Servlect对象总结（笔记内容八）

2022年2月6号总结上学期。思维导图加上第一模块Servlect常看到的一些对象的总结。

思维导图 

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上面是学习模块的划分的思维导图。

 

 

 

 

 

 

 

 

 

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第一部分进入浏览页面的知识的回顾。

 

 

 

 

 

 

 

第二部分进入学习要点的解说。

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第三部分进入页面代码的实操与视图的展示。

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 代码模块

package comServlectF;

import java.io.IOException;

import javax.servlet.Servlet;
import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
/**
 *
 * @author MZFAITHDREAM
 * Servlect的介绍
 * **它是作为来自 Web 浏览器或其他 HTTP 客户端的请求和 HTTP 服务器上的数据库或应用程序之间的中间层。**

**使用 Servlet，您可以收集来自网页表单的用户输入，呈现来自数据库或者其他源的记录，还可以动态创建网页。**
 * 
 *
 */
public class Servlect1  implements Servlet{

	public Servlect1() {
		// TODO Auto-generated constructor stub
		System.out.println("这是ServlectA的构造方法");
	}
	@Override
	public void destroy() {
		// TODO Auto-generated method stub
		System.out.println("改程序运行完毕后销毁ServlectA");
		
	}

	@Override
	public ServletConfig getServletConfig() {
		// TODO Auto-generated method stub
		System.out.println("ServlectA ServletConfig方法");
		return null;
	}

	@Override
	public String getServletInfo() {
		// TODO Auto-generated method stub
		System.out.println(" ServletAgetServletInfo方法");
		return null;
	}

	@Override
	public void init(ServletConfig config) throws ServletException {
		// TODO Auto-generated method stub
		System.out.println("该程序应用的ServletAinit方法");
		
	}

	@Override
	public void service(ServletRequest req, ServletResponse res) throws ServletException, IOException {
		// TODO Auto-generated method stub
		System.out.println("这是ServlectA的servlect的方法");
		
	}

}







package comServlectF;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Servlet implementation class Servlect2
 */
@WebServlet("/BBB")
public class Servlect2 extends HttpServlet {
	private static final long serialVersionUID = 1L;
       
    /**
     * @see HttpServlet#HttpServlet()
     */
    public Servlect2() {
        super();
        System.out.println("这是Servlect2的抽象方法");
        // TODO Auto-generated constructor stub
    }
    @Override
    public void init() throws ServletException {
    	// TODO Auto-generated method stub
    	System.out.println("Servlect2加载数据");
    	super.init();
    }
    @Override
    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
    	// TODO Auto-generated method stub
    	System.out.println("这里开始运行Servlect的方法");
    	super.service(req, resp);
    }
    @Override
    protected void doDelete(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
    	// TODO Auto-generated method stub
    	super.doDelete(req, resp);
    	System.out.println("Servlect2的删除方法");
    }
   @Override
   	public void destroy() {
	// TODO Auto-generated method stub
	super.destroy();
	System.out.println("Servlect2销毁数据");
}

	/**
	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
	//response.getWriter().append("Served at: ").append(request.getContextPath());
		response.setContentType("text/html");
		response.setCharacterEncoding("UTF-8");
		PrintWriter pw =response.getWriter();
		pw.print("
我是第二个servlect2
");
	}

	/**
	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		doGet(request, response);
	}

}






package comServlectF;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Servlet implementation class Servlect3
 */
@WebServlet("/CCC")
public class Servlect3 extends HttpServlet {
	private static final long serialVersionUID = 1L;
       
    /**
     * @see HttpServlet#HttpServlet()
     */
    public Servlect3() {
        super();
        // TODO Auto-generated constructor stub
    }

	/**
	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		//response.getWriter().append("Served at: ").append(request.getContextPath());
		response.setContentType("text/html");
		response.setCharacterEncoding("UTF-8");
		PrintWriter pw =response.getWriter();
		pw.print("
我是第三个servlect3
");
	}

	/**
	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		doGet(request, response);
	}

}




package comServlectF;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Servlet implementation class Servlect2
 */
@WebServlet("/DDD")
public class Servlect4 extends HttpServlet {
	private static final long serialVersionUID = 1L;
       
