httpsession重写
时间: 2023-12-24 08:03:38 浏览: 30
如果您想要在Java Web应用程序中重写HttpSession,可以通过实现`HttpSession`接口的自定义类来实现。
下面是一个示例代码:
```java
import java.util.Enumeration;
import java.util.HashMap;
import java.util.Map;
import javax.servlet.ServletContext;
import javax.servlet.http.HttpSession;
import javax.servlet.http.HttpSessionContext;
public class CustomSession implements HttpSession {
private final String id;
private final Map<String, Object> attributes;
private boolean isNew = true;
public CustomSession(String id) {
this.id = id;
this.attributes = new HashMap<>();
}
@Override
public Object getAttribute(String name) {
return attributes.get(name);
}
@Override
public Enumeration<String> getAttributeNames() {
return new Vector<>(attributes.keySet()).elements();
}
@Override
public void setAttribute(String name, Object value) {
attributes.put(name, value);
}
@Override
public void removeAttribute(String name) {
attributes.remove(name);
}
@Override
public String getId() {
return id;
}
@Override
public long getCreationTime() {
throw new UnsupportedOperationException();
}
@Override
public long getLastAccessedTime() {
throw new UnsupportedOperationException();
}
@Override
public ServletContext getServletContext() {
throw new UnsupportedOperationException();
}
@Override
public void setMaxInactiveInterval(int interval) {
throw new UnsupportedOperationException();
}
@Override
public int getMaxInactiveInterval() {
throw new UnsupportedOperationException();
}
@Override
public HttpSessionContext getSessionContext() {
throw new UnsupportedOperationException();
}
@Override
public boolean isNew() {
return isNew;
}
public void setNew(boolean isNew) {
this.isNew = isNew;
}
}
```
在上面的代码中,`CustomSession`类实现了`HttpSession`接口,并重写了`getAttribute`、`setAttribute`、`removeAttribute`、`getId`和`isNew`等方法。在`CustomSession`中,使用一个`Map`来存储Session中的属性值。
然后,您需要在`HttpSessionListener`中创建`CustomSession`对象,并将其存储在一个`Map`对象中,例如:
```java
import java.util.HashMap;
import java.util.Map;
import javax.servlet.http.HttpSession;
import javax.servlet.http.HttpSessionEvent;
import javax.servlet.http.HttpSessionListener;
public class CustomSessionListener implements HttpSessionListener {
private final Map<String, HttpSession> sessions = new HashMap<>();
@Override
public void sessionCreated(HttpSessionEvent se) {
CustomSession session = new CustomSession(se.getSession().getId());
sessions.put(session.getId(), session);
}
@Override
public void sessionDestroyed(HttpSessionEvent se) {
sessions.remove(se.getSession().getId());
}
public HttpSession getSession(String id) {
return sessions.get(id);
}
}
```
在上面的代码中,`CustomSessionListener`实现了`HttpSessionListener`接口,并重写了`sessionCreated`和`sessionDestroyed`方法。在`sessionCreated`方法中,创建了一个新的`CustomSession`对象,并将其存储在一个`Map`对象中。在`sessionDestroyed`方法中,从`Map`中删除`CustomSession`对象。
最后,在`HttpSessionFilter`中获取`CustomSession`对象,例如:
```java
import java.io.IOException;
import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;
public class CustomSessionFilter implements Filter {
private final CustomSessionListener sessionListener = new CustomSessionListener();
@Override
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
HttpServletRequest req = (HttpServletRequest) request;
HttpSession session = sessionListener.getSession(req.getSession().getId());
if (session == null) {
session = new CustomSession(req.getSession().getId());
sessionListener.getSessionMap().put(session.getId(), session);
}
chain.doFilter(new CustomHttpServletRequest(req, session), response);
}
}
```
在上面的代码中,`CustomSessionFilter`实现了`Filter`接口,并重写了`doFilter`方法。在`doFilter`方法中,获取`CustomSession`对象,并将其存储在`Map`对象中。然后,使用`CustomHttpServletRequest`包装`HttpServletRequest`对象,并调用`chain.doFilter`方法。
这样就完成了HttpSession的重写。