【java】JavaWeb的一般配置

博主：本当迷
发布时间：2022 年 07 月 25 日
822 次浏览
暂无评论
4439字数
分类： java

### meave配置(pom.xml)

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

<groupId>org.example</groupId>
  <artifactId>TomcatMaven</artifactId>
  <version>1.0-SNAPSHOT</version>

<dependencies>
    <dependency>
      <groupId>javax.servlet</groupId>
      <artifactId>javax.servlet-api</artifactId>
      <version>3.1.0</version>
      <scope>provided</scope>  
    </dependency>

<dependency>
      <groupId>commons-io</groupId>
      <artifactId>commons-io</artifactId>
      <version>2.6</version>
    </dependency>

<dependency>
      <groupId>org.mybatis</groupId>
      <artifactId>mybatis</artifactId>
      <version>3.5.5</version>
    </dependency>

<dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <version>8.0.29</version>
    </dependency>

<dependency>
      <groupId>javax.servlet.jsp</groupId>
      <artifactId>jsp-api</artifactId>
      <version>2.2</version>
      <scope>provided</scope>
    </dependency>

<dependency>
      <groupId>jstl</groupId>
      <artifactId>jstl</artifactId>
      <version>1.2</version>
    </dependency>
    <dependency>
      <groupId>taglibs</groupId>
      <artifactId>standard</artifactId>
      <version>1.1.2</version>
    </dependency>

<dependency>
      <groupId>com.alibaba</groupId>
      <artifactId>fastjson</artifactId>
      <version>2.0.7.graal</version>
    </dependency>
      <dependency>
          <groupId>org.junit.jupiter</groupId>
          <artifactId>junit-jupiter</artifactId>
          <version>RELEASE</version>
          <scope>compile</scope>
      </dependency>

</dependencies>

<build>
    <plugins>
      <plugin>
        <groupId>org.apache.tomcat.maven</groupId>
        <artifactId>tomcat7-maven-plugin</artifactId>
        <version>2.2</version>
        <configuration>
          <port>80</port>
          <path>/</path>
        </configuration>
      </plugin>
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-compiler-plugin</artifactId>
        <configuration>
          <source>7</source>
          <target>7</target>
        </configuration>
      </plugin>
    </plugins>
  </build>
  
  <packaging>war</packaging>

</project>

```

## mybatis配置(mybatis-config.xml)

```java
<?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>
    
    <typeAliases>
        <package name="com.pojo"/>
    </typeAliases>

<environments default="development">
        <environment id="development">
            <transactionManager type="JDBC"/>
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.jdbc.Driver"/>
                <property name="url" value="jdbc:mysql:///mybatis?useSSL=false&useServerPrepStmts=true"/>
                <property name="username" value="root"/>
                <property name="password" value="Abc12345678"/>
            </dataSource>
        </environment>
    </environments>
    <mappers>
        
        <package name="com.mapper"/>
    </mappers>
</configuration>
```

## 目录一般结构

![image.png](https://www.bdmcom.cn/usr/uploads/2022/07/2503652449.png)

## SqlSessionFactoryUtil工具包

```java
package com.util;

import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;

import java.io.IOException;
import java.io.InputStream;

public class SqlSessionFactoryUtils {

private static SqlSessionFactory sqlSessionFactory;

static {
        //静态代码块会随着类的加载而自动执行，且只执行一次
        try {
            String resource = "mybatis-config.xml";
            InputStream inputStream = Resources.getResourceAsStream(resource);
            sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

public static SqlSessionFactory getSqlSessionFactory(){
        return sqlSessionFactory;
    }
}

```

## BrandMapper.xml

```java
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.mapper.BrandMapper">

<resultMap id="brandResultMap" type="brand">
        <result property="brandName" column="brand_name" />
        <result property="companyName" column="company_name" />
    </resultMap>
    <update id="update">
        update tb_brand
        set brand_name = #{brand.brandName}, company_name = #{brand.companyName}, ordered = #{brand.ordered}, description = #{brand.description}, status = #{brand.status}
        where id = #{brand.id}
    </update>

