Input and output streams are byte-based streams.
Readers and writers are character-based streams.
A reader reads character-based data from a data source. A writer writes character-based data to a data sink.
The following table lists Classes in Byte-based and Character-based Input Streams
| Byte-based Input Stream Class | Character-based Input Stream Class |
|---|---|
| InputStream | Reader |
| ByteArrayInputStream | CharArrayReader |
| StringBufferInputStream | StringReader |
| PipedInputStream | PipedReader |
| FileInputStream | FileReader |
| No corresponding class | InputStreamReader |
| FilterInputStream | FilterReader |
| BufferedInputStream | BufferedReader |
| PushbackInputStream | PushbackReader |
| DataInputStream | No corresponding class |
| ObjectInputStream | No corresponding class |
The following table compares Classes from Byte-based Output Streams and Character-based Output Streams
| Byte-based Output Stream Class | Character-based Output Stream Class |
|---|---|
| OutputStream | Writer |
| ByteArrayOutputStream | CharArrayWriter |
| No corresponding class | StringWriter |
| PipedOutputStream | PipedWriter |
| FileOutputStream | FileWriter |
| No corresponding class | OutputStreamWriter |
| FilterOutputStream | FilterWriter |
| BufferedOutputStream | BufferedWriter |
| DataOutputStream | No corresponding class |
| ObjectOutputStream | No corresponding class |
| PrintStream | PrintWriter |
Use the InputStreamReader class if you have a stream that supplies bytes and you want to read characters by getting those bytes decoded into characters.
Create a Reader object from an InputStream object using the platform default encoding
Reader reader = new InputStreamReader(iso);
Create a Reader object from an InputStream using the "US-ASCII" encoding
Reader reader = new InputStreamReader(iso, "US-ASCII");
You can create a Writer object to spit out characters from a bytes-based output stream, assuming that oso is an OutputStream object:
Create a Writer object from OutputStream using the platform default encoding
Writer writer = new OutputStreamWriter(oso);
Create a Writer object from OutputStream using the "US-ASCII" encoding
Writer writer = new OutputStreamWriter(oso, "US-ASCII");