    /**
     * @see HttpServlet#HttpServlet()
     */
    public Servlect4() {
        super();
        System.out.println("这第四个Servlect4的抽象方法");
        // TODO Auto-generated constructor stub
    }
    @Override
    public void init() throws ServletException {
    	// TODO Auto-generated method stub
    	System.out.println("Servlect4加载数据");
    	super.init();
    }
    @Override
    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
    	// TODO Auto-generated method stub
    	System.out.println("这里开始运行Servlect4的方法");
    	super.service(req, resp);
    }
    @Override
    protected void doDelete(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
    	// TODO Auto-generated method stub
    	super.doDelete(req, resp);
    	System.out.println("Servlect4的删除方法");
    }
   @Override
   	public void destroy() {
	// TODO Auto-generated method stub
	super.destroy();
	System.out.println("Servlect4销毁数据");
}

	/**
	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
	//response.getWriter().append("Served at: ").append(request.getContextPath());
		response.setContentType("text/html");
		response.setCharacterEncoding("UTF-8");
		PrintWriter pw =response.getWriter();
		pw.print("
我是第一个servlect4
");
	}

	/**
	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		doGet(request, response);
	}

}

---

package com.Web.Servlect.Servlect;

import java.io.IOException;
import java.util.Enumeration;

import javax.servlet.Servlet;
import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
/**
 * 2022/1/29号
 * 本案例要讲述的是Servlect的生命周期,了解Servlect的运行周期如何运行的.
 * @author MZFAITHDREAM
 *
 */

//第一个问题。请自己解释  implements  是接口 还是继承？
//第二个问题。Servlect的常用的那些方法。
//第三个问题。Servlect的运行周期如何运转的。
//第四个问题。请思考web.xml文件中的静态数据用什么对象获取到。
public class OneServlect  implements Servlet{

	public OneServlect() {
		// TODO Auto-generated constructor stub
		System.out.println("OneServlet的抽象方法");
	}
		
	
		
	@Override
	public void destroy() {
		System.err.println("OneServlet释放内存的方法内容");
	}

	@Override
	public ServletConfig getServletConfig() {
		System.out.println("获得静态数据的方法");
		return null;
	}

	@Override
	public String getServletInfo() {
		// TODO Auto-generated method stub
		System.out.println("getServletInfo() 的 Servlect的方法内容");
		return null;
	}

	@Override
//	第一种方式获得静态数据
	public void init(ServletConfig config) throws ServletException {
		// TODO Auto-generated method stub
		System.out.println("在web.xml文件中获取静态数据的方式");
		
		String a=config.getInitParameter("home");
		String b=config.getInitParameter("money");
		String c=config.getInitParameter("h");
		String d=config.getInitParameter("a");
		System.out.println(a+"==========="+b+"899"+c);
		System.out.println(d+"我已成功获得了静态数据的内容");
		
		//如果有多个静态数据，为避免执行重复的代码采用下面的方式获取
	Enumeration	e=config.getInitParameterNames();
	while (e.hasMoreElements()) {
		String key = (String) e.nextElement(); //home money
		String value =config.getInitParameter(key); //值一
		System.out.println(key+"@@@@"+value);
		
	}
	
		
	}
		


	@Override
	public void service(ServletRequest arg0, ServletResponse arg1) throws ServletException, IOException {
		// TODO Auto-generated method stub
		//等待浏览器访问
		System.out.println("servlect处于运行状态");
		
		
	}

}



package com.Web.Servlect.Servlect;

import java.io.IOException;

import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.annotation.WebInitParam;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Servlet implementation class TwoServlect
 */

/**
 * 2022/1/29
 * Servlect快速生成的的方法
 * @author MZFAITHDREAM
 *
 */
//问题一下面的俩行代码等价于web.xml文件中的那些代码。
@WebServlet(urlPatterns = "/B",initParams = {
		@WebInitParam(name="name",value="学生名称张三"),
		@WebInitParam(name="age",value="学生年龄20岁"),
})
public class TwoServlect extends HttpServlet {
	private static final long serialVersionUID = 1L;  
    /**
     * @see HttpServlet#HttpServlet()
     */
    public TwoServlect() {
      System.out.println("构造方法");
      
    }
    
    @Override
    public void service(ServletRequest arg0, ServletResponse arg1) throws ServletException, IOException {
    	// TODO Auto-generated method stub
    System.out.println("Servlect的方法");
    }

