如何检查文本板中的下一个空行并附加下一个输入

Question

您好，我的 UI 有问题。目前，我希望我的 UI 在每次单击保存时将输入附加到文本板中。单击保存按钮后，它将 return 到一个菜单，询问用户是否要输入另一个输入。如果用户单击是，它将 return 到输入部分。但是，当我第二次尝试输入时，它会覆盖我最初写的内容。如何更改我的代码以解决此问题？

  private void saveActionPerformed(java.awt.event.ActionEvent evt) {                                     
        // TODO add your handling code here:
        BufferedWriter output = null;
         FileInputStream fs = null;
        try {
            // TODO add your handling code here:
            File myFile = new File("C:/Users/kai/Desktop/sample.txt");
            fs = new FileInputStream("C:/Users/kai/Desktop/sample.txt");
            BufferedReader br = new BufferedReader(new InputStreamReader(fs));
             myFile.createNewFile();
            output = new BufferedWriter(new FileWriter(myFile));
            //output.flush();
            for(int i = 0; i<100; ++i){
                String line = br.readLine();
                if(line.equals(null)){
                   String name = text1.getText();
                   String id = text2.getText();
                   output.write(name + " " + id);
                   break;
                }

            }
           // output.newLine();




        } catch (IOException ex) {
            Logger.getLogger(setup.class.getName()).log(Level.SEVERE, null, ex);
        } finally {
            try {
                output.close();
            } catch (IOException ex) {
                Logger.getLogger(setup.class.getName()).log(Level.SEVERE, null, ex);
            }
        }

       this.dispose();
    }

Answer 1

However when I try inputing the second time, it will overwrite what I have written initially.

以附加模式打开 FileWriter。

阅读 FileWriter API 以找到合适的构造函数来使用。

Answer 2

一个新的 sample.txt 正在创建，甚至在从这里读取旧的之前。一种方法是将文本输入读入字符串并在新输出中添加换行符 ("\n") 并与输入连接以创建新的相同文件。

Answer 3

特别感谢 camickr 和 Kesavacharan。以下是我编辑的版本。如果您发现我的代码可以改进，请随时发表评论。

 private void saveActionPerformed(java.awt.event.ActionEvent evt) {                                     
        // TODO add your handling code here:
        BufferedWriter output = null;
         FileInputStream fs = null;
         FileWriter fout = null;
        try {
            // TODO add your handling code here:
            File myFile = new File("C:/Users/kai/Desktop/sample.txt");
            fs = new FileInputStream("C:/Users/kai/Desktop/sample.txt");
            BufferedReader br = new BufferedReader(new InputStreamReader(fs));
            output = new BufferedWriter(new FileWriter(myFile,true));
            PrintWriter fileout = new PrintWriter(output,true);
            for(int i = 0; i<100; ++i){
                String line = br.readLine();
                if(line==null){
                   String name = text1.getText();
                   String id = text2.getText();
                   fileout.println(name + " " + id);
                   break;
                }
            }




        } catch (IOException ex) {
            Logger.getLogger(setup.class.getName()).log(Level.SEVERE, null, ex);
        } finally {
            try {
                output.close();
            } catch (IOException ex) {
                Logger.getLogger(setup.class.getName()).log(Level.SEVERE, null, ex);
            }
        }

       this.dispose();
    }

如何检查文本板中的下一个空行并附加下一个输入

How to check the next empty line in textpad and append the next input

java

file-io

swing