org.fulib.tables

Class ObjectTable<T>

java.lang.Object

org.fulib.tables.Table<T>

org.fulib.tables.ObjectTable<T>

Type Parameters:

T - the type of values contained in the column this table points to

All Implemented Interfaces:

java.lang.Iterable<T>

public class ObjectTable<T>
extends Table<T>

A Table specialized for model objects. Using reflection, it provides more functionality for expanding and filtering based on attributes and associations.

Constructor Summary

Constructors

Constructor and Description
ObjectTable(java.lang.String colName, T... start)
ObjectTable(T... start)

Method Summary

Modifier and Type	Method and Description
void	addColumn(java.lang.String columnName, java.util.function.Function<java.util.LinkedHashMap<java.lang.String,java.lang.Object>,java.lang.Object> function) Deprecated. since 1.2; use Table.derive(String, Function) instead
ObjectTable<T>	dropColumns(java.lang.String... columnNames) Removes all given columns from the underlying data structure and ensures no duplicate rows exist afterwards.
<U> ObjectTable<U>	expand(java.lang.String columnName, java.util.function.Function<? super T,? extends U> function) Creates a new column with the given name by applying the given function to each object in the column pointed to by this table.
<U> ObjectTable<U>	expandAll(java.lang.String columnName, java.util.function.Function<? super T,? extends java.util.Collection<? extends U>> function) Creates a new column with the given name by applying the given function to each object in the column pointed to by this table, and flattening the result.
<U> Table<U>	expandAttribute(java.lang.String newColumnName, java.lang.String attrName) Creates a new column by expanding the given attribute from cells of the column this table points to.
BooleanTable	expandBoolean(java.lang.String newColumnName, java.lang.String attrName) Equivalent to:
doubleTable	expandDouble(java.lang.String newColumnName, java.lang.String attrName) Equivalent to:
floatTable	expandFloat(java.lang.String newColumnName, java.lang.String attrName) Equivalent to:
intTable	expandInt(java.lang.String newColumnName, java.lang.String attrName) Equivalent to:
<U> ObjectTable<U>	expandLink(java.lang.String newColumnName, java.lang.String linkName) Creates a new column by expanding the given link from the cells of the column this table points to.
longTable	expandLong(java.lang.String newColumnName, java.lang.String attrName) Equivalent to:
StringTable	expandString(java.lang.String newColumnName, java.lang.String attrName) Equivalent to:
ObjectTable<T>	filter(java.util.function.Predicate<? super T> predicate) Removes all rows from this table for which the predicate returned false when passed the cell value of the column this table points to.
ObjectTable<T>	filterRow(java.util.function.Predicate<java.util.LinkedHashMap<java.lang.String,java.lang.Object>> predicate) Deprecated. since 1.2; use Table.filterRows(Predicate) instead
org.fulib.yaml.ReflectorMap	getReflectorMap()
ObjectTable<T>	hasLink(java.lang.String linkName, ObjectTable<?> otherTable) Removes all rows where the cell value does not have the named link to the cell value of the other table in the same row.
ObjectTable<T>	selectColumns(java.lang.String... columnNames) Removes all columns from the underlying data structure except the given ones, and ensures no duplicate rows exist afterwards.
ObjectTable<T>	setColumnMap(java.util.LinkedHashMap<java.lang.String,java.lang.Integer> columnMap) Deprecated. since 1.2; for internal use only
ObjectTable<T>	setColumnName(java.lang.String columnName) Deprecated. since 1.2; set via the constructor and not meant to be changed afterward
void	setReflectorMap(org.fulib.yaml.ReflectorMap reflectorMap)
ObjectTable<T>	setTable(java.util.ArrayList<java.util.ArrayList<java.lang.Object>> table) Deprecated. since 1.2; for internal use only
java.util.LinkedHashSet<T>	toSet()

Methods inherited from class org.fulib.tables.Table

as, copy, derive, deriveAll, filterRows, getColumnMap, getColumnName, getTable, iterator, rowCount, stream, toList, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Constructor Detail

ObjectTable

@SafeVarargs
public ObjectTable(T... start)

ObjectTable

@SafeVarargs
public ObjectTable(java.lang.String colName,
                                T... start)

Method Detail

getReflectorMap

public org.fulib.yaml.ReflectorMap getReflectorMap()

setReflectorMap

public void setReflectorMap(org.fulib.yaml.ReflectorMap reflectorMap)

hasLink

public ObjectTable<T> hasLink(java.lang.String linkName,
                              ObjectTable<?> otherTable)

Removes all rows where the cell value does not have the named link to the cell value of the other table in the same row. This requires this and the other table to share the same underlying data structure. You can also pass this table as otherTable to check for self-associations.

