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Chapter 11 The java.io Package |
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CharArrayWriter
Name
CharArrayWriterSynopsis
- Class Name:
-
java.io.CharArrayWriter
- Superclass:
-
java.io.Writer
- Immediate Subclasses:
-
None
- Interfaces Implemented:
-
None
- Availability:
-
New as of JDK 1.1
Description
The CharArrayWriter class represents a stream whose data is written to an internal character array. This class is similar to ByteArrayOutputStream, but it operates on an array of Java characters instead of a byte array.
The data from a CharArrayWriter can be sent to another Writer using the writeTo() method. A copy of the array can be obtained using the toCharArray() method.
Class Summary
public class java.io.CharArrayWriter extends java.io.Writer {
// Variables
protected char[] buf;
protected int count;
// Constructors
public CharArrayWriter();
public CharArrayWriter(int initialSize);
// Instance Methods
public void close();
public void flush();
public void reset();
public int size();
public char[] toCharArray();
public String toString();
public void write(int c);
public void write(char[] c, int off, int len);
public void write(String str, int off, int len);
public void writeTo(Writer out);
}
Variables
buf
protected char[] buf
- Description
-
The buffer that holds data for this stream.
count
protected int count
- Description
-
A placeholder that marks the end of the data in the buffer.
Constructors
CharArrayWriter
public CharArrayWriter()
- Description
-
This constructor creates a CharArrayWriter with an internal buffer that has a default size of 32 characters. The buffer grows automatically as data is written to the stream.
public CharArrayWriter(int initialSize)
- Parameters
-
- initialSize
-
The initial buffer size.
- initialSize
- Description
-
This constructor creates a CharArrayWriter with an internal buffer that has a size of initialSize characters. The buffer grows automatically as data is written to the stream.
Instance Methods
close
public void close()
- Overrides
-
Writer.close()
- Description
-
This method does nothing. For most subclasses of Writer, this method releases any system resources that are associated with the Writer object. However, the CharArrayWriter's internal array may be needed for subsequent calls to toCharArray() or writeTo(). For this reason, close() does nothing, and the internal array is not released until the CharArrayWriter is garbage collected.
flush
public void flush()
- Overrides
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Writer.flush()
- Description
-
This method does nothing. The CharArrayWriter writes data directly into its internal array; thus it is never necessary to flush the stream.
reset
public void reset()
- Description
-
This method discards the current contents of the buffer and resets the position of the stream to zero. Subsequent data is written starting at the beginning of the array.
size
public int size()
- Description
-
This method returns the number of characters currently stored in this object's internal buffer. It is a count of the number of characters that have been written to the stream.
toCharArray
public char[] toCharArray()
- Returns
-
A copy of the data that has been written to this CharArrayWriter in the form of a char array.
- Description
-
This method copies the data in the internal array and returns a reference to the copy. The returned array is as long as the data that has been written to the stream, i.e., the same as size().
toString
public String toString()
- Returns
-
A copy of the data that has been written to this CharArrayWriter in the form of a String.
- Overrides
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Object.toString()
- Description
-
This method returns a reference to a String object created from the characters stored in this object's internal buffer.
write
public void write(int c)
- Parameters
-
- c
-
The value to write.
- c
- Overrides
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Writer.write(int)
- Description
-
This method writes the low-order 16 bits of the given value into the internal array. If the array is full, a larger array is allocated.
public void write(char[] c, int off, int len)
- Parameters
-
- c
-
An array of characters to write to the stream.
- off
-
An offset into the character array.
- len
-
The number of characters to write.
- c
- Overrides
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Writer.write(char[], int, int)
- Description
-
This method copies len characters to this object's internal array from c, starting off elements from the beginning of the array. If the internal array is full, a larger array is allocated.
public void write(String str, int off, int len)
- Parameters
-
- str
-
A String to write to the stream.
- off
-
An offset into the string.
- len
-
The number of characters to write.
- str
- Overrides
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Writer.write(String, int, int)
- Description
-
This method copies len characters to this object's internal array from str, starting off characters from the beginning of the given string. If the internal array is full, a larger array is allocated.
writeTo
public void writeTo(Writer out) throws IOException
- Parameters
-
- out
-
The destination stream.
- out
- Throws
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- IOException
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If any kind of I/O error occurs.
- IOException
- Description
-
This method writes the contents of this object's internal buffer to the given Writer. All the data that has been written to this CharArrayWriter is written to out.
Inherited Methods
|
Method |
Inherited From |
Method |
Inherited From |
|---|---|---|---|
|
clone() |
Object |
equals(Object) |
Object |
|
finalize() |
Object |
getClass() |
Object |
|
hashCode() |
Object |
notify() |
Object |
|
notifyAll() |
Object |
wait() |
Object |
|
wait(long) |
Object |
wait(long, int) |
Object |
|
write(char[]) |
Writer |
write(String) |
Writer |
See Also
IOException, String, Writer
|
 |
|
| CharArrayReader |  |
CharConversionException |
