技术教程 编程教程 spring和mybatis集成，自动生成model、mapper，增加mybatis分页功能 正文

spring和mybatis集成，自动生成model、mapper，增加mybatis分页功能

2023-05-30,,

软件简介

Spring是一个流行的控制反转（IoC）和面向切面（AOP）的容器框架，在java webapp开发中使用广泛。http://projects.spring.io/spring-framework/

MyBatis是一个基于Java的数据持久层框架，其原名是iBatis，在升级到3.0版本后，更名为MyBatis。https://github.com/mybatis/mybatis-3/

MyBatis Generator是一个MyBatis的代码生成器，通过配置，可自动生成数据操作接口、实体类以及mapper.xml文件。https://github.com/mybatis/generator

maven开发环境搭建

使用eclipseIDE，新建maven工程。

在pom.xml文件中，添加如下内容，引入相关jar。

spring版本是3.1.0，mybatis版本是3.4.0，mybatis-generator版本是1.3.5。

<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.founder</groupId>

    <artifactId>datacenter</artifactId>

    <version>0.0.1-SNAPSHOT</version>

    <packaging>jar</packaging>

    <name>datacenter</name>

    <url>http://maven.apache.org</url>

    <properties>

        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>

        <fasterxml.jackson.version>2.1.1</fasterxml.jackson.version>

        <spring.version>3.1.0.RELEASE</spring.version>

    </properties>

    <dependencies>

        <dependency>

            <groupId>junit</groupId>

            <artifactId>junit</artifactId>

            <version>3.8.1</version>

            <scope>test</scope>

        </dependency>

        <dependency>

            <groupId>junit</groupId>

            <artifactId>junit-dep</artifactId>

            <version>4.9</version>

            <scope>test</scope>

        </dependency>

        <dependency>

            <groupId>com.google.protobuf</groupId>

            <artifactId>protobuf-java</artifactId>

            <version>2.5.0</version>

        </dependency>

        <dependency>

            <groupId>com.fasterxml.jackson.core</groupId>

            <artifactId>jackson-core</artifactId>

            <version>${fasterxml.jackson.version}</version>

        </dependency>

        <dependency>

            <groupId>com.fasterxml.jackson.core</groupId>

            <artifactId>jackson-annotations</artifactId>

            <version>${fasterxml.jackson.version}</version>

        </dependency>

        <dependency>

            <groupId>com.fasterxml.jackson.core</groupId>

            <artifactId>jackson-databind</artifactId>

            <version>${fasterxml.jackson.version}</version>

        </dependency>

        <dependency>

            <groupId>com.fasterxml.jackson.dataformat</groupId>

            <artifactId>jackson-dataformat-xml</artifactId>

            <version>${fasterxml.jackson.version}</version>

        </dependency>

        <dependency>

            <groupId>com.alibaba</groupId>

            <artifactId>fastjson</artifactId>

            <version>1.2.15</version>

        </dependency>

        <dependency>

            <groupId>org.jdom</groupId>

            <artifactId>jdom</artifactId>

            <version>1.1.3</version>

        </dependency>

        <dependency>

            <groupId>org.dom4j</groupId>

            <artifactId>dom4j</artifactId>

            <version>2.0.0</version>

        </dependency>

        <dependency>

            <groupId>org.springframework</groupId>

            <artifactId>spring-webmvc</artifactId>

            <version>${spring.version}</version>

        </dependency>

        <dependency>

            <groupId>org.springframework</groupId>

            <artifactId>spring-tx</artifactId>

            <version>${spring.version}</version>

        </dependency>

        <dependency>

            <groupId>org.springframework</groupId>

            <artifactId>spring-jdbc</artifactId>

            <version>${spring.version}</version>

        </dependency>

        <dependency>

            <groupId>org.springframework</groupId>

            <artifactId>spring-aop</artifactId>

            <version>${spring.version}</version>

        </dependency>

        <!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java -->

        <dependency>

            <groupId>mysql</groupId>

            <artifactId>mysql-connector-java</artifactId>

            <version>5.1.39</version>

        </dependency>

        <!-- https://mvnrepository.com/artifact/org.mybatis/mybatis -->

        <dependency>

            <groupId>org.mybatis</groupId>

            <artifactId>mybatis</artifactId>

            <version>3.4.0</version>

        </dependency>

        <dependency>

            <groupId>org.mybatis</groupId>

            <artifactId>mybatis-spring</artifactId>

            <version>1.3.0</version>

        </dependency>

        <!-- https://mvnrepository.com/artifact/org.mybatis.generator/mybatis-generator -->

        <dependency>

            <groupId>org.mybatis.generator</groupId>

            <artifactId>mybatis-generator</artifactId>

            <version>1.3.5</version>

            <type>pom</type>

        </dependency>

        <!-- https://mvnrepository.com/artifact/org.mybatis.generator/mybatis-generator-core -->

        <dependency>

            <groupId>org.mybatis.generator</groupId>

            <artifactId>mybatis-generator-core</artifactId>

            <version>1.3.5</version>

        </dependency>

    </dependencies>

    <build>

        <plugins>

            <plugin>

                <groupId>org.apache.maven.plugins</groupId>

                <artifactId>maven-compiler-plugin</artifactId>

                <configuration>

                    <source>1.7</source>

                    <target>1.7</target>

                </configuration>

            </plugin>

        </plugins>

    </build>

</project>

工程目录结构

数据库建表

CREATE TABLE `user` (

  `id` int(11) NOT NULL AUTO_INCREMENT,

  `name` varchar(255) DEFAULT NULL,

  `password` varchar(255) DEFAULT NULL,

  `lastLoginTime` datetime DEFAULT NULL,

  PRIMARY KEY (`id`)

) ENGINE=InnoDB AUTO_INCREMENT=22 DEFAULT CHARSET=utf8;

生成mybatis的代码

为了生成mybatis的代码，首先需要创建一个配置文件，告诉mybatis generator必须的变量。

配置文件保存在src/main/conf/build-mybatis.xml中。

具体配置信息参考官网http://www.mybatis.org/generator/index.html。

注意，配置文件中，添加了一个plugin，这是为生成分页操作添加的，具体内容，后面会讲解。

table中的tableName设置为%，意味着为mysql数据库中的所有表生成对应的代码文件。

mysql中表明使用“_”或者“-”分隔，自动生成的代码文件名中会去掉，并且其后面的字母会升级为大写。

指定好生成的代码文件的保存地址，共有三个。

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE generatorConfiguration

  PUBLIC "-//mybatis.org//DTD MyBatis Generator Configuration 1.0//EN"

  "http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd">

<generatorConfiguration>

    <!--数据库驱动 -->

    <classPathEntry

        location="C:\Users\.m2\repository\mysql\mysql-connector-java\5.1.39\mysql-connector-java-5.1.39.jar" />

    <context

        id="MySQL2Tables"

        targetRuntime="MyBatis3"

        defaultModelType="flat">

        <plugin type="com.founder.datacenter.utils.mybatis.MySQLPaginationPlugin" />

        <commentGenerator>

            <property

                name="suppressDate"

                value="true" />

            <property

                name="suppressAllComments"

                value="true" />

        </commentGenerator>

        <!--数据库链接地址账号密码 -->

        <jdbcConnection

            driverClass="com.mysql.jdbc.Driver"

            connectionURL="jdbc:mysql://localhost:3306/mybatis?useSSL=false"

            userId="root"

            password="123456">

        </jdbcConnection>

        <javaTypeResolver>

            <property

                name="forceBigDecimals"

                value="false" />

        </javaTypeResolver>

        <!--生成Model类存放位置 -->

        <javaModelGenerator

            targetPackage="com.founder.datacenter.model"

            targetProject="src/main/java">

            <property

                name="enableSubPackages"

                value="true" />

            <property

                name="trimStrings"

                value="true" />

        </javaModelGenerator>

        <!--生成映射文件存放位置 -->

        <sqlMapGenerator

            targetPackage="com.founder.datacenter.dao.mapper"

            targetProject="src/main/java">

            <property

                name="enableSubPackages"

                value="true" />

        </sqlMapGenerator>

        <!--生成Dao类存放位置 -->

        <javaClientGenerator

            type="XMLMAPPER"

            targetPackage="com.founder.datacenter.dao.mapper"

            targetProject="src/main/java">

            <property

                name="enableSubPackages"

                value="true" />

        </javaClientGenerator>

        <!--生成对应表及类名 -->

        <table

            tableName="%"

            enableCountByExample="true"

            enableUpdateByExample="true"

            enableDeleteByExample="true"

            enableSelectByExample="true"

            selectByExampleQueryId="false"></table>

    </context>

</generatorConfiguration>

编写代码生成脚本

package com.founder.datacenter.utils.mybatis;

import java.io.File;

import java.io.IOException;

import java.sql.SQLException;

import java.util.ArrayList;

import java.util.List;

import org.mybatis.generator.api.MyBatisGenerator;

import org.mybatis.generator.config.Configuration;

import org.mybatis.generator.config.xml.ConfigurationParser;

import org.mybatis.generator.exception.InvalidConfigurationException;

import org.mybatis.generator.exception.XMLParserException;

import org.mybatis.generator.internal.DefaultShellCallback;

public class MyBatisGeneratorTool {

    public static void main(String[] args) {

        List<String> warnings = new ArrayList<String>();

        boolean overwrite = true;

