Vector

You can create a vector using the createVector method provided in the Utils class. The method declaration is as follows:

public static Vector createVector(DATA_TYPE type, int size, int capacity, int extraParam)

Parameters

• type：Specifies the type of elements stored in the vector, such as DT_INT, DT_DATE, etc.

• size：The initial size of the vector. If set to non-zero, the elements will be random.

• capacity：The capacity allocated for the vector at construction. Setting it reasonably can improve insertion speed.

• scale：Used when creating decimal-related vectors. This parameter specifies the decimal scale.

Supported data types include:

DT_VOID, DT_BOOL, DT_BYTE, DT_SHORT, DT_INT, DT_LONG,DT_DATE, DT_MONTH, DT_TIME, 
DT_MINUTE, DT_SECOND, DT_DATETIME, DT_TIMESTAMP, DT_NANOTIME, DT_NANOTIMESTAMP, 
DT_FLOAT,DT_DOUBLE, DT_SYMBOL, DT_STRING, DT_UUID, DT_DATEHOUR, DT_DATEMINUTE, 
DT_IPADDR,DT_INT128, DT_BLOB, DT_DECIMAL, DT_COMPLEX, DT_POINT, DT_DURATION, 
DT_DECIMAL32, DT_DECIMAL64, DT_DECIMAL128

Example:

// Create an INT vector with size 0 and capacity 5
Vector intVector = Utils.createVector(DT_INT, 0, 5);
// Create a DT_DECIMAL32 vector with size 0, capacity 5, and scale 3
Vector decimalVector = Utils.createVector(DT_DECIMAL32, 0, 5, 3);

You can also create a vector using the constructor of each vector type.

• You can specify size and capacity to create a vector with a given size and capacity.

• You can also pass actual values to construct a vector, usually using an array or a List.

• The supported Java native types for each vector type can be found in the Scalar.

Example:

// Create an INT vector with size 0 and capacity 6
BasicIntVector bbv = new BasicIntVector(0,6);

// Create an INT vector with specified elements using List<Integer>
List<Integer> list = new ArrayList<>();
list.add(5);
list.add(7);
list.add(8);
list.add(Integer.MIN_VALUE);
list.add(null);
BasicIntVector intVector = new BasicIntVector(list);

// Create an INT vector with specified elements using int[]
BasicIntVector intVector2 = new BasicIntVector(new int[]{1, 2, 3, 4, 5, 6, 7, 8, 9, 10});

// Create a DT_DECIMAL32 vector with specified elements using String[]
String[] tmp_string_v = {"0.0","-123.00432","132.204234","100.0"};
BasicDecimal32Vector decimal32Vector = new BasicDecimal32Vector(tmp_string_v, 4);

Add a scalar element to the end of the vector.

add(Object value)

The supported Java native types for add can be found in the Scalar.

Example:

Vector intVector = Utils.createVector(DT_INT, 0, 5);
intVector.add(10);
System.out.println(intVector.getString());
// [10]

BasicIntVector intVector = new BasicIntVector(new int[]{1, 2, 3, 4, 5, 6, 7, 8, 9});
intVector.add(10);
System.out.println(intVector.getString());
// [1,2,3,4,5,6,7,8,9,10]

Get the element at the specified index:

public Entity get(int index)

Example:

BasicIntVector intVector = new BasicIntVector(new int[]{1, 2, 3, 4});
intVector.Append(new BasicIntVector(new int[]{26,31,23,24}));
Entity elem = intVector.get(5);
System.out.println(elem.getString());
// 31

Get a sub-vector of specified indices. Returns a vector.

public Vector getSubVector(int[] indices)

Example:

BasicIntVector intVector = new BasicIntVector(new int[]{1, 2, 3, 4});
intVector.Append(new BasicIntVector(new int[]{26,31,23,24}));
Vector subVector = intVector.getSubVector(new int[]{0, 3, 5});
System.out.println(subVector.getString());

Add or modify a scalar element at a specified index:

public void set(int index, Object value) // Can directly add Java native types
public void set(int index, Entity value) // Can construct a specific Entity to add

The supported Java native types for set(int index, Object value) can be found in the Scalar.

Example:

BasicDoubleVector bbv = new BasicDoubleVector(6,6);
bbv.set(0, 1.11);
bbv.set(1, null);
bbv.set(2, -1.33);
bbv.set(3, 2.99);
bbv.set(4, 0.0);
bbv.set(5, 4.13);
System.out.println(bbv.getString());
// [1.11,,-1.33,2.99,0,4.13]