    	@Override
    	public void init(ServletConfig config) throws ServletException {
    		// TODO Auto-generated method stub
    	System.out.println("请用init的方法完成存放二个数据并存放起来构造");
    	String aa=config.getInitParameter("name");
      	String bb=config.getInitParameter("age");
      	System.out.println(aa+"===="+bb);
    	
    	}
    	
    	
   
	/**
	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		response.getWriter().append("Served at: ").append(request.getContextPath());
	}

	/**
	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		doGet(request, response);
	}

	
	@Override
	public void destroy() {
		// TODO Auto-generated method stub
		System.out.println("Servlect的销毁方法");
	}
	
	
}


package com.Web.Servlect.Servlect;

import java.io.IOException;

import javax.servlet.ServletConfig;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebInitParam;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
/**
 * Servlet implementation class Servlet1
 */
@WebServlet(urlPatterns = "/C",initParams = {
		//增加静态数据的第一个学生
		@WebInitParam(name="a",value="我是获取静态数据的方式")
		
})
/**
 * 2022/1/29
 * 回顾获取静态数据和学习动态数据的方式
 * @author MZFAITHDREAM
 * Servlect对象三	response，将信息发送给浏览器。
 * 思考问题。在Servlect中如何共享数据？
 *
 */
public class TreeServlect extends HttpServlet {
	private static final long serialVersionUID = 1L;

    /**
     * Default constructor. 
     */
    public TreeServlect() {
        // TODO Auto-generated constructor stub
    }

	/**
	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
	 */
    @Override
    public void init() throws ServletException {
    	// TODO Auto-generated method stub
    	super.init();
    	//定义4个静态数据
    	ServletConfig config=getServletConfig();
    	String a=config.getInitParameter("a");
    	System.out.println(a);
    }
 
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		//设置 发送给浏览器的文本信息HTML文本格式
		//response.setContentType("text/html");
		response.setContentType("text/html");
		//设置发送给浏览器文本utf-8
		//response.setCharacterEncoding("UTF-8");
		response.setCharacterEncoding("UTF-8");
		//因为浏览器是使用get请求
		//所以Servlet do-get
		//servlet1相打篮球
		//1获取ServletContext对象
		ServletContext  sc=getServletContext();
		//获取web.xml文件中的镜头数据
		String a=sc.getInitParameter("lq");
		String c= (String) sc.getInitParameter("dt");
		//获得servlet4共享的排球
		String b= (String) sc.getAttribute("pq");
		String d= (String) sc.getAttribute("as");
		String e= (String) sc.getAttribute("gx");
		
		//删除排球
		sc.removeAttribute("pq");
		//给浏览器发送数据
		response.getWriter().append("
Servlet1获得静态数据用来访问lq:"+a+"
");
		response.getWriter().append("
Servlet1获得静态数据用来访问dt:"+c+"
");
		response.getWriter().append("
response.getWriter().append方法打印内容
");
		response.getWriter().append("
Servlet4获得动态态数据用来访问pq:"+b+"
");
		response.getWriter().append("
Servlet4获得动态态数据用来访问as:"+d+"
");
		response.getWriter().append("
Servlet4获得动态态数据用来访问as:"+e+"
");
		
	}

	/**
	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		doGet(request, response);
	}

}



package com.Web.Servlect.Servlect;

import java.io.IOException;

import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Servlet implementation class Servlet4
 */
@WebServlet("/D")
public class FourServlect extends HttpServlet {
	private static final long serialVersionUID = 1L;
       
    /**
     * @see HttpServlet#HttpServlet()
     * 由个人共享出来的动态数据
     */
    public FourServlect() {
        super();
        // TODO Auto-generated constructor stub
    }

	/**
	 * 创建对象 ServletContext sc=getServletContext();获取对象
	 * sc.setAttribute("pq", "排球"); 接收对象 
	 * 删除对象 sc.removeAttribute("pq");
	 * 
	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		//servlet4共享班级 共享数据
		//共享动态数据
		response.setContentType("text/html");
		//设置发送给浏览器文本utf-8
		//response.setCharacterEncoding("UTF-8");
		response.setCharacterEncoding("UTF-8");
		//获取ServletContext 对象
		ServletContext sc=getServletContext();
		//将排球共享数据 setAttribute方法共享数据。
		//在java中object是任何数据类型的父类。
		//身份的多种类型；向上转型
		sc.setAttribute("pq", "我是共享的数据内容排球");
		sc.setAttribute("as", "我是共享的数据as采用的是setAttribut获得");
		sc.setAttribute("gx", "我是在Servlect中共享的数据gx采用的是setAttribut获得");
		//身份的多种类型；向上转型(强制转型)
		//获得动态数据
		//疯狂java讲义
		//getimitParameter只能获得静态数据
		 String  aa= (String) sc.getAttribute("pq");
		 String  bb= (String) sc.getAttribute("as");
		 String  cc= (String) sc.getAttribute("gx");
		 
