HttpServletRequest增加header
由于在请求中请求域的属性在请求转发,路由等过程中,请求域的值会丢失,在项目项目中使用请求头来传递信息,但是HttpRequest并没有实现增加请求头的方法,所以找到他的子类来实现
class MutableHttpServletRequest extends HttpServletRequestWrapper {
// holds custom header and value mapping
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);
}
public String getHeader(String name) {
// check the custom headers first
String headerValue = customHeaders.get(name);
if (headerValue != null){
return headerValue;
}
// else return from into the original wrapped object
return ((HttpServletRequest) getRequest()).getHeader(name);
}
public Enumeration<String> getHeaderNames() {
// create a set of the custom header names
Set<String> set = new HashSet<String>(customHeaders.keySet());
// now add the headers from the wrapped request object
@SuppressWarnings("unchecked")
Enumeration<String> e = ((HttpServletRequest) getRequest()).getHeaderNames();
while (e.hasMoreElements()) {
// add the names of the request headers into the list
String n = e.nextElement();
set.add(n);
}
// create an enumeration from the set and return
return Collections.enumeration(set);
}
}
使用:
public class SecurityFilter implements javax.servlet.Filter {
@Override
public void destroy() {
}
@Override
public void doFilter(ServletRequest request, ServletResponse response,
FilterChain chain) throws IOException, ServletException {
HttpServletRequest req = (HttpServletRequest) request;
MutableHttpServletRequest mutableRequest = new MutableHttpServletRequest(req);
...
mutableRequest.putHeader("x-custom-header", "custom value");
chain.doFilter(mutableRequest, response);
}
@Override
public void init(FilterConfig filterConfig) throws ServletException {
}
}
但是项目中我使用的SpringCloud ZUUL中使用这样 的方式失败:
@Component
public class AccessFilter extends ZuulFilter {
private Logger log = LoggerFactory.getLogger(AccessFilter.class);
@Autowired
private VerificationHelper helper;
private BufferedReader reader=null;
@Autowired
private KeyAndFrequencyService service;
@Autowired
private ZuulTest zuulTest;
@Autowired
private PermissionHandler permissionHandler;
@Override
public String filterType() {
//前置过滤器
return "pre";
}
@Override
public int filterOrder() {
//优先级,数字越大,优先级越低
return 0;
}
@Override
public boolean shouldFilter() {
//是否执行该过滤器,true代表需要过滤
return true;
}
@Override
public Object run() {
RequestContext ctx = RequestContext.getCurrentContext();
HttpServletRequest request = ctx.getRequest();
try {
permissionHandler.setTokenExpireTime(200000000);
String type = request.getHeader("type");
zuulTest.say();
System.out.println("......................................................");
if (type == null) {
System.out.println("......................................................验证1");
Object object = helper.AccessZuul(request, ctx);
return object;
} else {
System.out.println("......................................................验证2");
PermissionResult result=permissionHandler.check(request);
System.out.println(result);
if(result.isState()){
MutableHttpServletRequest mutRequest=new MutableHttpServletRequest (request);
//增加头部信息
DasAccountInfo accountInfo= permissionHandler.GetDasAccountInfoById(Integer.parseInt(result.getUserId()));
mutRequest.putHeader("dasAccountInfo", JSON.toJSONString(disablePropertyName())) ;RequestContext.getCurrentContext().setRequest(mutRequest);
ctx.setSendZuulResponse(true);// 对该请求进行路由
ctx.setResponseStatusCode(200);
ctx.set("isSuccess", true);
}else{
ctx.setSendZuulResponse(false);// 过滤该请求,不对其进行路由
ctx.setResponseStatusCode(401);// 返回错误码
ctx.setResponseBody("{\"code\":0,\"result\":\"网关验证失败!验证方式为2\"}");// 返回错误内容