Essentially equivalent to:

    this.filterRows(row -> {
       Object source = row.get(this.getColumn());
       Object target = row.get(otherTable.getColumn());
       Object linkValue = source.get<linkName>(); // via reflection
       return linkValue == target || linkValue instanceof Collection && ((Collection) linkValue).contains(other);
    });
 

Parameters:

linkName - the name of the property on this table's objects

otherTable - the table pointing to the column with link targets

Returns:

this instance, to allow method chaining

See Also:

Table.filterRows(Predicate)

expandLink

public <U> ObjectTable<U> expandLink(java.lang.String newColumnName,
                                     java.lang.String linkName)

Creates a new column by expanding the given link from the cells of the column this table points to. Links may be simple objects or collections, the latter of which will be flattened. Links that are null do not create a row.

Essentially equivalent to:

    this.expandAll(newColumnName, source -> {
       final Object target = source.get<linkName>(); // via reflection
       if (target instanceof Collection) {
          return target;
       }
       else if (target == null) {
          return Collections.emptyList();
       }
       else {
          return Collections.singleton(target);
       }
    }
 

Type Parameters:

U - the type of the target objects

Parameters:

newColumnName - the name of the new column

linkName - the name of the property to expand

Returns:

a table pointing to the new column

See Also:

expandAll(String, Function)

expandAttribute

public <U> Table<U> expandAttribute(java.lang.String newColumnName,
                                    java.lang.String attrName)

Creates a new column by expanding the given attribute from cells of the column this table points to.

Essentially equivalent to:

    this.expand(newColumnName, start -> {
       return start.get<attrName>(); // via reflection
    });
 

Type Parameters:

U - the type of the attribute

Parameters:

newColumnName - the name of the new column

attrName - the name of the attribute to expand

Returns:

a table pointing to the new column

Since:

1.2

See Also:

expand(String, Function)

expandDouble

public doubleTable expandDouble(java.lang.String newColumnName,
                                java.lang.String attrName)

Equivalent to:

    this.expandAttribute(newColumnName, attrName).as(doubleTable.class);
 

Parameters:

newColumnName - the name of the new column

attrName - the name of the attribute to expand

Returns:

a table pointing to the new column

See Also:

expandAttribute(String, String)

expandFloat

public floatTable expandFloat(java.lang.String newColumnName,
                              java.lang.String attrName)

Equivalent to:

    this.expandAttribute(newColumnName, attrName).as(floatTable.class);
 

Parameters:

newColumnName - the name of the new column

attrName - the name of the attribute to expand

Returns:

a table pointing to the new column

See Also:

expandAttribute(String, String)

expandInt

public intTable expandInt(java.lang.String newColumnName,
                          java.lang.String attrName)

Equivalent to:

    this.expandAttribute(newColumnName, attrName).as(intTable.class);
 

Parameters:

newColumnName - the name of the new column

attrName - the name of the attribute to expand

Returns:

a table pointing to the new column

See Also:

expandAttribute(String, String)

expandLong

public longTable expandLong(java.lang.String newColumnName,
                            java.lang.String attrName)

Equivalent to:

    this.expandAttribute(newColumnName, attrName).as(longTable.class);
 

Parameters:

newColumnName - the name of the new column

attrName - the name of the attribute to expand

Returns:

a table pointing to the new column

See Also:

expandAttribute(String, String)

expandString

public StringTable expandString(java.lang.String newColumnName,
                                java.lang.String attrName)

Equivalent to:

    this.expandAttribute(newColumnName, attrName).as(StringTable.class);
 

Parameters:

newColumnName - the name of the new column

attrName - the name of the attribute to expand

Returns:

a table pointing to the new column

See Also:

expandAttribute(String, String)

expandBoolean

public BooleanTable expandBoolean(java.lang.String newColumnName,
                                  java.lang.String attrName)

Equivalent to:

    this.expandAttribute(newColumnName, attrName).as(BooleanTable.class);
 

Parameters:

newColumnName - the name of the new column

attrName - the name of the attribute to expand

Returns:

a table pointing to the new column

See Also:

expandAttribute(String, String)

expand

public <U> ObjectTable<U> expand(java.lang.String columnName,
                                 java.util.function.Function<? super T,? extends U> function)

Description copied from class: Table

Creates a new column with the given name by applying the given function to each object in the column pointed to by this table.

Example:

 Table<Integer> a = new Table<>("A", 1, 2, 3);
 Table<Integer> b = a.expand("B", i -> i * 2);
 

b

A	B
1	2
2	4
3	6

Overrides:

expand in class Table<T>

Type Parameters:

U - the cell type of the new column

Parameters:

columnName - the name of the new column

function - the function that computes a value for the new column

Returns:

a table pointing to the new column

expandAll

public <U> ObjectTable<U> expandAll(java.lang.String columnName,
                                    java.util.function.Function<? super T,? extends java.util.Collection<? extends U>> function)

Description copied from class: Table

Creates a new column with the given name by applying the given function to each object in the column pointed to by this table, and flattening the result.