<delete id="deleteByIds" >
        delete from tb_brand where id in
        <foreach collection="ids" item="id" separator="," open="(" close=")">
            #{id}
        </foreach>
    </delete>
    <select id="selectByPageAndCondition" resultMap="brandResultMap">
        select *
        from tb_brand
        <where>
            <if test="brand.brandName != null and brand.brandName != ''">
                and brand_name like #{brand.brandName}
            </if>
            <if test="brand.companyName != null and brand.companyName != ''">
                and company_name like #{brand.companyName}
            </if>
            <if test="brand.status != null">
                and status = #{brand.status}
            </if>
        </where>
        limit #{begin}, #{size}
    </select>

<select id="selectTotalCountByCondition" resultType="java.lang.Integer">
        select count(*)
        from tb_brand
        <where>
            <if test="brandName != null and brandName != ''">
                and brand_name like #{brandName}
            </if>
            <if test="companyName != null and companyName != ''">
                and company_name like #{companyName}
            </if>
            <if test="status != null">
                and status = #{status}
            </if>
        </where>
    </select>
</mapper>
```

## BaseServlet

我们可以通过BaseServlet替换HttpServlet, 根据请求的最后一段路径来进行分发请求

```java
package com.web;

/**
 * @code Description
 * @code author 本当迷
 * @code date 2022/7/24-20:24
 */

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

/**
 * 替换HttpServlet, 根据请求的最后一段路径来进行分发
 */
public class BaseServlet extends HttpServlet {

// 根据请求的最后一段路径来进行分发
    @Override
    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        // 1.获取请求路径
        final String uri = req.getRequestURI();

// 2.获取最后一段路径，方法名
        final int index = uri.lastIndexOf('/');
        final String methodName = uri.substring(index + 1);

// 3.执行方法
        // 3.1获取BrandServlet / UserServlet 字节码对象 Class
        final Class<? extends BaseServlet> aClass = this.getClass();

// 3.3获取方法Method对象
        try {
            final Method method = aClass.getMethod(methodName, HttpServletRequest.class, HttpServletResponse.class);

// 3.4执行方法
            method.invoke(this, req, resp);
        } catch (NoSuchMethodException | InvocationTargetException | IllegalAccessException e) {
            throw new RuntimeException(e);
        }

}
}

```

## BrandMapper SQL处理

```java
package com.mapper;

import com.pojo.Brand;
import org.apache.ibatis.annotations.*;

import java.util.List;

public interface BrandMapper {

/**
     * 查询所有
     * @return
     */
    @Select("select * from tb_brand")
    @ResultMap("brandResultMap")
    List<Brand> selectAll();

/**
     * 添加
     * @param brand
     */
    @Insert("insert into tb_brand values(null,#{brandName},#{companyName},#{ordered},#{description},#{status})")
    void add(Brand brand);

/**
     *  批量删除
     * @param ids
     */
    void deleteByIds(@Param("ids") int[] ids);

/**
     * 分页查询 
     * @param begin
     * @param size
     * @return
     */
    @Select("select * from tb_brand limit #{begin}, #{size}")
    List<Brand> selectByPage(@Param("begin") int begin, @Param("size") int size);

/**
     * 返回总页数
     * @return
     */
    @Select("select count(*) from tb_brand")
    int selectTotalCount();

/**
     * 分页条件查询 含模糊查询
     * @param begin
     * @param size
     * @return
     */
    List<Brand> selectByPageAndCondition(@Param("begin") int begin,@Param("size") int size,@Param("brand") Brand brand);

/**
     * 根据条件查询总记录数
     * @return
     */
    int selectTotalCountByCondition(Brand brand);

/**
     * 通过id修改对应信息
     * @param brand 用户id
     */

void update(@Param("brand") Brand brand);

}

```

## BrandServlet增删改查

```java
package com.web;

import com.alibaba.fastjson.JSON;
import com.pojo.Brand;
import com.pojo.PageBean;
import com.service.BrandService;
import com.service.impl.BrandServiceImpl;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.BufferedReader;
import java.io.IOException;
import java.util.Arrays;
import java.util.List;

