当前位置：首页 > news >正文

Jsp/Servlet根据请求参数自动填充Java对象：表单Bean

news 来源：原创 2024/5/7 20:30:34

（1）问题的引出：

为了简单方便我们需要一种可以一次性全部提交表单数据的技术，也就是要说的：Bean表单

（2）BeanUtilities代码如下：

package com.lc.ch04Biaodanshuju;

import java.util.*;
import javax.servlet.http.*;
import org.apache.commons.beanutils.BeanUtils;

public class BeanUtilities {
  
  public static void populateBean(Object formBean,
                                  HttpServletRequest request) {
    populateBean(formBean, request.getParameterMap());
  }
  
  public static void populateBean(Object bean,
                                  Map propertyMap) {
    try {
      BeanUtils.populate(bean, propertyMap);
    } catch(Exception e) {
      // Empty catch. The two possible exceptions are
      // java.lang.IllegalAccessException and
      // java.lang.reflect.InvocationTargetException.
      // In both cases, just skip the bean operation.
    }
  }
}

（3）一下是利用一个收集保险雇员保险信息的servlet，用它来确定可行的保险计划和相关的费用。

package com.lc.ch04Biaodanshuju;


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

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


public class SubmitInsuranceInfo extends HttpServlet {
  public void doGet(HttpServletRequest request,
                    HttpServletResponse response)
      throws ServletException, IOException {
    InsuranceInfo info = new InsuranceInfo();
    BeanUtilities.populateBean(info, request);
    response.setContentType("text/html");
    PrintWriter out = response.getWriter();
    String docType =
      "<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.0 " +
      "Transitional//EN\">\n";
    String title = "Insurance Info for " + info.getName();
    out.println(docType +
                "<HTML>\n" +
                "<HEAD><TITLE>" + title + "</TITLE></HEAD>\n" +
                "<BODY BGCOLOR=\"#FDF5E6\">\n" +
                "<CENTER>\n" +
                "<H1>" + title + "</H1>\n" +
                "<UL>\n" +
                "  <LI>Employee ID: " +
                   info.getEmployeeID() + "\n" +
                "  <LI>Number of children: " +
                   info.getNumChildren() + "\n" +
                "  <LI>Married?: " +
                   info.isMarried() + "\n" +
                "</UL></CENTER></BODY></HTML>");
  }
}

（4）连接数据库的javabean

package com.lc.ch04Biaodanshuju;

public class InsuranceInfo {
  private String name = "No name specified";
  private String employeeID = "No ID specified";
  private int numChildren = 0;
  private boolean isMarried = false;

  public String getName() {
    return(name);
  }

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

  public String getEmployeeID() {
    return(employeeID);
  }

  
  public void setEmployeeID(String employeeID) {
    this.employeeID = ServletUtilities.filter(employeeID);
  }

  public int getNumChildren() {
    return(numChildren);
  }

  public void setNumChildren(int numChildren) {
    this.numChildren = numChildren;
  }
  
  public boolean isMarried() {
    return(isMarried);
  }

  public void setMarried(boolean isMarried) {
    this.isMarried = isMarried;
  }
}

（5）

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">

<HTML><HEAD><TITLE>Employee Insurance Signup</TITLE></HEAD>
<BODY BGCOLOR="#FDF5E6">
<CENTER>
<H1>Employee Insurance Signup</H1>

<FORM ACTION="/servlet/coreservlets.SubmitInsuranceInfo">
  Name:  <INPUT TYPE="TEXT" NAME="name"><BR>
  Employee ID: <INPUT TYPE="TEXT" NAME="employeeID"><BR>
  Number of Children:  <INPUT TYPE="TEXT" NAME="numChildren"><BR>
  <INPUT TYPE="CHECKBOX" NAME="married" VALUE="true">Married?<BR>
  <CENTER><INPUT TYPE="SUBMIT"></CENTER>
</FORM>

</CENTER></BODY></HTML>

（6）jar包的获取与使用：我们要使用工具类必学的jar包，下载地址： http://download.csdn.net/detail/u010870518/7867181 别忘了添加配置！