        String genCfg = "/build-mybatis.xml";

        File configFile = new File(MyBatisGeneratorTool.class.getResource(genCfg).getFile());

        ConfigurationParser cp = new ConfigurationParser(warnings);

        Configuration config = null;

        try {

            config = cp.parseConfiguration(configFile);

        } catch (IOException e) {

            e.printStackTrace();

        } catch (XMLParserException e) {

            e.printStackTrace();

        }

        DefaultShellCallback callback = new DefaultShellCallback(overwrite);

        MyBatisGenerator myBatisGenerator = null;

        try {

            myBatisGenerator = new MyBatisGenerator(config, callback, warnings);

        } catch (InvalidConfigurationException e) {

            e.printStackTrace();

        }

        try {

            myBatisGenerator.generate(null);

        } catch (SQLException e) {

            e.printStackTrace();

        } catch (IOException e) {

            e.printStackTrace();

        } catch (InterruptedException e) {

            e.printStackTrace();

        }

    }

}

脚本运行后，会在指定的目录生成代码文件。

测试生成的代码

首先在src/main/conf目录下添加配置文件，其中包括jsbc.properties的配置文件，mybatis-spring的配置文件，以及service bean的配置文件。

spring相关的配置文件放置在src/main/conf/spring目录下。

jdbc.properties

jdbc.driverClassName:com.mysql.jdbc.Driver

jdbc.url:jdbc:mysql://localhost:3306/mybatis?useSSL=false

jdbc.username:root

jdbc.password:123456

spring-mybatis.xml

<?xml version="1.0" encoding="utf-8"?>

<beans xmlns="http://www.springframework.org/schema/beans"

    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context"

    xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx"

    xmlns:jee="http://www.springframework.org/schema/jee"

    xsi:schemaLocation="http://www.springframework.org/schema/beans

           http://www.springframework.org/schema/beans/spring-beans-3.0.xsd

           http://www.springframework.org/schema/context

           http://www.springframework.org/schema/context/spring-context-3.0.xsd

           http://www.springframework.org/schema/aop

           http://www.springframework.org/schema/aop/spring-aop-3.0.xsd

           http://www.springframework.org/schema/jee

           http://www.springframework.org/schema/jee/spring-jee-3.0.xsd

           http://www.springframework.org/schema/tx

           http://www.springframework.org/schema/tx/spring-tx-3.2.xsd">

    <!-- 引入dbconfig.properties属性文件 -->

    <context:property-placeholder location="classpath:jdbc.properties" />

    <!-- ========================================配置数据源========================================= -->

    <!-- 配置数据源 -->

    <bean id="dataSource"

        class="org.springframework.jdbc.datasource.DriverManagerDataSource">

        <property name="driverClassName">

            <value>${jdbc.driverClassName}</value>

        </property>

        <property name="url">

            <value>${jdbc.url}</value>

        </property>

        <property name="username">

            <value>${jdbc.username}</value>

        </property>

        <property name="password">

            <value>${jdbc.password}</value>

        </property>

    </bean>

    <!-- 自动扫描目录下所有SQL映射的xml文件, -->

    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">

        <property name="dataSource" ref="dataSource" />

        <property name="mapperLocations" value="classpath:com/founder/datacenter/dao/mapper/*.xml" />

    </bean>

    <!-- 扫描指定包以及子包下的所有映射接口类 -->

    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">

        <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory" />

        <property name="basePackage" value="com.founder.datacenter.dao.mapper" />

    </bean>

    <!-- 配置Spring的事务管理器 -->

    <bean id="transactionManager"

        class="org.springframework.jdbc.datasource.DataSourceTransactionManager">

        <property name="dataSource" ref="dataSource" />

    </bean>

    <!-- 注解方式配置事物 -->

    <tx:annotation-driven transaction-manager="transactionManager" />

</beans>

spring-service.xml

<?xml version="1.0" encoding="utf-8"?>

<beans xmlns="http://www.springframework.org/schema/beans"

