个人项目总结(二)

桃扇骨 2022-02-25 01:28 216阅读 0赞

## 完成Service层 ##

1.导包(上一个博客引入)  
2.创建IBaseService

public interface IBaseService<T,ID extends Serializable>{
        //添加与修改数据
        void save(T t);
        //根据id删除一条数据
        void delete(ID id);
        //根据id查询到一条数据
        T findOne(ID id);
        //查询所有数据
        List<T> findAll();
        //根据Query拿到分页对象(分页)
        Page findPageByQuery(BaseQuery baseQuery);
        //根据Query拿到对应的所有数据(不分页)
        List<T> findByQuery(BaseQuery baseQuery);
        //根据jpql与对应的参数拿到数据
        List findByJpql(String jpql,Object... values);

\}  
3.创建BaseServiceImpl

@Transactional(readOnly = true,propagation = SUPPORTS)
    	//propagation = SUPPORTS:事务传播机制     
    	//REQUIRED   必须有事务，有就有当前事务，没有就创建
    	//REQUIRED_NEW   不管有没有，都只开单独事务
    	//NEVER   永远不需要
    	//SUPPORTS   有没有事务都支持
    public class BaseServiceImpl<T,ID  extends Serializable> implements IBaseService<T,ID>{
        //注意:Spring 4.x 中可以为子类注入子类对应的泛型类型的成员变量的引用
        @Autowired
        private BaseRepository<T,ID> baseRepository;
        @Override
        @Transactional(
        public void save(T t) {
            baseRepository.save(t);
        }
        @Override
        @Transactional(
        public void delete(ID id) {
            baseRepository.delete(id);
        }
        @Override
        public T findOne(ID id) {
            return baseRepository.findOne(id);
        }
        @Override
        public List<T> findAll() {
            return baseRepository.findAll();
        }
        @Override
        public Page findPageByQuery(BaseQuery baseQuery) {
            return baseRepository.findPageByQuery(baseQuery);
        }
        @Override
        public List<T> findByQuery(BaseQuery baseQuery) {
            return baseRepository.findByQuery(baseQuery);
        }
        @Override
        public List findByJpql(String jpql, Object... values) {
            return baseRepository.findByJpql(jpql, values);
        }
    }

4.创建IEmployeeService

//注：在开发中，业务后期是有很多功能的(不只是我们最简单的CRUD)
    public interface IEmployeeService extends IBaseService<Employee,Long> {
    }

5.创建EmployeeServiceImpl

@Service
    public class EmployeeServiceImpl extends BaseServiceImpl<Employee,Long> implements IEmployeeService {
    }

## 集成SpringMVC ##

1.引入相应jar包  
首先确定咱们已经引入SpringMVC的核心jar包，这个包咱们之前在pom.xml中已经引入，这里主要是给大家提醒一下。

<dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-web</artifactId>
            <version>${org.springframework.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>${org.springframework.version}</version>
        </dependency>

2.配置applicationContext-mvc.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:mvc="http://www.springframework.org/schema/mvc"
           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
             http://www.springframework.org/schema/mvc
             http://www.springframework.org/schema/mvc/spring-mvc.xsd ">
        
        <mvc:default-servlet-handler />
        
        
        <context:component-scan base-package="cn.itsource.pss.web" />
        
        <mvc:annotation-driven />
        
        <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
            
            
            
            <property name="prefix" value="/WEB-INF/views/" />
            
            <property name="suffix" value=".jsp" />
        </bean>
        
        <bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
            
            <property name="maxUploadSize">
                <value>1048576</value>
            </property>
        </bean>
    </beans>

3.配置web.xml  
项目自带的web.xml的版本可能有错误，直接拷贝一下的

<?xml version="1.0" encoding="UTF-8"?>
        <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee"
                 xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"
                 id="WebApp_ID" version="3.1">
      
        <context-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>classpath:applicationContext.xml</param-value>
        </context-param>
        
        <listener>
            <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
        </listener>
    
        
        <filter>
            <filter-name>characterEncodingFilter</filter-name>
            <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
            <init-param>
                <param-name>encoding</param-name>
                <param-value>UTF-8</param-value>
            </init-param>
            <init-param>
                <param-name>forceEncoding</param-name>
                <param-value>true</param-value>
            </init-param>
        </filter>
        <filter-mapping>
            <filter-name>characterEncodingFilter</filter-name>
            <url-pattern>/*</url-pattern>
        </filter-mapping>
    
        
        <servlet>
            <servlet-name>dispatcher</servlet-name>
            <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
            <init-param>
                
                <param-name>contextConfigLocation</param-name>
                
                <param-value>classpath:applicationContext-mvc.xml</param-value>
            </init-param>
            
            <load-on-startup>1</load-on-startup>
        </servlet>
        <servlet-mapping>
            <servlet-name>dispatcher</servlet-name>
            <url-pattern>/</url-pattern>
        </servlet-mapping>
    
