Prasanth kumar Kumar ,

In LR parameter are replaced in strings when they are used in a certain context. E.g. certain arguments of lr.* or web.* functions. Consult the LRP help and look for a section called PARAMETERIZATION.

When you want to resolve parameters in other places you have to call explicitly to do so: see lr.eval_string(). E.g,:

String recordNumber = lr.eval_string("{p_recordNbr}")

Be careful with 'final' and 'static' Strings in combination with lr.eval_string().

Nothing worked. Especially i want to replace value in messageStr but it's not happening while using LR.eval_string. 

String recordNumber= Ir.eval string({p_recordNbr}");

String record Number="{p_recordNbr}";

System.out.println(recordNumber);

String messageStr="{\n\t \"leadLoadHeaderId\": \"12345\", \n\t \"recordNbr\":\"(p_recordNbr}\",\n\t \"firstName\":\"abcName.....

System.out.println(messageStr);

Output:

Actions.java(19): Notify: Parameter Substitution: parameter "p_recordNbr" "33447"

System.out: {p_recordNbr}

System.out: {

"leadLoadHeaderId": "12345",

"recordNbr": "(p_recordNbr)",

"firstName": "abcName",

It's working even after using le.eval_string. but how to replace in messageStr. Can we write eval function directly? But it's not working or can we use variable recordNumber ? Could you suggest 

String recordNumber =Ir.eval string("{p_recordNbr}");

System.out.println(recordNumber);

String messageStr="{\n\t \"leadLoadHeaderId\": \"12345\", \n\t \"recordlibr\":\"lr.eval_string("{p_recordNbr}"\, \n \t \"firstName\": \"abcName\"......

System.out.println(messageStr);

);

Here is the output

Actions.java(19): Notify: Parameter Substitution: parameter "p_recordNbr" "33447"

System.out: 33447

System.out: {

"leadLoadHeaderId": "12345",

"recordNbr" : "lr.eval_string("{p_recordNbr}")"

Thanks it worked 

Nice, you discovered that you cannot use method-calls inside a String, like you can in Python with f-strings