    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context"

    xmlns:aop="http://www.springframework.org/schema/aop" xmlns:mvc="http://www.springframework.org/schema/mvc"

    xmlns:jee="http://www.springframework.org/schema/jee"

    xsi:schemaLocation="http://www.springframework.org/schema/beans

           http://www.springframework.org/schema/beans/spring-beans-3.0.xsd

           http://www.springframework.org/schema/context

           http://www.springframework.org/schema/context/spring-context-3.0.xsd

           http://www.springframework.org/schema/aop

           http://www.springframework.org/schema/aop/spring-aop-3.0.xsd

           http://www.springframework.org/schema/jee

           http://www.springframework.org/schema/jee/spring-jee-3.0.xsd

           http://www.springframework.org/schema/mvc

           http://www.springframework.org/schema/mvc/spring-mvc-3.1.xsd">

    <!--其实component-scan 就有了annotation-config的功能即把需要的类注册到了spring容器中 -->

    <context:component-scan base-package="com.founder.datacenter.service" />

    <!-- 可以使用@Service注解，完成service的bean声明，不必在spring文件中添加bean -->

</beans>

ExampleService.java

package com.founder.datacenter.service;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.stereotype.Service;

import com.founder.datacenter.dao.mapper.UserMapper;

import com.founder.datacenter.model.User;

import com.founder.datacenter.model.UserExample;

@Service("ExampleService")

public class ExampleService {

    @Autowired

    private UserMapper userMapper;

    public boolean existUser(String name) {

        UserExample userE = new UserExample();

        userE.createCriteria().andNameEqualTo(name);

        userE.setDistinct(true);

        List<User> user = userMapper.selectByExample(userE);

        if (user.size() > 0)

            return true;

        else

            return false;

    }

}

测试代码

package com.founder.datacenter;

import static org.junit.Assert.assertEquals;

import org.junit.After;

import org.junit.Before;

import org.junit.Test;

import org.springframework.beans.factory.BeanFactory;

import org.springframework.context.support.ClassPathXmlApplicationContext;

import com.founder.datacenter.service.ExampleService;

public class AppTest {

    BeanFactory factory;

    @Before

    public void before() {

        factory = new ClassPathXmlApplicationContext("spring/spring-*.xml");

        System.out.println("@Before");

    }

    @After

    public void after() {

        System.out.println("@After");

    }

    @Test

    public void exitTest() {

        ExampleService service = factory.getBean("ExampleService", ExampleService.class);

        assertEquals(service.existUser("mahuan2"), true);

    }

}

mysql表中插入了一条name为mahuan2的数据。

测试结果通过。

分页功能添加

原始生成的代码是无法完成分页功能的，因为需要添加自定义插件，增加分页功能。

插件代码

package com.founder.ebd.util.mybatis;

import java.util.List;

import org.mybatis.generator.api.CommentGenerator;

import org.mybatis.generator.api.IntrospectedColumn;

import org.mybatis.generator.api.IntrospectedTable;

import org.mybatis.generator.api.Plugin;

import org.mybatis.generator.api.PluginAdapter;

import org.mybatis.generator.api.dom.java.Field;

import org.mybatis.generator.api.dom.java.FullyQualifiedJavaType;

import org.mybatis.generator.api.dom.java.JavaVisibility;

import org.mybatis.generator.api.dom.java.Method;

import org.mybatis.generator.api.dom.java.Parameter;

import org.mybatis.generator.api.dom.java.TopLevelClass;

import org.mybatis.generator.api.dom.xml.Attribute;

import org.mybatis.generator.api.dom.xml.TextElement;

import org.mybatis.generator.api.dom.xml.XmlElement;

public class MySQLPaginationPlugin extends PluginAdapter {

    @Override

    public boolean modelExampleClassGenerated(TopLevelClass topLevelClass, IntrospectedTable introspectedTable) {

        // add field, getter, setter for limit clause

        addLimit(topLevelClass, introspectedTable, "limitStart");

        addLimit(topLevelClass, introspectedTable, "count");

        // add the method that get the only Criteria

        addCriteriaGetter(topLevelClass, introspectedTable);

        return super.modelExampleClassGenerated(topLevelClass, introspectedTable);

    }

    @Override

    public boolean sqlMapSelectByExampleWithoutBLOBsElementGenerated(XmlElement element, IntrospectedTable introspectedTable) {

        XmlElement isNotNullElement = new XmlElement("if"); //$NON-NLS-1$

        isNotNullElement.addAttribute(new Attribute("test", "limitStart != null and limitStart >= 0")); //$NON-NLS-1$ //$NON-NLS-2$

        isNotNullElement.addElement(new TextElement("limit ${limitStart} , ${count}"));

        element.addElement(isNotNullElement);

        return super.sqlMapUpdateByExampleWithoutBLOBsElementGenerated(element, introspectedTable);

