gshute.util
Class DatabaseTable

java.lang.Object
  |
  +--gshute.util.DatabaseTable

public class DatabaseTable

extends java.lang.Object

A DatabaseTable is a poor-person's table in a database.

All tables are in separate files. The first row in the file contains the names of the table columns separated by colons. The remaining lines contain values for rows separated by colons. The number of values in each row should be the same as the number of table columns.

Inner Class Summary

class

DatabaseTable.Row A Row provides access to the data in a row of a database table.

Field Summary

protected java.util.List	columns
protected java.lang.String	keyColumnName
protected java.util.List	rows

Constructor Summary

DatabaseTable(java.lang.String tn)
new DatabaseTable(tn) returns a database connection to the table named tn.

Method Summary

protected int	columnIndex(java.lang.String n) columnIndex(n) returns the index in columns of the column whose name is n.
java.util.Iterator	columnNames() dbt.columnNames(n) returns an iterator for the column names of dbt.
DatabaseTable.Row	getRow(java.lang.String k) dbt.getRow(k) returns the table row whose key (first column) is k, or null if there is no such row.
java.util.Iterator	getRows() dbt.getRows() returns an iterator for all of the table rows in dbt.
java.util.Iterator	getRows(java.lang.String col, java.lang.String val) dbt.getRows(col, val) returns an iterator for the table rows whose value in the column named col is val.
java.util.Iterator	getValues(java.lang.String col1, java.lang.String col2, java.lang.String val) dbt.getValues(col1, col2, val) returns an iterator for the values in col1 of dbt for rows whose value in the column named col2 is val.
boolean	isColumnName(java.lang.String n) dbt.isColumnName(n) returns true if n is the name of a column in dbt.
protected void	processData(java.lang.String dat)
protected void	processHeader(java.lang.String hdr)
protected int	rowIndex(java.lang.String k) rowIndex(k) returns the index in rows of the entry whose key is k.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

rows

protected java.util.List rows

columns

protected java.util.List columns

keyColumnName

protected java.lang.String keyColumnName

Constructor Detail

DatabaseTable

public DatabaseTable(java.lang.String tn)

new DatabaseTable(tn) returns a database connection to the table named tn.

Method Detail

isColumnName

public boolean isColumnName(java.lang.String n)

dbt.isColumnName(n) returns true if n is the name of a column in dbt.

columnNames

public java.util.Iterator columnNames()

dbt.columnNames(n) returns an iterator for the column names of dbt.

getRow

public DatabaseTable.Row getRow(java.lang.String k)

dbt.getRow(k) returns the table row whose key (first column) is k, or null if there is no such row.

getRows

public java.util.Iterator getRows()

dbt.getRows() returns an iterator for all of the table rows in dbt.

getRows

public java.util.Iterator getRows(java.lang.String col,
                                  java.lang.String val)

dbt.getRows(col, val) returns an iterator for the table rows whose value in the column named col is val.

Preconditions: isColumnName(col) is true.

getValues

public java.util.Iterator getValues(java.lang.String col1,
                                    java.lang.String col2,
                                    java.lang.String val)

dbt.getValues(col1, col2, val) returns an iterator for the values in col1 of dbt for rows whose value in the column named col2 is val. This method emulates a simple join in a relational database.

Preconditions: isColumnName(col1) is true. isColumnName(col2) is true.

rowIndex

protected int rowIndex(java.lang.String k)

rowIndex(k) returns the index in rows of the entry whose key is k. If there is no such entry then rowIndex(k) returns -1.

columnIndex

protected int columnIndex(java.lang.String n)

columnIndex(n) returns the index in columns of the column whose name is n. If there is no such column then columnIndex(n) returns -1.

processHeader

protected void processHeader(java.lang.String hdr)

processData

protected void processData(java.lang.String dat)