Example:

 Table<Integer> a = new Table<>("A", 1, 2);
 Table<Integer> b = a.expandAll("B", i -> Arrays.asList(i + 10, i + 20));
 

b

A	B
1	11
1	21
2	12
2	22

Overrides:

expandAll in class Table<T>

Type Parameters:

U - the cell type of the new column

Parameters:

columnName - the name of the new column

function - the function that computes a collection of values for the new column

Returns:

a table pointing to the new column

selectColumns

public ObjectTable<T> selectColumns(java.lang.String... columnNames)

Description copied from class: Table

Removes all columns from the underlying data structure except the given ones, and ensures no duplicate rows exist afterwards. If one of the given column names is not part of this table, an IllegalArgumentException is thrown and no changes are made. Note the original order of columns is unaffected by the order of the given names.

After this operation, table instances with the same underlying data that pointed to a columns not part of the given ones will throw an exception when operated on in any way that accesses their corresponding column.

Example:

 Table<String> names = new StringTable("Alice", "Bob", "Charlie", "alice");
 Table<String> uppercase = names.expand("uppercase", String::toUpperCase);
 Table<String> lowercase = names.expand("lowercase", String::toLowerCase);
 

before

A	uppercase	lowercase
Alice	ALICE	alice
Bob	BOB	bob
Charlie	CHARLIE	charlie
alice	ALICE	alice

 names.selectColumns("uppercase", "lowercase");
 

after

uppercase	lowercase
ALICE	alice
BOB	bob
CHARLIE	charlie

 names.toList(); // throws IllegalStateException
 

Overrides:

selectColumns in class Table<T>

Parameters:

columnNames - the names of columns to retain

Returns:

this instance, to allow method chaining

dropColumns

public ObjectTable<T> dropColumns(java.lang.String... columnNames)

Description copied from class: Table

Removes all given columns from the underlying data structure and ensures no duplicate rows exist afterwards. Given column names that don't exist are ignored.

After this operation, table instances with the same underlying data that pointed to one of these columns will throw an exception when operated on in any way that accesses their corresponding column.

Example:

 Table<String> names = new StringTable("Alice", "Bob", "Charlie", "alice");
 Table<String> uppercase = names.expand("uppercase", String::toUpperCase);
 Table<String> lowercase = names.expand("lowercase", String::toLowerCase);
 

before

A	uppercase	lowercase
Alice	ALICE	alice
Bob	BOB	bob
Charlie	CHARLIE	charlie
alice	ALICE	alice

 names.dropColumns(names.getColumnName());
 

after

uppercase	lowercase
ALICE	alice
BOB	bob
CHARLIE	charlie

 names.toList(); // throws IllegalStateException
 

Overrides:

dropColumns in class Table<T>

Parameters:

columnNames - the names of columns to drop

Returns:

this instance, to allow method chaining

filter

public ObjectTable<T> filter(java.util.function.Predicate<? super T> predicate)

Description copied from class: Table

Removes all rows from this table for which the predicate returned false when passed the cell value of the column this table points to.

Example:

 final Table<Integer> numbers = new Table<>("A", 1, 2, 3, 4, 5, 6, 7, 8, 9, 10);
 numbers.filter(i -> i % 2 == 0);
 

result

A
2
4
6
8
10

Overrides:

filter in class Table<T>

Parameters:

predicate - the predicate that determines which rows should be kept

Returns:

this table, to allow method chaining

toSet

public java.util.LinkedHashSet<T> toSet()

Overrides:

toSet in class Table<T>

Returns:

a set of cell values of the column this table instance points to

setColumnName

@Deprecated
public ObjectTable<T> setColumnName(java.lang.String columnName)

Deprecated. since 1.2; set via the constructor and not meant to be changed afterward

Parameters:

columnName - the name of the column this table should point to

Returns:

this instance, to allow method chaining

setTable

@Deprecated
public ObjectTable<T> setTable(java.util.ArrayList<java.util.ArrayList<java.lang.Object>> table)

Deprecated. since 1.2; for internal use only

Parameters:

table - the list of rows

Returns:

this instance, to allow method chaining

setColumnMap

@Deprecated
public ObjectTable<T> setColumnMap(java.util.LinkedHashMap<java.lang.String,java.lang.Integer> columnMap)

Deprecated. since 1.2; for internal use only

Parameters:

columnMap - the map from column name to index in the lists that make up rows

Returns:

this instance, to allow method chaining

addColumn

@Deprecated
public void addColumn(java.lang.String columnName,
                                  java.util.function.Function<java.util.LinkedHashMap<java.lang.String,java.lang.Object>,java.lang.Object> function)

Deprecated. since 1.2; use Table.derive(String, Function) instead

Same as Table.derive(String, Function), except it has stricter requirements on the parameter type of the predicate and does not return a table pointing to the new column.

Parameters:

columnName - the name of the new column

function - the function that computes a value for the new column

See Also:

Table.derive(String, Function)

filterRow

@Deprecated
public ObjectTable<T> filterRow(java.util.function.Predicate<java.util.LinkedHashMap<java.lang.String,java.lang.Object>> predicate)

Deprecated. since 1.2; use Table.filterRows(Predicate) instead

Same as Table.filterRows(Predicate), except it has stricter requirements on the parameter type of the predicate.

Parameters:

predicate - the predicate that determines which rows should be kept

Returns:

this table, to allow method chaining

See Also:

Table.filterRows(Predicate)