		 
		 //对象三	 response对象将数据发送给浏览器  
		response.getWriter().append("
获得本页面的动态数据 "+aa+"
");
		response.getWriter().append("
获得本页面的动态数据 "+bb+"
");
		response.getWriter().append("
获得本页面的动态数据 "+cc+"
");
	}

	/**
	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		doGet(request, response);
	}

}




package com.Web.Servlect.Servlect;

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

import javax.servlet.ServletConfig;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebInitParam;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Servlet implementation class Servlet1
 */
@WebServlet(urlPatterns = "/E",initParams = {
		//增加静态数据的第一个学生
		@WebInitParam(name="a",value="胡二伤悲"),
		@WebInitParam(name="age",value="40岁"),
		@WebInitParam(name="height",value="169cm"),
		@WebInitParam(name="weight",value="60kg")
		
})
public class FiveServlect extends HttpServlet {
	private static final long serialVersionUID = 1L;

    /**
     * Default constructor. 
     */
    public FiveServlect() {
        // TODO Auto-generated constructor stub
    	System.out.println(" Servlet6()    Servlet6()    Servlet6()");
    }

	/**
	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
	 */
    @Override
    public void init() throws ServletException {
    	// TODO Auto-generated method stub
    	super.init();
    	//定义4个静态数据
    	ServletConfig config=getServletConfig();
    	String a=config.getInitParameter("a");
    	String b=config.getInitParameter("age");
    	String c=config.getInitParameter("height");
    	String e=config.getInitParameter("weight");
    	System.out.println(a+"===="+b+"#######"+c+"-----"+e);
    	System.out.println(e);
    	System.out.println("创建静态数据的方法");
    	System.out.println("ServletConfig config=getServletConfig();");
    	System.out.println("访问静态数据的方法");
    	System.out.println("String a=config.getInitParameter(\"a\");");
    	
    }
 
   
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		response.setContentType("text/html");
		response.setCharacterEncoding("UTF-8");
				// 获得text.txt完整路径
				ServletContext sc=getServletContext();
				//指定文件名称获取完整路径
				String path=sc.getRealPath("text.txt");
				//控制台打印输出文件完整路径
				System.out.println(path);
				//将text.txt读取出来
				//IO inputStream /outputStream输出流。
				//网上下载的图片以自己为主场输入
				//总结：始终以自己为主场，观察数据流向。
				/* InputStream is=sc.getResourceAsStream("/text.txt"); */
				InputStream is=sc.getResourceAsStream("/text.txt");
				//分析:1.假设text.txt是一部一百万的小说
				//当读取大量数据的时候，采取分段读取，部分读取
				//一般情况下，一次读取1024字节byte=1kb 512个字
				byte[] bytes=new byte[1024];
				//分析:2.数据非常少的时候
				//定义一个变量，用于记录每一次读取的字节数
				//判断记录的字节数是否小于1024，表示快读取结束
				int count=-1;//-1标记为读取结束
				//定义一个字符串用于汇总每次读取的部分字符串内容
				String sum="";
				//循环读取
				while ((count=is.read(bytes))!=-1) {
					//需要将每一次读取的字节数组转换成字符串
					String s=new String(bytes, 0, count);
					sum+=s;
				}
				
				System.out.println(sum);
				
				//response.getWriter().append("Served at: ").append(request.getContextPath());
				
		
		response.getWriter().append("Servlet1获得静态数据用来访问lq:");
		response.getWriter().append("response.getWriter().append方法打印内容");
		response.getWriter().append("Servlet1获得静态数据用来访问pq:");
		
	}

	/**
	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		doGet(request, response);
	}

}




package com.Web.Servlect.Servlect;
/**
 * 对象四request，将浏览器中的数据发送给服务器。
 */
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Servlet implementation class Servlet1
 */
@WebServlet("/AA")
public class RequestServlect extends HttpServlet {
	private static final long serialVersionUID = 1L;
       
