16Maven

1.什么是maven

2.Maven能解决什么问题

3.Maven的两个精典作用

3.1Maven的依赖管理

3.2项目的一键构建

 

4.maven的安装

4.1maven软件下载

4.2maven的安装

4.3maven配置

然后把MVEN_HOME加入到path路径。

4.4Maven版本测试

5.Maven仓库

5.1maven仓库的分类

5.2maven本地仓库的配置

6.maven工程

6.1maven工程的目录结构

6.2maven的生命周期

6.3maven的概念模型

7.idea开发maven项目

7.1maven的配置

7.2在idea中创建一个maven的Web工程

7.3指定web

 

在webapp包中new一个文件，发现有JSP选项。然而在java文件夹中new一个文件却没有JSP选项。

要想让java文件夹也可以像webapp一样，那么需要设置一下项目结构：

7.4servlet实例

package com.itheima.servelt;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

public class MyServlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doGet(request, response);
    }


    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        request.getRequestDispatcher("/hello.jsp").forward(request, response);
    }
}

<!DOCTYPE web-app PUBLIC
 "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
 "http://java.sun.com/dtd/web-app_2_3.dtd" >

<web-app>
  <display-name>Archetype Created Web Application</display-name>
    <servlet>
        <servlet-name>MyServlet</servlet-name>
        <servlet-class>com.itheima.servelt.MyServlet</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>MyServlet</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>

</web-app>

<?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>com.itheima</groupId>
    <artifactId>maven_web</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>war</packaging>
    <!--放置的都是项目运行所依赖的jar包-->
    <dependencies>
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>servlet-api</artifactId>
            <version>2.5</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>javax.servlet.jsp</groupId>
            <artifactId>jsp-api</artifactId>
            <version>2.0</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
            <scope>test</scope>
        </dependency>
    </dependencies>
    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.tomcat.maven</groupId>
                <artifactId>tomcat7-maven-plugin</artifactId>
                <version>2.2</version>
                <configuration>
                    <port>8888</port>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <configuration>
                    <target>1.8</target>
                    <source>1.8</source>
                    <encoding>UTF-8</encoding>
                </configuration>
            </plugin>
        </plugins>

    </build>

</project>

7.5maven从mysql中取数据

<?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>com.itheima</groupId>
    <artifactId>maven_mysql</artifactId>
    <version>1.0-SNAPSHOT</version>

    <dependencies>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.6</version>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
        </dependency>
    </dependencies>
</project>

package com.itheima.dao;

import com.itheima.domain.Items;

import java.util.List;

public interface ItemsDao {
    public List<Items> findAll() throws Exception;
}

package com.itheima.dao.impl;

import com.itheima.dao.ItemsDao;
import com.itheima.domain.Items;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.ArrayList;
import java.util.List;

public class ItemDaoImpl implements ItemsDao {
    public List<Items> findAll() throws Exception {
        List<Items> list = new ArrayList<Items>();
        Connection connection = null;
        PreparedStatement preparedStatement = null;
        ResultSet rs = null;
        try {
            //加载驱动类
            Class.forName("com.mysql.jdbc.Driver");
            //先获取connection对象
            connection = DriverManager.getConnection("jdbc:mysql:///maven","root","123456");
            //获取操作数据库的对象
            preparedStatement = connection.prepareCall("select * from items");
            //执行数据库查询操作
            rs = preparedStatement.executeQuery();
            //把数据库结果集，转为java的list集合

            while (rs.next()) {
                Items items = new Items();
                items.setId(rs.getInt("id"));
                items.setName(rs.getString("name"));
                list.add(items);
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            connection.close();
            preparedStatement.close();
            rs.close();
        }

        return list;
    }
}

package com.itheima.domain;

public class Items {
    private Integer id;
    private  String name;

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }


}

package com.itheima;

import com.itheima.dao.ItemsDao;
import com.itheima.dao.impl.ItemDaoImpl;
import com.itheima.domain.Items;
import org.junit.Test;
import java.util.List;

public class ItemsTest {
    @Test
    public void findAll() throws Exception {
        ItemsDao itemsDao = new ItemDaoImpl();
        List<Items> list = itemsDao.findAll();
        for (Items items : list) {
            System.out.println(items.getName());
        }
    }
}