Jackson 2.18.2 · com.fasterxml.jackson.dataformat.csv.CsvSchema

Simple FormatSchema sub-type that defines properties of a CSV document to read or write. Properties supported currently are:

columns (List of ColumnDef) [default: empty List]: Ordered list of columns (which may be empty, see below). Each column has name (mandatory) as well as type (optional; if not defined, defaults to "String"). Note that
useHeader (boolean) [default: false]: whether the first line of physical document defines column names (true) or not (false): if enabled, parser will take first-line values to define column names; and generator will output column names as the first line
quoteChar (char) [default: double-quote ('")]: character used for quoting values that contain quote characters or linefeeds.
columnSeparator (char) [default: comma (',')]: character used to separate values. Other commonly used values include tab ('\t') and pipe ('|')
arrayElementSeparator (String) [default: semicolon (";")]: string used to separate array elements.
lineSeparator (String) [default: "\n"]: character used to separate data rows. Only used by generator; parser accepts three standard linefeeds ("\r", "\r\n", "\n").
escapeChar (int) [default: -1 meaning "none"]: character, if any, used to escape values. Most commonly defined as backslash ('\'). Only used by parser; generator only uses quoting, including doubling up of quotes to indicate quote char itself.
skipFirstDataRow (boolean) [default: false]: whether the first data line (either first line of the document, if useHeader=false, or second, if useHeader=true) should be completely ignored by parser. Needed to support CSV-like file formats that include additional non-data content before real data begins (specifically some database dumps do this)
nullValue (String) [default: "" (empty String)]: When asked to write Java `null`, this String value will be used instead.
With 2.6, value will also be recognized during value reads.
strictHeaders (boolean) [default: false] (added in Jackson 2.7): whether names of columns defined in the schema MUST match with actual declaration from the header row (if header row handling enabled): if true, they must be and an exception if thrown if order differs: if false, no verification is performed.
allowComments (boolean) [default: false]: whether lines that start with character "#" are processed as comment lines and skipped/ignored.
anyProperty (String] [default: none]: if "any properties" (properties for 'extra' columns; ones not specified in schema) are enabled, they are mapped to this name: leaving it as null disables use of "any properties" (and they are either ignored, or an exception is thrown, depending on other settings); setting it to a non-null String value will expose all extra properties under one specified name. Most often used with Jackson @JsonAnySetter annotation.
Note that schemas without any columns are legal, but if no columns are added, behavior of parser/generator is usually different and content will be exposed as logical Arrays instead of Objects.
There are 4 ways to create CsvSchema instances:
- Manually build one, using Builder
- Modify existing schema (using withXxx methods or rebuild for creating Builder)
- Create schema based on a POJO definition (Class), using CsvMapper methods like CsvMapper#schemaFor(java.lang.Class).
- Request that CsvParser reads schema from the first line: enable "useHeader" property for the initial schema, and let parser read column names from the document itself.

Nested and Inner Type Summary

Modifier and Type	Class and Description
public static class	CsvSchema.Builder Class used for building `CsvSchema` instances.
public static class	CsvSchema.Column Representation of info for a single column
public static enum	CsvSchema.ColumnType Enumeration that defines optional type indicators that can be passed with schema.