    /**
     * @see HttpServlet#HttpServlet()
     */
    public RequestServlect() {
        super();
        System.out.println("Servlet1 在运行HttpServletRequest 的方法");
        // TODO Auto-generated constructor stub
    }

	/**
	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		//获得浏览器的请求，得到请求信息
		//得到请求的URL地址
		String a=request.getRequestURL().toString();
		System.out.println(a);
		
		//得到请求的数据
		String b=request.getRequestURI();
		System.out.println(b);
		
		//得到请求的URL地址中附带的参数
		String c=request.getQueryString();
		System.out.println(c);
		
		//得到来访者的IP地址
		String d=request.getRemoteAddr();
		System.out.println(d);
		
		//来访者的主机名
		String e=request.getRemoteHost();
		System.out.println(e);
		
		//来访者的端口号
		int f=request.getRemotePort();
		System.out.println(f);
		
		//得到请求URL地址时使用的方法（重要）
		String h=request.getMethod();
		System.out.println(h);
		
		//获取WEB服务器的IP地址
		String l=request.getLocalAddr();
		System.out.println(l);
		
		//获取WEB服务器的主机名
		String n=request.getLocalName();
		System.out.println(n);
		
		//获取WEB服务器的端口号
		int m=request.getLocalPort();
		System.out.println(m);
	}


	/**
	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		doGet(request, response);
	}

}



package com.Web.Servlect.Servlect;

import java.io.IOException;
import java.util.Arrays;
import java.util.Enumeration;
import java.util.Map;
import java.util.Map.Entry;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Servlet implementation class Servlet2
 */
/**
 *  response获取浏览器的数据
 * @author MZFAITHDREAM
 *
 */
@WebServlet("/BB")
public class RequestServlect2 extends HttpServlet {
	private static final long serialVersionUID = 1L;
       
    /**
     * @see HttpServlet#HttpServlet()
     */
    public RequestServlect2() {
        super();
        // TODO Auto-generated constructor stub
    }

	/**
	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
				//获得浏览器发送过来的姓名和年龄的数据
				String a=request.getParameter("name");
				String b=request.getParameter("age");
				String c=request.getParameter("phone");
				String d=request.getParameter("QQ");
				String e=request.getParameter("wexing");
				
				System.out.println("获得浏览器发送给Servlet的数据为:"+a+"--"+b+"--"+c);
				
				//当浏览器发送的数据是同一个名称多个不同的数据
				//servlet需要使用以下这个方法去接收这种数据
				String[] ss=request.getParameterValues("hobby");
				System.out.println(Arrays.toString(ss));
				//tomcat服务器的编码格式是:ISO-8859-1
				//注意:servlet获得浏览器表单发送的数据时，
				//获得的名称一定要和表单上文本框定义的name属性中的名称保持一致
			
				//当浏览器发送大量数据给servlet的时候
				//如果使用getParameter一个个获得，效率太慢
				//使用以下方法可以节省代码，加快开发速度
				Enumeration e1= request.getParameterNames();
				while (e1.hasMoreElements()) {
					//循环获得的是浏览器发给servlet的数据的名称
					String name=e1.nextElement();
					if (name.equals("hobby")) {
						String[] str=request.getParameterValues(name);
						System.out.println(name+"："+Arrays.toString(str));
					}else {
						String value=request.getParameter(name);
						System.out.println(name+"："+value);
					}
					
				}
				
				//使用Map集合获得浏览器发送的所有数据
				Map map=request.getParameterMap();
				for (Entry entry : map.entrySet()) {
					String name=entry.getKey();
					String[] values=entry.getValue();
					System.out.println(name+"%"+Arrays.toString(values));
				}
				System.out.println("运行完成");
				System.out.println("http://localhost:8080/Day06-2/Servlet2?name=hubinjkf&age=23&phone=16745637856&qq=2675648967&wexing=16745679076&hobby=%E7%9C%8B%E4%B9%A6&hobby=%E7%9C%8B%E5%B0%8F%E5%AD%A6%E5%A6%B9&hobby=%E5%AD%A6%E4%B9%A0mysql");
			}

	/**
	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		doGet(request, response);
	}

}




package com.Web.Servlect.Servlect;

