java - 使用 FileWriter Java 写入现有文件

Question

无论如何我可以使用 Filewriter 写入已经存在的文件

例如，当用户单击提交按钮时：

FileWriter writer = new FileWriter("myfile.csv");
writer.append("LastName");
writer.append(',');
writer.append("FirstName");
writer.append('/n');

writer.append(LastNameTextField.getText());
writer.append(',');
writer.append(FirstNameTextField.getText());

我希望能够将新数据写入已经存在的 myfile.csv 而不必每次都重新创建一个全新的数据

Answer 1

是的。像这样使用构造函数：

FileWriter writer = new FileWriter("myfile.csv",true);

Answer 2

FileWriter

public FileWriter(File file,
                  boolean append)
           throws IOException

Constructs a FileWriter object given a File object. If the second argument is true, then bytes will be written to the end of the file rather than the beginning.