Field Summary

Modifier and Type	Field and Description
protected final String	_anyPropertyName If "any properties" (properties for 'extra' columns; ones not specified in schema) are enabled, they are mapped to this name: leaving it as `null` disables use of "any properties" (and they are either ignored, or an exception is thrown, depending on other settings); setting it to a non-null String value will expose all extra properties under one specified name.
protected final String	_arrayElementSeparator
protected final CsvSchema.Column[]	_columns Column definitions, needed for optional header and/or mapping of field names to column positions.
protected final Map<String, CsvSchema.Column>	_columnsByName
protected final char	_columnSeparator
protected final int	_escapeChar
protected int	_features Bitflag for general-purpose on/off features.
protected final char[]	_lineSeparator
protected final char[]	_nullValue
protected transient String	_nullValueAsString
protected final int	_quoteChar
public static final String	DEFAULT_ANY_PROPERTY_NAME By default no "any properties" (properties for 'extra' columns; ones not specified in schema) are used, so `null` is used as marker.
public static final String	DEFAULT_ARRAY_ELEMENT_SEPARATOR Default separator for array elements within a column value is semicolon.
public static final char	DEFAULT_COLUMN_SEPARATOR Default separator for column values is comma (hence "Comma-Separated Values")
protected static final int	DEFAULT_ENCODING_FEATURES
public static final int	DEFAULT_ESCAPE_CHAR By default, no escape character is used -- this is denoted by int value that does not map to a valid character
public static final char[]	DEFAULT_LINEFEED
public static final char[]	DEFAULT_NULL_VALUE By default, nulls are written as empty Strings (""); and no coercion is performed from any String (higher level databind may, however, coerce Strings into Java nulls).
public static final char	DEFAULT_QUOTE_CHAR
protected static final int	ENCODING_FEATURE_ALLOW_COMMENTS
protected static final int	ENCODING_FEATURE_REORDER_COLUMNS
protected static final int	ENCODING_FEATURE_SKIP_FIRST_DATA_ROW
protected static final int	ENCODING_FEATURE_STRICT_HEADERS
protected static final int	ENCODING_FEATURE_USE_HEADER
public static final String	NO_ARRAY_ELEMENT_SEPARATOR Marker for the case where no array element separator is used
protected static final char[]	NO_CHARS
protected static final CsvSchema.Column[]	NO_COLUMNS
private static final long	serialVersionUID

Constructor Summary

Access	Constructor and Description
public	CsvSchema(CsvSchema.Column[] columns, int features, char columnSeparator, int quoteChar, int escapeChar, char[] lineSeparator, String arrayElementSeparator, char[] nullValue, String anyPropertyName)
protected	CsvSchema(CsvSchema.Column[] columns, int features, char columnSeparator, int quoteChar, int escapeChar, char[] lineSeparator, String arrayElementSeparator, char[] nullValue, Map<String, CsvSchema.Column> columnsByName, String anyPropertyName) Copy constructor used for creating variants using `withXxx()` methods.
protected	CsvSchema(CsvSchema base, CsvSchema.Column[] columns) Copy constructor used for creating variants using `sortedBy()` methods.
protected	CsvSchema(CsvSchema base, int features) Copy constructor used for creating variants for on/off features

