request.getParameter用发放
时间: 2024-01-18 22:02:04 浏览: 23
请求.getParameter()方法是用于从HTTP请求中获取参数的方法。它可以用于获取表单数据,URL参数以及任何其他发送到服务器的参数。在Java Servlet中,可以使用此方法来检索客户端提交的表单数据或URL参数。使用此方法需要提供参数的名称,并且如果找到该名称的参数,则该方法将返回该参数的值。如果没有找到参数,则该方法将返回null。 例如,如果您有一个名为“username”的表单字段,并且您想要获取用户在该字段中输入的值,则可以使用以下代码:
String username = request.getParameter("username");
在此示例中,“request”是一个HttpServletRequest对象,它表示当前请求。如果找到名为“username”的参数,则将该参数的值分配给变量“username”。如果没有找到该参数,则“username”将为null。
相关问题
request.setCharacterEncoding("utf-8"); response.setContentType("text/html;charset=utf-8"); int id = Integer.parseInt(request.getParameter("id")); String name = request.getParameter("name"); String description = request.getParameter("description"); String price = request.getParameter("price"); String category = request.getParameter("category"); String manufacturer = request.getParameter("manufacturer"); String stockQuantity = request.getParameter("stockQuantity"); String isAvailable = request.getParameter("isAvailable"); Product product = new Product(id, name, description, Double.parseDouble(price), category, manufacturer, Integer.parseInt(stockQuantity), null, LocalDateTime.now(), isAvailable); ProductDao productDao = new ProductDao(); int update = productDao.update(product); if(update > 0){ request.getRequestDispatcher("productListServlet").forward(request,response);添加注释
这段代码是一个Servlet中的doPost方法的代码片段,主要作用是根据请求中的参数更新商品信息,并将请求转发到商品列表页面。注释可以如下添加:
```
// 设置请求和响应的编码格式为UTF-8
request.setCharacterEncoding("utf-8");
response.setContentType("text/html;charset=utf-8");
// 从请求中获取商品的各个属性值
int id = Integer.parseInt(request.getParameter("id"));
String name = request.getParameter("name");
String description = request.getParameter("description");
String price = request.getParameter("price");
String category = request.getParameter("category");
String manufacturer = request.getParameter("manufacturer");
String stockQuantity = request.getParameter("stockQuantity");
String isAvailable = request.getParameter("isAvailable");
// 创建一个Product对象,用于更新商品信息
Product product = new Product(id, name, description, Double.parseDouble(price), category, manufacturer,
Integer.parseInt(stockQuantity), null, LocalDateTime.now(), isAvailable);
// 创建一个ProductDao对象,用于更新商品信息
ProductDao productDao = new ProductDao();
// 更新商品信息,并获取更新结果
int update = productDao.update(product);
// 如果更新成功,就将请求转发到商品列表页面
if(update > 0){
request.getRequestDispatcher("productListServlet").forward(request,response);
}
```
String jiudianmingcheng=request.getParameter("jiudianmingcheng"); String kefangbianhao=request.getParameter("kefangbianhao"); String jiage=request.getParameter("jiage"); String yudingshijian=request.getParameter("yudingshijian"); String yudingtianshu=request.getParameter("yudingtianshu"); String nindexingming=request.getParameter("nindexingming"); String nindedianhua=request.getParameter("nindedianhua"); String nindeshenfenzheng=request.getParameter("nindeshenfenzheng"); String beizhu=request.getParameter("beizhu"); String yonghuming=request.getParameter("yonghuming"); String sql="insert into jiudianyuding(jiudianmingcheng,kefangbianhao,jiage,yudingshijian,yudingtianshu,nindexingming,nindedianhua,nindeshenfenzheng,beizhu,yonghuming) values('"+jiudianmingcheng+"','"+kefangbianhao+"','"+jiage+"','"+yudingshijian+"','"+yudingtianshu+"','"+nindexingming+"','"+nindedianhua+"','"+nindeshenfenzheng+"','"+beizhu+"','"+yonghuming+"') "; connDbBean.executeUpdate(sql); out.print("<script>alert('操作成功!!');location.href='jiudianxinxilist.jsp';</script>");请给代码标上注释
这段代码主要是在进行Java Web开发中,向数据库中插入一条酒店预订信息的操作。具体解释如下:
```java
// 通过request.getParameter()方法获取前端页面传递过来的参数并存储在对应的变量中
String jiudianmingcheng=request.getParameter("jiudianmingcheng");
String kefangbianhao=request.getParameter("kefangbianhao");
String jiage=request.getParameter("jiage");
String yudingshijian=request.getParameter("yudingshijian");
String yudingtianshu=request.getParameter("yudingtianshu");
String nindexingming=request.getParameter("nindexingming");
String nindedianhua=request.getParameter("nindedianhua");
String nindeshenfenzheng=request.getParameter("nindeshenfenzheng");
String beizhu=request.getParameter("beizhu");
String yonghuming=request.getParameter("yonghuming");
// 构建 SQL 语句,将获取到的参数插入到数据库表 jiudianyuding 中
String sql="insert into jiudianyuding(jiudianmingcheng,kefangbianhao,jiage,yudingshijian,yudingtianshu,nindexingming,nindedianhua,nindeshenfenzheng,beizhu,yonghuming) values('"+jiudianmingcheng+"','"+kefangbianhao+"','"+jiage+"','"+yudingshijian+"','"+yudingtianshu+"','"+nindexingming+"','"+nindedianhua+"','"+nindeshenfenzheng+"','"+beizhu+"','"+yonghuming+"') ";
// 执行 SQL 语句,将数据插入到数据库中
connDbBean.executeUpdate(sql);
// 在前端页面弹出提示框,提示操作成功,并跳转到 jiudianxinxilist.jsp 页面
out.print("<script>alert('操作成功!!');location.href='jiudianxinxilist.jsp';</script>");
```
注释已经标在代码中了,主要是通过获取request对象中的参数,构建 SQL 语句并执行插入操作,最后在前端页面弹出提示框并跳转至对应的页面。