经过多年,spring data jpa越来越完善,在版本迭代的过程中,会不断增加功能,今天看新的reference发现有querydsl.然后搜索到上面的参考资料2
无论是jpaspecificationexecutor,还是querydslpredicateexecutor,它俩都提供了使用predicate(意义相同,都是构建where子句;类不同,javax.persistence.criteria.predicate,com.querydsl.core.types.predicate)去构建查询,使用比较方便.
关于两者的简单使用,上面的参考资料2有介绍.文末也有总结,从概括来看,我个人认为应倾向使用querydslpredicateexecutor,querydsl不仅适用于jpa repositories,还支持mongodb.
下面是个例子
1.pom.xml
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<project xmlns="http://maven.apache.org/pom/4.0.0" xmlns:xsi="http://www.w3.org/2001/xmlschema-instance" xsi:schemalocation="http://maven.apache.org/pom/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelversion>4.0.0</modelversion> <groupid>org.exam</groupid> <artifactid>testjava</artifactid> <version>1.0.0</version> <name>${project.artifactid}</name> <properties> <project.build.sourceencoding>utf-8</project.build.sourceencoding> <project.reporting.outputencoding>utf-8</project.reporting.outputencoding> <java.version>1.8</java.version> <spring.version>4.2.5.release</spring.version> <spring-data.version>hopper-sr1</spring-data.version> <querydsl.version>4.1.1</querydsl.version> <hibernate.version>5.1.0.final</hibernate.version> <tomcat.version>8.0.32</tomcat.version> <logback.version>1.1.7</logback.version> <mysql.version>5.1.33</mysql.version> <junit.version>4.12</junit.version> </properties> <dependencymanagement> <dependencies> <dependency> <groupid>org.springframework</groupid> <artifactid>spring-framework-bom</artifactid> <version>${spring.version}</version> <scope>import</scope> <type>pom</type> </dependency> <dependency> <groupid>org.springframework.data</groupid> <artifactid>spring-data-releasetrain</artifactid> <version>${spring-data.version}</version> <scope>import</scope> <type>pom</type> </dependency> </dependencies> </dependencymanagement> <build> <plugins> <plugin> <groupid>org.apache.maven.plugins</groupid> <artifactid>maven-compiler-plugin</artifactid> <version>3.1</version> <configuration> <source>${java.version}</source> <target>${java.version}</target> </configuration> </plugin> <plugin> <groupid>com.mysema.maven</groupid> <artifactid>maven-apt-plugin</artifactid> <version>1.0.4</version> <executions> <execution> <phase>generate-sources</phase> <goals> <goal>process</goal> </goals> <configuration> <outputdirectory>target/generated-sources</outputdirectory> <processor>com.querydsl.apt.jpa.jpaannotationprocessor</processor> </configuration> </execution> </executions> </plugin> </plugins> </build> <dependencies> <dependency> <groupid>org.springframework.data</groupid> <artifactid>spring-data-jpa</artifactid> </dependency> <dependency> <groupid>org.springframework.data</groupid> <artifactid>spring-data-mongodb</artifactid> </dependency> <dependency> <groupid>com.querydsl</groupid> <artifactid>querydsl-apt</artifactid> <version>${querydsl.version}</version> <scope>provided</scope> </dependency> <dependency> <groupid>com.querydsl</groupid> <artifactid>querydsl-jpa</artifactid> <version>${querydsl.version}</version> </dependency> <dependency> <groupid>com.querydsl</groupid> <artifactid>querydsl-mongodb</artifactid> <version>${querydsl.version}</version> </dependency> <dependency> <groupid>org.hibernate</groupid> <artifactid>hibernate-entitymanager</artifactid> <version>${hibernate.version}</version> </dependency> <dependency> <groupid>org.apache.tomcat</groupid> <artifactid>tomcat-jdbc</artifactid> <version>${tomcat.version}</version> </dependency> <dependency> <groupid>org.springframework</groupid> <artifactid>spring-test</artifactid> </dependency> <dependency> <groupid>ch.qos.logback</groupid> <artifactid>logback-classic</artifactid> <version>${logback.version}</version> </dependency> <dependency> <groupid>mysql</groupid> <artifactid>mysql-connector-java</artifactid> <version>${mysql.version}</version> </dependency> <dependency> <groupid>junit</groupid> <artifactid>junit</artifactid> <version>${junit.version}</version> </dependency> </dependencies> <repositories> <repository> <id>central</id> <name>central repository</name> <url>http://repo1.maven.org/maven2</url> <layout>default</layout> <snapshots> <enabled>false</enabled> </snapshots> </repository> </repositories></project> |
2.domain类
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package org.exam.domain;import org.springframework.data.mongodb.core.mapping.document;import javax.persistence.column;import javax.persistence.entity;import javax.persistence.id;import java.io.serializable;@entity@documentpublic class employee implements serializable { @id @column(length = 38) private string id; @column(length = 32) private string name; private long salary; private long departmentid; //setter和getter略} |
3.repository类