Method Summary

Modifier and Type	Method and Description
private static CsvSchema.Column[]	_link(CsvSchema.Column[] orig) Helper method used for chaining columns together using next-linkage, as well as ensuring that indexes are correct.
protected static String	_validArrayElementSeparator(String sep)
protected CsvSchema	_withColumn(int ix, CsvSchema.Column toReplace)
protected CsvSchema	_withFeature(int feature, boolean state)
public boolean	allowsComments()
public static CsvSchema.Builder	builder()
public CsvSchema.Column	column(int index) Accessor for column at specified index (0-based); index having to be within 0 <= index < size()
public CsvSchema.Column	column(String name)
public CsvSchema.Column	column(String name, int probableIndex) Optimized variant where a hint is given as to likely index of the column name.
public int	Returns: Index of the specified column, if one exists; `-1` if not columnIndex(String Name of column to find name) Method for finding index of a named column within this schema.
public String	columnName(int index)
public static CsvSchema	emptySchema() Accessor for creating a "default" CSV schema instance, with following settings: Does NOT use header line Uses double quotes ('"') for quoting of field values (if necessary) Uses comma (',') as the field separator Uses Unix linefeed ('\n') as row separator Does NOT use any escape characters Does NOT have any columns defined
public String	getAnyPropertyName()
public String	getArrayElementSeparator()
public String	getColumnDesc() Method for getting description of column definitions in developer-readable form
public List<String>	getColumnNames() Accessor for getting names of included columns, in the order they are included in the schema.
public Collection<String>	getColumnNames(Collection<String> names) Accessor for getting names of included columns, added in given `Collection`.
public char	getColumnSeparator()
public int	getEscapeChar()
public char[]	getLineSeparator()
public char[]	Returns: Null value defined, as char array, if one is defined to be recognized; Java null if not. getNullValue()
public char[]	getNullValueOrEmpty() Same as `getNullValue()` except that undefined null value (one that remains as `null`, or explicitly set as such) will be returned as empty `char[]`
public String	getNullValueString()
public int	getQuoteChar()
public String	getSchemaType() Implements com.fasterxml.jackson.core.FormatSchema.getSchemaType. Method that can be used to get an identifier that can be used for diagnostics purposes, to indicate what kind of data format this schema is used for: typically it is a short name of format itself, but it can also contain additional information in cases where data format supports multiple types of schemas.
public boolean	hasArrayElementSeparator()
public Iterator<CsvSchema.Column>	iterator() Implements java.lang.Iterable.iterator. Returns an iterator over elements of type `T`.
public CsvSchema.Builder	rebuild() Helper method for constructing Builder that can be used to create modified schema.
public boolean	reordersColumns()
public int	Returns: Number of columns this schema defines size() Accessor for finding out how many columns this schema defines.
public boolean	skipsFirstDataRow()
public CsvSchema	sortedBy(String... columnNames) Mutant factory method that will construct a new instance in which columns are sorted based on names given as argument.
public CsvSchema	sortedBy(Comparator<String> cmp) Mutant factory method that will construct a new instance in which columns are sorted using given `Comparator` over column names.
public boolean	strictHeaders()
public String	toString() Overrides java.lang.Object.toString. Returns a string representation of the object.
public boolean	usesEscapeChar()
public boolean	usesHeader()
public boolean	usesQuoteChar()
public CsvSchema	withAllowComments(boolean state) Method to indicate whether "hash comments" are allowed for document described by this schema.
public CsvSchema	withAnyPropertyName(String name)
public CsvSchema	withArrayElementSeparator(String separator)
public CsvSchema	Returns: Either this schema (if column did not change), or newly constructed `CsvSchema` with changed column withColumn(String Name of column to replace columnName, UnaryOperator<CsvSchema.Column> Transformation to apply to the column transformer) Mutant factory method that will try to replace specified column with changed definition (but same name), leaving other columns as-is.
public CsvSchema	Returns: Either this schema (if column did not change), or newly constructed `CsvSchema` with changed column withColumn(int Index of column to replace columnIndex, UnaryOperator<CsvSchema.Column> Transformation to apply to the column transformer) Mutant factory method that will try to replace specified column with changed definition (but same name), leaving other columns as-is.
public CsvSchema	Returns: A copy of itself, ensuring the setting for the column reordering feature. withColumnReordering(boolean New value for setting state) Returns a clone of this instance by changing or setting the column reordering flag
public CsvSchema	withColumnSeparator(char sep)
public CsvSchema	Returns: Either this schema (if nothing changed), or newly constructed `CsvSchema` with appended columns. withColumnsFrom(CsvSchema toAppend) Mutant factory method that will try to combine columns of this schema with those from `toAppend`, starting with columns of this instance, and ignoring duplicates (if any) from argument `toAppend`.
public CsvSchema	withComments() Method to indicate that "hash comments" ARE allowed for document described by this schema.
public CsvSchema	withEscapeChar(char c)
public CsvSchema	withHeader() Helper method for constructing and returning schema instance that is similar to this one, except that it will be using header line.
public CsvSchema	withLineSeparator(String sep)
public CsvSchema	withNullValue(String nvl)
public CsvSchema	withoutArrayElementSeparator()
public CsvSchema	withoutColumns()
public CsvSchema	withoutComments() Method to indicate that "hash comments" are NOT allowed for document described by this schema.
public CsvSchema	withoutEscapeChar()
public CsvSchema	withoutHeader() Helper method for construcing and returning schema instance that is similar to this one, except that it will not be using header line.
public CsvSchema	withoutQuoteChar()
public CsvSchema	withQuoteChar(char c)
public CsvSchema	withSkipFirstDataRow(boolean state)
public CsvSchema	Returns: A copy of itself, ensuring the setting for the strict headers feature. withStrictHeaders(boolean New value for setting state) Returns a clone of this instance by changing or setting the strict headers flag
public CsvSchema	withUseHeader(boolean state)

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll wait wait wait

public Class CsvSchema

Nested and Inner Type Summary

Field Summary

Constructor Summary

Method Summary