HttpServletResponse对象获取请求行信息
方法列表
String reqMethod = request.getMethod()
String reqURI=request.getRequestURI();
String reqURI=request.getRequestURI();
StringBuffer reqURL=request.getRequestURL();
String reqPath=request.getContextPath();
String queryString=request.getQueryString();
String reqClient=request.getRemoteAddr();实例
HTML
<!DOCTYPE html>
<html>
<head>
<title>request获取请求行内容</title>
<meta charset="utf-8">
</head>
<body>
<form action="/WEB/lineServlet" method="post" >
姓名：<input type="text" name="name"><br>
年龄：<input type="text" name="age"><br>
<input type="submit" value="提交">
</form>
</body>
</html>java
package servlet;
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 LineServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// 设置编码方式
response.setCharacterEncoding("UTF-8");
response.setContentType("text/html; charset=UTF-8");
// 获得PrintWriter输出对象
PrintWriter writer = response.getWriter();
// 1、获取请求方式
String reqMethod = request.getMethod();
writer.write("请求方式method: " + reqMethod);
writer.print("<br>");
//2、获得请求的资源相关的内容
String reqURI=request.getRequestURI();
StringBuffer reqURL=request.getRequestURL();
writer.write("请求内容URI: " + reqURI);
writer.print("<br>");
writer.write("请求内容URL: " + reqURL);
writer.print("<br>");
//获得web应用的名称
String reqPath=request.getContextPath();
writer.write("web应用contextPath: " + reqPath);
writer.print("<br>");
//地址后的参数的字符串
String queryString=request.getQueryString();
writer.write("参数的字符串queryString: " + queryString);
writer.print("<br>");
//3、获得客户机的信息---获得访问者IP地址
String reqClient=request.getRemoteAddr();
writer.write("客户机的信息RemoteAddr: " + reqClient);
}
public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doGet(request, response);
}
}HttpServletResponse和HttpServletRequest解析
最近有这么一个诉求，我在A服务器中的java调用执行一个python文件，并将其返回值返回给B服务器的客户端。当时在想A服务器暴露一个接口，然后使用runtime API调用即可，但是返回值这块我却有点苦恼。我的本意是直接返回IO流，因为生成的数据可大可小，无规律，但是我发现这样是不可以的。
[org.springframework.http.converter.HttpMessageNotWritableException: No converter found for return value of type: class org.springframework.boot.loader.jar.JarURLConnection$2]
后来兜兜转转发现了HttpServletResponse 可以来解决这个问题。
HttpServletResponse和HttpServletRequest
Web服务器收到客户端的http请求，会针对每一次请求，分别创建一个用于代表请求的request对象、和代表响应的response对象。request和response对象即然代表请求和响应，那我们要获取客户机提交过来的数据，只需要找request对象就行了。要向客户机输出数据，只需要找response对象就行了。
本文主讲HttpServletResponse，HttpServletRequest碰到合适的场景我会将他补全。
HttpServletResponse
HttpServletResponse对象代表服务器的响应。这个对象中封装了向客户端发送数据、发送响应头，发送响应状态码的方法。
他的作用如下
1、保存流对象
使用HttpServletResponse 我们可以将IO流读出来在写入HttpServletResponse中的OutputStream中。然后别的客户端访问的时候方便获取
相关代码
@RequestMapping(value = "/testHdf")
@ResponseBody
public void testHdfs(String csv, String sql, HttpServletResponse response) {
BufferedInputStream bis = null;
try {
Process process = Runtime.getRuntime().exec("python /blazingsql/testData/zgh/aaa.py");
process.waitFor();
bis = new BufferedInputStream(process.getInputStream());
OutputStream os = null;
byte[] buff = new byte[1024];
os = response.getOutputStream();
int i = bis.read(buff);
while (i != -1) {
os.write(buff, 0, buff.length);
os.flush();
i = bis.read(buff);
}
} catch (IOException e) {
e.printStackTrace();
} catch (InterruptedException e) {
} finally {
if (bis != null) {
try {
bis.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
2、下载文件
使用HttpServletResponse可以下载文件，很方便
下载文件是，设置这些参数很重要
response.setHeader(“Content-Disposition”, “attachment;filename=”+ URLEncoder.encode(“demo.csv”, “UTF-8”));
response.setHeader(“Connection”, “close”);
response.setHeader(“Content-Type”, “application/octet-stream”);相关代码
@RequestMapping(value = "/download")
@ResponseBody
public void download(String path,HttpServletResponse response) throws UnsupportedEncodingException {
response.reset();
response.setHeader("Content-Disposition", "attachment;filename="+ URLEncoder.encode("demo.csv", "UTF-8"));
response.setHeader("Connection", "close");
response.setHeader("Content-Type", "application/octet-stream");
OutputStream ops = null;
FileInputStream fis =null;
byte[] buffer = new byte[8192];
int bytesRead = 0;
try {
ops = response.getOutputStream();
fis = new FileInputStream(path);
while((bytesRead = fis.read(buffer, 0, 8192)) != -1){
ops.write(buffer, 0, bytesRead);
}
ops.flush();
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
if(fis != null){
fis.close();
}
if(ops != null){
ops.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
以上为个人经验，希望能给大家一个参考，也希望大家多多支持编程网。
