Руководство по Hibernate. Руководство по Hibernate
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Обработка “пакетов”.Давайте рассмотрим ситуацию, в которой нам необходимо выполнить 100,000 записей в таблицу базы данных (далее – БД). Рассмотрим примитивный сопособ: Session session = sessionFactory.openSession(); Transaction transaction = session.beginTransaction(); for(int i = 0; i < 100_000; i++){ Developer developer = new Developer(/*Some parameters*/); session.save(developer); } transaction.commit(); session.close(); На первый взгляд кажется, что мы получим 100_000 записей в нашу БД, но на практике мы получим OutOfMemoryException примерно в тот момент, когда попытаемся выполнить 50_000 – тысячную запись. Это вызвано тем, что Hibernate кэширует все сохраняемые объекты в кэш сессии. Как же нам решить данную проблему? Для этого нам необходимо использовать обработку пакетов (batch processing). Например, мы говорим Hibernate, что хотим вставлять каждые 50 объектов, как единый пакет. Для этого нам необходимо установить hibernate.jdbc.atch_size на 50 и написать, примерно, такой кусок кода: Session session = sessionFactory.openSession(); Transaction transaction = session.beginTransaction(); for(int i = 0; i < 100000; i++){ Developer developer = new Developer(/*Some parameters*/); session.save(developer); if(i % 50 == 0){ session.flush(); session.clear(); } } transaction.commit(); session.close(); Для понимания того, как это работает на практике – рассмотрим пример небольшого приложения. Пример: Шаг 1. Создаём таблицу в нашей БД HIBRNATE_DEVELOPERS CREATE TABLE HIBERNATE_DEVELOPERS ( id INT NOT NULL auto_increment, FIRST_NAME VARCHAR(50) default NULL, LAST_NAME VARCHAR(50) default NULL, SPECIALTY VARCHAR(50) default NULL, EXPERIENCE INT default NULL, SALARY INT default NULL, PRIMARY KEY (id) ); Шаг 2 . Создадим POJO – класс Developer.java package net.proselyte.hibernate.batch; public class Developer { private int id; private String firstName; private String lastName; private String specialty; private int experience; private int salary; /** * Default Constructor */ public Developer() { } /** * Plain constructor */ public Developer(String firstName, String lastName, String specialty, int experience, int salary) { this.firstName = firstName; this.lastName = lastName; this.specialty = specialty; this.experience = experience; this.salary = salary; } /** * Getters and Setters */ public int getId() { return id; } public void setId(int id) { this.id = id; } public String getFirstName() { return firstName; } public void setFirstName(String firstName) { this.firstName = firstName; } public String getLastName() { return lastName; } public void setLastName(String lastName) { this.lastName = lastName; } public String getSpecialty() { return specialty; } public void setSpecialty(String specialty) { this.specialty = specialty; } public int getExperience() { return experience; } public void setExperience(int experience) { this.experience = experience; } public int getSalary() { return salary; } public void setSalary(int salary) { this.salary = salary; } /** * toString method (optional) */ @Override public String toString() { return "id: " + id + "\nFirst Name: " + firstName + "\nLast Name: " + lastName + "\nSpecialty: " + specialty + "\nExperience: " + experience + "\nSalary: " + salary + "\n"; } } Шаг 3. Создаём конфигруационные файлы hibernate.cfg.xml "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd"> org.hibernate.dialect.MySQLDialect com.mysql.jdbc.Driver jdbc:mysql://localhost/ИМЯ_ВАШЕЙ_БАЗЫ_ДАННЫХ ВАШЕ_ИМЯ_ПОЛЬЗОВАТЕЛЯ ВАШ_ПАРОЛЬ 50 Developer.hbm.xml "-//Hibernate/Hibernate Mapping DTD//EN" "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd"> This class contains developer details. Шаг 4. Создаём класс DeveloperRunner.java DeveloperRunner.java package net.proselyte.hibernate.batch; import org.hibernate.Session; import org.hibernate.SessionFactory; import org.hibernate.Transaction; import org.hibernate.cfg.Configuration; public class DeveloperRunner { private static SessionFactory sessionFactory; public static void main(String[] args) { sessionFactory = new Configuration().configure().buildSessionFactory(); DeveloperRunner developerRunner = new DeveloperRunner(); System.out.println("Adding 100,000 developer's records to the database..."); developerRunner.addDevelopers(); System.out.println("100,000 developer's records successfully added to the database..."); sessionFactory.close(); } public void addDevelopers() { Session session = sessionFactory.openSession(); Transaction transaction = null; Integer developerId = null; transaction = session.beginTransaction(); for (int i = 0; i < 100_000; i++) { String firstName = "First Name " + i; String lastName = "Last Name " + i; String specialty = "Specialty " + i; int experience = i; int salary = i * 10; Developer developer = new Developer(firstName, lastName, specialty, experience, salary); session.save(developer); if (i % 50 == 0) { session.flush(); session.clear(); } } transaction.commit(); session.close(); } } Если всё было дслеано правильно, то в результате работы программы мыполучим, примерно, следующий результат: /usr/lib/jvm/java-8-oracle/bin/java -Didea.launcher.port=7533 -Didea.launcher.bin.path=/home/proselyte/Programming/Soft/IntellijIdea/bin -Dfile.encoding=UTF-8 -classpath /usr/lib/jvm/java-8-oracle/jre/lib/management-agent.jar:/usr/lib/jvm/java-8-oracle/jre/lib/plugin.jar:/usr/lib/jvm/java-8-oracle/jre/lib/rt.jar:/usr/lib/jvm/java-8-oracle/jre/lib/jsse.jar:/usr/lib/jvm/java-8-oracle/jre/lib/charsets.jar:/usr/lib/jvm/java-8-oracle/jre/lib/jce.jar:/usr/lib/jvm/java-8-oracle/jre/lib/resources.jar:/usr/lib/jvm/java-8-oracle/jre/lib/deploy.jar:/usr/lib/jvm/java-8-oracle/jre/lib/jfxswt.jar:/usr/lib/jvm/java-8-oracle/jre/lib/javaws.jar:/usr/lib/jvm/java-8-oracle/jre/lib/jfr.jar:/usr/lib/jvm/java-8-oracle/jre/lib/ext/dnsns.jar:/usr/lib/jvm/java-8-oracle/jre/lib/ext/sunpkcs11.jar:/usr/lib/jvm/java-8-oracle/jre/lib/ext/sunec.jar:/usr/lib/jvm/java-8-oracle/jre/lib/ext/sunjce_provider.jar:/usr/lib/jvm/java-8-oracle/jre/lib/ext/jaccess.jar:/usr/lib/jvm/java-8-oracle/jre/lib/ext/nashorn.jar:/usr/lib/jvm/java-8-oracle/jre/lib/ext/localedata.jar:/usr/lib/jvm/java-8-oracle/jre/lib/ext/zipfs.jar:/usr/lib/jvm/java-8-oracle/jre/lib/ext/cldrdata.jar:/usr/lib/jvm/java-8-oracle/jre/lib/ext/jfxrt.jar:/home/proselyte/Programming/IdeaProjects/ProselyteTutorials/Hibernate/target/classes:/home/proselyte/.m2/repository/org/springframework/spring-core/4.1.1.RELEASE/spring-core-4.1.1.RELEASE.jar:/home/proselyte/.m2/repository/commons-logging/commons-logging/1.1.3/commons-logging-1.1.3.jar:/home/proselyte/.m2/repository/org/springframework/spring-web/4.1.1.RELEASE/spring-web-4.1.1.RELEASE.jar:/home/proselyte/.m2/repository/org/springframework/spring-aop/4.1.1.RELEASE/spring-aop-4.1.1.RELEASE.jar:/home/proselyte/.m2/repository/aopalliance/aopalliance/1.0/aopalliance-1.0.jar:/home/proselyte/.m2/repository/org/springframework/spring-beans/4.1.1.RELEASE/spring-beans-4.1.1.RELEASE.jar:/home/proselyte/.m2/repository/org/springframework/spring-context/4.1.1.RELEASE/spring-context-4.1.1.RELEASE.jar:/home/proselyte/.m2/repository/javax/servlet/servlet-api/2.5/servlet-api-2.5.jar:/home/proselyte/.m2/repository/org/springframework/spring-webmvc/4.1.1.RELEASE/spring-webmvc-4.1.1.RELEASE.jar:/home/proselyte/.m2/repository/org/springframework/spring-expression/4.1.1.RELEASE/spring-expression-4.1.1.RELEASE.jar:/home/proselyte/.m2/repository/org/springframework/integration/spring-integration-file/4.2.1.RELEASE/spring-integration-file-4.2.1.RELEASE.jar:/home/proselyte/.m2/repository/org/springframework/integration/spring-integration-core/4.2.1.RELEASE/spring-integration-core-4.2.1.RELEASE.jar:/home/proselyte/.m2/repository/org/springframework/spring-messaging/4.2.2.RELEASE/spring-messaging-4.2.2.RELEASE.jar:/home/proselyte/.m2/repository/org/springframework/retry/spring-retry/1.1.2.RELEASE/spring-retry-1.1.2.RELEASE.jar:/home/proselyte/.m2/repository/org/springframework/spring-tx/4.2.2.RELEASE/spring-tx-4.2.2.RELEASE.jar:/home/proselyte/.m2/repository/commons-io/commons-io/2.4/commons-io-2.4.jar:/home/proselyte/.m2/repository/org/hibernate/hibernate-core/5.1.0.Final/hibernate-core-5.1.0.Final.jar:/home/proselyte/.m2/repository/org/jboss/logging/jboss-logging/3.3.0.Final/jboss-logging-3.3.0.Final.jar:/home/proselyte/.m2/repository/org/hibernate/javax/persistence/hibernate-jpa-2.1-api/1.0.0.Final/hibernate-jpa-2.1-api-1.0.0.Final.jar:/home/proselyte/.m2/repository/org/javassist/javassist/3.20.0-GA/javassist-3.20.0-GA.jar:/home/proselyte/.m2/repository/antlr/antlr/2.7.7/antlr-2.7.7.jar:/home/proselyte/.m2/repository/org/apache/geronimo/specs/geronimo-jta_1.1_spec/1.1.1/geronimo-jta_1.1_spec-1.1.1.jar:/home/proselyte/.m2/repository/org/jboss/jandex/2.0.0.Final/jandex-2.0.0.Final.jar:/home/proselyte/.m2/repository/com/fasterxml/classmate/1.3.0/classmate-1.3.0.jar:/home/proselyte/.m2/repository/dom4j/dom4j/1.6.1/dom4j-1.6.1.jar:/home/proselyte/.m2/repository/xml-apis/xml-apis/1.0.b2/xml-apis-1.0.b2.jar:/home/proselyte/.m2/repository/org/hibernate/common/hibernate-commons-annotations/5.0.1.Final/hibernate-commons-annotations-5.0.1.Final.jar:/home/proselyte/.m2/repository/javassist/javassist/3.12.1.GA/javassist-3.12.1.GA.jar:/home/proselyte/.m2/repository/mysql/mysql-connector-java/5.1.38/mysql-connector-java-5.1.38.jar:/home/proselyte/Programming/Soft/IntellijIdea/lib/idea_rt.jar com.intellij.rt.execution.application.AppMain net.proselyte.hibernate.batch.DeveloperRunner Feb 24, 2016 12:54:18 PM org.hibernate.Version logVersion INFO: HHH000412: Hibernate Core {5.1.0.Final} Feb 24, 2016 12:54:18 PM org.hibernate.cfg.Environment INFO: HHH000206: hibernate.properties not found Feb 24, 2016 12:54:18 PM org.hibernate.cfg.Environment buildBytecodeProvider INFO: HHH000021: Bytecode provider name : javassist