details

    • Csv

      public Csv()

  • Method Details

    • write

      public int write(Writer writer, ResultSet rs) throws SQLException
      Writes the result set to a file in the CSV format.
      Parameters:
      writer - the writer
      rs - the result set
      Returns:
      the number of rows written
      Throws:
      SQLException - on failure

    • write

      public int write(String outputFileName, ResultSet rs, String charset) throws SQLException
      Writes the result set to a file in the CSV format. The result set is read using the following loop: 
       while (rs.next()) {
     writeRow(row);
 }
      Parameters:
      outputFileName - the name of the csv file
      rs - the result set - the result set must be positioned before the first row.
      charset - the charset or null to use the system default charset
      Returns:
      the number of rows written
      Throws:
      SQLException - on failure

    • write

      public int write(Connection conn, String outputFileName, String sql, String charset) throws SQLException
      Writes the result set of a query to a file in the CSV format.
      Parameters:
      conn - the connection
      outputFileName - the file name
      sql - the query
      charset - the charset or null to use the system default charset (see system property file.encoding)
      Returns:
      the number of rows written
      Throws:
      SQLException - on failure

    • read

      public ResultSet read(String inputFileName, String[] colNames, String charset) throws SQLException
      Reads from the CSV file and returns a result set. The rows in the result set are created on demand, that means the file is kept open until all rows are read or the result set is closed. If the columns are read from the CSV file, then the following rules are used: columns names that start with a letter or '_', and only contain letters, '_', and digits, are considered case insensitive and are converted to uppercase. Other column names are considered case sensitive (that means they need to be quoted when accessed).
      Parameters:
      inputFileName - the file name
      colNames - or null if the column names should be read from the CSV file
      charset - the charset or null to use the system default charset
      Returns:
      the result set
      Throws:
      SQLException - on failure

    • read

      public ResultSet read(Reader reader, String[] colNames) throws IOException
      Reads CSV data from a reader and returns a result set. The rows in the result set are created on demand, that means the reader is kept open until all rows are read or the result set is closed.
      Parameters:
      reader - the reader
      colNames - or null if the column names should be read from the CSV file
      Returns:
      the result set
      Throws:
      IOException - on failure

    • readRow

      public Object[] readRow() throws SQLException
      INTERNAL
      Specified by:
      readRow in interface SimpleRowSource
      Returns:
      the row or null
      Throws:
      SQLException - on failure

    • close

      public void close()
      INTERNAL
      Specified by:
      close in interface SimpleRowSource

    • reset

      public void reset() throws SQLException
      INTERNAL
      Specified by:
      reset in interface SimpleRowSource
      Throws:
      SQLException - if this operation is not supported

    • setFieldSeparatorWrite

      public void setFieldSeparatorWrite(String fieldSeparatorWrite)
      Override the field separator for writing. The default is ",".
      Parameters:
      fieldSeparatorWrite - the field separator

    • getFieldSeparatorWrite

      public String getFieldSeparatorWrite()
      Get the current field separator for writing.
      Returns:
      the field separator

    • setCaseSensitiveColumnNames

      public void setCaseSensitiveColumnNames(boolean caseSensitiveColumnNames)
      Override the case sensitive column names setting. The default is false. If enabled, the case of all column names is always preserved.
      Parameters:
      caseSensitiveColumnNames - whether column names are case sensitive

    • getCaseSensitiveColumnNames

      public boolean getCaseSensitiveColumnNames()
      Get the current case sensitive column names setting.
      Returns:
      whether column names are case sensitive

    • setFieldSeparatorRead

      public void setFieldSeparatorRead(char fieldSeparatorRead)
      Override the field separator for reading. The default is ','.
      Parameters:
      fieldSeparatorRead - the field separator

    • getFieldSeparatorRead

      public char getFieldSeparatorRead()
      Get the current field separator for reading.
      Returns:
      the field separator

    • setLineCommentCharacter

      public void setLineCommentCharacter(char lineCommentCharacter)
      Set the line comment character. The default is character code 0 (line comments are disabled).
      Parameters:
      lineCommentCharacter - the line comment character

    • getLineCommentCharacter

      public char getLineCommentCharacter()
      Get the line comment character.
      Returns:
      the line comment character, or 0 if disabled

    • setFieldDelimiter

      public void setFieldDelimiter(char fieldDelimiter)
      Set the field delimiter. The default is " (a double quote). The value 0 means no field delimiter is used.
      Parameters:
      fieldDelimiter - the field delimiter

    • getFieldDelimiter

      public char getFieldDelimiter()
      Get the current field delimiter.
      Returns:
      the field delimiter

    • setEscapeCharacter

      public void setEscapeCharacter(char escapeCharacter)
      Set the escape character. The escape character is used to escape the field delimiter. This is needed if the data contains the field delimiter. The default escape character is " (a double quote), which is the same as the field delimiter. If the field delimiter and the escape character are both " (double quote), and the data contains a double quote, then an additional double quote is added. Example: 
       Data: He said "Hello".
 Escape character: "
 Field delimiter: "
 CSV file: "He said ""Hello""."
      If the field delimiter is a double quote and the escape character is a backslash, then escaping is done similar to Java (however, only the field delimiter is escaped). Example: 
       Data: He said "Hello".
 Escape character: \
 Field delimiter: "
 CSV file: "He said \"Hello\"."
      The value 0 means no escape character is used.
      Parameters:
      escapeCharacter - the escape character

    • getEscapeCharacter

      public char getEscapeCharacter()
      Get the current escape character.
      Returns:
      the escape character

    • setLineSeparator

      public void setLineSeparator(String lineSeparator)
      Set the line separator used for writing. This is usually a line feed (\n or \r\n depending on the system settings). The line separator is written after each row (including the last row), so this option can include an end-of-row marker if needed.
      Parameters:
      lineSeparator - the line separator

    • getLineSeparator

      public String getLineSeparator()
      Get the line separator used for writing.
      Returns:
      the line separator

    • setQuotedNulls

      public void setQuotedNulls(boolean quotedNulls)
      Defines if the null values must be quoted.
      Parameters:
      quotedNulls - True if the null values must be quoted.

    • isQuotedNulls

      public boolean isQuotedNulls()
      Returns true if the null values are quoted.
      Returns:
      True if the null values are quoted.

    • setNullString

      public void setNullString(String nullString)
      Set the value that represents NULL. It is only used for non-delimited values.
      Parameters:
      nullString - the null

    • getNullString

      public String getNullString()
      Get the current null string.
      Returns:
      the null string.

    • setPreserveWhitespace

      public void setPreserveWhitespace(boolean value)
      Enable or disable preserving whitespace in unquoted text.
      Parameters:
      value - the new value for the setting

    • getPreserveWhitespace

      public boolean getPreserveWhitespace()
      Whether whitespace in unquoted text is preserved.
      Returns:
      the current value for the setting

    • setWriteColumnHeader

      public void setWriteColumnHeader(boolean value)
      Enable or disable writing the column header.
      Parameters:
      value - the new value for the setting

    • getWriteColumnHeader

      public boolean getWriteColumnHeader()
      Whether the column header is written.
      Returns:
      the current value for the setting

    • setOptions

      public String setOptions(String options)
      INTERNAL. Parse and set the CSV options.
      Parameters:
      options - the options
      Returns:
      the character set