/**
* Appends a string to the file and returns the offset of the start of the string.
*
* @param str the string to be written.
* @return the offset of the start of the string that was written.
* @throws IOException if an I/O error occurs or the offset would be larger than 2^32-1.
*/
private long writeString(String str) throws IOException {
// Write the string at the end of the file.
long pos = stringFile.length();
if (pos > MASK32) throw new IOException("String file too large");
stringFile.seek(pos);
stringFile.writeUTF(str);
return pos;
}
/**
* Writes the Item Code to the Items Random Access File
*
* @param file - the Items Random Access File
*/
private void writeCodeToFile(RandomAccessFile file) {
String code = getCode();
while (code.length() != 6) {
code = "0" + code;
}
try {
file.writeUTF(code);
} catch (Exception e) {
}
}
public static void main(String args[]) {
try {
String fname = "d:\\q.txt";
String mode;
// mode = "r";//r : file must exist
mode = "rw"; // rw : file will be created or opened
// open the file
RandomAccessFile raf = new RandomAccessFile(fname, mode);
/*
//seek and write demo
raf.seek(10);//position file r/w pointer at index 10 wrt BOF
//a seek beyond file size causes file to grow upto the seek value
raf.write(65);//raf.write('A');
*/
// r/w java datatypes
int i1, i2;
float f1, f2;
char c1, c2;
String s1, s2;
i1 = -10;
f1 = 1234.5678F;
c1 = 'q';
s1 = "hello files";
raf.seek(0); // reach BOF
raf.writeInt(i1);
raf.writeFloat(f1);
raf.writeChar(c1);
raf.writeUTF(s1);
raf.seek(0); // reach BOF
i2 = raf.readInt();
f2 = raf.readFloat();
c2 = raf.readChar();
s2 = raf.readUTF();
System.out.println(i2);
System.out.println(f2);
System.out.println(c2);
System.out.println(s2);
// close the file
raf.close();
} catch (IOException ex) {
System.out.println(ex); // ex converts into ex.toString()
}
} // main
/**
* Writes the username of the user that created the Item to the Items Random Access File
*
* @param file- the Item's Random Access File
*/
private void writeCreatedBy(RandomAccessFile file) {
String createdBy = getCreatedBy();
try {
while (createdBy.length() != 20) {
createdBy = createdBy + " ";
}
file.writeUTF(createdBy);
} catch (Exception e) {
}
}
/**
* Writes the Item Name to the Items Random Access File
*
* @param file - the Items Random Access File
*/
private void writeNameToFile(RandomAccessFile file) {
String name = getName();
while (name.length() != 200) {
name = name + " ";
}
try {
file.writeUTF(name);
} catch (Exception e) {
}
}
/**
* Writes the Item description to the Items Random Access File
*
* @param file - the Items Random Access File
*/
private void writeDescriptionToFile(RandomAccessFile file) {
String description = getDescription();
if (description == null || description.equals("")) { // As description is optional
description = "<No description>";
}
while (description.length() != 200) {
description = description + " ";
}
try {
file.writeUTF(description);
} catch (Exception e) {
}
}
public My_Room_AC_db(String name) {
y = new ArrayList<String>();
try {
raf = new RandomAccessFile("ac_db.dat", "r");
String arr2[] = name.split("#");
while (true) {
String rec = raf.readUTF();
String arr[] = rec.split("#");
if (arr[0].equals(arr2[0])) {
y.add(name);
} else {
y.add(rec);
}
}
} catch (Exception ep) {
} finally {
try {
// if(raf!=null)
raf.close();
File f = new File("ac_db.dat", "r");
f.delete();
} catch (Exception ex) {
}
}
raf = null;
try {
raf = new RandomAccessFile("ac_db.dat", "rw");
for (String ss : y) {
raf.writeUTF(ss);
}
} catch (Exception ef) {
} finally {
try {
raf.close();
} catch (Exception ex) {
}
}
}
public boolean writeObj(Object obj, String fileName) {
RandomAccessFile file = null;
if (!this.configDirExists(fileName)) {
return false;
}
try {
file = new RandomAccessFile(fileName, "rw");
String xml = xstream.toXML(obj);
file.writeUTF(xml);
} catch (IOException ex) {
ex.printStackTrace();
return false;
} finally {
try {
file.close();
} catch (IOException ex) {
Logger.getLogger(ConfigLoader.class.getName()).log(Level.SEVERE, null, ex);
}
}
return true;
}