Feb 24, 2016 12:54:18 PM org.hibernate.annotations.common.reflection.java.JavaReflectionManager INFO: HCANN000001: Hibernate Commons Annotations {5.0.1.Final} Feb 24, 2016 12:54:20 PM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl configure WARN: HHH10001002: Using Hibernate built-in connection pool (not for production use!) Feb 24, 2016 12:54:20 PM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl buildCreator INFO: HHH10001005: using driver [com.mysql.jdbc.Driver] at URL [jdbc:mysql://localhost/PROSELYTE_TUTORIAL] Feb 24, 2016 12:54:20 PM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl buildCreator INFO: HHH10001001: Connection properties: {user=root, password=****} Feb 24, 2016 12:54:20 PM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl buildCreator INFO: HHH10001003: Autocommit mode: false Feb 24, 2016 12:54:20 PM org.hibernate.engine.jdbc.connections.internal.PooledConnections INFO: HHH000115: Hibernate connection pool size: 20 (min=1) Wed Feb 24 12:54:20 EET 2016 WARN: Establishing SSL connection without server's identity verification is not recommended. According to MySQL 5.5.45+, 5.6.26+ and 5.7.6+ requirements SSL connection must be established by default if explicit option isn't set. For compliance with existing applications not using SSL the verifyServerCertificate property is set to 'false'. You need either to explicitly disable SSL by setting useSSL=false, or set useSSL=true and provide truststore for server certificate verification. Feb 24, 2016 12:54:20 PM org.hibernate.dialect.Dialect INFO: HHH000400: Using dialect: org.hibernate.dialect.MySQLDialect Adding 100,000 developer's records to the database... 100,000 developer's records successfully added to the database... Feb 24, 2016 12:54:41 PM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl stop INFO: HHH10001008: Cleaning up connection pool [jdbc:mysql://localhost/PROSELYTE_TUTORIAL] Примерно, вот так будет выглядеть наша таблица HIBERNATE_DEVELOPERS +--------+------------------+-----------------+-----------------+------------+--------+ | id | FIRST_NAME | LAST_NAME | SPECIALTY | EXPERIENCE | SALARY | +--------+------------------+-----------------+-----------------+------------+--------+ | 100061 | First Name 99988 | Last Name 99988 | Specialty 99988 | 99988 | 999880 | | 100062 | First Name 99989 | Last Name 99989 | Specialty 99989 | 99989 | 999890 | | 100063 | First Name 99990 | Last Name 99990 | Specialty 99990 | 99990 | 999900 | | 100064 | First Name 99991 | Last Name 99991 | Specialty 99991 | 99991 | 999910 | | 100065 | First Name 99992 | Last Name 99992 | Specialty 99992 | 99992 | 999920 | | 100066 | First Name 99993 | Last Name 99993 | Specialty 99993 | 99993 | 999930 | | 100067 | First Name 99994 | Last Name 99994 | Specialty 99994 | 99994 | 999940 | | 100068 | First Name 99995 | Last Name 99995 | Specialty 99995 | 99995 | 999950 | | 100069 | First Name 99996 | Last Name 99996 | Specialty 99996 | 99996 | 999960 | | 100070 | First Name 99997 | Last Name 99997 | Specialty 99997 | 99997 | 999970 | | 100071 | First Name 99998 | Last Name 99998 | Specialty 99998 | 99998 | 999980 | | 100072 | First Name 99999 | Last Name 99999 | Specialty 99999 | 99999 | 999990 | +--------+------------------+-----------------+-----------------+------------ |