Various paths in Web engineering (Eclipse development)

Currently encountered in the Web project to write URLs and path files have

• In WebContent. jsp/.html
• servlet classes in SRC
• SRC generic class for non-servlet classes

. jsp/.html

Action for Form form submission

1. Jump to. jsp

Use relative paths relative to the Web engineering root directory

　　　　

 <!--  from jsp1.jsp to jsp2.jsp  Span style= "COLOR: #008000" >-->  <!--  jsp1.jsp in the form  -->  <  form  action  = "file/jsp2.jsp"  >  

<!---<!---<Action =".. /jsp1.jsp ">

2. Jump to Servlet1

Not relevant to the package

　　　　

// Servlet1.java Map Address @WebServlet (name = "Servlet1", Urlpatterns = {"/servlet1"})

<!---<!---<Action =".. /servlet1 ">

Change the map address of the servlet so that the servlet maps to a folder with jsp2.jsp

// @WebServlet After modifying the map address of the Servlet1 (name = "Servlet1", Urlpatterns = {"/file/servlet1"})

<!---<!---<Action  = "Servlet1">

Change the servlet mapping address again, the servlet maps to the virtual directory

// after modifying the mapping address of the SERVLET1 again, map to the Virtualfile virtual directory @WebServlet (name = "Servlet1", Urlpatterns = {"/virtualfile/ Servlet1 "})

<!---<!---<Action =".. /virtualfile/servlet1 ">

servlet classes in SRC

1. Map address in URL annotations, contact with JSP (HTML)

2. Access resource files in WebContent 1.txt (according to the engineering structure in Tomcat)

// use Getservletcontext (). Getrealpath () to get the absolute path to the Web project this. Getservletcontext (). Getrealpath ("/sourcefile/1.txt"); // filepath= // D:\tomcat\apache-tomcat-8.0.50-windows-x64\apache-tomcat-8.0.50\webapps\test3\sourceFile\1.txt New BufferedReader (new FileReader (FilePath));

　

2. Access the resource file in SRC

// access the files in src to get the absolute path according to the project directory in Tomcat // servlet does not map to virtual directory this. Getservletcontext (). Getrealpath ("/web-inf/classes/2.txt"new bufferedwriter (  New FileWriter (FilePath));

　

　3. Redirect to Servlet (JSP), only with relative path

// REDIRECT uses relative path, URL changes response.sendredirect ("file/jsp2.jsp");

4, request forward to servlet (servlet), you can use relative path, absolute path

// relative Path RequestDispatcher rd = Request.getrequestdispatcher ("Servlet2"); Rd.forward (request,response); // Absolute Path RequestDispatcher rd = Request.getrequestdispatcher ("/servlet2"); Rd.forward (request,response);              

SRC generic class for non-servlet classes

　　

1. General class access to resource files in WebContent

// use class to get the directory where this class is located (without Pacakage, only to classes), // get the absolute path of the resource file using GetResource () // in WebContent two times to return to the parent directory (Web-inf, project name Urltest) New File (Normalclass.  Class. getClassLoader (). GetResource (".. /.. /sourcefile/1.txt "new FileInputStream (FilePath);

2. General class interview resource file in src

// use class to get the directory where this class is located (without Pacakage, only to classes), // get the absolute path of the resource file using GetResource () New File (Normalclass.  Class. getClassLoader (). GetResource ("2.txt"new FileInputStream (FilePath);

Various paths in Web engineering (Eclipse development)