我如何打开java文件而不删除其内容？

Question

public void write() {
    try {
        file = new File("c:\\Users\\Me\\Desktop\\text.txt");
        
        if(!file.exists())            // I found this somewhere on the internet for File class
            file.createNewFile();     // not to remove contents. I have no idea if it works
        
        writer = new Formatter(file);
    
    } catch(Exception e) {
        e.printStackTrace();
    }

    writer.format("%s  %s ", nameInput.getText(),lastNameInput.getText());
    
    writer.close();
}

Answer 1

首先，这里的代码是：

if(!file.exists())            
        file.createNewFile();

它只在路径中不存在的情况下创建一个新文件。

要在不覆盖文件的情况下写入文件,建议您执行以下操作：

FileWriter fileWriter;
public void write() {
try {
    file = new File("c:\\Users\\Me\\Desktop\\text.txt");

    if(!file.exists())            
        file.createNewFile();

    // use a FileWriter to take the file to write on 
    fileWriter = new FileWriter(file, true); // true means that you do not overwrite the file
    writer = new Formatter(fileWriter); // than you put your FileWriter in the Formatter

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

writer.format("%s  %s ", nameInput.getText(),lastNameInput.getText());

writer.close();
}