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package org.exam.repository.jpa;import org.exam.domain.employee;import org.springframework.data.querydsl.querydslpredicateexecutor;import org.springframework.data.repository.pagingandsortingrepository;import java.util.collection;public interface jpaemployeerepository extends pagingandsortingrepository<employee,string>,querydslpredicateexecutor<employee>{ collection<employee> findbyidin(collection<string> ids);} |
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package org.exam.repository.mongo;import org.exam.domain.employee;import org.springframework.data.querydsl.querydslpredicateexecutor;import org.springframework.data.repository.pagingandsortingrepository;import java.util.collection;public interface mongoemployeerepository extends pagingandsortingrepository<employee, string>, querydslpredicateexecutor<employee> { collection<employee> findbyidin(collection<string> ids);} |
jpa有jparepository,mongodb有mongorepository,它俩都继承pagingandsortingrepository
3.配置类
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package org.exam.config;import com.mongodb.mongoclient;import com.mongodb.writeconcern;import org.apache.tomcat.jdbc.pool.datasource;import org.springframework.context.annotation.bean;import org.springframework.context.annotation.configuration;import org.springframework.context.annotation.propertysource;import org.springframework.core.env.environment;import org.springframework.data.jpa.repository.config.enablejparepositories;import org.springframework.data.mongodb.mongodbfactory;import org.springframework.data.mongodb.core.mongotemplate;import org.springframework.data.mongodb.core.simplemongodbfactory;import org.springframework.data.mongodb.core.writeresultchecking;import org.springframework.data.mongodb.repository.config.enablemongorepositories;import org.springframework.orm.jpa.jpatransactionmanager;import org.springframework.orm.jpa.localcontainerentitymanagerfactorybean;import org.springframework.orm.jpa.vendor.database;import org.springframework.orm.jpa.vendor.hibernatejpavendoradapter;import org.springframework.transaction.platformtransactionmanager;import org.springframework.transaction.annotation.enabletransactionmanagement;import javax.annotation.resource;import java.net.unknownhostexception;import java.util.properties;@configuration@propertysource("classpath:config.properties")@enabletransactionmanagement@enablejparepositories(basepackages = "org.exam.repository.jpa")@enablemongorepositories(basepackages = "org.exam.repository.mongo")public class appconfig { @resource private environment env; @bean(destroymethod = "close") public datasource datasource() { datasource datasource = new datasource(); datasource.setdriverclassname(env.getproperty("ds.driverclassname")); datasource.seturl(env.getproperty("ds.url")); datasource.setusername(env.getproperty("ds.username")); datasource.setpassword(env.getproperty("ds.password")); datasource.setinitialsize(env.getproperty("ds.initialsize", integer.class)); datasource.setminidle(env.getproperty("ds.minidle", integer.class)); datasource.setmaxidle(env.getproperty("ds.maxidle", integer.class)); datasource.setmaxactive(env.getproperty("ds.maxactive", integer.class)); return datasource; } @bean public localcontainerentitymanagerfactorybean entitymanagerfactory() { hibernatejpavendoradapter jpavendoradapter = new hibernatejpavendoradapter(); jpavendoradapter.setdatabase(database.valueof(env.getproperty("jpa.database"))); jpavendoradapter.setgenerateddl(env.getproperty("jpa.generateddl",boolean.class)); jpavendoradapter.setshowsql(env.getproperty("jpa.showsql",boolean.class)); localcontainerentitymanagerfactorybean emf = new localcontainerentitymanagerfactorybean(); emf.setdatasource(datasource()); emf.setpackagestoscan("org.exam.domain"); emf.setjpavendoradapter(jpavendoradapter); properties properties = new properties(); properties.setproperty("hibernate.default_schema", env.getproperty("jpa.defaultschema")); emf.setjpaproperties(properties); return emf; } @bean public platformtransactionmanager transactionmanager() { return new jpatransactionmanager(entitymanagerfactory().getobject()); } @bean public mongodbfactory mongodbfactory() throws unknownhostexception { return new simplemongodbfactory(new mongoclient(env.getproperty("mongo.host"), env.getproperty("mongo.port", integer.class)), env.getproperty("mongo.db")); } @bean public mongotemplate mongotemplate() throws unknownhostexception { mongotemplate mongotemplate = new mongotemplate(mongodbfactory()); mongotemplate.setwriteresultchecking(writeresultchecking.exception); mongotemplate.setwriteconcern(writeconcern.normal); return mongotemplate; }} |
4.测试类
