详解非spring框架下使用querydsl的方法

程序员文章站 2024-02-24 19:59:22

querydsl是一个采用api代替拼凑字符串来构造查询语句，可跟 hibernate 和 jpa 等框架结合使用。网上很多教程都是结合spring jpa框架下使用的教程...

querydsl是一个采用api代替拼凑字符串来构造查询语句，可跟 hibernate 和 jpa 等框架结合使用。网上很多教程都是结合spring jpa框架下使用的教程，本文介绍的是非spring环境下querydsl jpa整合使用。

1、使用eclipse生成jpa实体类，idea也能生成同样jpa实体类。

鼠标右键打开jpa tools工具：

详解非spring框架下使用querydsl的方法

创建数据库链接：

详解非spring框架下使用querydsl的方法

选择那些数据库表需要生成jpa实体类：

详解非spring框架下使用querydsl的方法

关联表生成：

详解非spring框架下使用querydsl的方法

设置实体生成属性：

详解非spring框架下使用querydsl的方法

单个实体属性修改

详解非spring框架下使用querydsl的方法

生成的jpa实体类adminlog.java

package com.test.db.entity;

import java.io.serializable;
import javax.persistence.*;
import java.util.date;


/**
 * the persistent class for the admin_log database table.
 * 
 */
@entity
@table(name="admin_log")
@namedquery(name="adminlog.findall", query="select a from adminlog a")
public class adminlog implements serializable {
	private static final long serialversionuid = 1l;

	@id
	@generatedvalue(strategy=generationtype.auto)
	@column(unique=true, nullable=false)
	private string id;

	@column(name="action_id", length=20)
	private string actionid;

	@column(name="client_ip", length=15)
	private string clientip;

	@column(name="controller_id", length=20)
	private string controllerid;

	@temporal(temporaltype.timestamp)
	@column(name="create_date")
	private date createdate;

	@column(name="create_user", length=50)
	private string createuser;

	@column(name="func_name", length=50)
	private string funcname;

	@column(name="module_name", length=50)
	private string modulename;

	@column(name="right_name", length=50)
	private string rightname;

	@column(length=200)
	private string url;

	public adminlog() {
	}

	public string getid() {
		return this.id;
	}

	public void setid(string id) {
		this.id = id;
	}

	public string getactionid() {
		return this.actionid;
	}

	public void setactionid(string actionid) {
		this.actionid = actionid;
	}

	public string getclientip() {
		return this.clientip;
	}

	public void setclientip(string clientip) {
		this.clientip = clientip;
	}

	public string getcontrollerid() {
		return this.controllerid;
	}

	public void setcontrollerid(string controllerid) {
		this.controllerid = controllerid;
	}

	public date getcreatedate() {
		return this.createdate;
	}

	public void setcreatedate(date createdate) {
		this.createdate = createdate;
	}

	public string getcreateuser() {
		return this.createuser;
	}

	public void setcreateuser(string createuser) {
		this.createuser = createuser;
	}

	public string getfuncname() {
		return this.funcname;
	}

	public void setfuncname(string funcname) {
		this.funcname = funcname;
	}

	public string getmodulename() {
		return this.modulename;
	}

	public void setmodulename(string modulename) {
		this.modulename = modulename;
	}