    }

    @Override

    public boolean sqlMapSelectByExampleWithBLOBsElementGenerated(XmlElement element, IntrospectedTable introspectedTable) {

        XmlElement isNotNullElement = new XmlElement("if"); //$NON-NLS-1$

        isNotNullElement.addAttribute(new Attribute("test", "limitStart != null and limitStart >= 0")); //$NON-NLS-1$ //$NON-NLS-2$

        isNotNullElement.addElement(new TextElement("limit ${limitStart} , ${count}"));

        element.addElement(isNotNullElement);

        return super.sqlMapUpdateByExampleWithoutBLOBsElementGenerated(element, introspectedTable);

    }

    @Override

    public boolean modelGetterMethodGenerated(Method method, TopLevelClass topLevelClass, IntrospectedColumn introspectedColumn,

            IntrospectedTable introspectedTable, Plugin.ModelClassType modelClassType) {

        return super.modelGetterMethodGenerated(method, topLevelClass, introspectedColumn, introspectedTable, modelClassType);

    }

    private void addLimit(TopLevelClass topLevelClass, IntrospectedTable introspectedTable, String name) {

        CommentGenerator commentGenerator = context.getCommentGenerator();

        Field field = new Field();

        field.setVisibility(JavaVisibility.PROTECTED);

        field.setType(FullyQualifiedJavaType.getIntInstance());

        field.setName(name);

        field.setInitializationString("-1");

        commentGenerator.addFieldComment(field, introspectedTable);

        topLevelClass.addField(field);

        char c = name.charAt(0);

        String camel = Character.toUpperCase(c) + name.substring(1);

        Method method = new Method();

        method.setVisibility(JavaVisibility.PUBLIC);

        method.setName("set" + camel);

        method.addParameter(new Parameter(FullyQualifiedJavaType.getIntInstance(), name));

        method.addBodyLine("this." + name + "=" + name + ";");

        commentGenerator.addGeneralMethodComment(method, introspectedTable);

        topLevelClass.addMethod(method);

        method = new Method();

        method.setVisibility(JavaVisibility.PUBLIC);

        method.setReturnType(FullyQualifiedJavaType.getIntInstance());

        method.setName("get" + camel);

        method.addBodyLine("return " + name + ";");

        commentGenerator.addGeneralMethodComment(method, introspectedTable);

        topLevelClass.addMethod(method);

    }

    private void addCriteriaGetter(TopLevelClass topLevelClass, IntrospectedTable introspectedTable) {

        CommentGenerator commentGenerator = context.getCommentGenerator();

        Method method = new Method();

        method.setVisibility(JavaVisibility.PUBLIC);

        method.setName("getCriteria");

        method.setReturnType(new FullyQualifiedJavaType("Criteria"));

        method.addBodyLine("if (oredCriteria.size() != 0) {return oredCriteria.get(0);}");

        method.addBodyLine("Criteria criteria = createCriteriaInternal();");

        method.addBodyLine("oredCriteria.add(criteria);");

        method.addBodyLine("return criteria;");

        commentGenerator.addGeneralMethodComment(method, introspectedTable);

        topLevelClass.addMethod(method);

    }

    @Override

    public boolean validate(List<String> arg0) {

        // TODO Auto-generated method stub

        return true;

    }

}

mysql的分页形式为limit startIndex，count的形式。

在build-mybatis.xml中增加插件信息，在生成代码后，便可以使用分页功能了。

生成代码中，UserExample增加了两个变量，UserMapper.xml相应的增加了limit的语句。

使用分页的代码

package com.founder.datacenter.service;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.stereotype.Service;

import com.founder.datacenter.dao.mapper.UserMapper;

import com.founder.datacenter.model.User;

import com.founder.datacenter.model.UserExample;

@Service("ExampleService")

public class ExampleService {

    @Autowired

    private UserMapper userMapper;

    public boolean existUser(String name) {

        UserExample userE = new UserExample();

        userE.createCriteria().andNameEqualTo(name);

        userE.setLimitStart(0);

        userE.setCount(1);

        userE.setDistinct(true);

        List<User> user = userMapper.selectByExample(userE);

        if (user.size() > 0)

            return true;

        else

            return false;

    }

}

表示在select的结果集中，从0索引开始，选择一行数据。

测试代码通过。

spring和mybatis集成，自动生成model、mapper，增加mybatis分页功能的相关教程结束。

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