通过HttpServletRequest重写+filter 添加header
问题说明
需要做的事情比较简单,就是通过filter 重写httpservletrequest ,同时给予request 添加header
主要是通过HttpServletRequestWrapper 进行处理,代码写死了,只是一个简单的演示。
自定义HttpServletRequest(实现HttpServletRequestWrapper)
package com.example.demo;
import java.util.*;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
final class MutableHttpServletRequest extends HttpServletRequestWrapper {
private final Map<String, String> customHeaders;
public MutableHttpServletRequest(HttpServletRequest request){
super(request);
this.customHeaders = new HashMap<String, String>();
}
public void putHeader(String name, String value){
this.customHeaders.put(name, value);
}
@Override
public String getHeader(String name) {
if (name=="userid") {
return "dalong";
}
return "demo";
}
public Map<String, String> getCustomHeaders() {
return customHeaders;
}
@Override
public Enumeration<String> getHeaders(String name) {
if (null != name && name.equals("userid")) {
return new Enumeration<String>() {
private boolean hasGetted = false;
@Override
public boolean hasMoreElements() {
return !hasGetted;
}
@Override
public String nextElement() {
if (hasGetted) {
throw new NoSuchElementException();
} else {
hasGetted = true;
return "dalong";
}
}
};
}
return super.getHeaders(name);
}
}
filter
调用自定义HttpServletRequestWrapper 实现header 添加
package com.example.demo;
import org.springframework.web.filter.OncePerRequestFilter;
import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
@WebFilter(urlPatterns = "/*",filterName = "tokenfilter")
public class UserIdFilter extends OncePerRequestFilter {
@Override
protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain) throws ServletException, IOException {
MutableHttpServletRequest newrequest = new MutableHttpServletRequest(request);
System.out.printf("filter running");
filterChain.doFilter(newrequest,response);
}
}
scan
添加scan 自动注入filter
package com.example.demo;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.web.servlet.ServletComponentScan;
@SpringBootApplication
@ServletComponentScan
public class DemoApplication {
public static void main(String[] args) {
SpringApplication.run(DemoApplication.class, args);
}
}
service
rest api 测试
package com.example.demo;
import org.springframework.web.bind.annotation.RequestHeader;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;
import javax.servlet.http.HttpServletRequest;
@RestController
public class UserService {
@RequestMapping(value = "/user",method= RequestMethod.GET)
public Object Userinfo(HttpServletRequest request,@RequestHeader String userid){
// User user =new User(request.getHeader("userid"),222);
User user =new User(userid,222);
return user;
}
}
user entity
用户实体,用来测试的
package com.example.demo;
public class User {
private String username;
private int age;
public User(String username, int age) {
this.username = username;
this.age = age;
}
public User() {
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
}
applicaiton 入口
package com.example.demo;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.web.servlet.ServletComponentScan;
@SpringBootApplication
@ServletComponentScan
public class DemoApplication {
public static void main(String[] args) {
SpringApplication.run(DemoApplication.class, args);
}
}
测试效果
curl -i http://localhost:8080/user
HTTP/1.1 200
Content-Type: application/json;charset=UTF-8
Transfer-Encoding: chunked
Date: Sat, 11 May 2019 15:09:19 GMT
{"username":"dalong","age":222}%
说明
getHeaders 也是需要实现的,不然基于注解的@RequestHeader
不生效
参考资料
http://wilddiary.com/adding-custom-headers-java-httpservletrequest/
https://github.com/rongfengliang/HttpServletRequst-Rewrite-Demo