package test.request;
import java.io.IOException;
import java.io.InputStream;
import java.lang.reflect.InvocationTargetException;
import java.util.Enumeration;
import java.util.Map;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.sun.org.apache.commons.beanutils.BeanUtils;
//HttpServletRequest獲取請求頭和請求數據
//請求數據一半來說要先檢查再使用，檢查非空和不是空格
public class RequestDemo2 extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
System.out.println("---------獲取請求數據方式1-------------");
// 獲取指定的請求數據
String value = request.getParameter("username");
if (value != null && !value.trim().equals("")) {
System.out.println(value);
}
System.out.println("---------獲取請求數據方式2-------------");
// 獲取所有的請求數據
Enumeration e = request.getParameterNames();
while (e.hasMoreElements()) {
String paramName = (String) e.nextElement();
String value2 = request.getParameter(paramName);
System.out.println(paramName + "=" + value2);
}
System.out.println("---------獲取請求數據方式3-------------");
// 獲取所有的請求數據，同名的只能獲取一次，就是第一次
String[] values = request.getParameterValues("username");
for (int i = 0; values != null && i < values.length; i++) {
System.out.println(values[i]);
}
System.out.println("---------獲取請求數據方式4-------------");
// 這個特別實用，框架的模型驅動，這個Map的value肯定是String數組類型，因爲有同名的請求數據
// 實際開發中是不會 request.getParameter("username");用這種方式的，都是要創建一個model的
Map<String, String[]> map = request.getParameterMap();
User user = new User();
try {
// 用map中的數據填充bean
BeanUtils.populate(user, map);
} catch (IllegalAccessException e1) {
e1.printStackTrace();
} catch (InvocationTargetException e1) {
e1.printStackTrace();
}
System.out.println(user.getPassword());
System.out.println("---------獲取請求數據方式5-------------");
// request.getInputStream();是上傳文件的時候獲取數據的方式
// 普通數據是獲取不到的
InputStream in = request.getInputStream();
int len = 0;
byte[] buffer = new byte[1024];
while ((len = in.read(buffer)) > 0) {
System.out.println(new String(buffer, 0, len));
}
}
// 獲取請求頭
private void test1(HttpServletRequest request) {
System.out.println("---------獲取請求頭方式1-------------");
// 拿到指定的請求頭
System.out.println(request.getHeader("cache-control"));
System.out.println("---------獲取請求頭方式2-------------");
// 拿到所有指定的請求頭
Enumeration e = request.getHeaders("cache-control");
while (e.hasMoreElements()) {
String headValue = (String) e.nextElement();
System.out.println(headValue);
}
System.out.println("---------獲取請求頭方式3-------------");
// 拿到所有請求頭
Enumeration e1 = request.getHeaderNames();
while (e1.hasMoreElements()) {
String headerName = (String) e1.nextElement();
String headValue = request.getHeader(headerName);
System.out.println(headerName + "=" + headValue);
}
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
}package test.request;
public class User {
private String[] username;
public String[] getUsername() {
return username;
}
public void setUsername(String[] username) {
this.username = username;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
private String password;
}<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>給RequestDemo2發送請求數據</title>
</head>
<body>
<!-- 瀏覽器可以通過兩種方式向服務器發送請求數據 超鏈接方式後面跟了中文要經過url編碼後再提交 -->
<a href="/day06/servlet/RequestDemo2?username=xxx">點點</a><br/>
<form action="/day06/servlet/RequestDemo2" method="post">
用戶名1：<input type="text" name="username"/><br/>
用戶名2：<input type="text" name="username"/><br/>
密碼：<input type="password" name="password"/><br/>
<input type="submit" value="提交"/>
</form>
</body>
</html>
此程序還需用到commons-beanutils-1.9.0.jar和commons-logging-1.1.3.jar這兩個jar包
