ssm中逆向工程与分页的应用

港控/mmm° 2021-09-27 10:16 318阅读 0赞

昨天对springboot中的mybatis逆向工程与分页应用进行了整理，今天对ssm项目中的逆向工程与分页进行整理。  
项目运行环境：eclipse+jdk1.8+maven+tomcat

# 搭建ssm项目 #

首先新建maven project,项目Archetype选择：maven-archetype-webapp,项目新建完毕，会出现生成的index.jsp报错。  
造成原因：项目没有依赖javax.servlet相关类包，这些类包在tomcat类库中  
有两种解决方案：  
方法一：添加依赖

<dependency>
        <groupId>javax.servlet</groupId>
        <artifactId>servlet-api</artifactId>
        <version>2.5</version>
    </dependency>

方法二：依赖tomcat类库，前提是eclipse已经有tomcat服务器  
依次 右击项目—>build path —> configure build path — >libraries — > add libraries —> Server Runtime — >选择tomcat服务器lib —> ok  
项目建成依次添加依赖，代码如下：

<properties>
        <spring.version>4.3.7.RELEASE</spring.version>
    </properties>
    
    <dependencies>
        
        <dependency>
          <groupId>junit</groupId>
          <artifactId>junit</artifactId>
          <version>3.8.1</version>
          <scope>test</scope>
        </dependency>
    
        
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>servlet-api</artifactId>
            <version>2.5</version>
        </dependency>
    
        
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-core</artifactId>
            <version>${spring.version}</version>
        </dependency>
    
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-beans</artifactId>
            <version>${spring.version}</version>
        </dependency>
    
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</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-tx</artifactId>
            <version>${spring.version}</version>
        </dependency>
    
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-web</artifactId>
            <version>${spring.version}</version>
        </dependency>
    
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>${spring.version}</version>
        </dependency>
    
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-test</artifactId>
            <version>${spring.version}</version>
            <scope>test</scope>
        </dependency>
    
        
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.4.2</version>
        </dependency>
    
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis-spring</artifactId>
            <version>1.3.1</version>
        </dependency>
    
        
        <dependency>
            <groupId>com.github.pagehelper</groupId>
            <artifactId>pagehelper</artifactId>
            <version>5.1.2</version>
        </dependency>
    
        
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.37</version>
        </dependency>
    
        
        <dependency>
            <groupId>c3p0</groupId>
            <artifactId>c3p0</artifactId>
            <version>0.9.1.2</version>
        </dependency>
    </dependencies>

maven install下载好依赖包。  
在src/main/resources文件夹下添加文件jdbc.properties,代码如下：

jdbc.driver=com.mysql.jdbc.Driver
    jdbc.url=jdbc:mysql://127.0.0.1:3306/test?useUnicode=true&characterEncoding=utf8
    jdbc.username=root
    jdbc.password=123456

在src/main/resources文件夹下添加文件mybatis-config.xml，代码如下：

<?xml version="1.0" encoding="UTF-8"?>
    <!DOCTYPE configuration
      PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
      "http://mybatis.org/dtd/mybatis-3-config.dtd">
    <configuration>
        
        <settings>
            
            <setting name="useGeneratedKeys" value="true" />
    
            
            <setting name="useColumnLabel" value="true" />
    
            
            <setting name="mapUnderscoreToCamelCase" value="true" />
        </settings>
    </configuration>

在src/main/resources文件夹下添加文件夹spring,在spring中添加文件spring-dao.xml，代码如下：

<?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"
        xsi:schemaLocation="http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/context
        http://www.springframework.org/schema/context/spring-context.xsd">
        
        
        <context:property-placeholder location="classpath:jdbc.properties"/>
        
        <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
            
            <property name="driverClass" value="${jdbc.driver}" />
            <property name="jdbcUrl" value="${jdbc.url}" />
            <property name="user" value="${jdbc.username}" />
            <property name="password" value="${jdbc.password}" />
            
