org.nuiton.topia.persistence.pager.PaginationParameter Maven / Gradle / Ivy
package org.nuiton.topia.persistence.pager;
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import com.google.common.base.Preconditions;
import com.google.common.collect.Iterables;
import com.google.common.collect.Lists;
import java.io.Serializable;
import java.util.Collections;
import java.util.LinkedList;
import java.util.List;
/**
* This class represents the necessary information to do pagination (page number, size, ...).
*
* @author Arnaud Thimel (Code Lutin)
* @since 3.0
*/
public class PaginationParameter implements Serializable {
private static final long serialVersionUID = 1L;
/**
* All results.
*/
protected static final int ALL_PAGE_SIZE = -1;
/**
* An instance that represents a page of ALL elements
*/
public static final PaginationParameter ALL = PaginationParameter.of(0, ALL_PAGE_SIZE);
/**
* 0-based page number
*/
protected int pageNumber;
/**
* The size of each page. Value can be -1 (for infinite pageSize) or greater than 0
*/
protected int pageSize;
/**
* The list of order clauses. This instance is unmodifiable and never null.
*/
protected List orderClauses;
protected PaginationParameter(int pageNumber, int pageSize) {
this(pageNumber, pageSize, new LinkedList<>());
}
protected PaginationParameter(int pageNumber, int pageSize, List orderClauses) {
Preconditions.checkArgument(pageNumber >= 0, "pageNumber cannot be lower than 0");
Preconditions.checkArgument(pageSize == -1 || pageSize > 0, "pageSize can only be -1 or greater than 0");
Preconditions.checkArgument(pageSize != -1 || pageNumber == 0, "This is non-sense to have pageNumber>1 if pageSize==-1");
this.pageNumber = pageNumber;
this.pageSize = pageSize;
this.orderClauses = Collections.unmodifiableList(orderClauses);
}
/**
* Method to create a PaginationParameter only based on pageNumber and pageSize (no order clauses).
*
* @param pageNumber the index (0-based) of the page
* @param pageSize the size of each page. Value can be -1 (for infinite pageSize) or greater than 0
* @return an immutable PaginationParameter instance
*/
public static PaginationParameter of(int pageNumber, int pageSize) {
return new PaginationParameter(pageNumber, pageSize);
}
/**
* Method to create a PaginationParameter based on pageNumber, pageSize and a single order clause.
*
* If you have an unknown number of order clauses, you should use the {@link #builder(int, int)}
* method together with {@link PaginationParameterBuilder#addOrder(String, boolean)} and
* {@link PaginationParameterBuilder#build()} methods.
*
* @param pageNumber the index (0-based) of the page
* @param pageSize the size of each page. Value can be -1 (for infinite pageSize) or greater than 0
* @param orderClause1 an order clause attribute name. It comes together with {code}orderDesc1{/code}
* @param orderDesc1 the asc/desc property associated with {code}orderClause1{/code}
* @return an immutable PaginationParameter instance
* @see PaginationOrder
* @see PaginationParameterBuilder
*/
public static PaginationParameter of(int pageNumber, int pageSize,
String orderClause1, boolean orderDesc1) {
return builder(pageNumber, pageSize)
.addOrder(orderClause1, orderDesc1)
.build();
}
/**
* Method to create a PaginationParameter based on pageNumber, pageSize and two order clauses.
*
* If you have an unknown number of order clauses, you should use the {@link #builder(int, int)}
* method together with {@link PaginationParameterBuilder#addOrder(String, boolean)} and
* {@link PaginationParameterBuilder#build()} methods.
*
* @param pageNumber the index (0-based) of the page
* @param pageSize the size of each page. Value can be -1 (for infinite pageSize) or greater than 0
* @param orderClause1 an order clause attribute name. It comes together with {code}orderDesc1{/code}
* @param orderDesc1 the asc/desc property associated with {code}orderClause1{/code}
* @param orderClause2 an order clause attribute name. It comes together with {code}orderDesc2{/code}
* @param orderDesc2 the asc/desc property associated with {code}orderClause2{/code}
* @return an immutable PaginationParameter instance
* @see PaginationOrder
* @see PaginationParameterBuilder
*/
public static PaginationParameter of(int pageNumber, int pageSize,
String orderClause1, boolean orderDesc1,
String orderClause2, boolean orderDesc2) {
return builder(pageNumber, pageSize)
.addOrder(orderClause1, orderDesc1)
.addOrder(orderClause2, orderDesc2)
.build();
}
/**
* Method to create a PaginationParameter based on pageNumber, pageSize and three order clauses.
*
* If you have more order clauses, or an unknown number of clauses, you should use the {@link #builder(int, int)}
* method together with {@link PaginationParameterBuilder#addOrder(String, boolean)} and
* {@link PaginationParameterBuilder#build()} methods.
*
* @param pageNumber the index (0-based) of the page
* @param pageSize the size of each page. Value can be -1 (for infinite pageSize) or greater than 0
* @param orderClause1 an order clause attribute name. It comes together with {code}orderDesc1{/code}
* @param orderDesc1 the asc/desc property associated with {code}orderClause1{/code}
* @param orderClause2 an order clause attribute name. It comes together with {code}orderDesc2{/code}
* @param orderDesc2 the asc/desc property associated with {code}orderClause2{/code}
* @param orderClause3 an order clause attribute name. It comes together with {code}orderDesc3{/code}
* @param orderDesc3 the asc/desc property associated with {code}orderClause3{/code}
* @return an immutable PaginationParameter instance
* @see PaginationOrder
* @see PaginationParameterBuilder
*/
public static PaginationParameter of(int pageNumber, int pageSize,
String orderClause1, boolean orderDesc1,
String orderClause2, boolean orderDesc2,
String orderClause3, boolean orderDesc3) {
return builder(pageNumber, pageSize)
.addOrder(orderClause1, orderDesc1)
.addOrder(orderClause2, orderDesc2)
.addOrder(orderClause3, orderDesc3)
.build();
}
/**
* Method to create a PaginationParameter using the {@link PaginationParameterBuilder}.
