com.hpe.adm.nga.sdk.query.Query Maven / Gradle / Ivy
/*
* © Copyright 2016-2020 Micro Focus or one of its affiliates.
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.hpe.adm.nga.sdk.query;
/**
*
*
* The class to build complex queries. An instance of this class is created using the {@link #statement(String, QueryMethod, Object)} or
* {@link #not(String, QueryMethod, Object)} methods.
*
*
* See the REST API documentation for information as to how to build queries. This API supports building queries in a simplified Builder pattern
*
*
* Each query statement consists of the field name, query method and the object of the query. The object can be a simple primitive or a further {@code Query} object
*
*
* For example:
*
* To build a query such as {@code name eq 'entity_name'} the following code is used:
*
{@code Query.statement("name", QueryMethod.EqualTo, "entity_name");}
*
* To negate this statement such as {@code !name eq 'entity_name'} the following code is used:
*
{@code Query.not("name", QueryMethod.EqualTo, "entity_name");}
*
*
* These statements produce a {@code QueryBuilder} object. By calling the {@link QueryBuilder#build()} method this creates a {@code Query object} which can then
* be used in conjunction with entity or other contexts
*
*
* {@code Query} objects can be chained together (and/or) by using the correct methods such as {@link QueryBuilder#and(QueryBuilder)} (QueryBuilder)} or
* {@link QueryBuilder#orNot(String, QueryMethod, Object)}
*
* {@link QueryBuilder#build()} should be called once the entire query has been built
*
*/
public class Query {
protected String queryString = "";
protected Query() {}
/**
* Negates the given query string
* @param queryString - input query string
* @return resulting string after negation
*/
private static String negate(String queryString) {
return "!" + queryString;
}
/**
* QueryBuilder Statement
* @param fieldName - field name
* @param method - comparison function to use
* @param fieldValue - value to compare with
* @return The new object that can be used to build the query
*/
public static QueryBuilder statement(String fieldName, QueryMethod method, Object fieldValue) {
return new QueryBuilder(method.getAction().apply(fieldName, fieldValue));
}
/**
* QueryBuilder not
* @param fieldName - field name
* @param method - comparison function to use
* @param fieldValue - value to compare with
* @return The new object that can be used to build the query
*/
public static QueryBuilder not(String fieldName, QueryMethod method, Object fieldValue) {
return new QueryBuilder(negate(method.getAction().apply(fieldName, fieldValue)));
}
/**
* Constructor
* @param builder - the query builder to use for building the query
*/
private Query(QueryBuilder builder) {
queryString = builder.queryString;
}
/**
* Accessor method of query string
* @return query string
*/
public String getQueryString() {
return queryString;
}
/**
* @return a string representation of the object.
*/
@Override
public String toString() {
return queryString;
}
/**
* Object that is used to build {@link Query} objects.
* @see Query for more information
*/
public static class QueryBuilder {
private String queryString = "";
private QueryBuilder(String queryString) {
this.queryString = queryString;
}
/**
* Accessor method for the query builder string.
* @return query builder's string
*/
private String getQueryString() {
return queryString;
}
/**
* Builds a query from the current builder
* @return builded query
*/
public Query build() {
return new Query(this);
}
/**
* Generates a builder by applying the logical "and" operator between the current builder and the resulting operation of the input values.
* @param fieldName - field name
* @param method - comparison function to use
* @param fieldValue - value to compare with
* @return resulting builder
*/
public QueryBuilder and(String fieldName, QueryMethod method, Object fieldValue) {
String rightQueryString = method.getAction().apply(fieldName, fieldValue);
queryString += ";" + rightQueryString;
return this;
}
/**
* Generates a builder by applying the logical "and" operator between the current builder and the resulting operation of the input values after negation.
* @param fieldName - field name
* @param method - comparison function to use
* @param fieldValue - value to compare with
* @return resulting builder
*/
public QueryBuilder andNot(String fieldName, QueryMethod method, Object fieldValue) {
queryString += ";" + negate(method.getAction().apply(fieldName, fieldValue));
return this;
}
/**
* Generates a builder by applying the logical "and" operator between the current builder and the input builder.
* @param qb - query builder
* @return resulting builder
*/
public QueryBuilder and(QueryBuilder qb) {
queryString += ";" + qb.getQueryString();
return this;
}
/**
* Generates a builder by applying the logical "and" operator between the current builder and the input builder after negation.
* @param qb - query builder
* @return resulting builder
*/
public QueryBuilder andNot(QueryBuilder qb) {
queryString += ";" + negate(qb.getQueryString());
return this;
}
/**
* Generates a builder by applying the logical "or" operator between the current builder and the resulting operation of the input values.
* @param fieldName - field name
* @param method - comparison function to use
* @param fieldValue - value to compare with
* @return resulting builder
*/
public QueryBuilder or(String fieldName, QueryMethod method, Object fieldValue) {
String rightQueryString = method.getAction().apply(fieldName, fieldValue);
queryString += "||" + rightQueryString;
return this;
}
/**
* Generates a builder by applying the logical "or" operator between the current builder and the resulting operation of the input values after negation.
* @param fieldName - field name
* @param method - comparison function to use
* @param fieldValue - value to compare with
* @return resulting builder
*/
public QueryBuilder orNot(String fieldName, QueryMethod method, Object fieldValue) {
queryString += "||" + negate(method.getAction().apply(fieldName, fieldValue));
return this;
}
/**
* Generates a builder by applying the logical "or" operator between the current builder and the input builder.
* @param qb - query builder
* @return resulting builder
*/
public QueryBuilder or(QueryBuilder qb) {
queryString += "||" + qb.getQueryString();
return this;
}
/**
* Generates a builder by applying the logical "or" operator between the current builder and the input builder after negation.
* @param qb - query builder
* @return resulting builder
*/
public QueryBuilder orNot(QueryBuilder qb) {
queryString += "||" + negate(qb.getQueryString());
return this;
}
/**
* Wraps current builder content into a parenthesis
* @return with parentheses
*/
private QueryBuilder parenthesis() {
queryString = "(" + queryString + ")";
return this;
}
/**
* Wraps current builder content into a parenthesis
* @param queryBuilder {@link QueryBuilder} to wrap into parenthesis
* @return enclose the inner query of the QueryBuilder in parenthesis
*/
public static QueryBuilder parenthesis(QueryBuilder queryBuilder) {
return queryBuilder.parenthesis();
}
}
}