Java J2EE：在此场景下理解isCommitted和过滤器
我正在处理一个筛选器，此代码无法执行/response.write（如果请求中涉及“转发”）。但是，对于简单地向用户发送HTML内容的基本servlet来说，它工作得很好。如何使用此代码处理“转发” 例如，下面是一个过滤器，它简单地捕获文本内容并尝试操作该内容Java J2EE：在此场景下理解isCommitted和过滤器,java,servlets,Java,Servlets,我正在处理一个筛选器，此代码无法执行/response.write（如果请求中涉及“转发”）。但是，对于简单地向用户发送HTML内容的基本servlet来说，它工作得很好。如何使用此代码处理“转发” 例如，下面是一个过滤器，它简单地捕获文本内容并尝试操作该内容 public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain chain) throws IOExcept
public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain chain) throws IOException, ServletException {
HttpServletRequest request = (HttpServletRequest) servletRequest;
HttpServletResponse response = (HttpServletResponse) servletResponse;
HttpSession session = request.getSession(false);
CharResponseWrapper responseWrapper = new CharResponseWrapper((HttpServletResponse) response);
chain.doFilter(request, responseWrapper);
final boolean commit1 = responseWrapper.isCommitted();
final boolean commit2 = response.isCommitted();
if (!commit2) {
final String res = responseWrapper.toString().replaceAll("(?i)</form>", "<input type=\"hidden\" name=\"superval\" value=\""+superval"\"/></form>");
response.getWriter().write(res);
}
return;
}
public class TestCommitServlet2 extends HttpServlet {
private static final long serialVersionUID = 1L;
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
final PrintWriter out = resp.getWriter();
resp.setContentType("text/html");
out.println("<html><body>(v-1)testing<form action='test'><input type='submit' value='Run' /> </form></body></html>");
}
@Override
protected void doPost(final HttpServletRequest req, final HttpServletResponse resp) throws ServletException, IOException {
doGet(req, resp);
}
}
公共类TestCommitServlet2扩展了HttpServlet{
私有静态最终长serialVersionUID=1L；
@凌驾
受保护的void doGet（HttpServletRequest-req，HttpServletResponse-resp）抛出ServletException，IOException{
最终PrintWriter out=resp.getWriter（）；
分别为setContentType（“文本/html”）；
out.println（“v-1）测试”）；
}
@凌驾
受保护的void doPost（最终HttpServletRequest请求、最终HttpServletResponse响应）抛出ServletException、IOException{
doGet（需求、响应）；
}
}
我正在使用Servlet API 3.0来检查这个场景。 在调用TestCommitServlet2时，使用servlet代码和过滤器，我可以看到以下输出
http://localhost:8080/Question/TestCommitServlet2
(v-1)testing
Button here
com.koitoer.CharResponseWrapper@5b5b6746
http://localhost:8080/Question/TestCommitServlet
(v-1)testing
Button here
@WebFilter(filterName = "/MyFilter", urlPatterns = { "/TestCommitServlet2" }, dispatcherTypes = {
DispatcherType.FORWARD, DispatcherType.REQUEST })
public class MyFilter implements Filter {
(v-1)testing
Button
com.koitoer.CharResponseWrapper@1b3bea22
responseWrapper.toString().replaceAll
由于responseWrapper.toString（）返回如下内容，所以您做得不对CharResponseWrapper@5b5b6746，而不是内容，如果要修改响应，请使用从HttpServletResponseWrapper扩展而来的包装器，并重写正确的方法来操作outpustream。我使用Servlet API 3.0来检查此场景。 在调用TestCommitServlet2时，使用servlet代码和过滤器，我可以看到以下输出
http://localhost:8080/Question/TestCommitServlet2
(v-1)testing
Button here
com.koitoer.CharResponseWrapper@5b5b6746
http://localhost:8080/Question/TestCommitServlet
(v-1)testing
Button here
@WebFilter(filterName = "/MyFilter", urlPatterns = { "/TestCommitServlet2" }, dispatcherTypes = {
DispatcherType.FORWARD, DispatcherType.REQUEST })
public class MyFilter implements Filter {
(v-1)testing
Button
com.koitoer.CharResponseWrapper@1b3bea22
responseWrapper.toString().replaceAll
由于responseWrapper.toString（）返回如下内容，所以您做得不对CharResponseWrapper@5b5b6746，而不是内容，如果要修改响应，请使用从HttpServletResponseWrapper扩展而来的包装器，并重写正确的方法来操作outpustream。我使用Servlet API 3.0来检查此场景。 在调用TestCommitServlet2时，使用servlet代码和过滤器，我可以看到以下输出
http://localhost:8080/Question/TestCommitServlet2
(v-1)testing
Button here
com.koitoer.CharResponseWrapper@5b5b6746
http://localhost:8080/Question/TestCommitServlet
(v-1)testing
Button here
@WebFilter(filterName = "/MyFilter", urlPatterns = { "/TestCommitServlet2" }, dispatcherTypes = {
DispatcherType.FORWARD, DispatcherType.REQUEST })
public class MyFilter implements Filter {
(v-1)testing
Button
com.koitoer.CharResponseWrapper@1b3bea22
responseWrapper.toString().replaceAll
由于responseWrapper.toString（）返回如下内容，所以您做得不对CharResponseWrapper@5b5b6746，而不是内容，如果要修改响应，请使用从HttpServletResponseWrapper扩展而来的包装器，并重写正确的方法来操作outpustream。我使用Servlet API 3.0来检查此场景。 在调用TestCommitServlet2时，使用servlet代码和过滤器，我可以看到以下输出
http://localhost:8080/Question/TestCommitServlet2
(v-1)testing
Button here
com.koitoer.CharResponseWrapper@5b5b6746
http://localhost:8080/Question/TestCommitServlet
(v-1)testing
Button here
@WebFilter(filterName = "/MyFilter", urlPatterns = { "/TestCommitServlet2" }, dispatcherTypes = {
DispatcherType.FORWARD, DispatcherType.REQUEST })
public class MyFilter implements Filter {
(v-1)testing
Button
com.koitoer.CharResponseWrapper@1b3bea22