Question

怎么获取httpservletrequest

Answer 1

1、request.getRequestURL()

返回的是完整的url，包括Http协议，端口号，servlet名字和映射路径，但它不包含请求参数。
2、request.getRequestURI()

得到的是request URL的部分值，并且web容器没有decode过的

3、request.getContextPath() 
返回 the context of the request.

4、request.getServletPath() 
返回调用servlet的部分url.

5、request.getQueryString() 
返回url路径后面的查询字符串

示例：

当前url：http://localhost:8080/CarsiLogCenter_new/idpstat.jsp?action=idp.sptopn

request.getRequestURL() http://localhost:8080/CarsiLogCenter_new/idpstat.jsp
request.getRequestURI() /CarsiLogCenter_new/idpstat.jsp
request.getContextPath()/CarsiLogCenter_newrequest.getServletPath() /idpstat.jsp
request.getQueryString()action=idp.sptopn

Answer 2

在RequestContextListener类中有如下代码，其中红色标注的为关键代码：

public class RequestContextListener implements ServletRequestListener {

...
...
...

public void requestInitialized(ServletRequestEvent requestEvent) {
if (!(requestEvent.getServletRequest() instanceof HttpServletRequest)) {
throw new IllegalArgumentException("");
}
HttpServletRequest request = (HttpServletRequest) requestEvent.getServletRequest();
ServletRequestAttributes attributes = new ServletRequestAttributes(request);
request.setAttribute(REQUEST_ATTRIBUTES_ATTRIBUTE, attributes);
LocaleContextHolder.setLocale(request.getLocale());
RequestContextHolder.setRequestAttributes(attributes);
}
...
...
...
}

public class ServletRequestAttributes extends AbstractRequestAttributes {

...
...
...

private final HttpServletRequest request;

...
...
...

/**
* Create a new ServletRequestAttributes instance for the given request.
* @param request current HTTP request
*/
public ServletRequestAttributes(HttpServletRequest request) {
Assert.notNull(request, "Request must not be null");
this.request = request;
}
}

2、在普通类中获取对象

HttpServletRequest request = ((ServletRequestAttributes)RequestContextHolder.getRequestAttributes()).getRequest();