Java 21-10 text files and collections store data between each other

sometimes, we encounter situations where we write data to a text file separately. Like what:

　　　requirement : To store string data in the ArrayList collection into a text file

　　　Analysis :

A string class is stored in the A:arraylist collection

B: the file to be stored is a text file, so with a character stream, in order to quickly, with buffer character stream a

Data source:

Arraylist<string>-----iterate through the collection to get the data

Destination:

C.txt------FileWriter------bufferedwriter

1      public Static voidMain (string[] Args)throwsIOException {2         //Encapsulating Data (creating collection Objects)3Arraylist<string> Arry =NewArrayList ();4         //Add Data5Arry.add ("i");6Arry.add ("want");7Arry.add ("sleep. ");8         9         //Package DestinationTenBufferedWriter BW =NewBufferedWriter (NewFileWriter ("c.txt")); oneString line =NULL; a         intLen = 0; -         //iterate through the array, write the data to the destination -          for(String S:arry) { the Bw.write (s); - Bw.newline (); - Bw.flush (); -         } + bw.close (); -  +}

again, Sometimes we need to extract the data from the text file and store it in the collection:

　　requirement: reads data from a text file (each behavior is a string of Data) into the collection and iterates through the collection

　　Analysis:

A: the data is read from a text file, the stream is entered with a buffered character Bufferreader

B: because in order to be fast, the use of each behavior is a string of data read, so the collection type is the String class

Data source:
Copy.txt--filereader--bufferedreader
Destination:
Arraylist<string>

1  public Static voidMain (string[] Args)throwsIOException {2         //Encapsulating Data Sources3BufferedReader br =NewBufferedReader (NewFileReader ("copy.txt"));4         //encapsulate Destination (create Collection)5Arraylist<string> Arry =NewArrayList ();6         //reads data from the data source and writes the data to the collection7String line =NULL;8          while(line = Br.readline ())! =NULL){9 Arry.add (line);Ten         } one br.close (); a          -         //iterating through an array -          for(String S:arry) { the System.out.println (s); -         } -  -}

Java 21-10 text files and collections store data between each other