Writer writer = new Writer();
String data = writer.toString();/* the value is not casting and displaying null...*/
Is there any other way to convert
Several answers suggest using StringWriter
.
It's important to realize that StringWriter
uses StringBuffer
internally, meaning that it's thread-safe and has a significant synchronization overhead.
If you need thread-safety for the writer, then StringWriter
is the way to go.
If you don't need a thread safe Writer
(i.e. the writer is only used as a local variable in a single method) and you care for performance — consider using StringBuilderWriter from the commons-io library.
StringBuilderWriter
is almost the same as StringWriter
, but uses StringBuilder
instead of StringBuffer
.
Sample usage:
Writer writer = new StringBuilderWriter();
String data = writer.toString();
Note — Log4j has its own StringBuilderWriter implementation which is almost identical to the commons-io version.
I would use a specialized writer if I wanted to make a String out of it.
Writer writer = new StringWriter();
String data = writer.toString(); // now it works fine
If you want a Writer
implementation that results in a String
, use a StringWriter.