import java.util.StringTokenizer;import java.util.regex.Pattern;import org.junit.Test;public class TestStringToken {  @Test  public void subSting() {    String str = "java,javac,javae";    String s1 = str.substring(2);//"va,javac,javae"    String s2 = str.substring(0,2);//"ja"    System.out.println(s1);    System.out.println(s2);  }  @Test  public void stringTokenizer() {    String str = "java,javac,javae";    StringTokenizer stringTokenizer = new StringTokenizer(str, ",");//   while (stringTokenizer.hasMoreElements()) {//     Object object = (Object) stringTokenizer.nextElement();//     System.out.println(String.valueOf(object));//     //   }    while (stringTokenizer.hasMoreTokens()) {      System.out.println(stringTokenizer.nextToken());    }  }  @Test  public void split() {    String str = "java,javac,javae";    String[] s = str.split(",");    for (String string : s) {      System.out.println(string);    }  }  //使用正則表達式  @Test  public void pattern() {    String str = "java,javac,javae";    Pattern p = Pattern.compile(",");    String[] s = p.split(str);    for (String string : s) {      System.out.println(string);    }  }}