Evaluate a string containing a constant name

Hi,
how can I evaluate a string containing a constant name
such as
String a= " Integer.MAX_INT";
thx a lot,
tiz

Er...no. Integer.MAX_INT is an int, and you can't call methods on primitive types. :-)
What you might need to do is check for these constants and set the values yourself. Otherwise you'll have a load of difficulty parsing strings and what-not.

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Evalutate a string containing a numeric expression

I need a function which would evaluate a string containing numbers and operators like "1+1" and return 2. The function should take into account precedence and all arithmetic and logical operators
Thanks
Mita

Why don't you use the JDK compiler APIs (com.sun.javac.Main class) to compile on the fly a class implementing this interface:
public interface Evaluator {
public double evaluate() {
return xxx;
where xxx is your expression?
Obviously, you build this class' source at runtime when you get the expression as input, and after you compile it you load it with Class.ForName(), instanciate it with newIstance() and the call the "evaluate" method.
The advantage of this approach is that you can use "automagically" every expression available in java language. And with some extra effort of text-processing, even the Math functions!!!
Giorgio Maone

Obtain string of IN variable name in PL/SQL

Hi,
Odd question. Is there a way to access an IN variable's object name in a procedure?
eg.
procedure (var1    IN VARCHAR2(6),
                var2    IN VARCHAR2(6),
                var3    IN VARCHAR2(6))
IS....You run this procedure and pass in parameters of:
var1 => 'abcdef',
var2 => 'defghi',
var3 => 'ghikjl';
In the code, I want to access the number in the string of the +variable name: var1+
In a naive sense,
num_of_in_var := substr(var1, 4,1) would be what i was hoping to achieve, but,
var1 is set to 'abcdef' so,
num_of_in_var := substr(var1, 4,1) would return 'd'.
Any thoughts?
Thanks
Edited by: chris001 on Nov 20, 2012 1:16 PM

Here's an example of how (what you want to do using a procedure or function), can be done using a ADT/UDT (Advance/User Defined Type) in Oracle.
This approach will not work for standard procedures and functions as this type of dynamic referencing of the code unit/object to itself, is not possible.
SQL> create or replace type TSomeObject as object(
2          name    varchar2(10),
3          id      integer,
4          day     date,
5
6          member function PropertyByNumber( n integer ) return varchar2
7 );
8 /
Type created.
SQL>
SQL> create or replace type body TSomeObject as
2
3          member function PropertyByNumber( n integer ) return varchar2 is
4                  PLSQL_PROP_GET constant varchar2(1000) :=
5                          'declare
6                                  obj     TSomeObject;
7                          begin
8                                  obj := :1;
9                                  :2 := to_char( obj.#PROPERTY# );
10                          end;';
11
12                  type            TStrings is table of varchar2(30);
13                  property        TStrings;
14                  dynamicBlock    varchar2(1000);
15                  res             varchar2(4000);
16          begin
17                  select
18                          a.attr_name bulk collect into property
19                  from    user_type_attrs a
20                  where   a.type_name = 'TSOMEOBJECT'
21                  order by
22                          a.attr_no;
23
24                  dynamicBlock := replace( PLSQL_PROP_GET, '#PROPERTY#', property(n) );
25                  execute immediate dynamicBlock
26                  using   in self,
27                          out res;
28
29                  return( res );
30          end;
31
32 end;
33 /
Type body created.
SQL>
SQL> declare
2          obj     TSomeObject;
3 begin
4          obj := new TSomeObject( 'John Doe', 123, trunc(sysdate) );
5
6          for i in 1..3 loop
7                  dbms_output.put_line( 'property '||i||'='||obj.PropertyByNumber(i) );
8          end loop;
9 end;
10 /
property 1=John Doe
property 2=123
property 3=2012/11/23 00:00:00
PL/SQL procedure successfully completed.
SQL> Simplistic example (the PropertyByNumber could be a static class method defined in the abstract parent class) - and one that requires the object to essentially duplicate itself via a bind variable call to dynamic code. Not really the best of approaches, but demonstrates the flexibility (to do even interestingly weird stuff) in PL/SQL.

