com.github.fangzhengjin.common.component.jpa.JpaHelper.kt Maven / Gradle / Ivy

Go to download
@file:Suppress("DEPRECATION")

package com.github.fangzhengjin.common.component.jpa

import com.github.fangzhengjin.common.component.jpa.transformer.AliasToLittleCamelCaseMapResultTransformer
import org.hibernate.query.internal.NativeQueryImpl
import org.hibernate.transform.Transformers
import org.intellij.lang.annotations.Language
import org.springframework.data.domain.Page
import org.springframework.data.domain.PageImpl
import org.springframework.data.domain.PageRequest
import org.springframework.data.domain.Pageable
import javax.persistence.EntityManager

/**
 * @author fangzhengjin
 * date 2018-7-13 16:55
 * @version V1.0
 * title: JpaHelper
 * package com.github.fangzhengjin.common.component.jpa
 * description:
 */


object JpaHelper {
    private lateinit var entityManager: EntityManager
    const val DEFAULT_JPA_NATIVE_QUERY_LANGUAGE = "Oracle"
    fun init(entityManager: EntityManager): JpaHelper {
        this.entityManager = entityManager
        return this
    }

    @JvmStatic
    fun getPageable(page: Int, size: Int): PageRequest {
        return PageRequest.of(if (page <= 1) 0 else page - 1, size)
    }

    /**
     *  本地查询 使用页码分页 每行结果封装至Map 结果集key处理为小驼峰
     */
    @JvmStatic
    fun nativeQueryTransformLittleCamelCaseMapResultToPage(
        @Language(DEFAULT_JPA_NATIVE_QUERY_LANGUAGE)
        querySql: String,
        @Language(DEFAULT_JPA_NATIVE_QUERY_LANGUAGE)
        countSql: String,
        page: Int,
        size: Int
    ): Page {
        return nativeQueryTransformLittleCamelCaseMapResultToPage(querySql, countSql, getPageable(page, size))
    }

    /**
     * 本地查询 使用Pageable分页 每行结果封装至Map 结果集key处理为小驼峰
     */
    @JvmStatic
    fun nativeQueryTransformLittleCamelCaseMapResultToPage(
        @Language(DEFAULT_JPA_NATIVE_QUERY_LANGUAGE)
        querySql: String,
        @Language(DEFAULT_JPA_NATIVE_QUERY_LANGUAGE)
        countSql: String,
        pageable: Pageable
    ): Page {
        val query = entityManager.createNativeQuery(querySql)
        query.firstResult = pageable.offset.toInt()
        query.maxResults = pageable.pageSize
        query.unwrap(NativeQueryImpl::class.java)
            .setResultTransformer(AliasToLittleCamelCaseMapResultTransformer.INSTANCE)

        val countQuery = nativeQueryNoTransformerSingleObjectResult(countSql)
        return PageImpl(query.resultList, pageable, countQuery.toString().toLong())
    }

    /**
     * 本地查询 每行结果封装至Map 结果集key处理为小驼峰
     */
    @JvmStatic
    fun nativeQueryTransformLittleCamelCaseMapResult(
        @Language(DEFAULT_JPA_NATIVE_QUERY_LANGUAGE)
        querySql: String
    ): MutableList {
        val query = entityManager.createNativeQuery(querySql)
        query.unwrap(NativeQueryImpl::class.java)
            .setResultTransformer(AliasToLittleCamelCaseMapResultTransformer.INSTANCE)
        return query.resultList
    }

    /**
     * 本地查询 每行结果封装至Map 原生样式 不作处理
     */
    @JvmStatic
    fun nativeQueryNoTransformerMapResultToList(
        @Language(DEFAULT_JPA_NATIVE_QUERY_LANGUAGE)
        querySql: String
    ): MutableList {
        val query = entityManager.createNativeQuery(querySql)
        query.unwrap(NativeQueryImpl::class.java).setResultTransformer(Transformers.ALIAS_TO_ENTITY_MAP)
        return query.resultList
    }

    /**
     * 本地查询 每行结果封装至指定对象
     */
    @Suppress("UNCHECKED_CAST")
    @JvmStatic
    fun  nativeQueryTransformerCustomizeEntityResultToList(
        @Language(DEFAULT_JPA_NATIVE_QUERY_LANGUAGE)
        querySql: String,
        target: Class
    ): MutableList {
        val query = entityManager.createNativeQuery(querySql)
        query.unwrap(NativeQueryImpl::class.java).setResultTransformer(Transformers.aliasToBean(target))
        @Suppress("UNCHECKED_CAST")
        return query.resultList as MutableList
    }

    /**
     * 本地查询 返回原生List
     */
    @JvmStatic
    fun nativeQueryNoTransformerObjectToList(
        @Language(DEFAULT_JPA_NATIVE_QUERY_LANGUAGE)
        querySql: String
    ): MutableList =
        entityManager.createNativeQuery(querySql).resultList


    /**
     * 本地查询 只返回第一个结果集
     */
    @JvmStatic
    fun nativeQueryNoTransformerSingleObjectResult(
        @Language(DEFAULT_JPA_NATIVE_QUERY_LANGUAGE)
        querySql: String
    ): Any? =
        entityManager.createNativeQuery(querySql).singleResult
}