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

/**
 * Servlet implementation class Servlet3
 */
@WebServlet("/CC")
public class RequestServlect3 extends HttpServlet {
	private static final long serialVersionUID = 1L;
       
    /**
     * @see HttpServlet#HttpServlet()
     */
    public RequestServlect3() {
        super();
        System.out.println(" 开始Servlet3() 运行中request.setAttribute(\"apple\", \"苹果\");");
    }

	/**
	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		//当浏览器访问Servlet3的时候,Servlet3自己跳转到Servlet4,
				//由Servlet4回复消息给浏览器
				request.setAttribute("apple", "苹果");
				request.setAttribute("banner", "香蕉");
				request.setAttribute("ma", "五十个一百万");
//				请求转发
				request.getRequestDispatcher("RequestServlect4")
							.forward(request, response);
	}
	/**
	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		doGet(request, response);
	}

}




package com.Web.Servlect.Servlect;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Servlet implementation class Servlet4
 */
@WebServlet("/RequestServlect4")
public class RequestServlect4 extends HttpServlet {
	private static final long serialVersionUID = 1L;
       
    /**
     * @see HttpServlet#HttpServlet()
     */
    public RequestServlect4() {
        super();
        // TODO Auto-generated constructor stub
    }

	/**
	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		response.setContentType("text/html");
		response.setCharacterEncoding("UTF-8");
		PrintWriter pw=response.getWriter();
		String a=(String) request.getAttribute("apple");
		String b=(String) request.getAttribute("banner");
		String c =(String) request.getAttribute("ma");
		
		pw.print("
收到Servlet3的请求,回复消息给浏览器,任务已完成,获得Servlet3携带的数据为:"+a+"
");
		pw.print("
收到Servlet3的请求,回复消息给浏览器,任务已完成,获得Servlet3携带的数据为:"+b+"
");
		pw.print("
收到Servlet3的请求,回复消息给浏览器,任务已完成,获得Servlet3携带的数据为:"+c+"
");
	}

	/**
	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		doGet(request, response);
	}

}

---

package comMyFilter;

import java.io.IOException;
import java.io.OutputStream;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;

public class MyFilter implements Filter{
	
	
	String a;
	String b;


	public MyFilter() {
		// TODO Auto-generated constructor
		System.out.println("我创建了第一个MyFilter过滤器");
	}
	/**
	 * 过滤器
	 */

	@Override
	public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
			throws IOException, ServletException {
			response.setContentType("text/html");
			response.setCharacterEncoding("UTF-8");
		
			String name=request.getParameter("name");
			String psd=request.getParameter("psd");
			
			//比较拦截用户名和名码
			if(name.equals(a)&&psd.equals(b)) {
				chain.doFilter(request,response); 
				
			}else {
				OutputStream os=response.getOutputStream();
				os.write("用户名不在密码有误，属于非法用户".getBytes());
			}
			
					
			System.out.println("我是myfilter开始拦截请求地址哦哦");
			
			
			
		
		
	}

	@Override
	public void init(FilterConfig config) throws ServletException {
		// TODO Auto-generated method stub

		 a = config.getInitParameter("username");
		 b=config.getInitParameter("password");
		
		System.out.println("FilterConfig用来加载初始化数据");
	}
	
	@Override
	public void destroy() {
		System.out.println("Filter所有方法运行完毕后销毁过滤器");
		
		
	}

}



package comMyFilter;

import java.io.IOException;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.annotation.WebFilter;

/**
 * Servlet Filter implementation class MyFilter1
 */
//你要阻止的Servlect,/*拦截所有的内容。
@WebFilter("/Servlect2")
/**
 * 过滤器的讲解
 * @author MZFAITHDREAM
 *
 */

public class MyFilter1 implements Filter {

    /**
     * Default constructor. 
     */
    public MyFilter1() {
        // TODO Auto-generated constructor stub
    	System.out.println("构造方法");
    }

	/**
	 * @see Filter#destroy()
	 */
	public void destroy() {
		// TODO Auto-generated method stub
		System.out.println("销毁数据");
	}

	/**
	 * @see Filter#doFilter(ServletRequest, ServletResponse, FilterChain)
	 */
	public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
//		设置编码格式
		response.setContentType("text/html");
		response.setCharacterEncoding("UTF-8");
		System.out.println("我是myfilter1开始拦截请求地址哦哦");
		//实施访问
		chain.doFilter(request, response);
	}


	public void init(FilterConfig fConfig) throws ServletException {
		// TODO Auto-generated method stub
		System.out.println("加载数据");
	}

