File 类的 listFiles() 方法返回一个数组，该数组保存由当前（文件）对象。
将文件夹中所有文件的内容读取到单个文件中 -
- 通过传递创建文件对象所需的文件路径作为参数。
- 使用 Scanner 或任何其他读取器读取每个文件的内容。
- 将读取的内容附加到 StringBuffer 中。
- 将 StringBuffer 内容写入所需的输出文件。
示例
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.Scanner;
public class Test {
public static void main(String args[]) throws IOException {
//Creating a File object for directory
File directoryPath = new File("D:\SampleDirectory");
//List of all files and directories
File filesList[] = directoryPath.listFiles();
System.out.println("List of files and directories in the specified directory:");
Scanner sc = null;
StringBuffer sb = new StringBuffer();
for(File file : filesList) {
System.out.println("File name: "+file.getName());
System.out.println("File path: "+file.getAbsolutePath());
System.out.println("Size :"+file.getTotalSpace());
//Instantiating the Scanner class
sc= new Scanner(file);
String input;
while (sc.hasNextLine()) {
input = sc.nextLine();
sb.append(input+" ");
}
System.out.println("Contents of the file: "+sb.toString());
System.out.println(" ");
//Instantiating the FileOutputStream class
FileOutputStream fileOut = new FileOutputStream("D:\output.txt");
//Instantiating the DataOutputStream class
DataOutputStream outputStream = new DataOutputStream(fileOut);
//Writing UTF data to the output stream
outputStream.write(sb.toString().getBytes());
outputStream.flush();
System.out.println("Data entered into the file");
}
}
}输出
List of files and directories in the specified directory: File name: sample1.txt File path: D:\SampleDirectory\sample1.txt Contents of the file: sample text file1 Data entered into the file File name: sample2.txt File path: D:\SampleDirectory\sample2.txt Contents of the file: sample text file2 Data entered into the file File name: sample3.txt File path: D:\SampleDirectory\sample3.txt Contents of the file: sample text file3 Data entered into the file
