从Java中的文件读取数据

Question

I have a text file in the following format:

Details.txt

The file is a .txt file. I want to read course title from this file and print corresponding textbook and instructor information. But i am not sure about what process to follow ? storing the information in an array won't be efficient! How should i proceed ? NOTE: I can't change the info in the file, it should not be changed!! obviously the file will be read by the following code:

File newFile=new File("C:/details");

but how should i extract the data from this file according to the labels course title, textbook and instructor!?

Answer 1

Use String Tokenizer and separate each string and then store them in a Linked List or Array List. Have Separate List for each title like course title, instructor etc. and then print them

Answer 2

Use Scanner class

Scanner s=new Scanner(new File("C:/Details.txt"));
while(s.hasNext())
{
  System.out.println(s.nextLine());
}

if you want in work by word then use String Tokenizer

see this article

Answer 3

//Find the directory for the SD Card using the API
//*Don't* hardcode "/sdcard"
File sdcard = Environment.getExternalStorageDirectory();

//Get the text file
File file = new File(sdcard,"file.txt");

//Read text from file
StringBuilder text = new StringBuilder();

try {
    BufferedReader br = new BufferedReader(new FileReader(file));
    String line;

    while ((line = br.readLine()) != null) {
        text.append(line);
        text.append('\n');
    }
}
catch (IOException e) {
    //You'll need to add proper error handling here
}

//Find the view by its id
TextView tv = (TextView)findViewById(R.id.text_view);

//Set the text
tv.setText(text);

Answer 4

you can use FileUtils.readFileToString(new File(""C:/details.txt");

Now you can extract the required data based on your wish

Answer 5

1. First read the file correctly line by line, and search for your entered course title, lets consider "Java"

2. Now you hit your title and you know you need 3 consecutive lines from your file as all information related to that title are there.

    if(str.startsWith(title)); { // for title = "Java" line1 = 1st line // contains ISBN and First Name line2 = 2nd line // Title and Last Name line3 = 3rd line // Author and Department line4 = 4th line // Email break; // this will take you out of while loop } 

3. Now on those four lines do string operations and extract your data as you need and use it.

I am home so I can't give you exact code. But if you follow this it will solve your issue. Let me know if any problem you got while doing this.

Follow this to get some info on String operations