Question

用Java读取文件。我得到“FileNotFound”异常。例外：

java.io.FileNotFoundException: something.txt (The file was not found)
    at java.io.FileInputStream.open(Native Method)
    at java.io.FileInputStream.<init>(Unknown Source)
    at java.io.FileReader.<init>(Unknown Source)
    at rmihello.ReadStringFromFileLineByLine.main(ReadStringFromFileLineByLine.java:13)

即使我的文件位于我的源代码旁边的bin中：我也尝试过给我文件的整个路径，例如

path = "C:/Users/Alexander/Desktop/java/something.txt"

或

path = "cd 'C:/Users/Alexander/Desktop/java/something.txt'"

所有这一切都失败了这是我的代码

import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;

public class ReadStringFromFileLineByLine {

    public static void main(String[] args) {
        try {
            String path = "something.txt";
            File file = new File(path);
            FileReader fileReader = new FileReader(file);
            BufferedReader bufferedReader = new BufferedReader(fileReader);
            StringBuffer stringBuffer = new StringBuffer();
            String line;
            while ((line = bufferedReader.readLine()) != null) {
                stringBuffer.append(line);
                stringBuffer.append("\n");
            }
            fileReader.close();
            System.out.println("Contents of file:");
            System.out.println(stringBuffer.toString());
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

Answer 1

正如评论中所提到的，您的代码应该像这样开始：

 Path file = ; //Specify the path to your file

查看Reading, Writing, and Creating Files in Java了解更多信息

修改

只需像这样编辑你的代码就可以了。

public static void main(String[] args){ String path = "C://Something.txt"; // I put the file under the C: path in my example try { File file = new File(path); FileReader fileReader = new FileReader(file); BufferedReader bufferedReader = new BufferedReader(fileReader); StringBuffer stringBuffer = new StringBuffer(); String line; while ((line = bufferedReader.readLine()) != null) { stringBuffer.append(line); stringBuffer.append("\n"); } fileReader.close(); System.out.println("Contents of file:"); System.out.println(stringBuffer.toString()); } catch (IOException e) { e.printStackTrace(); } }

然后只需更改路径以适合您的路径。

Answer 2

相对路径增加了文件未找到的不确定性。在尝试替代方案时，请处理错误：

    File file = new File("C:/.../something.txt");
    try {
        ...
    } catch (FileNotFoundException e) {
       File full = file.getAbsoluteFile();
       File dir = file.getParentFile();
       while (dir != null && !dir.exists()) {
           dir = dir.getParentFile();
       }
       System.out.printf("File %s does not exist under %s%n",
               full.getPath(),
               dir == null ? "/" : dir.getPath());
    } catch (IOException e2) {
    }

提示：

StringBuilder更快，是StringBuffer的继承者。

新风格（自Java 7起）：

Path path = Paths.get("C:/...");
byte[] content = Files.readAllBytes(path);
String contentText = new String(content); // Default encoding

Answer 3

如果您将文本文件插入名为text_files的文件夹中，则可以使用

访问它

文件f =新文件（“text_files / something.txt”）;

在java中读取.text文件

3 个答案: