Servlet的5種方式實現表單提交（註冊小功能），後臺獲取表單資料
阿新 • • 發佈：2018-12-31
用servlet實現一個註冊的小功能 ，後臺獲取資料。
註冊頁面：
註冊頁面程式碼 ：
<!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <title>Insert title here</title> </head> <body> <form action="/RequestDemo/RequestDemo3" method="post"> 使用者名稱：<input type="text" name="userName"><br/> 密碼：<input type="text" name="pwd"><br/> 性別：<input type="radio" name="sex" value="男" checked="checked">男 <input type="radio" name="sex" value="女">女<br/> 愛好：<input type="checkbox" name="hobby" value="足球">足球<input type="checkbox" name="hobby" value="籃球">籃球 <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>---請選擇---</option> <option value="bj">北京</option> <option value="sh">上海</option> <option value="sy">瀋陽</option> </select> <br/> <input type="submit" value="點選註冊"> </form> </body> </html>
人員實體類： 注意：人員實體類要與表單中的name一致，約定要優於編碼
package com.chensi.bean; //實體類中的欄位要與表單中的欄位一致，約定優於編碼 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頁面(後臺接收資料方法一)
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 獲得填寫的表單資料 */ @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"); //獲取傳過來的表單資料,根據表單中的name獲取所填寫的值 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); } }
得到的資料：
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 獲得填寫的表單資料 */ @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"); //獲取傳過來的表單資料,根據表單中的name獲取所填寫的值 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); } }
得到的資料：
接收方法三： 利用反射賦值給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 獲得填寫的表單資料 */ @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"); //獲取傳過來的表單資料,根據表單中的name獲取所填寫的值 try { User u = new User(); System.out.println("資料封裝之前: "+u); //獲取到表單資料 Map<String, String[]> map = request.getParameterMap(); for(Map.Entry<String,String[]> m:map.entrySet()){ String name = m.getKey(); String[] value = m.getValue(); //建立一個屬性描述器 PropertyDescriptor pd = new PropertyDescriptor(name, User.class); //得到setter屬性 Method setter = pd.getWriteMethod(); if(value.length==1){ setter.invoke(u, value[0]); }else{ setter.invoke(u, (Object)value); } } System.out.println("封裝資料之後: "+u); } catch (IntrospectionException | IllegalAccessException | IllegalArgumentException | InvocationTargetException e) { e.printStackTrace(); } } protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request, response); } }
得到的結果：
接收方法四：使用apache 的 BeanUtils 工具來進行封裝資料（ps：這個Benautils工具，Struts框架就是使用這個來獲取表單資料的哦！）
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 獲得填寫的表單資料 */ @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"); //獲取傳過來的表單資料,根據表單中的name獲取所填寫的值 //方法四：使用beanUtil來封裝User類 User u = new User(); System.out.println("沒有使用BeanUtil封裝之前： "+u); try { BeanUtils.populate(u, request.getParameterMap()); System.out.println("使用BeanUtils封裝之後： "+u); } catch (IllegalAccessException | InvocationTargetException e) { e.printStackTrace(); } } protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request, response); } }
得到的結果：
接收方法 方式五： 使用inputStream流來進行接收（一般字串啥的不用這個方法，一般是檔案上傳下載時候才會使用這種方法）因為接收到的字串各種亂碼，編碼問題解決不好
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 獲得填寫的表單資料 */ @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"); //獲取傳過來的表單資料,根據表單中的name獲取所填寫的值 response.setContentType("text/html;charset=UTF-8"); //獲取表單資料 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); } }
得到的結果：（各種亂碼 。。。。）