Evaluate a string

Hi,
I have a string that contains a logical expression, for example String str="(true | false) & true".
I want to evaluate this expression just like if it was a boolean.
So I would like to write
if (str) { int test=0; }But this piece of code is wrong. I need a function "eval" that evaluate the expression contained in str, so that I can write
if (eval(str)) { int test=0; }How can I do ? Thank you for your answers

Never worked with it yet, but have a look at the javax.script package (since java 1.6).
Piet

When String instances in Constant Pool will be GC'ed?

Hi all,
I'm involved in an application development; where we are storing numerous string objects into multiple HashMaps. Since the string objects created/placed in HashMap may have duplicate values; we're calling String::intern() method to make use of String Constant Pool feature in Java. But, my concern is - When the Constant String instance will be removed from Pool? Is it follow the same behaviour that if no references are presentm it is eligible for GC; i.e., removal of an instance from all HashMaps?
Please help.
Thanks & regards,
R Kaja Mohideen

EJP wrote:
How do you figure?Doesn't say so in the Javadoc. It talks about another pool ...You're taking "A pool of strings, initially empty, is maintained privately by the class String." as meaning it's not "the constant pool"? I wouldn't interpret it that way. And based on the JVM spec, I don't see anything saying the intern()ed Strings go to a different pool than "the constant pool". And if it is a separate pool, then what does go into "the constant pool"?
http://java.sun.com/docs/books/jvms/second_edition/html/Overview.doc.html#22972
"A runtime constant pool is a per-class or per-interface runtime representation of the constant_pool table in a class file (§4.4). It contains several kinds of constants, ranging from numeric literals known at compile time to method and field references that must be resolved at run time. "
"Each runtime constant pool is allocated from the Java virtual machine's method area (§3.5.4)."
http://java.sun.com/docs/books/jvms/second_edition/html/Overview.doc.html#6656
"The Java virtual machine has a method area that is shared among all Java virtual machine threads. [...] It stores per-class structures such as the runtime constant pool, field and method data, and the code for methods and constructors [...]"
http://java.sun.com/docs/books/jvms/second_edition/html/ConstantPool.doc.html#73272
"The Java virtual machine maintains a per-type constant pool (§3.5.5),"
"A string literal (§2.3) is derived from a CONSTANT_String_info structure (§4.4.3) in the binary representation of a class or interface. The CONSTANT_String_info structure gives the sequence of Unicode characters constituting the string literal.
The Java programming language requires that identical string literals (that is, literals that contain the same sequence of characters) must refer to the same instance of class String. In addition, if the method String.intern is called on any string, the result is a reference to the same class instance that would be returned if that string appeared as a literal. Thus,
("a" + "b" + "c").intern() == "abc"
must have the value true.
To derive a string literal, the Java virtual machine examines the sequence of characters given by the CONSTANT_String_info structure.
If the method String.intern has previously been called on an instance of class String containing a sequence of Unicode characters identical to that given by the CONSTANT_String_info structure, then the result of string literal derivation is a reference to that same instance of class String.
Otherwise, a new instance of class String is created containing the sequence of Unicode characters given by the CONSTANT_String_info structure; that class instance is the result of string literal derivation. Finally, the intern method of the new String instance is invoked."
Edited by: jverd on Jan 23, 2012 8:09 AM

Code to check whether a given string contains alphanumeric

Can anyone post the Code to check whether a given string contains only alphanumeric and no special characters

<Rule name='isAlphaNumericString'>
<RuleArgument name='testStr'/>
<block>
<defvar name='counter'>
0
</defvar>
<defvar name='splitString'>
<while>
<lt>
<ref>counter</ref>
<length>
<ref>testStr</ref>
</length>
</lt>
<append name='splitList'>
<substr>
<ref>testStr</ref>
<ref>counter</ref>
1
</substr>
</append>
<set name='counter'>
<add>
<ref>counter</ref>
1
</add>
</set>
</while>
<ref>splitList</ref>
</defvar>
<containsAll>
<list>
<s>A</s>
<s>B</s>
<s>C</s>
<s>D</s>
<s>E</s>
<s>F</s>
<s>G</s>
<s>H</s>
<s>I</s>
<s>J</s>
<s>K</s>
<s>L</s>
<s>M</s>
<s>N</s>
<s>O</s>
<s>P</s>
<s>Q</s>
<s>R</s>
<s>S</s>
<s>T</s>
<s>U</s>
<s>V</s>
<s>W</s>
<s>X</s>
<s>Y</s>
<s>Z</s>
<s>a</s>
<s>b</s>
<s>c</s>
<s>d</s>
<s>e</s>
<s>f</s>
<s>g</s>
<s>h</s>
<s>i</s>
<s>j</s>
<s>k</s>
<s>l</s>
<s>m</s>
<s>n</s>
<s>o</s>
<s>p</s>
<s>q</s>
<s>r</s>
<s>s</s>
<s>t</s>
<s>u</s>
<s>v</s>
<s>w</s>
<s>x</s>
<s>y</s>
<s>z</s>
<s>0</s>
<s>1</s>
<s>2</s>
<s>3</s>
<s>4</s>
<s>5</s>
<s>6</s>
<s>7</s>
<s>8</s>
<s>9</s>
</list>
<ref>splitString</ref>
</containsAll>
</block>
</Rule>
It Retruns 1 if it contains only alphanumeric otherwise 0

