Various paths in the web project (eclipse development)

The files that need to write url and path in the web project currently encountered are: 

• webContent中.jsp/.html
• servlet class in src
• src normal class of non-servlet class

.jsp/.html

form submit action

1. Jump to .jsp

Use relative paths, relative to the web project root directory

 

<!-- from JSP1.jsp to JSP2.jsp --> 
<!-- JSP1.jsp中的form --> 
<form action="File/JSP2.jsp">

<!-- from JSP2.jsp to JSP1.jsp --> 
<!-- JSP2.jsp中的form --> 
<form action="../JSP1.jsp">

 

2. Jump to servlet1

has nothing to do with package

 

// Mapping address of Servlet1.java@WebServlet 
(name = "Servlet1", urlPatterns = { "/Servlet1" })

<!-- from JSP2.jsp to Servlet1 --> 
<!-- JSP2.jsp中的form --> 
<form action="../Servlet1">

 

Change the mapping address of the servlet so that the servlet is mapped to a folder with JSP2.jsp

// After modifying the mapping address of servlet1@WebServlet 
(name = "Servlet1", urlPatterns = { "/File/Servlet1" })

<!-- from JSP2.jsp to Servlet1 --> 
<!-- JSP2.jsp中的form --> 
<form action="Servlet1">

 

 Change the servlet mapping address again, and the servlet is mapped to the virtual directory

// After modifying the mapping address of servlet1 again, map it to the virtualFile virtual directory 
@WebServlet(name = "Servlet1", urlPatterns = { "/virtualFile/Servlet1" })

<!-- from JSP2.jsp to Servlet1 --> 
<!-- JSP2.jsp中的form --> 
<form action="../virtualFile/Servlet1">

 

servlet class in src

    1. The mapping address in the url annotation, contact jsp (html)

    2. Access the resource file 1.txt in webContent (according to the project structure in tomcat)

 

//利用getServletContext().getRealPath()
String filePath = 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
BufferedReader br = new BufferedReader(new FileReader(filePath));

　

　　2. Access resource files in src

// To access the files in src, the absolute path should be obtained according to the project directory in tomcat
 // The servlet should not be mapped to the virtual directory 
String filePath = this .getServletContext().getRealPath("/WEB-INF/classes/2.txt" ) ;
BufferedWriter br = new BufferedWriter(new FileWriter(filePath));

　

　3. Redirect to servlet (jsp), only relative path can be used

// Redirect using relative path, url changes 
response.sendRedirect("File/JSP2.jsp");

 

　4. The request is forwarded to the servlet (servlet), and the relative path and absolute path can be used.

// Relative path 
RequestDispatcher rd = request.getRequestDispatcher("Servlet2" );
rd.forward(request,response);
// Absolute path 
RequestDispatcher rd = request.getRequestDispatcher("/Servlet2" );
rd.forward(request,response);              

 

src normal class of non-servlet class

 

Access resource files in webContent

// Use class to get the directory where this class is located (excluding pacakage, only to classes),
 // Use getResource() to get the absolute path of the resource file
 // In webContent, you need to return to the upper-level directory twice (WEB-INF, project name URLTest) 
File filePath = new File(NormalClass.class.getClassLoader ( ).getResource("../../sourceFile/1.txt" ).getPath());
FileInputStream fn = new FileInputStream(filePath);

 

Access resource files in src

// Use class to get the directory where this class is located (excluding pacakage, only to classes),
 // Use getResource() to get the absolute path of the resource file 
File filePath = new File(NormalClass.class .getClassLoader ().getResource("2. txt" ).getPath());
FileInputStream fn = new FileInputStream(filePath);