}



package comMyFilter;

import java.io.IOException;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.annotation.WebFilter;

/**
 * Servlet Filter implementation class MyFilter2
 */
@WebFilter("/BBB")
public class MyFilter2 implements Filter {

    /**
     * Default constructor. 
     */
    public MyFilter2() {
        // TODO Auto-generated constructor stub
    }

	/**
	 * @see Filter#destroy()
	 */
	public void destroy() {
		// TODO Auto-generated method stub
	}

	/**
	 * @see Filter#doFilter(ServletRequest, ServletResponse, FilterChain)
	 */
	public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
		// TODO Auto-generated method stub
		// place your code here
		response.setContentType("text/html");
		response.setCharacterEncoding("UTF-8");
		System.out.println("我是myfilter2开始拦截请求地址哦哦");
		//实施访问
		chain.doFilter(request, response);
		
	}

	/**
	 * @see Filter#init(FilterConfig)
	 */
	public void init(FilterConfig fConfig) throws ServletException {
		// TODO Auto-generated method stub
	}

}




package comMyFilter;

import java.io.IOException;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.annotation.WebFilter;

/**
 * Servlet Filter implementation class MyFilter3
 */
@WebFilter("/CCC")
public class MyFilter3 implements Filter {

    /**
     * Default constructor. 
     */
    public MyFilter3() {
        // TODO Auto-generated constructor stub
    }

	/**
	 * @see Filter#destroy()
	 */
	public void destroy() {
		// TODO Auto-generated method stub
	}

	/**
	 * @see Filter#doFilter(ServletRequest, ServletResponse, FilterChain)
	 */
	public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
		// TODO Auto-generated method stub
		// place your code here

		response.setContentType("text/html");
		response.setCharacterEncoding("UTF-8");
		System.out.println("我是myfilter3开始拦截请求地址哦哦");
		//实施访问
		chain.doFilter(request, response);
	}

	/**
	 * @see Filter#init(FilterConfig)
	 */
	public void init(FilterConfig fConfig) throws ServletException {
		// TODO Auto-generated method stub
	}

}




package comMyFilter;

import java.io.IOException;
import java.io.OutputStream;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;

public class MyFilter4 implements Filter{
	


	public MyFilter4() {
		// TODO Auto-generated constructor
		System.out.println("我创建了第一个MyFilter过滤器");
	}

	@Override
	public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
			throws IOException, ServletException {
			response.setContentType("text/html");
			response.setCharacterEncoding("UTF-8");	
			System.out.println("我是myfilter开始拦截请求地址哦哦");
		
	}

	@Override
	public void init(FilterConfig config) throws ServletException {
		// TODO Auto-generated method stub

		
		System.out.println("FilterConfig用来加载初始化数据");
	}
	
	@Override
	public void destroy() {
		System.out.println("Filter所有方法运行完毕后销毁过滤器");
		
		
	}

}

---

---

项目视图展示。

localhost:8080/AAAcom.Web.Servlect/BB?name=胡滨&age=23&phone=13765524387&qq=123456&wexing=123&hobby=看书&hobby=打游戏

 

 

 

 

Servlect总结的一些概念

第一部分.Servlect的介绍。
1_1什么是Servlect.
1 Servlet的简介。
它是作为来自 Web 浏览器或其他 HTTP 客户端的请求和 HTTP 服务器上的数据库或应用程序之间的中间层。

