i am trying to put this together so it opens a file sorts the data saves a file and appends a file i have got my self so confused. can any one help????
this is the code Ive got so far.
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
public class studentData {
public static void main(String[] args) {
FileDemo fd = new FileDemo();
fd.writeFile();
String txt = fd.readFile();
System.out.println(txt);
}
// write data to file report
public void writeFile() {
String fileName = "c:\\report.txt";
try {
BufferedWriter writer = new BufferedWriter(new FileWriter(fileName,true));
writer.write("Test report.");
writer.newLine();
writer.write("Line2");
writer.close();
} catch (IOException e) {
e.printStackTrace();
}
}
// read data1 text file
public String readFile() {
String fileName = "c:\\data1.txt";
String LS = System.getProperty("line.separator");
StringBuffer fileContent = new StringBuffer();
try {
FileReader fr = new FileReader(fileName);
BufferedReader reader = new BufferedReader(new FileReader(fileName));
String line;
while ((line = reader.readLine()) != null) {
fileContent.append(line).append(LS);
}
} catch (IOException e) {
e.printStackTrace();
}
return fileContent.toString();
}
}
//Appending to a File
try {
BufferedWriter out = new BufferedWriter(new FileWriter("filename", true));
out.write("aString");
out.close();
} catch (IOException e) {
}
// Returns the contents of the file in a byte array.
public static byte[] getBytesFromFile(File file) throws IOException {
InputStream is = new FileInputStream(file);
// Get the size of the file
long length = file.length();
// You cannot create an array using a long type.
// It needs to be an int type.
// Before converting to an int type, check
// to ensure that file is not larger than Integer.MAX_VALUE.
if (length > Integer.MAX_VALUE) {
// File is too large
}
// Create the byte array to hold the data
byte[] bytes = new byte[(int)length];
// Read in the bytes
int offset = 0;
int numRead = 0;
while (offset < bytes.length
&& (numRead=is.read(bytes, offset, bytes.length-offset)) >= 0) {
offset += numRead;
}
// Ensure all the bytes have been read in
if (offset < bytes.length) {
throw new IOException("Could not completely read file "+file.getName());
}
// Close the input stream and return bytes
is.close();
return bytes;
}Here is the code of java program to Read text File Line by Line
import java.io.*;
class FileRead
{
public static void main(String args[])
{
try{
// Open the file that is the first
// command line parameter
FileInputStream fstream = new FileInputStream("textfile.txt");
// Get the object of DataInputStream
DataInputStream in = new DataInputStream(fstream);
BufferedReader br = new BufferedReader(new InputStreamReader(in));
String strLine;
//Read File Line By Line
while ((strLine = br.readLine()) != null) {
// Print the content on the console
System.out.println (strLine);
}
//Close the input stream
in.close();
}catch (Exception e){//Catch exception if any
System.err.println("Error: " + e.getMessage());
}
}
}