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package org.exam.repository.jpa;import org.exam.config.appconfig;import org.exam.domain.employee;import org.junit.test;import org.junit.runner.runwith;import org.springframework.beans.factory.annotation.autowired;import org.springframework.data.domain.page;import org.springframework.data.domain.pagerequest;import org.springframework.test.annotation.rollback;import org.springframework.test.context.contextconfiguration;import org.springframework.test.context.junit4.springjunit4classrunner;import org.springframework.test.context.support.annotationconfigcontextloader;import org.springframework.transaction.annotation.transactional;import java.util.uuid;@runwith(springjunit4classrunner.class)@contextconfiguration(loader = annotationconfigcontextloader.class, classes = {appconfig.class})@transactional(transactionmanager = "transactionmanager")//rollback默认为truepublic class jpaemployeerepositorytest { @autowired private jpaemployeerepository jpaemployeerepository; @test @rollback(false) public void testsave() { for (int i = 0; i < 5; i++) { employee employee = new employee(); employee.setid(uuid.randomuuid().tostring()); employee.setname("name"); employee.setdepartmentid(1 + i); employee.setsalary(6800 + i); jpaemployeerepository.save(employee); } } @test public void testfindall() { page<employee> all = jpaemployeerepository.findall(null, new pagerequest(0, 8)); for (employee employee : all) { system.out.println("employee = " + employee); } }} |
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package org.exam.repository.mongo;import com.mongodb.mongoclient;import org.exam.config.appconfig;import org.exam.domain.employee;import org.junit.test;import org.junit.runner.runwith;import org.springframework.beans.factory.annotation.autowired;import org.springframework.data.domain.page;import org.springframework.data.domain.pagerequest;import org.springframework.data.geo.circle;import org.springframework.data.mongodb.core.mongotemplate;import org.springframework.test.context.contextconfiguration;import org.springframework.test.context.junit4.springjunit4classrunner;import org.springframework.test.context.support.annotationconfigcontextloader;import java.net.unknownhostexception;@runwith(springjunit4classrunner.class)@contextconfiguration(loader = annotationconfigcontextloader.class, classes = {appconfig.class})public class mongoemployeerepositorytest { @autowired private mongoemployeerepository mongoemployeerepository; public static void main(string[] args) throws unknownhostexception { mongotemplate template = new mongotemplate(new mongoclient("127.0.0.1", 27017), "test"); circle circle = new circle(-73.99171, 40.738868, 0.01); system.out.println(); } @test public void testfindall() { page<employee> all = mongoemployeerepository.findall(null, new pagerequest(0, 8)); for (employee employee : all) { system.out.println("employee = " + employee); } }} |
5.其它config.properties,logback.xml文件不太重要,篇幅关系就省略.
再了解一下比较大的需求,从几张表来取几个字段的数据,返回分页排序数据.
1.在appconfig注册jpaqueryfactory bean
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@beanpublic jpaqueryfactory jpaqueryfactory(entitymanager entitymanager) { return new jpaqueryfactory(new hqltemplates(), entitymanager);} |
2.建一个dto(数据传输对象)
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public class userdto { private string empname; private string deptname; private long salary; //setter,getter略} |
3.查询例子测试
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private page<userdto> findall(string empname,pageable pageable) { qemployee qemp = qemployee.employee; qdepartment qdep = qdepartment.department; list<predicate> criteria = new arraylist<>(); if (stringutils.hastext(empname)){ criteria.add(qemp.name.eq(empname.trim())); } jpaquery<?> query = jpaqueryfactory.from(qemp).innerjoin(qdep).on(qemp.deptid.eq(qdep.id)).where(criteria.toarray(new predicate[criteria.size()])); long total = query.fetchcount(); list<userdto> content; if (pageable == null || total > pageable.getoffset()) { map<string, simpleexpression<?>> map = new hashmap<>(); map.put("deptname", qdep.name); map.put("empname", qemp.name); map.put("salary", qemp.salary); content = querydslutils.applypagination(pageable, query).select(projections.bean(userdto.class, map)).fetch(); } else { content = collections.emptylist(); } return new pageimpl<>(content, pageable, total);}@testpublic void test() { pageable pageable = new pagerequest(0, 10, new qsort(new orderspecifier<>(order.desc, qemployee.employee.salary), new orderspecifier<>(order.asc, qdepartment.department.name))); page<userdto> page = findall("name", pageable); for (userdto userdto : page) { system.out.println("userdto = " + userdto); }} |
参考资料
1:http://docs.spring.io/spring-data/jpa/docs/1.10.x/reference/pdf/spring-data-jpa-reference.pdf
2:https://spring.io/blog/2011/04/26/advanced-spring-data-jpa-specifications-and-querydsl/
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持服务器之家。
原文链接：https://blog.csdn.net/xiejx618/article/details/51480265