Construct a string containing a command

Hi experts
please help me
Is there a way to dynamically construct code, such as:
I'd like to write a method that receives as input a string identifying a node name, and use it as follows:
wdcontext.current<InputNodeName>Element.get<AttributeName><do whatever I want>
OR
Is there a way to construct a string containing a command, and then execute it?
Such as: If I construct the following in a string by concatenating different parts of the string: wdcontext.current<InputNodeName>Element.get<AtributeName>.<do whatever I want>
Can I then pass the resulting string to some function that actually executes it?

Hi,
Unfortunately - there is no way to construct the command dynamically so that the command will execute. The parameters that are part of teh command may be dynamic (using Super classes and method overloading).
However, in case you want to write a single method that does all the function calling then what you need to do is:
1.) Make a context attribute that will hold some code (1,2,3 or A,B,C etc)
2.) Create the method that will read this attribute.
3.) After reading the attribute write a switch case or an if statement that will run your command.
Of course for this you will need to know all the required commands at design time.
Thanks.
p256960

How to find out whether the String contains chinese characters

I need to check if the string contains chinese characters in Java. Does anyone know how to do it? thx.

Since Java strings contain UNICODE code points, check the content against the relevant page here - http://www.unicode.org/charts/ .

How to parse a string containing xml data

Hi,
Is it possible to parse a string containing xml data into a array list?
my string contains xml data as <blood_group>
 <choice id ='1' value='A +ve'/>
 <choice id ='2' value='B +ve'/>
 <choice id ='3' value='O +ve'/>
</blood_group>how can i get "value" into array list?

There are lot of Java XML parsing API's available, e.g. JAXP, DOM4J, JXPath, etc.
Of course you can also write it yourself. Look which methods the String API offers you, e.g. substring and *indexOf.

How to use string as a column name

Hello,
I have a fn getField() that returns a column delimited string - amt1,amt2 . I want to use this string as the column name in a second query on table MASTER_AMT and get the values for amt1 and amt2...so when i try....
select getField( 'NPC_NOYTG' ) FROM MASTER_AMT
WHERE ACTI_CODE = 'NPOR';
the o/p i get is...
GETFIELD('NPC_NOYTG')
AMT1,AMT2,AMT3
instead of...
AMT1 AMT2
500 0
that i require.
Any ideas on how to convert the string returned to a column name?
Thanks very much
rgds

Try this ....
In SQL*PLUS
SQL> var ref_c refcursor
--- Then type the follwing at SQL prompt
declare
cursor cur is
select column_name
from user_tab_columns a,
     (select upper(getField( 'NPC_NOYTG')) fld FROM MASTER_AMT
     WHERE ACTI_CODE = 'NPOR') col_lst
WHERE
instr(chr(44) || col_lst.fld || chr(44),chr(44) || a.COLUMN_NAME || chr(44) ) > 0
AND table_name = 'MASTER_AMT';
v_str varchar2(1000):= ' ';
begin
for c in cur loop
v_str := v_str || c.column_name || ',' ;
end loop;
v_str := substr(v_str,1,len(v_str)-1);
open :ref_c for
'select ' || v_str || ' from master_amt';
end;
--- after executing the above block, type the following at SQL prompt
SQL > print ref_c
Please let me know if this works for you. This should for any number of columns returned by the function.
Shakti
(http://www.impact-sol.com)
(Developers of Guggi Oracle)

Best way to split a single string containing 2 words into word1 and word2

Whats the best way to take a string containing 2 words and split it into 2 strings ?
eg. "red ferrari"
string1 "red"
string2 "ferrari"

If your list is always going to have exactly two words, then yes. Otherwise it depends on your requierments.

