I have this code that creates a file and saves the users input, but it keeps overwriting and I want it to save each entry a user gives. How can I do this?
File file = new File("info.txt");
BufferedWriter output = null;
try {
output = new BufferedWriter(new FileWriter(file));
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
try {
output.write("Users pick: " + myint+ "\t");
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
try {
output.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
//file writer
Change
output = new BufferedWriter(new FileWriter(file));
to
output = new BufferedWriter(new FileWriter(file,true));
for opening the file in append mode.
Related
I have created a java gui which takes values from the user send it to python file for processing and then displays the output from the python file onto the java gui. This is working perfectly on eclipse but when i exported it into a jar file the output is not displayed. I've seen a bunch of other questions like this but they do not give a solution that would help me.
This is how i connect my python script to java.
public void connection(String name)
{
ProcessBuilder pb= new ProcessBuilder("python","recomold.py","--movie_name",name);
///System.out.println("running file");
Process process = null;
try {
process = pb.start();
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
int err = 0;
try {
err = process.waitFor();
} catch (InterruptedException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
// System.out.println("any errors?"+(err==0 ? "no" : "yes"));
/* try {
System.out.println("python output "+ output(process.getInputStream()));
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}*/
try {
matches.setText(output(process.getInputStream()));
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
private String output(InputStream inputStream) throws IOException {
StringBuilder sb = new StringBuilder();
BufferedReader br = null;
try{
br= new BufferedReader(new InputStreamReader(inputStream));
String line = null;
while((line=br.readLine())!=null)
{
sb.append(line+"\n");
//descp.setText("<html><br/><html>");
//sb.append("\n");
}
}
finally
{
br.close();
}
return sb.toString();
}
I asked a question earlier about extracting RAR archives in Java and someone pointed me to JUnrar. The official site is down but it seems to be quite widely used as I found a lot of discussions about it online.
Could someone show me how to use JUnrar to extract all the files in an archive? I found a little snippet online but it doesn't seem to work. It shows each item in the archive to be a directory even if it is a file.
Archive rar = new Archive(new File("C://Weather_Icons.rar"));
FileHeader fh = rar.nextFileHeader();
while(fh != null){
if (fh.isDirectory()) {
logger.severe("directory: " + fh.getFileNameString() );
}
//File out = new File(fh.getFileNameString());
//FileOutputStream os = new FileOutputStream(out);
//rar.extractFile(fh, os);
//os.close();
fh=rar.nextFileHeader();
}
Thanks.
May be you should also check this snippet code. A copy of which can be found below.
public class MVTest {
/**
* #param args
*/
public static void main(String[] args) {
String filename = "/home/rogiel/fs/home/movies/vp.mp3.part1.rar";
File f = new File(filename);
Archive a = null;
try {
a = new Archive(new FileVolumeManager(f));
} catch (RarException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
if (a != null) {
a.getMainHeader().print();
FileHeader fh = a.nextFileHeader();
while (fh != null) {
try {
File out = new File("/home/rogiel/fs/test/"
+ fh.getFileNameString().trim());
System.out.println(out.getAbsolutePath());
FileOutputStream os = new FileOutputStream(out);
a.extractFile(fh, os);
os.close();
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (RarException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
fh = a.nextFileHeader();
}
}
}
}
I have created a program to convert text to xml by using ReverseXSL API.
This program is to be executed by an application by calling static method (static int transformXSL).
I am able to execute and produce output with running from Eclipse. However, When I ran program (jar) by using application it stuck somewhere and I couldnt find anything.
Then, I debugged by "Debug as...-> Remote Java Application" in Eclipse from Application and found "InvocationTargetException" at ClassLoaders.callStaticFunction.
