spring和mybatis集成，自动生成modelmapper，增加mybatis分页功能

Posted 2020-08-08

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>

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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>

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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();
        }
    }
}

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 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.datacenter.utils.mybatis;

import java.util.List;

import org.mybatis.generator.api.CommentGenerator;
import org.mybatis.generator.api.IntrospectedTable;
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");
        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);
    }

    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);
    }

    @Override
    public boolean validate(List<String> arg0) {
        // TODO Auto-generated method stub
        return true;
    }

}

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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。