	public string getrightname() {
		return this.rightname;
	}

	public void setrightname(string rightname) {
		this.rightname = rightname;
	}

	public string geturl() {
		return this.url;
	}

	public void seturl(string url) {
		this.url = url;
	}

}

2、生成querydsl查询类

maven pom.xml文件

<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/maven-v4_0_0.xsd">
	<modelversion>4.0.0</modelversion>
	<groupid>com.test.db</groupid>
	<artifactid>dbtest</artifactid>
	<packaging>jar</packaging>
	<version>1.0-snapshot</version>
	<name>dbtest</name>
	<url>http://maven.apache.org</url>
	<properties>
		<querydsl.version>4.2.1</querydsl.version>
	</properties>
	<dependencies>
		<dependency>
			<groupid>junit</groupid>
			<artifactid>junit</artifactid>
			<version>3.8.1</version>
			<scope>test</scope>
		</dependency>
		<dependency>
			<groupid>com.querydsl</groupid>
			<artifactid>querydsl-sql</artifactid>
			<version>${querydsl.version}</version>
		</dependency>
		<dependency>
			<groupid>com.querydsl</groupid>
			<artifactid>querydsl-apt</artifactid>
			<version>${querydsl.version}</version>
		</dependency>
		<dependency>
			<groupid>com.querydsl</groupid>
			<artifactid>querydsl-jpa</artifactid>
			<version>${querydsl.version}</version>
		</dependency>
		<dependency>
			<groupid>com.querydsl</groupid>
			<artifactid>querydsl-sql-codegen</artifactid>
			<version>${querydsl.version}</version>
			<scope>provided</scope>
		</dependency>
		<dependency>
			<groupid>org.eclipse.persistence</groupid>
			<artifactid>org.eclipse.persistence.jpa</artifactid>
			<version>2.6.0</version>
		</dependency>

		<dependency>
			<groupid>org.slf4j</groupid>
			<artifactid>slf4j-log4j12</artifactid>
			<version>1.6.1</version>
		</dependency>

		<dependency>
			<groupid>mysql</groupid>
			<artifactid>mysql-connector-java</artifactid>
			<version>8.0.11</version>
		</dependency>
		<dependency>
			<groupid>com.alibaba</groupid>
			<artifactid>druid</artifactid>
			<version>1.1.10</version>
		</dependency>

		<dependency>
			<groupid>org.hibernate</groupid>
			<artifactid>hibernate-entitymanager</artifactid>
			<version>5.4.0.final</version>
		</dependency>
	</dependencies>

	<build>
		<plugins>
			<!-- 生成jpa实体插件 -->
			<plugin>
				<groupid>com.querydsl</groupid>
				<artifactid>querydsl-maven-plugin</artifactid>
				<version>${querydsl.version}</version>
				<executions>
					<execution>
						<phase>generate-sources</phase>
						<goals>
							<goal>jpa-export</goal>
						</goals>
						<configuration>
							<targetfolder>${project.basedir}/target/generated-sources/java</targetfolder>
							<packages>com.test.db.entity</packages>
						</configuration>
					</execution>
				</executions>
			</plugin>
 			<!-- 生成jpa实体插件 -->
 			<!-- 
 			<plugin>
		   <groupid>com.mysema.maven</groupid>
		   <artifactid>apt-maven-plugin</artifactid>
		   <version>1.1.3</version>
		   <executions>
		    <execution>
		     <goals>
		      <goal>process</goal>
		     </goals>
		     <configuration>
		      <outputdirectory>target/generated-sources/java</outputdirectory>
		      <processor>com.querydsl.apt.jpa.jpaannotationprocessor</processor>
		     </configuration>
		    </execution>
		   </executions>
		  </plugin>
		   -->
			<plugin>
				<groupid>org.apache.maven.plugins</groupid>
				<artifactid>maven-compiler-plugin</artifactid>
				<version>3.1</version>
				<configuration>
					<source>1.8</source>
					<target>1.8</target>
					<encoding>utf-8</encoding>
				</configuration>
			</plugin>
		</plugins>
	</build>
</project>

执行命令mvn compile或mvn eclipse:eclipse生成jpa实体对应的querydsl查询类

adminlog.java对应的querydsl对应查询类

package com.test.db.entity;

import static com.querydsl.core.types.pathmetadatafactory.*;

import com.querydsl.core.types.dsl.*;

import com.querydsl.core.types.pathmetadata;
import javax.annotation.generated;
import com.querydsl.core.types.path;


