NetBeans IDE 向导自动生成JPA代码创建数据库CRUD

Bertha 。 2023-09-30 11:12 10阅读 0赞

在数据库中创建表

CREATE TABLE `books` (
    	`bid` VARCHAR(255) NOT NULL COLLATE 'utf8mb4_unicode_ci',
    	`author` VARCHAR(255) NULL DEFAULT NULL COLLATE 'utf8mb4_unicode_ci',
    	`status` VARCHAR(255) NULL DEFAULT NULL COLLATE 'utf8mb4_unicode_ci',
    	`title` VARCHAR(255) NULL DEFAULT NULL COLLATE 'utf8mb4_unicode_ci',
    	PRIMARY KEY (`bid`) USING BTREE
    )
    COLLATE='utf8mb4_unicode_ci'
    ENGINE=InnoDB
    ;

在NetBeans IDE中创建maven管理的应用

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使用向导从数据库表创建实体类：

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使用向导从实体类创建控制器类：

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手工编写main方法调用自动生成的Controller进行CRUD

/*
     * Click nbfs://nbhost/SystemFileSystem/Templates/Licenses/license-default.txt to change this license
     * Click nbfs://nbhost/SystemFileSystem/Templates/Project/Maven2/JavaApp/src/main/java/${packagePath}/${mainClassName}.java to edit this template
     */
    package com.example.jpanetbeans4;
    
    import java.util.List;
    import javax.persistence.EntityManagerFactory;
    import javax.persistence.Persistence;
    
    /**
     *
     * @author Administrator
     */
    public class Jpanetbeans4 {
    
        public static void main(String[] args) throws Exception {
            System.out.println("Hello World!");
            String PERSISTENCE_UNIT_NAME = "com.example_jpanetbeans4_jar_1.0-SNAPSHOTPU";
            EntityManagerFactory emFactory = Persistence.createEntityManagerFactory(PERSISTENCE_UNIT_NAME);
            BooksJpaController bjc = new BooksJpaController(emFactory);
            Books book1 = new Books();
            book1.setAuthor("author1");
            book1.setBid("1001");
            book1.setTitle("title1");
            book1.setStatus("status1");
            bjc.create(book1);
            Books book2 = new Books();
            book2.setAuthor("author2");
            book2.setBid("1002");
            book2.setTitle("title2");
            book2.setStatus("status2");
            bjc.create(book2);
            Books book1up = new Books();
            book1up.setAuthor("author1up");
            book1up.setBid("1001");
            book1up.setTitle("title1up");
            book1up.setStatus("status1up");
            bjc.edit(book1up);
            System.out.println(bjc.getBooksCount());
            List<Books> booklist = bjc.findBooksEntities();
            for (Books book : booklist) {
                System.out.println(book.getBid() + ":" + book.getTitle() + ":" + book.getAuthor() + ":" + book.getStatus());
    
            }
            Books bookfind = bjc.findBooks("1001");
    
            System.out.println(bookfind.getBid() + ":" + bookfind.getTitle() + ":" + bookfind.getAuthor() + ":" + bookfind.getStatus());
            bjc.destroy("1001");
            booklist = bjc.findBooksEntities();
            for (Books book : booklist) {
                System.out.println(book.getBid() + ":" + book.getTitle() + ":" + book.getAuthor() + ":" + book.getStatus());
    
            }
        }
    }

在pom.xml中增加数据库驱动包

<?xml version="1.0" encoding="UTF-8"?>
    <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>com.example</groupId>
        <artifactId>jpanetbeans</artifactId>
        <version>1.0-SNAPSHOT</version>
        <dependencies>
            <dependency>
                <groupId>mysql</groupId>
                <artifactId>mysql-connector-java</artifactId>
                <version>8.0.28</version>
            </dependency>
            <dependency>
                <groupId>org.eclipse.persistence</groupId>
                <artifactId>org.eclipse.persistence.core</artifactId>
                <version>2.7.9</version>
            </dependency>
            <dependency>
                <groupId>org.eclipse.persistence</groupId>
                <artifactId>org.eclipse.persistence.asm</artifactId>
                <version>9.1.0</version>
            </dependency>
            <dependency>
                <groupId>org.eclipse.persistence</groupId>
                <artifactId>org.eclipse.persistence.antlr</artifactId>
                <version>2.7.9</version>
            </dependency>
            <dependency>
                <groupId>org.eclipse.persistence</groupId>
                <artifactId>org.eclipse.persistence.jpa</artifactId>
                <version>2.7.9</version>
            </dependency>
            <dependency>
                <groupId>org.eclipse.persistence</groupId>
                <artifactId>org.eclipse.persistence.jpa.jpql</artifactId>
                <version>2.7.9</version>
            </dependency>
            <dependency>
                <groupId>org.eclipse.persistence</groupId>
                <artifactId>org.eclipse.persistence.moxy</artifactId>
                <version>2.7.9</version>
            </dependency>
            <dependency>
                <groupId>org.eclipse.persistence</groupId>
                <artifactId>javax.persistence</artifactId>
                <version>2.2.1</version>
            </dependency>
            <dependency>
                <groupId>org.eclipse.persistence</groupId>
                <artifactId>org.eclipse.persistence.jpa.modelgen.processor</artifactId>
                <version>2.7.9</version>
                <scope>provided</scope>
            </dependency>
        </dependencies>
        <properties>
            <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
            <maven.compiler.source>1.8</maven.compiler.source>
            <maven.compiler.target>1.8</maven.compiler.target>
            <exec.mainClass>com.example.jpanetbeans.Jpanetbeans</exec.mainClass>
        </properties>
    </project>

