用Java编写文本文件的最简单方法是什么？

Question

我想知道用 Java 编写文本文件的最简单（也是最简单）的方法是什么。请简单，因为我是初学者：D

我在网上搜索并找到了这段代码，但我理解了其中的 50%。

import java.io.BufferedWriter;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;

public class WriteToFileExample {
public static void main(String[] args) {
    try {

        String content = "This is the content to write into file";

        File file = new  File("C:/Users/Geroge/SkyDrive/Documents/inputFile.txt");

        // if file doesnt exists, then create it
        if (!file.exists()) {
            file.createNewFile();
        }

        FileWriter fw = new FileWriter(file.getAbsoluteFile());
        BufferedWriter bw = new BufferedWriter(fw);
        bw.write(content);
        bw.close();

        System.out.println("Done");

    } catch (IOException e) {
        e.printStackTrace();
    }
}

}

Answer 1

追加文件FileWriter(String fileName, boolean append)

try {   // this is for monitoring runtime Exception within the block 

        String content = "This is the content to write into file"; // content to write into the file

        File file = new  File("C:/Users/Geroge/SkyDrive/Documents/inputFile.txt"); // here file not created here

        // if file doesnt exists, then create it
        if (!file.exists()) {   // checks whether the file is Exist or not
            file.createNewFile();   // here if file not exist new file created 
        }

        FileWriter fw = new FileWriter(file.getAbsoluteFile(), true); // creating fileWriter object with the file
        BufferedWriter bw = new BufferedWriter(fw); // creating bufferWriter which is used to write the content into the file
        bw.write(content); // write method is used to write the given content into the file
        bw.close(); // Closes the stream, flushing it first. Once the stream has been closed, further write() or flush() invocations will cause an IOException to be thrown. Closing a previously closed stream has no effect. 

        System.out.println("Done");

    } catch (IOException e) { // if any exception occurs it will catch
        e.printStackTrace();
    }

Answer 2

您可以使用来自 Apache Commons 的 FileUtils：

import org.apache.commons.io.FileUtils;

final File file = new File("test.txt");
FileUtils.writeStringToFile(file, "your content", StandardCharsets.UTF_8);

Answer 3

您可以使用JAVA 7 new File API 来做到这一点。

代码示例： `

public class FileWriter7 {
    public static void main(String[] args) throws IOException {
        List<String> lines = Arrays.asList(new String[] { "This is the content to write into file" });
        String filepath = "C:/Users/Geroge/SkyDrive/Documents/inputFile.txt";
        writeSmallTextFile(lines, filepath);
    }

    private static void writeSmallTextFile(List<String> aLines, String aFileName) throws IOException {
        Path path = Paths.get(aFileName);
        Files.write(path, aLines, StandardCharsets.UTF_8);
    }
}

`

Answer 4

您的代码是最简单的。但是，我总是尝试进一步优化代码。这是一个示例。

try (BufferedWriter bw = new BufferedWriter(new FileWriter(new File("./output/output.txt")))) {
    bw.write("Hello, This is a test message");
    bw.close();
    }catch (FileNotFoundException ex) {
    System.out.println(ex.toString());
    }

Answer 5

Files.write() 正如@Dilip Kumar 所说的简单解决方案。我曾经使用这种方式，直到遇到问题，不能影响行分隔符（Unix/Windows）CR LF。

所以现在我使用 Java 8 流文件写入方式，这让我可以即时操作内容。 :)

List<String> lines = Arrays.asList(new String[] { "line1", "line2" });

Path path = Paths.get(fullFileName);
try (BufferedWriter writer = Files.newBufferedWriter(path)) {   
    writer.write(lines.stream()
                      .reduce((sum,currLine) ->  sum + "\n"  + currLine)
                      .get());
}     

通过这种方式，我可以指定行分隔符，或者我可以执行任何类型的魔法，例如 TRIM、大写、过滤等。

Answer 6

对于 Java 7 及更高版本，使用 Files 的单行：

String text = "Text to save to file";
Files.write(Paths.get("./fileName.txt"), text.getBytes());

Answer 7

File file = new File("path/file.name");
IOUtils.write("content", new FileOutputStream(file));

IOUtils 也可用于使用 java 8 轻松写入/读取文件。

Answer 8

String content = "your content here";
Path path = Paths.get("/data/output.txt");
if(!Files.exists(path)){
    Files.createFile(path);
}
BufferedWriter writer = Files.newBufferedWriter(path);
writer.write(content);

Answer 9

在Java 11或更高版本中，writeString可以从java.nio.file.Files使用，

String content = "This is my content";
String fileName = "myFile.txt";
Files.writeString(Paths.get(fileName), content); 

带选项：

Files.writeString(Paths.get(fileName), content, StandardOpenOption.CREATE)

有关java.nio.file.Files 和StandardOpenOption 的更多文档