    </web-app>

4.创建Controller与页面

@Controller
    @RequestMapping("/employee")
    public class EmployeeController {
    
        @Autowired
        private IEmployeeService employeeService;
    
        @RequestMapping("/index")
        public String index() {
            //根据配置，这里会跳到/WEB-INF/views/employee/employee.jsp页面
            return "employee/employee";
        }
        @RequestMapping("/list")
        @ResponseBody
        public List<Employee> list(){
            return employeeService.findAll();
        }
    
    }

## 添加easyui界面 ##

1.将easyui的文件夹赋值到webapp文件夹下  
2.导入相应文件

3.抽取一个head.jsp  
将上面的代码放到head.jsp中  
在后面需要引入easyui文件的页面上添加包含标签

<%@include file="/WEB-INF/views/head.jsp" %>

4.easyui帮助文档地址([http://www.jeasyui.net/][http_www.jeasyui.net])

5.注册事件拓展方法  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0p1bmVfRmx5aW5nRnJvc3Q_size_16_color_FFFFFF_t_70]

## 完成查询功能 ##

1.分页查询注意事项  
① easyui前台传来的分页数据是page和rows，可能与进后台接受参数的字段不同，如果不同可以在Query类中用gett/sett方法解决  
![在这里插入图片描述][20190331105323791.png]  
② 后台向前台传值，easyui接受分页数据是总条数是tatol，每页数据是rows  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0p1bmVfRmx5aW5nRnJvc3Q_size_16_color_FFFFFF_t_70 1]  
创建一个UiPage 类专门向easyui传值

public class UiPage {
        private long total; //总条数
        private List rows; //每页数据
        public UiPage(){}
        public UiPage(Page page){
            total = page.getTotalElements();
            rows = page.getContent();
        }
        get,set省略
    }

2.运用formatter属性解决datagrid中的图片，或对象的现实问题

在js中完善formatObj方法

function formatObjt(data) {
        if(data){
      	  return data.img
        };
        return "";
    }

1.  no-session问题  
    ![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0p1bmVfRmx5aW5nRnJvc3Q_size_16_color_FFFFFF_t_70 2]主要原因是在EntityManager关闭后去查询数据库  
    fetch=FechType.LAZY // 懒加载，使用时采取数据库查询  
    ![在这里插入图片描述][20190331112158607.png]  
    在web.xml中配置

<filter>
        <filter-name>openEntity</filter-name>
        <filter-class>org.springframework.orm.jpa.support.OpenEntityManagerInViewFilter</filter-class>
    </filter>
    <filter-mapping>
        <filter-name>openEntity</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>

4.解决no-session后还会出现一个no serializer错误  
原因是jpa实现懒加载，内部会添加一些属性，对SpringMvc来说，有些属性会导致JSON生成出错  
解决方法  
① 生成jSON时忽略掉jap给字段内部添加的字段

@JsonIgnoreProperties(value={"hibernateLazyInitializer","handler","fieldHandler"})

② 先创建一个CustomMapper类继承ObjectMapper

public class CustomMapper extends ObjectMapper {
        public CustomMapper() {
            this.setSerializationInclusion(JsonInclude.Include.NON_NULL);
            // 设置 SerializationFeature.FAIL_ON_EMPTY_BEANS 为 false
            this.configure(SerializationFeature.FAIL_ON_EMPTY_BEANS, false);
        }
    }

再配置applicationContext-mvc.xml

<mvc:annotation-driven>
        <mvc:message-converters>
            <bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
                <property name="supportedMediaTypes">
                    <list>
                        <value>application/json; charset=UTF-8</value>
                        <value>application/x-www-form-urlencoded; charset=UTF-8</value>
                    </list>
                </property>
                
                <property name="objectMapper">
                    <bean class="cn.itsource.pss.common.CustomMapper"></bean>
                </property>
            </bean>
        </mvc:message-converters>
    </mvc:annotation-driven>

[http_www.jeasyui.net]: http://www.jeasyui.net/
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0p1bmVfRmx5aW5nRnJvc3Q_size_16_color_FFFFFF_t_70]: /images/20220225/8e9bbd9d88334f6ab8e2437fd7b533fe.png
[20190331105323791.png]: /images/20220225/2ac3d0909f864c79b3d5feb85efc4a9a.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0p1bmVfRmx5aW5nRnJvc3Q_size_16_color_FFFFFF_t_70 1]: /images/20220225/b74340aa76d44f28b231587476c1c0ba.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0p1bmVfRmx5aW5nRnJvc3Q_size_16_color_FFFFFF_t_70 2]: /images/20220225/94dfadc370174ecf950167007842d79a.png
[20190331112158607.png]: /images/20220225/ef381f39d8c34e638f96db211fb59343.png