搭建轻量级java web框架

Posted 2020-06-14

     MVC这种常用的设计模式可以将应用程序解耦。

     若用Servlet来充当C，会产生大量的Servlet。作为一个轻量级框架，我们的目标减少Servlet的数量，对某一业务主题使用统一的Controller，依赖注入Service，结果放入Request或者Response。

     本章目标是打造如下的Controller代码：

/**
 * 处理客户管理的相关请求
 */
@Controller
public class CustomerController {
    @Inject
    private CustomerService customerService;

    /**
     * 进入客户列表界面
     */
    @Action("get:/customerListIndex")
    public View customerListIndex(Param param) {
        List<Customer> customerList = customerService.getCustomerList();
        return new View("customerList.jsp").addModel("customerList", customerList);
    }

    /**
     * 显示客户基本信息
     */
    @Action("get:/customerDetailIndex")
    public View show(Param param) {
        long id = param.getLong("id");
        Customer customer = customerService.getCustomer(id);
        return new View("customerDetail.jsp").addModel("customer", customer);
    }

    /**
     * 创建客户界面
     */
    @Action("get:/customerInsertIndex")
    public View customerInsertIndex(Param param) {
        return new View("customerCreateIndex.jsp");
    }

    /**
     * 创建客户 
     */
    @Action("get:/customerInsert")
    public Data customerInsert(Param param){
        Map<String, Object> fieldMap = param.getMap();
        boolean result = customerService.insertCustomer(fieldMap);
        return new Data(result);
    }

    /**
     * 编辑客户界面
     */
    @Action("get:/customerEditIndex")
    public View customerEditIndex(Param param){
        long id = param.getLong("id");
        Customer customer = customerService.getCustomer(id);
        return new View("customerEditIndex.jsp").addModel("customer",customer);
    }

    /**
     * 编辑客户
     */
    @Action("pub:/customerEdit")
    public Data customerEdit(Param param) {
        long id = param.getLong("id");
        Map<String,, Object> fieldMap = param.getMap();
        boolean result = customerService.updateCustomer(id, fieldMap);
        return new Data(result);
    }

    /**
     * 删除客户
     */
    @Action("delete:/customerDelete")
    public Data customerDelete(Param param) {
        long id = param.getLong("id");
        boolean result = customerService.deleteCustomer(id);
        return new Data(result);
    }
}

     其中，View对应jsp，Data对应Json数据。

3.2 搭建开发环境

3.2.1 创建框架项目

    创建普通的java项目，添加pom.xml文件。敲入三坐标：

<?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>smartFramework</groupId>
    <artifactId>smartFramework</artifactId>
    <version>1.0.0</version>

</project>

    添加Servlet、JSP、JSTL依赖。

<dependencies>
    <!-- Servlet -->
    <dependency>
        <groupId>javax.servlet</groupId>
        <artifactId>javax.servlet-api</artifactId>
        <version>3.1.0</version>
        <scope>provided</scope>
    </dependency>
    <!-- JSP -->
    <dependency>
        <groupId>javax.servlet.jsp</groupId>
        <artifactId>jsp-api</artifactId>
        <version>2.2</version>
        <scope>provided</scope>
    </dependency>
    <!-- JSTL -->
    <dependency>
        <groupId>javax.servlet</groupId>
        <artifactId>jstl</artifactId>
        <version>1.2</version>
        <scope>runtime</scope>
    </dependency>
</dependencies>

     引入SLF4J和Log4J两个依赖，其中SLF4J为Log4J的接口。

<!-- SLF4J -->
<dependency>
    <groupId>org.slf4j</groupId>
    <artifactId>slf4j-log4j12</artifactId>
    <version>1.7.7</version>
</dependency>

     引入mysql与java驱动依赖。

<!-- MySQL -->
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>5.1.33</version>
    <scope>runtime</scope>
</dependency>

     引入Json序列化依赖。

<!-- Jackson -->
<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-databind</artifactId>
    <version>2.5.2</version>
</dependency>

     常用工具类依赖。

<!-- Apache Commons Lang -->
<dependency>
    <groupId>org.apache.commons</groupId>
    <artifactId>commons-lang3</artifactId>
    <version>3.3.2</version>
</dependency>
<!-- Apache Commons Collections -->
<dependency>
    <groupId>org.apache.commons</groupId>
    <artifactId>commons-collections4</artifactId>
    <version>4.0</version>
</dependency>

     JDBC类库，DbUtils。

<!-- Apache Commons DbUtils -->
<dependency>
    <groupId>commons-dbutils</groupId>
    <artifactId>commons-dbutils</artifactId>
    <version>1.6</version>
</dependency>

     数据库连接池依赖。

<!-- Apache Commons DBCP -->
<dependency>
    <groupId>org.apache.commons</groupId>
    <artifactId>commons-dbcp2</artifactId>
    <version>2.0.1</version>
</dependency>

3.2.2 创建示例项目