ctx.set("isSuccess", false);
}
}
}catch (Exception e){
e.printStackTrace();
log.error("网关报错!!!",e.fillInStackTrace());
}
return null;
}
使用zuul网关的自带的设置请求头的方法,在网关中设置的请求头可以被路由下面的服务获取到:
ctx.getZuulRequestHeaders().put("dasAccountInfo", JSON.toJSONString(disablePropertyName()));
修改HttpServletRequest中header的信息
废话一堆:由于业务有统一的鉴权系统,页面请求时在header中带过来gsid,正常业务没有问题,但是当需要下载文件时,前端统一用json解析响应,当响应文件时,对于前端来说不好处理,就决定使用简单的get请求下载文件,将gsid通过url带过来,这样的话后端鉴权就需要处理,当header中没有gsid时,从参数中取,为了尽可能少的改变公用的业务代码(指sso),就在当前项目中自定义权限拦截器。
总结一句,我就是想想header中加东西!!往下看具体实现方式:
新建拦截器类,继承原有的拦截器,重写其preHandle方法
@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object o) throws Exception {
String gsid = request.getHeader("GSID");
if(StringUtils.isBlank(gsid)){
String gsid= request.getParameter("GSID");
//使用反射,将gsid设置到request中的的header中去
reflectSetparam(request,"GSID",gsid);
log.info("请求连接中的gsid={}",request.getHeader("GSID"));
}
return super.preHandle(request, response, o);
}
说明:可以看到在方法中,
1、先进行header信息判断,如果header中没有GSID,就去请求参数中拿
gsid= request.getParameter("GSID");
2、通过反射将参数中的GSID键值对儿:“GSID”:“376645354562335”加入到header中去
话不多少,先上代码,再解释:
解释:
/**
* 修改header信息,key-value键值对儿加入到header中
* @param request
* @param key
* @param value
*/
private void reflectSetparam(HttpServletRequest request,String key,String value){
Class<? extends HttpServletRequest> requestClass = request.getClass();
System.out.println("request实现类="+requestClass.getName());
try {
Field request1 = requestClass.getDeclaredField("request");
request1.setAccessible(true);
Object o = request1.get(request);
Field coyoteRequest = o.getClass().getDeclaredField("coyoteRequest");
coyoteRequest.setAccessible(true);
Object o1 = coyoteRequest.get(o);
System.out.println("coyoteRequest实现类="+o1.getClass().getName());
Field headers = o1.getClass().getDeclaredField("headers");
headers.setAccessible(true);
MimeHeaders o2 = (MimeHeaders)headers.get(o1);
o2.addValue(key).setString(value);
} catch (Exception e) {
e.printStackTrace();
}
}
执行打印信息如下:
request实现类=org.apache.catalina.connector.RequestFacade
coyoteRequest实现类=org.apache.coyote.Request
看HttpServletRequest的源码,是个接口,并且我们获取header信息的方法是getHeader()方法,按常理其对象中应该有header字段,那么我们就去实现类中找这个字段,具体过程如下
步骤一:先找到具体的Request对象是哪个类,根据打印信息看源码
进入其中找到getHeader()方法,如下
public String getHeader(String name) {
if (this.request == null) {
throw new IllegalStateException(sm.getString("requestFacade.nullRequest"));
} else {
return this.request.getHeader(name);
}
}
然后我们找this.request
这个request,我们找到它的类型,点击去
这个类的全路径是:org.apache.catalina.connector.Request
这个类中找getHeader方法
public String getHeader(String name) {
return this.coyoteRequest.getHeader(name);
}
找到这个类中的coyoteRequest
protected org.apache.coyote.Request coyoteRequest;
是这样的
再找到getHeader()
public String getHeader(String name) {
return this.headers.getHeader(name);
}
好了,终于见到属性了
private final MimeHeaders headers = new MimeHeaders();
找到MineHeaders中的getHeader方法,
public String getHeader(String name) {
MessageBytes mh = this.getValue(name);
return mh != null ? mh.toString() : null;
}
看到最终header是一个MessageBytes对象,好找到这个对象进去,发现只能setValue,那就在MineHeaders中找在哪里实例化MessageBytes对象的
找了半天找到在createHeader()方法中实例化MimeHeaderField对象,然后这个对象实例化时会实例化MessageBytes对象
这里有name,value,靠谱
然后再在MimeHeader中找在addValue方法中有调用,就用这个试一下吧,然后就是最上面的我自定义的方法,在heade中加入了一个键值对儿。
测试请求:
http://127.0.0.1:32100/v1/CustomerRefundRest/exportRefund?gsid=abc114f1bd0d484084e5df3fe1c419b8&refundLongStartDate=1520611199000&refundLongEndDate=1522943999000
测试打印结果:
OVER!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三水点靠木。
如何给HttpServletRequest增加消息头
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