/**
 * @code Description
 * @code author 本当迷
 * @code date 2022/7/24-20:35
 */

@WebServlet("/brand/*")
public class BrandServlet extends BaseServlet{

private final BrandService brandService = new BrandServiceImpl();

/**
     * 查询所有数据
     * @param request
     * @param response
     * @throws ServletException
     * @throws IOException
     */
    public void selectAll(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        System.out.println("selectAll");
        // 1.调用service查询
        final List<Brand> brands = brandService.selectAll();

// 2.转为JSON
        final String jsonString = JSON.toJSONString(brands);

// 3.写数据
        response.setContentType("text/json;charset=utf-8");
        response.getWriter().write(jsonString);
    }

/**
     * 添加数据
     * @param request
     * @param response
     * @throws ServletException
     * @throws IOException
     */
    public void add(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        System.out.println("add");
        // 1.接受品牌数据
        final BufferedReader reader = request.getReader();

final String edit = request.getParameter("edit");
        System.out.println(edit);

// JSON数据
        final String params = reader.readLine();

// 转为Brand对象
        final Brand brand = JSON.parseObject(params, Brand.class);

System.out.println(brand);

if(edit.equals("false")){
            // 2.调用service添加
            brandService.add(brand);
        }else{
            brandService.update(brand);
        }
        response.getWriter().write("success");
    }

/**
     * 批量删除
     * @param request
     * @param response
     * @throws ServletException
     * @throws IOException
     */
    public void deleteIds(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        System.out.println("deleteIdS");
        // 1.接受品牌数据
        final BufferedReader reader = request.getReader();

// JSON数据
        final String params = reader.readLine();

// 转为Brand对象
        final int[] ints = JSON.parseObject(params, int[].class);

System.out.println(Arrays.toString(ints));

// 2.调用service添加
        brandService.deleteByIds(ints);

// 3.响应成功的信息
        response.getWriter().write("success");
    }

/**
     * 分页查询
     * @param request
     * @param response
     * @throws ServletException
     * @throws IOException
     */
    public void selectByPage(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // 1.接受 当前页码 和 每页展示条数
        final int currentPage = Integer.parseInt(request.getParameter("currentPage"));
        final int pageSize = Integer.parseInt(request.getParameter("pageSize"));

// 2.调用service查询
        final PageBean<Brand> brandPageBean = brandService.selectByPage(currentPage, pageSize);

// 2.转为JSON
        final String jsonString = JSON.toJSONString(brandPageBean);

// 3.写数据
        response.setContentType("text/json;charset=utf-8");
        response.getWriter().write(jsonString);
    }

/**
     * 分页条件查询
     * @param request
     * @param response
     * @throws ServletException
     * @throws IOException
     */
    public void selectByPageAndCondition(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        System.out.println("开始查询！——————————————————————————");
        //1. 接收 当前页码 和 每页展示条数    url?currentPage=1&pageSize=5
        String _currentPage = request.getParameter("currentPage");
        String _pageSize = request.getParameter("pageSize");

int currentPage = Integer.parseInt(_currentPage);
        int pageSize = Integer.parseInt(_pageSize);

// 获取查询条件对象
        BufferedReader br = request.getReader();
        String params = br.readLine();//json字符串

//转为 Brand
        Brand brand = JSON.parseObject(params, Brand.class);

//2. 调用service查询
        PageBean<Brand> pageBean = brandService.selectByPageAndCondition(currentPage,pageSize,brand);
        System.out.println(pageBean);

//2. 转为JSON
        String jsonString = JSON.toJSONString(pageBean);
        //3. 写数据
        response.setContentType("text/json;charset=utf-8");
        response.getWriter().write(jsonString);
    }

}

```

## 完结

![](https://www.bdmcom.cn/usr/uploads/2022/07/1185512746.png)

最后修改：2022 年 07 月 27 日

如果文章有用，请随意打赏。

发表评论取消回复
使用cookie技术保留您的个人信息以便您下次快速评论，继续评论表示您已同意该条款

评论 *

私密评论

名称 *

🎲

邮箱 *

地址

【java】JavaWeb的一般配置

本当迷 • 2022 年 07 月 25 日