How to split multiple operator in string in java

Question

I have string in java but not understand how to split these type of string using.

I have only arithmetic and logical operator .

 char[] operators = new char[] { '\\', 'x', '+', '-', '>', '*','<', '=' };
  String str_spit="usa_newyork=japan\london*44+jhon<last-987";

Actual String - >

 String a= QN_770_0=QN_770_0\10

and

 String b= QN_770_0>66

My Code:

ArrayList <String> logics;
        ArrayList <String>  logicQuestions = null;

        char[] operators = new char[] { '\\', 'x', '+', '-', '>', '<', '=' };   

        String str_spit="QN_770_0=QN_770_0\10";
         for ( jj = 0; jj < operators.length; jj++)
         {
        System.out.println("operators.toString()---->"+operators[jj]);
        //String[] questions = logicText.split(operators);
         String s = "" + operators[jj];
        String[] questions=str_spit.split(s);
        System.out.println("questions questions---->"+questions);
        //for each segment, save all question codes. 
        for (int j = 0; j < questions.length; j++)
        {
         String question = questions[j];
         System.out.println("questions questions---question->"+questions);
            if (question.startsWith("QN_") && !logicQuestions.contains(question))
                logicQuestions.add(question);
            System.out.println("logicQuestions---logicQuestions->"+logicQuestions);
        }

         }

Error:

operators.toString()---->\
Exception in thread "main" java.util.regex.PatternSyntaxException: Unexpected internal error near index 1
\
 ^

I assume you want to keep the operators, too, right? So you know what operations to perform? So just a straight `String#split` using a character class regex won't do it... — T.J. Crowder, May 02 '14 at 09:23
possible duplicate of [Java: use split() with multiple delimiters](http://stackoverflow.com/questions/5993779/java-use-split-with-multiple-delimiters) — Rahul, May 02 '14 at 09:26

score 2 · Accepted Answer · answered May 02 '14 at 09:29

2

Try using StringTokenizer

    String delim = new String(operators);    
    StringTokenizer st = new StringTokenizer(str_spit, delim);
    while (st.hasMoreTokens()) {
        System.out.println(st.nextToken());
    }

answered May 02 '14 at 09:29

Suren Raju

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score 0 · Answer 2 · answered May 02 '14 at 09:32

I would use the Javascript engine to do this. It will not only parse the String but evalate it for you and much, much more.

ScriptEngineManager manager = new ScriptEngineManager();
ScriptEngine engine = manager.getEngineByName("nashorn");
ScriptContext context = new SimpleScriptContext();
int scope = context.getScopes().get(0);
context.setAttribute("japan", 100, scope);
context.setAttribute("london", 10, scope);
context.setAttribute("jhon", -10, scope);
context.setAttribute("last", 1000, scope);

String str = "usa_newyork= japan / london * 44 + jhon < last - 987";

Object usa_newyork = engine.eval(str, context);
System.out.println(usa_newyork);

prints

false

How to split multiple operator in string in java

2 Answers2