com.shz.foundation.service.dynamic.DynamicSpecifications.java Source code

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Here is the source code for com.shz.foundation.service.dynamic.DynamicSpecifications.java

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/*******************************************************************************
 * Copyright (c) 2005, 2014 springside.github.io
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 *******************************************************************************/
package com.shz.foundation.service.dynamic;

import java.util.Collection;
import java.util.List;

import javax.persistence.criteria.CriteriaBuilder;
import javax.persistence.criteria.CriteriaQuery;
import javax.persistence.criteria.Path;
import javax.persistence.criteria.Predicate;
import javax.persistence.criteria.Root;

import org.apache.commons.lang3.StringUtils;
import com.shz.foundation.utils.Collections3;
import org.springframework.data.jpa.domain.Specification;

import com.google.common.collect.Lists;

public class DynamicSpecifications {

    public static <T> Specification<T> bySearchFilter(final Collection<SearchFilter> filters,
            final Class<T> entityClazz) {
        return new Specification<T>() {
            @Override
            public Predicate toPredicate(Root<T> root, CriteriaQuery<?> query, CriteriaBuilder builder) {
                if (Collections3.isNotEmpty(filters)) {

                    List<Predicate> predicates = Lists.newArrayList();
                    for (SearchFilter filter : filters) {
                        // nested path translate, Task??"user.name"filedName, ?Task.user.name
                        String[] names = StringUtils.split(filter.fieldName, ".");
                        Path expression = root.get(names[0]);
                        for (int i = 1; i < names.length; i++) {
                            expression = expression.get(names[i]);
                        }

                        // logic operator
                        switch (filter.operator) {
                        case EQ:
                            //??
                            Object value = filter.value;
                            if (isBoolean(value)) {
                                value = Boolean.parseBoolean(value.toString());
                            }
                            predicates.add(builder.equal(expression, value));
                            break;
                        case LIKE:
                            predicates.add(builder.like(expression, "%" + filter.value + "%"));
                            break;
                        case GT:
                            predicates.add(builder.greaterThan(expression, (Comparable) filter.value));
                            break;
                        case LT:
                            predicates.add(builder.lessThan(expression, (Comparable) filter.value));
                            break;
                        case GTE:
                            predicates.add(builder.greaterThanOrEqualTo(expression, (Comparable) filter.value));
                            break;
                        case LTE:
                            predicates.add(builder.lessThanOrEqualTo(expression, (Comparable) filter.value));
                            break;
                        }
                    }

                    // ? and ???
                    if (!predicates.isEmpty()) {
                        return builder.and(predicates.toArray(new Predicate[predicates.size()]));
                    }
                }

                return builder.conjunction();
            }

            private boolean isBoolean(Object value) {
                String valueString = value.toString().toLowerCase();
                if (valueString.equals("true") || valueString.equals("false"))
                    return true;
                return false;
            }
        };
    }
}