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Chapter 11 The java.io Package |
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DataInput
Name
DataInputSynopsis
- Interface Name:
-
java.io.DataInput
- Super-interface:
-
None
- Immediate Sub-interfaces:
-
java.io.ObjectInput
- Implemented By:
-
java.io.DataInputStream, java.io.RandomAccessFile
- Availability:
-
JDK 1.0 or later
Description
The DataInput interface defines methods for reading primitive data types and lines of text from an input stream in a machine-independent manner. All multibyte quantities are assumed to be in a format that stores the most significant byte as the first byte and the least significant byte as the last byte.
Interface Declaration
public abstract interface java.io.DataInput {
// Methods
public abstract boolean readBoolean();
public abstract byte readByte();
public abstract char readChar();
public abstract double readDouble();
public abstract float readFloat();
public abstract void readFully(byte[] b);
public abstract void readFully(byte[] b, int off, int len);
public abstract int readInt();
public abstract String readLine();
public abstract long readLong();
public abstract short readShort();
public abstract int readUnsignedByte();
public abstract int readUnsignedShort();
public abstract String readUTF();
public abstract int skipBytes(int n);
}
Methods
readBoolean
public abstract boolean readBoolean() throws IOException
- Returns
-
The boolean value read from the stream.
- Throws
-
- EOFException
-
If the end of the file is encountered.
- IOException
-
If any other kind of I/O error occurs.
- EOFException
- Description
-
This method reads a byte as a boolean value. A byte that contains a zero is read as false; that which contains a nonzero is read as true.
readByte
public abstract byte readByte() throws IOException
- Returns
-
The byte value read from the stream.
- Throws
-
- EOFException
-
If the end of the file is encountered.
- IOException
-
If any other kind of I/O error occurs.
- EOFException
- Description
-
This method reads a signed 8-bit byte.
readChar
public abstract char readChar() throws IOException
- Returns
-
The char value read from the stream.
- Throws
-
- EOFException
-
If the end of the file is encountered.
- IOException
-
If any other kind of I/O error occurs.
- EOFException
- Description
-
This method reads a 16-bit char.
readDouble
public abstract double readDouble() throws IOException
- Returns
-
The double value read from the stream.
- Throws
-
- EOFException
-
If the end of the file is encountered.
- IOException
-
If any other kind of I/O error occurs.
- EOFException
- Description
-
This method reads a 64-bit double quantity.
readFloat
public abstract float readFloat() throws IOException
- Returns
-
The float value read from the stream.
- Throws
-
- EOFException
-
If the end of the file is encountered.
- IOException
-
If any other kind of I/O error occurs.
- EOFException
- Description
-
This method reads a 32-bit float quantity.
readFully
public abstract void readFully(byte[] b) throws IOException
- Parameters
-
- b
-
The array to fill.
- b
- Throws
-
- EOFException
-
If the end of the file is encountered.
- IOException
-
If any other kind of I/O error occurs.
- EOFException
- Description
-
This method reads bytes into the given array b until the array is full.
public abstract void readFully(byte[] b, int off, int len) throws IOException
public abstract void readFully(byte[] b, int off, int len) throws IOException
- Parameters
-
- b
-
The array to fill.
- off
-
An offset into the array.
- len
-
The number of bytes to read.
- b
- Throws
-
- EOFException
-
If the end of the file is encountered.
- IOException
-
If any other kind of I/O error occurs.
- EOFException
- Description
-
This method reads len bytes into the given array, starting at offset off.
readInt
public abstract int readInt() throws IOException
- Returns
-
The int value read from the stream.
- Throws
-
- EOFException
-
If the end of the file is encountered.
- IOException
-
If any other kind of I/O error occurs.
- EOFException
- Description
-
This method reads a 32-bit int quantity.
readLine
public abstract String readLine() throws IOException
- Returns
-
A String that contains the line read from the stream.
- Throws
-
- EOFException
-
If the end of the file is encountered.
- IOException
-
If any other kind of I/O error occurs.
- EOFException
- Description
-
This method reads a String from the current position through the next line terminator. Implementations of this method should take care to look for any line terminator: "\n", "\r", or "\r\n".
readLong
public abstract long readLong() throws IOException
- Returns
-
The long value read from the stream.
- Throws
-
- EOFException
-
If the end of the file is encountered.
- IOException
-
If any other kind of I/O error occurs.
- EOFException
- Description
-
This method reads a 64-bit long quantity.
readShort
public abstract short readShort() throws IOException
- Returns
-
The short value read from the stream.
- Throws
-
- EOFException
-
If the end of the file is encountered.
- IOException
-
If any other kind of I/O error occurs.
- EOFException
- Description
-
This method reads a 16-bit short quantity.
readUnsignedByte
public abstract int readUnsignedByte() throws IOException
- Returns
-
The unsigned byte value read from the stream.
- Throws
-
- EOFException
-
If the end of the file is encountered.
- IOException
-
If any other kind of I/O error occurs.
- EOFException
- Description
-
This method reads an 8-bit byte as an unsigned quantity.
readUnsignedShort
public abstract int readUnsignedShort() throws IOException
- Returns
-
The unsigned short value read from the stream.
- Throws
-
- EOFException
-
If the end of the file is encountered.
- IOException
-
If any other kind of I/O error occurs.
- EOFException
- Description
-
This method reads a 16-bit short as an unsigned quantity.
readUTF
public abstract String readUTF() throws IOException
- Returns
-
The String read from the stream.
- Throws
-
- EOFException
-
If the end of the file is encountered.
- IOException
-
If any other kind of I/O error occurs.
- UTFDataFormatException
-
If the bytes do not represent a valid UTF-8 encoding.
- EOFException
- Description
-
This method reads a UTF-8 format String. See Appendix B, The UTF-8 Encoding, for information on the UTF-8 encoding.
skipBytes
public abstract int skipBytes(int n) throws IOException
- Parameters
-
- n
-
The number of bytes to skip.
- n
- Returns
-
The actual number of skipped bytes.
- Throws
-
- EOFException
-
If the end of the file is encountered.
- IOException
-
If any other kind of I/O error occurs.
- EOFException
- Description
-
This method skips over n bytes.
See Also
DataInputStream, EOFException, IOException, ObjectInput, RandomAccessFile, UTFDataFormatException
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DataInputStream |
