Package uk.ac.starlink.table.formats
Class AbstractTextTableWriter
java.lang.Object
uk.ac.starlink.table.formats.DocumentedStreamStarTableWriter
uk.ac.starlink.table.formats.AbstractTextTableWriter
- All Implemented Interfaces:
Documented
,DocumentedIOHandler
,StarTableWriter
- Direct Known Subclasses:
AsciiTableWriter
,IpacTableWriter
,TextTableWriter
A StarTableWriter which outputs text to a human-readable text file.
Table parameters (per-table metadata) can optionally be output
as well as the table data themselves.
- Author:
- Mark Taylor (Starlink)
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Constructor Summary
ConstructorsModifierConstructorDescriptionprotected
AbstractTextTableWriter
(String[] extensions, boolean writeParams) Constructor. -
Method Summary
Modifier and TypeMethodDescriptionprotected abstract String
formatValue
(Object val, ValueInfo vinfo, int width) Formats a data value for output.protected byte[]
Returns a byte array corresponding to a given string.Returns "text";int
Returns the maximum length for the value of a parameter as passed toprintParam(java.io.OutputStream, java.lang.String, java.lang.String, java.lang.Class<?>)
.int
Returns the maximum width for any output column.Returns a string suitable for use as the value of a MIME Content-Type header.int
getMinNameWidth
(ColumnInfo info) Returns the minimum width required to output the actual characters of the name for a given column.int
Returns the number of rows which will be sampled to work out the column width.boolean
Finds out whether the output will include table parameters.protected abstract void
printColumnHeads
(OutputStream strm, int[] colwidths, ColumnInfo[] cinfos) Outputs headings for the table columns.protected abstract void
printLine
(OutputStream strm, int[] colwidths, String[] data) Outputs a line of table data.protected abstract void
printParam
(OutputStream strm, String name, String value, Class<?> clazz) Outputs a parameter and its value.protected abstract void
printSeparator
(OutputStream strm, int[] colwidths) Outputs a decorative separator line, of the sort you might find between the column headings and the table data.void
setMaximumParameterLength
(int maxParamLength) Sets the maximum length for the value of a parameter that will be output.void
setMaxWidth
(int maxWidth) Sets the maximum width in characters for any output column.void
setSampledRows
(int sampledRows) Sets the number of rows which will be sampled before output is commenced to work out the column widths.void
setWriteParameters
(boolean writeParams) Set whether the output should include table parameters.void
writeStarTable
(StarTable startab, OutputStream strm) Writes a StarTable object to a given output stream.Methods inherited from class uk.ac.starlink.table.formats.DocumentedStreamStarTableWriter
getExtensions, looksLikeFile, writeStarTable
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
Methods inherited from interface uk.ac.starlink.table.Documented
getXmlDescription
Methods inherited from interface uk.ac.starlink.table.formats.DocumentedIOHandler
docIncludesExample, readText
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Constructor Details
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AbstractTextTableWriter
Constructor.- Parameters:
extensions
- list of lower-cased filename extensions, excluding the '.' characterwriteParams
- whether parameters will be written by default
-
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Method Details
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getFormatName
Returns "text";- Returns:
- "text"
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getMimeType
Description copied from interface:StarTableWriter
Returns a string suitable for use as the value of a MIME Content-Type header. If no suitable MIME type is available or known, one of "application/octet-stream
" (for binary formats) or "text/plain
" for ASCII ones) is recommended.- Returns:
- MIME content type
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writeStarTable
Description copied from interface:StarTableWriter
Writes a StarTable object to a given output stream. The implementation can assume that out is suitable for direct writing (for instance it should not normally wrap it in aBufferedOutputStream
), and should not close it at the end of the call.Not all table writers are capable of writing to a stream; an implementation may throw a
TableFormatException
to indicate that it cannot do so.- Parameters:
startab
- the table to writestrm
- the output stream to which startab should be written- Throws:
TableFormatException
- if this table cannot be written to a streamIOException
- if there is some I/O error
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setMaximumParameterLength
@ConfigMethod(property="maxParam", doc="<p>Maximum width in characters of an output table parameter. Parameters with values longer than this will be truncated.</p>") public void setMaximumParameterLength(int maxParamLength) Sets the maximum length for the value of a parameter that will be output.- Parameters:
maxParamLength
- maximum printable parameter length
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getMaximumParameterLength
public int getMaximumParameterLength()Returns the maximum length for the value of a parameter as passed toprintParam(java.io.OutputStream, java.lang.String, java.lang.String, java.lang.Class<?>)
. The default implementation currently returns 160.- Returns:
- maximum length for output string parameters
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setWriteParameters
@ConfigMethod(property="params", doc="<p>Whether to output table parameters as well as row data.</p>") public void setWriteParameters(boolean writeParams) Set whether the output should include table parameters. If so they are written as name:value pairs one per line before the start of the table proper.- Parameters:
writeParams
- true iff you want table parameters to be output as well as the table data
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getWriteParameters
public boolean getWriteParameters()Finds out whether the output will include table parameters.- Returns:
- true iff the table parameters will be output as well as the table data
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setMaxWidth
@ConfigMethod(property="maxCell", doc="<p>Maximum width in characters of an output table cell. Cells longer than this will be truncated.</p>") public void setMaxWidth(int maxWidth) Sets the maximum width in characters for any output column. Values longer than this may be truncated.- Parameters:
maxWidth
- maximum column value width in characters
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getMaxWidth
public int getMaxWidth()Returns the maximum width for any output column. Values longer than this may be truncated.- Returns:
- maximum permitted column width in characters
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getMinNameWidth
Returns the minimum width required to output the actual characters of the name for a given column. Padding applied subsequently by this object'sprintColumnHeads(java.io.OutputStream, int[], uk.ac.starlink.table.ColumnInfo[])
method does not need to be included.- Parameters:
info
- column metadata- Returns:
- minimum number of characters required for column title
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setSampledRows
@ConfigMethod(property="sampledRows", doc="<p>The number of rows examined on a first pass of the table to determine the width of each column. Only a representative number of rows needs to be examined, but if a formatted cell value after this limit is wider than the cells up to it, then such later wide cells may get truncated. If the value is <=0, all rows are examined in the first pass; this is the default, but it can be configured to some other value if that takes too long.</p>") public void setSampledRows(int sampledRows) Sets the number of rows which will be sampled before output is commenced to work out the column widths.- Parameters:
sampledRows
- number of rows to be sampled
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getSampledRows
public int getSampledRows()Returns the number of rows which will be sampled to work out the column width.- Returns:
- number of rows scanned
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formatValue
Formats a data value for output.- Parameters:
val
- the valuevinfo
- the metadata object describing val's typewidth
- maximum preferred width into which the value should be formatted- Returns:
- formatted string meaning value, preferably no longer than width characters
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printSeparator
Outputs a decorative separator line, of the sort you might find between the column headings and the table data.- Parameters:
strm
- stream to write intocolwidths
- column widths in characters- Throws:
IOException
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printColumnHeads
protected abstract void printColumnHeads(OutputStream strm, int[] colwidths, ColumnInfo[] cinfos) throws IOException Outputs headings for the table columns.- Parameters:
strm
- stream to write intocolwidths
- column widths in characterscinfos
- array of column headings- Throws:
IOException
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printLine
protected abstract void printLine(OutputStream strm, int[] colwidths, String[] data) throws IOException Outputs a line of table data.- Parameters:
strm
- stream to write intocolwidths
- column widths in charactersdata
- array of strings to be output, one per column- Throws:
IOException
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printParam
protected abstract void printParam(OutputStream strm, String name, String value, Class<?> clazz) throws IOException Outputs a parameter and its value.- Parameters:
strm
- stream to write intoname
- parameter namevalue
- formatted parameter valueclazz
- type of value- Throws:
IOException
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getBytes
Returns a byte array corresponding to a given string.- Parameters:
str
- string to decode
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