StreamTokenizer类nextToken()方法 (StreamTokenizer Class nextToken() method)

• nextToken() method is available in java.io package.

  nextToken()方法在java.io包中可用。

• nextToken() method is used to parse the next token from the input stream of this StreamTokenizer and the type of the next token is returned in the ttype field.

  nextToken()方法用于解析此StreamTokenizer的输入流中的下一个标记，并且下一个标记的类型在ttype字段中返回。

• nextToken() method is a non-static method, it is accessible with the class object only and if we try to access the method with the class name then we will get an error.

  nextToken()方法是一个非静态方法，只能通过类对象访问，如果尝试使用类名称访问该方法，则会收到错误消息。

• nextToken() method may throw an exception at the time of returning next token.

  nextToken()方法在返回下一个令牌时可能会引发异常。

  IOException: This exception may throw when getting any input/output error while performing.

  IOException：在执行过程中遇到任何输入/输出错误时，可能引发此异常。

Syntax:

句法：

Public int nextToken();

Parameter(s):

参数：

• It does not accept any parameter.

  它不接受任何参数。

Return value:

返回值：

The return type of the method is int, it gets the value of ttype field (i.e. type of the next token).

该方法的返回类型为int ，它获取ttype字段的值(即下一个标记的类型)。

Example:

例：

// Java program to demonstrate the example // of int nextToken() method of StreamTokenizerimport java.io.*;public class NextToken {
       public static void main(String[] args) {
           String str = "Hi, This is a mathematical expression : \n" +            " 2 * 4 = 8" + "8 + 5 = 13";        try {
               // Instantiates FileOutputStream  and ObjectOutputStream             FileOutputStream fos_stm = new FileOutputStream("D:\\includehelp.txt");            ObjectOutputStream obj_out_stm = new ObjectOutputStream(fos_stm);            // By using writeUTF() method is to            // write the given string in the file            obj_out_stm.writeUTF(str);            obj_out_stm.flush();            // Instantiates FileOutputStream  and ObjectOutputStream             ObjectInputStream obj_in_stm = new ObjectInputStream(new FileInputStream("D:\\includehelp.txt"));            // Instantiates StreamTokenizer and Reader            Reader reader = new BufferedReader(new InputStreamReader(obj_in_stm));            StreamTokenizer st = new StreamTokenizer(reader);            // Here, we are considering initially             // file is not empty            boolean end_of_file = false;            while (!end_of_file) {
                   // By using nextToken() method is to                // parse the next token from the stream                int token = st.nextToken();                switch (token) {
                       case StreamTokenizer.TT_EOF:                        System.out.println("End of File Found");                        end_of_file = true;                        break;                    case StreamTokenizer.TT_EOL:                        System.out.println("End of Line Found");                        break;                    case StreamTokenizer.TT_WORD:                        System.out.println("word: " + st.sval);                        break;                    case StreamTokenizer.TT_NUMBER:                        System.out.println("number: " + st.nval);                        break;                    default:                        System.out.println((char) token + " Found.");                }            }        } catch (Exception ex) {
               ex.printStackTrace();        }    }}

Output

输出量

= Found.word: Hi, Found.word: Thisword: isword: aword: mathematicalword: expression: Found.number: 2.0* Found.number: 4.0= Found.number: 88.0+ Found.number: 5.0= Found.number: 13.0End of File Found

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