使用 Servlet，您可以收集来自网页表单的用户输入，呈现来自数据库或者其他源的记录，还可以动态创建网页。

2 Servlet优势。
性能明显更好。

Servlet 在 Web 服务器的地址空间内执行。这样它就没有必要再创建一个单独的进程来处理每个客户端请求。

Servlet 是独立于平台的，因为它们是用 Java 编写的。

服务器上的 Java 安全管理器执行了一系列限制，以保护服务器计算机上的资源。因此，Servlet 是可信的。

Java 类库的全部功能对 Servlet 来说都是可用的。它可以通过 sockets 和 RMI 机制与 applets、数据库或其他软件进行交互。

.（java css html mysql jquery ）
3 Servlet 任务。
读取客户端（浏览器）发送的显式的数据。这包括网页上的 HTML 表单，或者也可以是来自 applet 或自定义的 HTTP 客户端程序的表单。
读取客户端（浏览器）发送的隐式的 HTTP 请求数据。这包括 cookies、媒体类型和浏览器能理解的压缩格式等等。
处理数据并生成结果。这个过程可能需要访问数据库，执行 RMI 或 CORBA 调用，调用 Web 服务，或者直接计算得出对应的响应。
发送显式的数据（即文档）到客户端（浏览器）。该文档的格式可以是多种多样的，包括文本文件（HTML 或 XML）、二进制文件（GIF 图像）、Excel 等。
发送隐式的 HTTP 响应到客户端（浏览器）。这包括告诉浏览器或其他客户端被返回的文档类型（例如 HTML），设置 cookies 和缓存参数，以及其他类似的任务。

1_3Servlect书写的三种形式。
 

public class OneServlet implements Servlet  {}
//采用的是接口
public class TwoServlet  extends GenericServlet {}
//采用的是继承
public class ThreeServlet  extends HttpServlet{}
//采用的是继承 理解什么是get 和 post的请求方式。

1_4Servlect的生命周期。
Servlet 生命周期可被定义为从创建直到毁灭的整个过程。以下是 Servlet 遵循的过程：

Servlet 抽象方法
Servlet 初始化后调用 init () 方法。

Servlet 调用 service() 方法来处理客户端的请求。

Servlet 销毁前调用 destroy() 方法。

最后，Servlet 是由 JVM 的垃圾回收器进行垃圾回收的。

1_5Servlet 方法介绍
init 方法被设计成只调用一次。它在第一次创建 Servlet 时被调用，在后续每次用户请求时不再调用。因此，它是用于一次性初始化，就像 Applet 的 init 方法一样。

service() 方法是执行实际任务的主要方法。Servlet 容器（即 Web 服务器）调用 service() 方法来处理来自客户端（浏览器）的请求，并把格式化的响应写回给客户端。

destroy() 方法只会被调用一次，在 Servlet 生命周期结束时

A_1对象ServletConfig对象,用途获取静态数据的俩种方式。

A_2对象 ServletContext对象。
1:用途:获取共享静态数据，获取共享动态数据，获取共享文件数据.
这个对象与我之后所讲的JSP四大域有关

A_3对象: Response 对象。
HttpServlet调用HttpResponse的有关方法，生成响应数据:
1:用途一:将数据发送给浏览器。
2:用途二生成图片的下载
3:用途三生成随机数
4:用途四 response.sendRedirect("Servlet2");重定向
重定向：属于浏览器的跳转.超链接
浏览地址发生改变
重定向为二次请求。
重定向可以访问不同服务器的跳转。

A_4 HttpServletRequest对象。
HttpServlet调用HttpResponse的有关方法，生成响应数据,用于服务器上接收浏览器发送过来的数据信息
HttpResponse一些用法
这个对象与我之后所讲的JSP四大域有关
1: 主要：将浏览器的数据发送给服务器。
2:个用途 请求转发
request.getRequestDispatcher("Servlet4") .forward(request, response);
请求转发和重定向区别:
重定向跳转浏览器地址会发生变化，
请求转发浏览器地址不会发生变化
重定向是两次请求，请求转发是一次请求
重定向属于浏览器跳转，请求转发属于服务器内部跳转
重定向跳转页面是不能发送数据，
请求转发是可以携带数据的
1.请求转发是在服务器完成的，重定向是在浏览器完成的
2.请求转发的速度快，重定向速度慢
3.请求转发的是同一次请求，重定向是二次不同的请求
4.请求转发地址栏没有变化，重定向地址栏有变化
5.转发必须是在同一台服务器下完成，重定向可以在不同的服务器下完成的

---

个人总结：从上面图片过程可以看出：当Servlect与Filter同时创建时,运行服务器首先调用的是Filter中。MyFilter()：构造方法<
1 销毁数据
2 Filter所有方法运行完毕后销毁过滤器
3 构造方法
4 加载数据
5 我创建了第一个MyFilter过滤器
6 FilterConfig用来加载初始化数据
当我去运行ServlectA时服务器运行以下方法 
1 ServlectA的构造方法
2 ServletAinit方法
3 ServlectA的servlect的方法