public abstract class ByteArrayTransfer extends Transfer
ByteArrayTransfer provides a platform specific
mechanism for converting a java byte[] to a platform
specific representation of the byte array and vice versa.
ByteArrayTransfer is never used directly but is sub-classed
by transfer agents that convert between data in a java format such as a
String and a platform specific byte array.
If the data you are converting does not map to a
byte[], you should sub-class Transfer directly
and do your own mapping to a platform data type.
The following snippet shows a subclass of ByteArrayTransfer that transfers
data defined by the class MyType.
public class MyType {
public String fileName;
public long fileLength;
public long lastModified;
}
public class MyTypeTransfer extends ByteArrayTransfer {
private static final String MYTYPENAME = "my_type_name";
private static final int MYTYPEID = registerType(MYTYPENAME);
private static MyTypeTransfer _instance = new MyTypeTransfer();
private MyTypeTransfer() {}
public static MyTypeTransfer getInstance () {
return _instance;
}
public void javaToNative (Object object, TransferData transferData) {
if (object == null || !(object instanceof MyType[])) return;
if (isSupportedType(transferData)) {
MyType[] myTypes = (MyType[]) object;
try {
// write data to a byte array and then ask super to convert to pMedium
ByteArrayOutputStream out = new ByteArrayOutputStream();
DataOutputStream writeOut = new DataOutputStream(out);
for (int i = 0, length = myTypes.length; i < length; i++){
byte[] buffer = myTypes[i].fileName.getBytes();
writeOut.writeInt(buffer.length);
writeOut.write(buffer);
writeOut.writeLong(myTypes[i].fileLength);
writeOut.writeLong(myTypes[i].lastModified);
}
byte[] buffer = out.toByteArray();
writeOut.close();
super.javaToNative(buffer, transferData);
} catch (IOException e) {
}
}
}
public Object nativeToJava(TransferData transferData){
if (isSupportedType(transferData)) {
byte[] buffer = (byte[])super.nativeToJava(transferData);
if (buffer == null) return null;
MyType[] myData = new MyType[0];
try {
ByteArrayInputStream in = new ByteArrayInputStream(buffer);
DataInputStream readIn = new DataInputStream(in);
while(readIn.available() > 20) {
MyType datum = new MyType();
int size = readIn.readInt();
byte[] name = new byte[size];
readIn.read(name);
datum.fileName = new String(name);
datum.fileLength = readIn.readLong();
datum.lastModified = readIn.readLong();
MyType[] newMyData = new MyType[myData.length + 1];
System.arraycopy(myData, 0, newMyData, 0, myData.length);
newMyData[myData.length] = datum;
myData = newMyData;
}
readIn.close();
} catch (IOException ex) {
return null;
}
return myData;
}
return null;
}
protected String[] getTypeNames(){
return new String[]{MYTYPENAME};
}
protected int[] getTypeIds(){
return new int[] {MYTYPEID};
}
}
Transfer| Constructor and Description |
|---|
ByteArrayTransfer() |
| Modifier and Type | Method and Description |
|---|---|
TransferData[] |
getSupportedTypes()
Returns a list of the platform specific data types that can be converted
using this transfer agent.
|
boolean |
isSupportedType(TransferData transferData)
Returns true if the
TransferData data type can be converted
using this transfer agent, or false otherwise (including if transferData is
null). |
void |
javaToNative(java.lang.Object object,
TransferData transferData)
This implementation of
javaToNative converts a java
byte[] to a platform specific representation. |
java.lang.Object |
nativeToJava(TransferData transferData)
This implementation of
nativeToJava converts a platform
specific representation of a byte array to a java byte[]. |
getTypeIds, getTypeNames, registerType, validatepublic TransferData[] getSupportedTypes()
Transfer
Only the data type fields of the TransferData objects are
filled in.
getSupportedTypes in class Transferpublic boolean isSupportedType(TransferData transferData)
TransferTransferData data type can be converted
using this transfer agent, or false otherwise (including if transferData is
null).isSupportedType in class TransfertransferData - a platform specific description of a data type; only
the data type fields of the TransferData object need
to be filled inpublic void javaToNative(java.lang.Object object,
TransferData transferData)
javaToNative converts a java
byte[] to a platform specific representation.javaToNative in class Transferobject - a java byte[] containing the data to be
convertedtransferData - an empty TransferData object that will be
filled in on return with the platform specific format of the dataTransfer.nativeToJava(org.eclipse.swt.dnd.TransferData)public java.lang.Object nativeToJava(TransferData transferData)
nativeToJava converts a platform
specific representation of a byte array to a java byte[].nativeToJava in class TransfertransferData - the platform specific representation of the data to be
convertedbyte[] containing the converted data if the
conversion was successful; otherwise nullTransfer.javaToNative(java.lang.Object, org.eclipse.swt.dnd.TransferData)
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are made available under the terms of the
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