Java Eclipse中动态Web项目中没有文件路径

Question

我在Eclipse中有一个动态的Web项目。 当我只执行WordFreq.java时，它可以工作。 如果要在MyServlet.java> doGet方法中执行相同的代码，则会出现以下错误：HTTP状态500-text.txt（系统找不到指定的文件）。 我到处都复制了文件（text.txt）：

• 项目根文件夹
• WebContent文件夹
• src文件夹
• 我项目中的任何子目录。

仍然出现此错误。

注意：我的工作区在D：/ ....中，而我的Apache服务器在C：/ ...中，我试图更改为完整路径，但仍然无法正常工作。

WordFreq.java

package cpd;
import java.io.*;
import java.util.Scanner;

public class WordFreq {

    public static void main(String[] args) throws IOException {
        File file1 = new File("text.txt");
        BufferedReader in = new BufferedReader(new FileReader(file1));
        String content = new Scanner(file1).useDelimiter("\\Z").next();
        CezarBun cezar = new CezarBun();
        System.out.println(cezar.criptare(content, 3));
        System.out.println("Frecventa literelor");
        System.out.println();
        int nextChar;
        char ch;
        double[] count = new double[26];
        while ((nextChar = in.read()) != -1) {
            ch = ((char) nextChar);
            if (ch >= 'a' && ch <= 'z') {
                count[ch - 'a']++;
            }
        }
        for (int i = 0; i < 26; i++) {
            System.out.printf("%c %d", i + 'a', (int) count[i]);
            System.out.println("Frecventa: " + count[i] / file1.length() * 100 + "%");
        }
        in.close();
        try {
            /*create a buffered reader that connects to the console, we use it so we can 
             read lines*/

            BufferedReader in2 = new BufferedReader(new InputStreamReader(System.in));
            //read a line from the console
            String lineFromInput = in2.readLine();
            //create an print writer for writing to a file
            PrintStream out = new PrintStream(new FileOutputStream("output.txt"));
            System.setOut(out);
            //output to the file a line
            out.println(lineFromInput);
            //close the stream
            out.close();
        } catch (IOException e1) {
            System.out.println("Error during reading/writing");
        }
    }
}

MyServlet.java

package cpd;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintStream;
import java.io.PrintWriter;
import java.util.Scanner;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Servlet implementation class MyServlet
 */
@WebServlet("/MyServlet")
public class MyServlet extends HttpServlet {

    private static final long serialVersionUID = 1L;

    /**
     * @see HttpServlet#HttpServlet()
     */
    public MyServlet() {
        super();
    }

    /**
     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse
     * response)
     */
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        response.setContentType("text/html");
        PrintWriter out = response.getWriter();
        out.print("A pornit servlet-ul" + "<br />");
    //inceput wordfreq
        File file1 = new File("text.txt");
        BufferedReader in = new BufferedReader(new FileReader(file1));
        String content = new Scanner(file1).useDelimiter("\\Z").next();
        CezarBun cezar = new CezarBun();
        System.out.println(cezar.criptare(content, 3));
        System.out.println("Frecventa literelor");
        System.out.println();
        int nextChar;
        char ch;
        double[] count = new double[26];
        while ((nextChar = in.read()) != -1) {
            ch = ((char) nextChar);
            if (ch >= 'a' && ch <= 'z') {
                count[ch - 'a']++;
            }
        }
        for (int i = 0; i < 26; i++) {
            System.out.printf("%c %d", i + 'a', (int) count[i]);
            System.out.println("        Frecventa:      " + count[i] / file1.length() * 100 + "%");

        }
        in.close();
        try {
            //create a buffered reader that connects to the console, we use it so we can read lines
            BufferedReader in2 = new BufferedReader(new InputStreamReader(System.in));
            //read a line from the console
            String lineFromInput = in2.readLine();
            //create an print writer for writing to a file
            PrintStream out2 = new PrintStream(new FileOutputStream("output.txt"));
            System.setOut(out2);
            //output to the file a line
            out2.println(lineFromInput);
            //close the file (VERY IMPORTANT!)
            out2.close();
        } catch (IOException e1) {
            System.out.println("Error during reading/writing");
        }
    //sfarsit wordfreq
    // freq = new WordFreqBun();
        //freq.wf();
        out.print("<br />");
        out.print("<a href='http://localhost:8080/CpdApplication/'>Inapoi la meniu</a>");
    }

    /**
     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse
     * response)
     */
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    }
}

Answer 1

您可以使用ServletContext.getResourceAsStream（）作为资源来访问文件，该文件可以位于Web应用程序中的任何位置。 如果您不希望浏览器访问它，建议将其保存在/ WEB-INF目录下。

ServletContext context = getServletContext();
InputStream is = context.getResourceAsStream("/file.txt");
BufferedReader in = new BufferedReader(new InputStreamReader(is));

ServletContext.getResource（） ：返回映射到给定路径的资源的URL。

ServletContext.getResourceAsStream（） ：以InputStream对象的形式返回位于指定路径处的资源。