            <property name="maxPoolSize" value="30" />
            <property name="minPoolSize" value="10" />
            
            <property name="autoCommitOnClose" value="false" />
            
            <property name="checkoutTimeout" value="10000" />
            
            <property name="acquireRetryAttempts" value="2" />
        </bean>
    
        
        <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
            
            <property name="dataSource" ref="dataSource" />
            
            <property name="configLocation" value="classpath:mybatis-config.xml" />
            
            <property name="typeAliasesPackage" value="com.luis.entity" />
            
            <property name="mapperLocations" value="classpath:mapper/*.xml" />
        </bean>
    
        
        <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
            
            <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory" />
            
            <property name="basePackage" value="com.luis.mapper" />
        </bean>
    </beans>

在spring中添加文spring-service.xml，代码如下：

在spring中添加文spring-web.xml，代码如下：

修改web.xml文件，代码如下：

<web-app>
        <servlet>
            <servlet-name>spring-dispatcher</servlet-name>
            <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
            <init-param>
                <param-name>contextConfigLocation</param-name>
                <param-value>classpath:spring/spring-*.xml</param-value>
            </init-param>
        </servlet>
    
        <servlet-mapping>
            <servlet-name>spring-dispatcher</servlet-name>
            <url-pattern>/</url-pattern>
        </servlet-mapping>
    
        <welcome-file-list>
            <welcome-file>index.jsp</welcome-file>
            <welcome-file>index.html</welcome-file>
        </welcome-file-list>
    </web-app>

至此，ssm项目搭建完毕！

# 逆向工程与分页应用 #

首先导入逆向工程项目，具体使用方法参见：[我的github][github]  
本文仍旧应用上篇的数据库，数据库表如下：

DROP TABLE IF EXISTS `user`;
    CREATE TABLE `user` (
      `id` bigint(20) NOT NULL,
      `name` varchar(255) NOT NULL,
      `age` int(4) NOT NULL,
      PRIMARY KEY (`id`)
    ) ENGINE=InnoDB DEFAULT CHARSET=utf8;
    
    INSERT INTO `user` VALUES ('1', 'wanger', '22');
    INSERT INTO `user` VALUES ('2', 'zhangsan', '18');
    INSERT INTO `user` VALUES ('3', 'lisi', '23');
    INSERT INTO `user` VALUES ('4', 'wangwu', '21');

运行文件生成mapper接口，实体类与xml文件。  
分页已经添加依赖，可直接应用。

<dependency>
        <groupId>com.github.pagehelper</groupId>
        <artifactId>pagehelper</artifactId>
        <version>5.1.2</version>
    </dependency>

另外在spring-dao.xml文件的SqlSessionFactory的bean中添加：

<property name="plugins">
        <array>
            <bean class="com.github.pagehelper.PageInterceptor">
                <property name="properties">
                    <value>
                    
                        helperDialect=mysql
                    </value>
                </property>
            </bean>
        </array>
    </property>

编写service层，UserService代码如下：

public interface UserService {
        User selectByName(String name);
        List<User> findAllUser(int pageNum, int pageSize);
    }

UserServiceImpl代码如下：

@Service
    public class UserServiceImpl implements UserService {
    
        @Autowired
        private UserMapper userMapper;
    
        public User selectByName(String name) {
            UserExample example = new UserExample();
            Criteria criteria = example.createCriteria();
            criteria.andNameEqualTo(name);
            List<User> users = userMapper.selectByExample(example);
            if (users != null && users.size() > 0) {
                return users.get(0);
            }
            return null;
        }
    
        /**
         * pageNum 开始页数
         * pageSize 每页显示的数据条数
         */
        public List<User> findAllUser(int pageNum, int pageSize) {
            //将参数传给方法实现分页
            PageHelper.startPage(pageNum, pageSize);
            UserExample example = new UserExample();
            List<User> list = userMapper.selectByExample(example);
            return list;
        }
    }