*
* @param pageNumber the index (0-based) of the page
* @param pageSize the size of each page. Value can be -1 (for infinite pageSize) or greater than 0
* @return an immutable PaginationParameter.Builder instance
*/
public static PaginationParameterBuilder builder(int pageNumber, int pageSize) {
return new PaginationParameterBuilder(pageNumber, pageSize);
}
public int getPageNumber() {
return pageNumber;
}
public int getPageSize() {
return pageSize;
}
public List getOrderClauses() {
return orderClauses;
}
/**
* Method that computes the start index of a page according to {@link #pageNumber} and {@link #pageSize}.
*
* @return the computed start index
*/
public int getStartIndex() {
if (pageNumber != 0) {
Preconditions.checkState(pageSize != -1, "This is non-sense to have pageNumber>1 if pageSize==-1");
}
return pageNumber * pageSize;
}
/**
* Method that computes the end index of a page according to {@link #pageNumber} and {@link #pageSize}. If the
* pageSize is -1, the end index will be {@link Integer#MAX_VALUE}.
*
* @return the computed end index
*/
public int getEndIndex() {
int endIndex = Integer.MAX_VALUE;
if (pageSize != -1) {
endIndex = getStartIndex() + pageSize - 1;
}
return endIndex;
}
@Override
public boolean equals(Object o) {
if (this == o) {
return true;
}
if (o == null || getClass() != o.getClass()) {
return false;
}
PaginationParameter that = (PaginationParameter) o;
if (pageNumber != that.pageNumber) {
return false;
}
if (pageSize != that.pageSize) {
return false;
}
return orderClauses.equals(that.orderClauses);
}
@Override
public int hashCode() {
int result = pageNumber;
result = 31 * result + pageSize;
result = 31 * result + orderClauses.hashCode();
return result;
}
/**
* Test if pagination parameter is about all results range.
*
* @return {@code true} if pagination parameter is about all results range
*/
public boolean isAll() {
return pageSize == ALL_PAGE_SIZE;
}
/**
* Class used to build an instance of PaginationParameter. Use the {@link #build()} method to create the
* {@link PaginationParameter}.
*
* @author Arnaud Thimel (Code Lutin)
* @since 3.0
*/
public static class PaginationParameterBuilder {
protected int pageNumber;
protected int pageSize;
protected List orderClauses;
/**
* Creates a Builder instance
*
* @param pageNumber the index (0-based) of the page
* @param pageSize the size of each page. Value can be -1 (for infinite pageSize) or greater than 0
*/
public PaginationParameterBuilder(int pageNumber, int pageSize) {
this.pageNumber = pageNumber;
this.pageSize = pageSize;
}
/**
* Adds an order clause
*
* @param clause an order clause attribute name. It comes together with {code}desc{/code}
* @param desc the asc/desc property associated with {code}clause{/code}
* @return the current Builder for a Fluent usage
*/
public PaginationParameterBuilder addOrder(String clause, boolean desc) {
if (orderClauses == null) {
orderClauses = Lists.newLinkedList();
}
PaginationOrder paginationOrder = new PaginationOrder(clause, desc);
orderClauses.add(paginationOrder);
return this;
}
/**
* Adds an ASC order clause
*
* @param clause an order clause attribute name
* @return the current Builder for a Fluent usage
*/
public PaginationParameterBuilder addAscOrder(String clause) {
return addOrder(clause, false);
}
/**
* Adds an DESC order clause
*
* @param clause an order clause attribute name
* @return the current Builder for a Fluent usage
*/
public PaginationParameterBuilder addDescOrder(String clause) {
return addOrder(clause, true);
}
/**
* Adds an order clause. The asc/desc value is guessed from the given {code}clause{/code}. The expected format
* is "column asc" or "column desc"
*
* @param clause an order clause attribute name. It comes together with {code}desc{/code}
* @return the current Builder for a Fluent usage
*/
public PaginationParameterBuilder addOrder(String clause) {
boolean desc = false;
String cleanedClause = clause;
int spaceIndex = clause.indexOf(' ');
if (spaceIndex != -1) {
cleanedClause = clause.substring(0, spaceIndex).trim();
desc = "desc".equalsIgnoreCase(clause.substring(spaceIndex + 1).trim());
}
return addOrder(cleanedClause, desc);
}
/**
* Adds an the given order clauses
*
* @param clauses an list of order clauses
* @return the current Builder for a Fluent usage
*/
public PaginationParameterBuilder addOrderClauses(Iterable clauses) {
if (orderClauses == null) {
orderClauses = Lists.newLinkedList();
}
if (clauses != null) {
Iterables.addAll(orderClauses, clauses);
}
return this;
}
/**
* Final method that instantiates the immutable PaginationParameter
*
* @return the immutable PaginationParameter built
*/
public PaginationParameter build() {
return new PaginationParameter(pageNumber, pageSize, orderClauses);
}
}
}