Servlet的5种方式实现表单提交（注册小功能），后台获取表单数据

用servlet实现一个注册的小功能，后台获取数据。

注册页面：

　　 Servlet的5种方式实现表单提交（注册小功能）

注册页面代码：

<!DOCTYPE html>

<html>

<head>

<meta charset="UTF-8">

<title>Insert title here</title>

</head>

<body>

    <form action="/RequestDemo/RequestDemo3" method="post">

        用户名：<input type="text" name="userName"><br/>

        密码：<input type="text" name="pwd"><br/>

        性别：<input type="radio" name="sex" value="男" checked="checked">男

            <input type="radio" name="sex" value="女">女<br/>

        爱好：<input type="checkbox" name="hobby" value="足球">足球

            <input type="checkbox" name="hobby" value="篮球">篮球

            <input type="checkbox" name="hobby" value="排球">排球

            <input type="checkbox" name="hobby" value="羽毛球">羽毛球<br/>

        所在城市：<select name="city">

                 <option>---请选择---</option>

                 <option value="bj">北京</option>

                 <option value="sh">上海</option>

                 <option value="sy">沈阳</option>

               </select>

               <br/>

        <input type="submit" value="点击注册">

    </form>

</body>

</html>

人员实体类：注意：人员实体类要与表单中的name一致，约定要优于编码

package com.chensi.bean;

//实体类中的字段要与表单中的字段一致，约定优于编码

public class User {

    private String userName;

    private String pwd;

    private String sex;

    private String[] hobby;

    private String city;

    public String getUserName() {

        return userName;

    }

    public void setUserName(String userName) {

        this.userName = userName;

    }

    public String getPwd() {

        return pwd;

    }

    public void setPwd(String pwd) {

        this.pwd = pwd;

    }

    public String getSex() {

        return sex;

    }

    public void setSex(String sex) {

        this.sex = sex;

    }

    public String[] getHobby() {

        return hobby;

    }

    public void setHobby(String[] hobby) {

        this.hobby = hobby;

    }

    public String getCity() {

        return city;

    }

    public void setCity(String city) {

        this.city = city;

    }

}

接收方法一： Servlet页面(后台接收数据方法一)

package com.chensi;

import java.io.IOException;

import java.util.Iterator;

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 获得填写的表单数据

 */

@WebServlet("/RequestDemo3")

public class RequestDemo3 extends HttpServlet {

    private static final long serialVersionUID = 1L;

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        request.setCharacterEncoding("UTF-8");

        //获取传过来的表单数据,根据表单中的name获取所填写的值

        String userName = request.getParameter("userName");

        String pwd = request.getParameter("pwd");

        String sex = request.getParameter("sex");

        String[] hobbys = request.getParameterValues("hobby");

        System.out.println(userName);

        System.out.println(pwd);

        System.out.println(sex);

        for (int i = 0; hobbys!=null&&i < hobbys.length; i++) {

            System.out.println(hobbys[i]+"\t");

        }

    }

    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        doGet(request, response);

    }

}

得到的数据：

　　　　 Servlet的5种方式实现表单提交（注册小功能）

接收方法二：

package com.chensi;

import java.io.IOException;

import java.util.Enumeration;

import java.util.Iterator;

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 获得填写的表单数据

 */

@WebServlet("/RequestDemo3")

public class RequestDemo3 extends HttpServlet {

    private static final long serialVersionUID = 1L;

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        request.setCharacterEncoding("UTF-8");

        //获取传过来的表单数据,根据表单中的name获取所填写的值

        Enumeration<String> names = request.getParameterNames();

        while (names.hasMoreElements()) {

            String strings = (String) names.nextElement();

            String[] parameterValues = request.getParameterValues(strings);

            for (int i = 0;parameterValues!=null&&i < parameterValues.length; i++) {

                System.out.println(strings+":"+parameterValues[i]+"\t");

            }

        }

    }

    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        doGet(request, response);

    }

}

得到的数据：

　　　　 Servlet的5种方式实现表单提交（注册小功能）

接收方法三：利用反射赋值给User

package com.chensi;

import java.beans.IntrospectionException;

import java.beans.PropertyDescriptor;

import java.io.IOException;

import java.lang.reflect.InvocationTargetException;

import java.lang.reflect.Method;

import java.util.Enumeration;

import java.util.Iterator;

import java.util.Map;

import javax.servlet.ServletException;

import javax.servlet.annotation.WebServlet;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import com.chensi.bean.User;

