为什么这段代码读取文件路径而不是文件中的文本?

Question

下面是我的readFromFile代码:

private void readFromFile(String file) {
    String string = "";
    //reading   
    try{
        InputStream ips=new FileInputStream(filename); 
        InputStreamReader ipsr=new InputStreamReader(ips);
        BufferedReader br=new BufferedReader(ipsr);
        String line;
        while ((line=br.readLine())!=null){                
            string += line + "n";
        }
        br.close(); 
        txaConversation.setText(string);
    }       
    catch (Exception e){
        System.out.println(e.toString());
    }
}

下面是我的对话框中"加载按钮"的代码:

JFileChooser fc = new JFileChooser();
    int choice = fc.showOpenDialog(null);
    if (choice == JFileChooser.APPROVE_OPTION) {
        String filename = fc.getSelectedFile().getAbsolutePath();
        readFromFile(filename);
        txaConversation.setText(filename);
    }

如果你会问，这里是writeToFile代码:

private void writeToFile(String filename) {
    try {
        String content = txaConversation.getText();
        File file = new File(filename);
        // 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();
}
}

和"button save"代码:

JFileChooser fc = new JFileChooser();
    int choice = fc.showSaveDialog(null);
    if (choice == JFileChooser.APPROVE_OPTION) {
        String filename = fc.getSelectedFile().getAbsolutePath();
        txaConversation.setText(filename);
        writeToFile(filename);
    }

当我保存它并从我的电脑上打开文本文件时，我可以看到文本。但是当我使用我的程序加载它时，它显示了文件路径

Answer 1

应该是ips.readLine()而不是br.readLine()

        int line;
        while ((line=ips.read())!=-1){                
            string += (char)line ;
        }

不需要

    InputStreamReader ipsr=new InputStreamReader(ips);
    BufferedReader br=new BufferedReader(ipsr);

Answer 2

您的意思是在您的UI中显示文件的名称，而不是内容?

JFileChooser fc = new JFileChooser();
int choice = fc.showOpenDialog(null);
if (choice == JFileChooser.APPROVE_OPTION) {
    String filename = fc.getSelectedFile().getAbsolutePath();
    readFromFile(filename); // This reads the file content, but does not store it
    txaConversation.setText(filename); // Previous content of filename variable is the absolute path
}

将最后两行更改为以下内容，您将显示文件

的内容

filename = readFromFile(filename);
txaConversation.setText(filename);

并将readFromFile方法更改为以下

private String readFromFile(String file) {
    String string = "";
    //reading   
    try{
        InputStream ips=new FileInputStream(filename); 
        InputStreamReader ipsr=new InputStreamReader(ips);
        BufferedReader br=new BufferedReader(ipsr);
        String line;
        while ((line=br.readLine())!=null){                
            string += line + "n";
        }
        br.close();
    }       
    catch (Exception e){
        System.out.println(e.toString());
    }
    return string;
}

我还强烈建议您查看finally块中的资源处理