详解非spring框架下使用querydsl的方法

网友投稿 491 2023-01-15


详解非spring框架下使用querydsl的方法

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:

创建数据库链接:

选择那些数据库表需要生成JPA实体类:

关联表生成:

设置实体生成属性:

单个实体属性修改

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

OwXxRoPxmlns:xsi="http://w3.org/2001/XMLSchema-instance"

xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">

4.0.0

com.test.db

dbtest

jar

1.0-SNAPSHOT

dbtest

http://maven.apache.org

4.2.1

junit

junit

3.8.1

test

com.querydsl

querydsl-sql

${querydsl.version}

com.querydsl

querydsl-apt

${querydsl.version}

com.querydsl

querydsl-jpa

${querydsl.version}

com.querydsl

querydsl-sql-codegen

${querydsl.version}

provided

org.eclipse.persistence

org.eclipse.persistence.jpa

2.6.0

org.slf4j

slf4j-log4j12

1.6.1

mysql

mysql-connector-java

8.0.11

com.alibaba

druid

1.1.10

OwXxRoP

org.hibernate

hibernate-entitymanager

5.4.0.Final

com.querydsl

querydsl-maven-plugin

${querydsl.version}

generate-sources

jpa-export

${project.basedir}/target/generated-sources/java

com.test.db.entity

org.apache.maven.plugins

maven-compiler-plugin

3.1

1.8

1.8

UTF-8

OwXxRoPxmlns:xsi="http://w3.org/2001/XMLSchema-instance"

xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">

4.0.0

com.test.db

dbtest

jar

1.0-SNAPSHOT

dbtest

http://maven.apache.org

4.2.1

junit

junit

3.8.1

test

com.querydsl

querydsl-sql

${querydsl.version}

com.querydsl

querydsl-apt

${querydsl.version}

com.querydsl

querydsl-jpa

${querydsl.version}

com.querydsl

querydsl-sql-codegen

${querydsl.version}

provided

org.eclipse.persistence

org.eclipse.persistence.jpa

2.6.0

org.slf4j

slf4j-log4j12

1.6.1

mysql

mysql-connector-java

8.0.11

com.alibaba

druid

1.1.10

OwXxRoP

org.hibernate

hibernate-entitymanager

5.4.0.Final

com.querydsl

querydsl-maven-plugin

${querydsl.version}

generate-sources

jpa-export

${project.basedir}/target/generated-sources/java

com.test.db.entity

org.apache.maven.plugins

maven-compiler-plugin

3.1

1.8

1.8

UTF-8

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 {

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 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:

xmlns:xsi="http://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">

org.hibernate.ejb.HibernatePersistence

xmlns:xsi="http://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">

org.hibernate.ejb.HibernatePersistence

测OwXxRoP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 list = queryFactory.selectFrom(adminModule).fetch();

list.forEach(module->{

System.out.prinOwXxRoPtln(module.getId() + "," + module.getDisplayLabel() + "," + module.getCreateDate());

});

}

}

querydsl官方文档:http://querydsl.com/static/querydsl/latest/reference/html/ch02.html#jpa_integration

java类库:https://21doc.net/java/awesomejava#database


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