向导使用的JPA实现是**EclipseLink，**也可以更改JPA实现为**Hibernate：**

<?xml version="1.0" encoding="UTF-8"?>
    <persistence version="2.1" xmlns="http://xmlns.jcp.org/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence http://xmlns.jcp.org/xml/ns/persistence/persistence_2_1.xsd">
        <persistence-unit name="com.example_jpanetbeans2_jar_1.0-SNAPSHOTPU" transaction-type="RESOURCE_LOCAL">
            <provider>org.hibernate.jpa.HibernatePersistenceProvider</provider>
            <class>com.example.jpanetbeans2.Books</class>
            <properties>
                <property name="javax.persistence.jdbc.url" value="jdbc:mysql://localhost:3306/db?autoReconnect=true&useSSL=false&useUnicode=true&characterEncoding=UTF-8&serverTimezone=Asia/Shanghai"/>
                <property name="javax.persistence.jdbc.user" value="root"/>
                <property name="javax.persistence.jdbc.driver" value="com.mysql.cj.jdbc.Driver"/>
                <property name="javax.persistence.jdbc.password" value="root"/>
                <property name="javax.persistence.schema-generation.database.action" value="drop-and-create"/>
                <property name = "hibernate.show_sql" value = "true" />
            </properties>
        </persistence-unit>
    </persistence>

更改为OpenJPA

<?xml version="1.0" encoding="UTF-8"?>
    <persistence version="2.1" xmlns="http://xmlns.jcp.org/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence http://xmlns.jcp.org/xml/ns/persistence/persistence_2_1.xsd">
        <persistence-unit name="com.example_jpanetbeans4_jar_1.0-SNAPSHOTPU" transaction-type="RESOURCE_LOCAL">
            <provider>org.apache.openjpa.persistence.PersistenceProviderImpl</provider>
            <class>com.example.jpanetbeans4.Books</class>
            <properties>
                <property name="javax.persistence.jdbc.url" value="jdbc:mysql://localhost:3306/db?autoReconnect=true&useSSL=false&useUnicode=true&characterEncoding=UTF-8&serverTimezone=Asia/Shanghai"/>
                <property name="javax.persistence.jdbc.user" value="root"/>
                <property name="javax.persistence.jdbc.driver" value="com.mysql.cj.jdbc.Driver"/>
                <property name="javax.persistence.jdbc.password" value="root"/>
                <property name="javax.persistence.schema-generation.database.action" value="drop-and-create"/>
            </properties>
        </persistence-unit>
    </persistence>

运行输出：

cd C:\Users\Administrator\Documents\NetBeansProjects\jpanetbeans4; "JAVA_HOME=C:\\Program Files\\Java\\jdk1.8.0_202" cmd /c "\"C:\\Program Files\\NetBeans-13\\netbeans\\java\\maven\\bin\\mvn.cmd\" -Dexec.vmArgs= \"-Dexec.args=${exec.vmArgs} -classpath %classpath ${exec.mainClass} ${exec.appArgs}\" \"-Dexec.executable=C:\\Program Files\\Java\\jdk1.8.0_202\\bin\\java.exe\" -Dexec.mainClass=com.example.jpanetbeans4.Jpanetbeans4 -Dexec.classpathScope=runtime -Dexec.appArgs= \"-Dmaven.ext.class.path=C:\\Program Files\\NetBeans-13\\netbeans\\java\\maven-nblib\\netbeans-eventspy.jar\" -Dfile.encoding=UTF-8 org.codehaus.mojo:exec-maven-plugin:3.0.0:exec"
    Running NetBeans Compile On Save execution. Phase execution is skipped and output directories of dependency projects (with Compile on Save turned on) will be used instead of their jar artifacts.
    Scanning for projects...
    
    ----------------------< com.example:jpanetbeans4 >----------------------
    Building jpanetbeans4 1.0-SNAPSHOT
    --------------------------------[ jar ]---------------------------------
    
    --- exec-maven-plugin:3.0.0:exec (default-cli) @ jpanetbeans4 ---
    Hello World!
    [EL Info]: 2022-03-26 22:38:31.319--ServerSession(893504292)--EclipseLink, version: Eclipse Persistence Services - 2.7.9.v20210604-2c549e2208
    2
    1001:title1up:author1up:status1up
    1002:title2:author2:status2
    1001:title1up:author1up:status1up
    1002:title2:author2:status2
    ------------------------------------------------------------------------
    BUILD SUCCESS
    ------------------------------------------------------------------------
    Total time:  3.505 s
    Finished at: 2022-03-26T22:38:32+08:00
    ------------------------------------------------------------------------

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