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how to convert list object into a string in java

Hi Experts,

I Want to get the list of names from the database
List<Object>names= ///getting from database
now i want convert this to String .
i have written the below code.
is there any to cut down my code.instead of using multiple for loops.
Thanks,

public String getNames(){
List<Object>names = dao.getDataFromDatabase()
for(Object object:names){
Object[] row = (Object[])object;
List<String>al = new ArrayList<>();
al.add((String) row[0]);
}
return convertlistToString(List<String>al)
}

Public String convertlistToString(List<String>al){
	StringBuilder commaSepValueBuilder = new StringBuilder();
    for ( int i = 0; i< al.size(); i++){
      //append the value into the builder
      commaSepValueBuilder.append(al.get(i));
       
      //if the value is not the last element of the list
      //then append the comma(,) as well
      if ( i != al.size()-1){
        commaSepValueBuilder.append(", ");
      }
    }
    commaSepValueBuilder.toString();

}

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SOLUTION

gurpsbassi

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CEHJ

return al.toString().replaceAll("\\[|\\]", "");
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That's ok, but better if optimized to

return al.toString().replaceAll("^\\[|\\]$", "");

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srikotesh

ASKER

Hi Experts,

i am getting o/p along with array.
[sri, nivas, rao]
i dont want array here
i need output like
sri, nivas, rao

gurpsbassi

Have you tried the solution?

srikotesh

ASKER

srikotesh

ASKER

yes i am getting the expected response.

List<String> ids = new ArrayList<String>();
	ids.add("sri");
	ids.add("ni");
	ids.add("vas");
	ids.add("rap");

	// CSV format
	String csv = ids.toString().replace("[", "").replace("]", "")
	            .replace(", ", ",");
	System.out.println("csv is "+csv);

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o/p:
sri,ni,vas,rap

srikotesh

ASKER

String csv = ids.toString().replace("[", "").replace("]", "");

CEHJ

There's no reason to change the solution that gurpsbassi and i showed

srikotesh

ASKER

Hi CEHJ,

i have verified that, list is coming with array

return al.toString().replaceAll("^\\[|\\]$", "");

[sri, ni, vas, rao, rrrr, rsss]

can u verify once how to modify this statement.

ASKER CERTIFIED SOLUTION

CEHJ

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srikotesh

ASKER

Excellent

CEHJ

Answer by gurpsbassi really