目录
一、Request继承体系
二、Request获取请求数据
一、Request继承体系
1、Tomcat需要解析请求数据，封装为request对象，并且创建request对象传递到service方法中
2、使用request对象，查阅JavaEE API文档的HttServletRequest接口
代码示例查看request全类名：
import javax.servlet.*;
import javax.servlet.http.*;
import javax.servlet.annotation.*;
import java.io.IOException;
@WebServlet("/demo2")
public class ServletDemo2 extends HttpServlet {
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
System.out.println(request);
}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doGet(request, response);
}
}
访问demo2路径：
控制台输出全类名：
二、Request获取请求数据
请求数据分为3部分：
1、请求行：GET/request-demo/req1?username=zhangsan HTTP/1.1
String getMethod()：获取请求方式：GET
String getContextPath()：获取虚拟目录（项目访问路径）：/request-demo
StringBuffer getRequestURL：获取URL（统一资源定位符）：http://localhost:8080/request-demo/req1
String getRequestURL()：获取URL（统一资源标识符）：/request-demo/req1
String getQueryString()：获取请求参数（GET方式）：username=zhangsan&password=123
以上方法代码示例：
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 java.io.BufferedReader;
import java.io.IOException;
@WebServlet("/req1")
public class RequestDemo1 extends HttpServlet {
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
//String getMethod() ：获取请求方式：GET
String method = req.getMethod();
System.out.println(method);//GET
//String getContextPath()：获取虚拟目录(项目访问路径):/request-demo
String contextPath = req.getContextPath();
System.out.println(contextPath);
//StringBuffer getRequestURL:获取URL(统一资源定位符)：http://localhost:8080/request-demo
StringBuffer url = req.getRequestURL();
System.out.println(url.toString());
//String getRequestURI()：获取URL(统一资源标识符)：/request-demo/req1
String uri = req.getRequestURI();
System.out.println(uri);
//String getQueryString()：获取请求参数（GEI方式）：username=zhangsan
String queryString = req.getQueryString();
System.out.println(queryString);
}
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
}
}
访问req1路径：
控制台输出：
2、请求头：User-Agent：Mozilla/5.0 Chrome/91.0.4472.106
String getHeader(String name)：根据请求头名称，获取值
以上方法代码示例：
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 java.io.BufferedReader;
import java.io.IOException;
@WebServlet("/req1")
public class RequestDemo1 extends HttpServlet {
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
//获取请求头：user-agent:浏览器版本信息
String agent = req.getHeader("user-agent");
System.out.println(agent);
}
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
}
}
访问req1路径：
控制台输出：
3、请求体：username=superbaby&password=123
ServletInputStream getInputStream()：获取字节输入流
BufferedReader getReader()：获取字符输入流
post请求需要表单，req.html代码：
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body>
<form action="/Tomcate-demo2/req4" method="get">
<input type="text" name="username"><br>
<input type="password" name="password"><br>
<input type="submit">
</form>
</body>
</html>
获取post请求参数代码：
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 java.io.BufferedReader;
import java.io.IOException;
@WebServlet("/req1")
public class RequestDemo1 extends HttpServlet {
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
}
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
//获取post请求体，请求参数
//1、获取字符输入流
BufferedReader br = req.getReader();
//2、读取数量
String line = br.readLine();
System.out.println(line);
}
}
访问req.html，并输出参数提交：
控制台输出：
