Java StreamTokenizer eolIsSignificant()方法及示例
StreamTokenizer类eolIsSignificant()方法
eolIsSignificant()方法在java.io包中可用。
eolIsSignificant()方法用于识别行尾是否被视为标记。当布尔变量设置为true时,如果指示将行的末尾视为标记,并nextToken()返回TT_EOL并在布尔值设置为false时读取行的末尾,则将type字段设置为该值,则表示结束该行的空格被视为空白,并且仅分配给单独的令牌。
eolIsSignificant()方法是一种非静态方法,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。
在检查行尾是否有意义时,eolIsSignificant()方法不会引发异常。
语法:
Public void eolIsSignificant(boolean status);
参数:
布尔状态–当它标识行尾字符是单独的标记时,此参数设置为true;否则,它标识行尾字符是空格。
返回值:
该方法的返回类型为void,不返回任何内容。
示例
//Java程序演示示例
//eolIsSignificant(booleanstatus)方法的
//StreamTokenizer-
import java.io.*;
public class EolIsSignificant {
public static void main(String[] args) {
String str = "Hi, This is a mathematical expression : \n" +
" 2 * 4 = 8" + "8 + 5 = 13";
try {
//实例化FileOutputStream和ObjectOutputStream-
FileOutputStream fos_stm = new FileOutputStream("D:\\includehelp.txt");
ObjectOutputStream obj_out_stm = new ObjectOutputStream(fos_stm);
//通过使用writeUTF()方法是
//将给定的字符串写入文件
obj_out_stm.writeUTF(str);
obj_out_stm.flush();
//实例化FileOutputStream和ObjectOutputStream-
ObjectInputStream obj_in_stm = new ObjectInputStream(new FileInputStream("D:\\includehelp.txt"));
//实例化StreamTokenizer和Reader-
Reader reader = new BufferedReader(new InputStreamReader(obj_in_stm));
StreamTokenizer st = new StreamTokenizer(reader);
//通过使用eolIsSignificant()方法是
//将行尾设置为空白
//即“\n”被视为空格,而不是"\n"considers as whitespace instead of
//找到行尾
st.eolIsSignificant(false);
//在这里,我们开始考虑
//文件不为空
boolean end_of_file = false;
while (!end_of_file) {
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();
}
}
}输出结果
= Found. word: Hi , Found. word: This word: is word: a word: mathematical word: expression : Found. number: 2.0 * Found. number: 4.0 = Found. number: 88.0 + Found. number: 5.0 = Found. number: 13.0 End of File Found