How to solve 'Microsoft.Advertising.WinRT.UI.winmd' contains duplicate type names.

Hi,
I am developing windows store 8.1 app. I need to perform unit testing of my app . When I add the project (to be tested) to unit test
library project by using Add reference I am getting these errors:
Error
5
The .winmd file 'Microsoft.Advertising.WinRT.UI.winmd' contains duplicate type names. Type 'Microsoft.Advertising.WinRT.UI.AdControl'
is already registered with the in-process server 'CLRHost.dll'.
UnitTestLibrary
Error
6
The .winmd file 'Microsoft.Advertising.WinRT.UI.winmd' contains duplicate type names. Type 'Microsoft.Advertising.WinRT.UI.AdSettingsFlyout'
is already registered with the in-process server 'CLRHost.dll'.
UnitTestLibrary
Error
7
The .winmd file 'Microsoft.Advertising.WinRT.UI.winmd' contains duplicate type names. Type
I found a blog here . I tried it but i coudn't see the xml file in this path C:\Program
Files (x86)\Microsoft SDKs\Windows\v8.0\ExtensionSDKs\MSAdvertisingXaml\6.1\SDKManifest.xml
I found the file in C:\Program Files (x86)\Microsoft SDKs\Windows\v8.1\ExtensionSDKs\MSAdvertisingXaml\8.1 . But when i tried to update it is displaying an access denied message

Hi Alok,
Thank you for posting in MSDN forum.
Based on your issue, to check if the issue is related to the specified unit test or the VS IDE issue. I suggest you can refer the following document to re-create a simple new unit test with windows store app and then add the windows store app as reference
to the Unit test project check this issue.
https://msdn.microsoft.com/en-us/library/windows/apps/jj159318.aspx
(1)If you did not get same error message in the new unit test project, I doubt that maybe you did not reference the windows store app successfully. So please refer the above document to reference it again check this issue.
If you still could not reference successfully, please share me the mainly code for the windows store and unit test project.
Or you could share me your solution include the reference project and unit test project.
You could upload your sample to the OneDrive and then copy link here.
(2) If you get same error message in the new unit test, I suggest you could try to repair or re-install the VS IDE and then check this issue again.
Hope it help you!
Best Regards,
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Execute a string containing a PL/SQL block

Hi,
I would like to build a string containing a PL/SQL block and execute it dynamically. Is there way to do this.
Note - The reason I want to this is because, based on certain table data dictionary views the declaration section of the PL/SQL block that I am building might vary
I tried to use EXECUTE IMMEDIATE, it didn't work, pls let me know if I am missing something.
DECLARE
v_str VARCHAR2(1000);
BEGIN
v_str := 'BEGIN NULL; END';
EXECUTE IMMEDIATE v_str;
END;
/

Hi,
Just happened to find it. EXECUTE IMMEDIATE can be used, the bug with my code was I didn't have a ; after the END statement. Corrected code is below, thanks for your time
DECLARE
v_str VARCHAR2(1000);
BEGIN
v_str := 'BEGIN NULL; END;';
EXECUTE IMMEDIATE v_str;
END;
/

Quick string question finding if a string contains a character

hello peeps
is there a quick way of checking if a string contains a specific character
e.g.
myString="test:test";
myString.contains(":");
would be true
any ideas on a quick way of doing it

is there a contains() method in 1.4.2? i couldnt see
it in the docsNo there isn't. But the 1.5 has a contains(CharSequence s) method.

Table SMOXHEAD contains no BDOC name

Hi all,
As we are crosschecking data in RSA3 for the datasource 0CRM_CONFIRM_I giving like infosource/Infoobject need to be maintained.
Later we come to know that the datasource 0CRM_CONFIRM_I was not maintained in BWA5 tcode.
I have given this datasouce in BWA1 and clicked on check button,its takes me to next screen giving error like " Table SMOXHEAD contains no BDOC name" .
Can any one explain me how to solve this problem?
and also if want to create BDOC for theis datasource how can we do it?(Please explain it in step by step)
Your help will be appreciated
Regards,
Praveena.

Have you see this thread
Re: Data source 0CRM_MKTELM5_ATTR is not active in Quality system

Evaluate a string containing a constant name

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