Java NetBeans-线程“主”中的异常java.io.FileNotFoundException：alice.txt系统找不到指定的文件

问题描述

我正在为HashMap编写代码，该代码在命令行中读取文件，但是我不确定是什么导致了此错误。是我不存在此文件，还是我使用错误的代码搜索文件？

        

        float[] vertices = {
                -0.5f,-0.5f,-0.0f,0.5f,0.0f,0.0f
        };
        FloatBuffer b = BufferUtils.createFloatBuffer(9);
        b.put(vertices);
        int VBO = glGenBuffers();
        int VAO = glGenVertexArrays();
        log.info("VBO:" + VBO + "VAO: " + VAO);
        // bind the Vertex Array Object first,then bind and set vertex buffer(s),and then configure vertex attributes(s).
        glBindVertexArray(VAO);

            
        glVertexAttribPointer(0,3,GL_FLOAT,false,12,0);
        glEnabLevertexAttribArray(0);
        glBindBuffer(GL_ARRAY_BUFFER,VBO);
        glBufferData(GL_ARRAY_BUFFER,vertices,GL_STATIC_DRAW);
        glBindVertexArray(0);       

            

        // Run the rendering loop until the user has attempted to close
        // the window or has pressed the ESCAPE key.
        while (!glfwWindowShouldClose(window))
            {
                // input
                // -----

                // render
                // ------
                glClearColor(0.2f,0.3f,1.0f);
                glClear(GL_COLOR_BUFFER_BIT);

                // draw our first triangle
                gluseProgram(shaderProgram);
                glBindVertexArray(VAO); // seeing as we only have a single VAO there's no need to bind it every time,but we'll do so to keep things a bit more organized
                glDrawArrays(GL_TRIANGLES,3);
                 glBindVertexArray(0); // no need to unbind it every time 
         
                // glfw: swap buffers and poll IO events (keys pressed/released,mouse moved etc.)
                // -------------------------------------------------------------------------------
                glfwSwapBuffers(window);
                glfwPollEvents();
            }

这是它引发的异常

import java.io.File;
import java.util.Arrays;
import java.util.Comparator;
import java.util.HashMap;
import java.util.Map;
import java.util.Scanner;
import java.util.Set;


public class WordFrequencies {

    @SuppressWarnings({"unchecked"})
    public static void main(String[] args) throws Exception {
        String path = new File(".").getAbsolutePath();
        path=path.substring(0,path.length() - 1);
        path+="alice.txt";
        File file = new File(path);
        String filename = "alice.txt";
        Map<String,Integer> frequencies = new HashMap<String,Integer>();
        Scanner sc = new Scanner(new File(filename));
        while (sc.hasNext()) {
            String word = sc.next();
            if (frequencies.containsKey(word)) {
                // increment the frequency count for this word by 1
                frequencies.put(word,frequencies.get(word)+1);
            } else {
                // start the frequency count at 1
                frequencies.put(word,1);
            }
        }
               
        System.out.println(frequencies);
       
        Set<Map.Entry<String,Integer>> entries = frequencies.entrySet();
       
        
        Map.Entry<String,Integer> [] entryArray = entries.toArray(new Map.Entry[0]);
               
        Arrays.sort(entryArray,new Comparator<Map.Entry<String,Integer>>() {
            public int compare(Map.Entry<String,Integer> o1,Map.Entry<String,Integer> o2) {
                return o1.getKey().compareto(o2.getKey());
            }
        });
       
        for (Map.Entry<String,Integer> entry : entryArray) System.out.println(entry);
       
        Arrays.sort(entryArray,Integer> o2) {
                return o1.getValue().compareto(o2.getValue());
            }
        });
        for (Map.Entry<String,Integer> entry : entryArray) System.out.println(entry);
       
    }

}

感谢您的帮助

解决方法

没有此类文件，并且引发了异常。 如果没有此类文件，则可以使用file.createNewFile（）处理此类情况。 另外，在使用Java I / O时-始终使用try / catch处理可能的异常：

if (!file.exists()) {
        try {
            file.createNewFile();
            // populate file,print it or do whatever you want
        } catch (IOException e) {
            e.printStackTrace();
        }
    }