编写web层，UserController代码如下：

@Controller
    public class UserController {
    
        @Autowired
        private UserService userService;
    
        @ResponseBody
        @RequestMapping("/test")
        public String querUserByName() {
            User user = userService.selectByName("wanger");
            System.out.println(user.toString());
            return "index";
        }
    
        @RequestMapping("/list")
        public String querUser() {
            List<User> list = userService.findAllUser(1, 2);
            //获取分页信息
            PageInfo<User> pageInfo = new PageInfo<User>(list);
            System.out.println(list.toString());
            System.out.println("total:" + pageInfo.getTotal());
            System.out.println("pages:" + pageInfo.getPages());
            System.out.println("pageSize:" + pageInfo.getPageSize());
            return "index";
        }
    }

# 测试 #

将项目部署到tomcat,启动，访问[http://localhost:8080/ssm-demo/test][http_localhost_8080_ssm-demo_test]，运行结果：

User [id=1, name=wang1er, age=22]

逆向工程与ssm项目搭建成功！  
访问[http://localhost:8080/ssm-demo/list][http_localhost_8080_ssm-demo_list]，运行结果：

Page{count=true, pageNum=1, pageSize=2, startRow=0, endRow=2, total=4, pages=2, reasonable=false, pageSizeZero=false}
    total:4
    pages:2
    pageSize:2

此处遇到的坑：照着网上的很多例子添加了plugins,分页过程中出现错误：

警告: Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sqlSessionFactory' defined in file [E:\code\eclipse-workspace\.metadata\.plugins\org.eclipse.wst.server.core\tmp0\wtpwebapps\ssm-demo\WEB-INF\classes\spring\spring-dao.xml]: Initialization of bean failed; nested exception is org.springframework.beans.ConversionNotSupportedException: Failed to convert property value of type 'java.lang.Object[]' to required type 'org.apache.ibatis.plugin.Interceptor[]' for property 'plugins'; nested exception is java.lang.IllegalStateException: Cannot convert value of type 'com.github.pagehelper.PageHelper' to required type 'org.apache.ibatis.plugin.Interceptor' for property 'plugins[0]': no matching editors or conversion strategy found
    九月 06, 2018 10:51:00 下午 org.springframework.web.servlet.DispatcherServlet initServletBean
    严重: Context initialization failed
    org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sqlSessionFactory' defined in file [E:\code\eclipse-workspace\.metadata\.plugins\org.eclipse.wst.server.core\tmp0\wtpwebapps\ssm-demo\WEB-INF\classes\spring\spring-dao.xml]: Initialization of bean failed; nested exception is org.springframework.beans.ConversionNotSupportedException: Failed to convert property value of type 'java.lang.Object[]' to required type 'org.apache.ibatis.plugin.Interceptor[]' for property 'plugins'; nested exception is java.lang.IllegalStateException: Cannot convert value of type 'com.github.pagehelper.PageHelper' to required type 'org.apache.ibatis.plugin.Interceptor' for property 'plugins[0]': no matching editors or conversion strategy found

花了很大时间，最后在[https://blog.csdn.net/wangyuanjun008/article/details/79121459][https_blog.csdn.net_wangyuanjun008_article_details_79121459]  
找到了解决方案。将plugins改为：

项目测试完毕！  
具体的项目代码，参见于：[github][github 1]

本文参考了：  
[https://blog.csdn.net/wangyuanjun008/article/details/79121459][https_blog.csdn.net_wangyuanjun008_article_details_79121459]

[github]: https://github.com/liuyi6/JavaWeb
[http_localhost_8080_ssm-demo_test]: http://localhost:8080/ssm-demo/test
[http_localhost_8080_ssm-demo_list]: http://localhost:8080/ssm-demo/list
[https_blog.csdn.net_wangyuanjun008_article_details_79121459]: https://blog.csdn.net/wangyuanjun008/article/details/79121459
[github 1]: https://github.com/liuyi6/JavaWeb/tree/master/ssm-demo