/**
 * qadminlog is a querydsl query type for adminlog
 */
@generated("com.querydsl.codegen.entityserializer")
public class qadminlog extends entitypathbase<adminlog> {

  private static final long serialversionuid = 392071999l;

  public static final qadminlog adminlog = new qadminlog("adminlog");

  public final stringpath actionid = createstring("actionid");

  public final stringpath clientip = createstring("clientip");

  public final stringpath controllerid = createstring("controllerid");

  public final datetimepath<java.util.date> createdate = createdatetime("createdate", java.util.date.class);

  public final stringpath createuser = createstring("createuser");

  public final stringpath funcname = createstring("funcname");

  public final stringpath id = createstring("id");

  public final stringpath modulename = createstring("modulename");

  public final stringpath rightname = createstring("rightname");

  public final stringpath url = createstring("url");

  public qadminlog(string variable) {
    super(adminlog.class, forvariable(variable));
  }

  public qadminlog(path<? extends adminlog> path) {
    super(path.gettype(), path.getmetadata());
  }

  public qadminlog(pathmetadata metadata) {
    super(adminlog.class, metadata);
  }

}

3、查询例子

jpa持久化meta-inf\persistence.xml配置文件，entitymanagerfactory创建实例时，需要读取该配置文件：

<?xml version="1.0" encoding="utf-8"?>
<persistence xmlns="http://java.sun.com/xml/ns/persistence"
  xmlns:xsi="http://www.w3.org/2001/xmlschema-instance"
  xsi:schemalocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd"
  version="2.0">
  <persistence-unit name="jpa" transaction-type="resource_local">
  <provider>org.hibernate.ejb.hibernatepersistence</provider>
    <properties>
      <!-- .mysqlinnodbdialect -->
    	<property name="hibernate.dialect" value="org.hibernate.dialect.mysql8dialect"/>
      <property name="javax.persistence.jdbc.driver" value="com.mysql.cj.jdbc.driver" />
			<property name="javax.persistence.jdbc.url" value="jdbc:mysql://127.0.0.1:3306/yiiboot?useunicode=true&characterencoding=utf-8&servertimezone=asia/shanghai&usessl=true" />
      <property name="javax.persistence.jdbc.user" value="root" />
      <property name="javax.persistence.jdbc.password" value="123" />

      <property name="connection.provider_class" value="com.alibaba.druid.support.hibernate.druidconnectionprovider" />
      <!-- 配置初始化大小、最小、最大 -->
      <property name="initialsize" value="1" />
      <property name="minidle" value="1" />
      <property name="maxactive" value="20" />
      <!-- 配置获取连接等待超时的时间 -->
      <property name="maxwait" value="60000" />

      <!-- 配置间隔多久才进行一次检测，检测需要关闭的空闲连接，单位是毫秒 -->
      <property name="timebetweenevictionrunsmillis" value="60000" />

      <!-- 配置一个连接在池中最小生存的时间，单位是毫秒 -->
      <property name="minevictableidletimemillis" value="300000" />
    </properties>
  </persistence-unit>
</persistence>

测试代码

package com.test.db.main;

import java.util.list;
import javax.persistence.entitymanagerfactory;
import javax.persistence.persistence;
import com.querydsl.jpa.impl.jpaqueryfactory;
import com.test.db.entity.adminmodule;
import com.test.db.entity.qadminmodule;

public class jpatest {
	public static void main(string[] args) throws exception{
		string persistenceunitname = "jpa";
		entitymanagerfactory entitymanagerfactory = 
		persistence.createentitymanagerfactory(persistenceunitname);
		jpaqueryfactory queryfactory = new jpaqueryfactory(entitymanagerfactory.createentitymanager());
		qadminmodule adminmodule = qadminmodule.adminmodule;
		list<adminmodule> list = queryfactory.selectfrom(adminmodule).fetch();
		list.foreach(module->{
			system.out.println(module.getid() + "," + module.getdisplaylabel() + "," + module.getcreatedate());
		});
	}
}

querydsl官方文档：

java类库：

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