/**

 * Servlet 获得填写的表单数据

 */

@WebServlet("/RequestDemo3")

public class RequestDemo3 extends HttpServlet {

    private static final long serialVersionUID = 1L;

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        request.setCharacterEncoding("UTF-8");

        //获取传过来的表单数据,根据表单中的name获取所填写的值

            try {

                User u = new User();

                System.out.println("数据封装之前: "+u);

                //获取到表单数据

                Map<String, String[]> map = request.getParameterMap();

                for(Map.Entry<String,String[]> m:map.entrySet()){

                    String name = m.getKey();

                    String[] value = m.getValue();

                    //创建一个属性描述器

                    PropertyDescriptor pd = new PropertyDescriptor(name, User.class);

                    //得到setter属性

                    Method setter = pd.getWriteMethod();

                    if(value.length==1){

                        setter.invoke(u, value[0]);

                    }else{

                        setter.invoke(u, (Object)value);

                    }

                }

                System.out.println("封装数据之后: "+u);

            } catch (IntrospectionException | IllegalAccessException | IllegalArgumentException | InvocationTargetException e) {

                e.printStackTrace();

            }

        }

    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        doGet(request, response);

    }

}

得到的结果：

　　 Servlet的5种方式实现表单提交（注册小功能）

接收方法四：使用apache 的 BeanUtils 工具来进行封装数据（ps：这个Benautils工具，Struts框架就是使用这个来获取表单数据的哦！）

package com.chensi;

import java.beans.IntrospectionException;

import java.beans.PropertyDescriptor;

import java.io.IOException;

import java.lang.reflect.InvocationTargetException;

import java.lang.reflect.Method;

import java.util.Enumeration;

import java.util.Iterator;

import java.util.Map;

import javax.servlet.ServletException;

import javax.servlet.annotation.WebServlet;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import org.apache.commons.beanutils.BeanUtils;

import com.chensi.bean.User;

/**

 * Servlet 获得填写的表单数据

 */

@WebServlet("/RequestDemo3")

public class RequestDemo3 extends HttpServlet {

    private static final long serialVersionUID = 1L;

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        request.setCharacterEncoding("UTF-8");

        //获取传过来的表单数据,根据表单中的name获取所填写的值

        //方法四：使用beanUtil来封装User类

        User u = new User();

        System.out.println("没有使用BeanUtil封装之前：  "+u);

        try {

            BeanUtils.populate(u, request.getParameterMap());

            System.out.println("使用BeanUtils封装之后：  "+u);

        } catch (IllegalAccessException | InvocationTargetException e) {

            e.printStackTrace();

        }

        }

    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        doGet(request, response);

    }

}

得到的结果：

　　　 Servlet的5种方式实现表单提交（注册小功能）

接收方法方式五：使用inputStream流来进行接收（一般字符串啥的不用这个方法，一般是文件上传下载时候才会使用这种方法）因为接收到的字符串各种乱码，编码问题解决不好

package com.chensi;

import java.beans.IntrospectionException;

import java.beans.PropertyDescriptor;

import java.io.IOException;

import java.lang.reflect.InvocationTargetException;

import java.lang.reflect.Method;

import java.util.Enumeration;

import java.util.Iterator;

import java.util.Map;

import javax.servlet.ServletException;

import javax.servlet.ServletInputStream;

import javax.servlet.annotation.WebServlet;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import org.apache.commons.beanutils.BeanUtils;

import com.chensi.bean.User;

/**

 * Servlet 获得填写的表单数据

 */

@WebServlet("/RequestDemo3")

public class RequestDemo3 extends HttpServlet {

    private static final long serialVersionUID = 1L;

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        request.setCharacterEncoding("UTF-8");

        //获取传过来的表单数据,根据表单中的name获取所填写的值

        response.setContentType("text/html;charset=UTF-8");

        //获取表单数据

        ServletInputStream sis = request.getInputStream();

        int len = 0;

        byte[] b = new byte[1024];

        while((len=sis.read(b))!=-1){

            System.out.println(new String(b, 0, len, "UTF-8"));

        }

        sis.close();

    }

    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        doGet(request, response);

    }

}

得到的结果：（各种乱码。。。。）

Servlet的5种方式实现表单提交（注册小功能）