Below Static method is called by application.
public class MyTest4 {
public MyTest4()
{
}
public static int transformXSL(String defFile, String inputFile, String XSLFile, String OutputFile) {
System.out.println("Dheeraj's method is called");
// start time
FileWriter fw=null;
try {
fw = new FileWriter("D://Countime.txt");
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
BufferedWriter output=new BufferedWriter(fw);
DateFormat sd=new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSS");
Date dt= new Date();
System.out.println("Date is calculated");
try {
output.write("Start Time:"+sd.format(dt).toString());
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
System.out.println(sd.format(dt));
FileReader myDEFReader=null, myXSLReader=null;
TransformerFactory tf = TransformerFactory.newInstance();
Transformer t=null;
FileInputStream inStream = null;
ByteArrayOutputStream outStream = null;
// Step 1:
//instantiate a transformer with the specified DEF and XSLT
if (new File(defFile).canRead())
{
try {
myDEFReader = new FileReader(defFile);
System.out.println("Definition file is read");
} catch (FileNotFoundException e) {
e.printStackTrace();
}
}
else myDEFReader = null;
if (new File(XSLFile).canRead())
try {
myXSLReader = new FileReader(XSLFile);
System.out.println("XSL file is read");
} catch (FileNotFoundException e) {
e.printStackTrace();
}
else myXSLReader = null;
try {
t = tf.newTransformer(myDEFReader, myXSLReader);
} catch (IOException e) {
e.printStackTrace();
}
System.out.println("Step 1: DEF AND XSLT Transformation completed");
// Step 2:
// Read Input data
try {
inStream = new FileInputStream(inputFile);
} catch (FileNotFoundException e) {
e.printStackTrace();
}
outStream = new ByteArrayOutputStream();
System.out.println("Step 2: Reading Input file: completed");
// Step 3:
// Transform Input
try {
try (BufferedReader br = new BufferedReader(new FileReader("D://2.txt"))) {
String line = null;
while ((line = br.readLine()) != null) {
System.out.println("Content: "+line);
}
}
System.out.println("File: "+inputFile.toString());
System.out.println("\n content: \n"+ inStream.toString());
System.out.println("Calling Transform Function");
t.transform(inStream, outStream);
System.out.println("Transformation is called");
outStream.close();
try(OutputStream outputStream = new FileOutputStream(OutputFile)) {
outStream.writeTo(outputStream);
System.out.println("Outstream is generated; Output file is creating");
}
System.out.println(outStream.toString());
} catch (TransformerException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (ParserException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (ParserConfigurationException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (FactoryConfigurationError e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (TransformerFactoryConfigurationError e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (javax.xml.transform.TransformerException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
System.out.println("output file is created");
// End time
Date dt2= new Date();
System.out.println(sd.format(dt2));
System.out.println("End time:"+dt2.toString());
try {
output.append("End Time:"+sd.format(dt2).toString());
output.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return 0;
}
}
String id = filedda.getText();
String pass= filedda1.getText();
try {
File inputFile = new File("E:/yoo.txt");
File tempfile = new File("E:/mytempfile.txt");
BufferedReader reader = new BufferedReader(new FileReader(inputFile));
BufferedWriter writer = new BufferedWriter(new FileWriter(tempfile));
String CurrentLine;
while((CurrentLine = reader.readLine())!=null){
if(CurrentLine.contains(id+pass)){
CurrentLine= CurrentLine.replace(id+pass, "");
}
writer.write(CurrentLine);
reader.close();
writer.close();
inputFile.delete();
tempfile.renameTo(inputFile);
}
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
What I am wanting it to do is: It will delete string which is id+pass from a file.
it is doing correctly if the scenario is like,
abc
cde
And my id+pass= cde
File output: abc
But if the id+pass= abc, then the whole file output becomes nothing.
You should only close the files after the while loop:
while(){
//...
}
reader.close();
writer.close();
You are closing the files early.
Close here :
}
reader.close();
writer.close();
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
Also if You are working on Swing, make sure its EDT safe.
When creating the FileWriter you should be providing true as a parameter to indicate you wish to append data.
Shown here.
e.g:
BufferedWriter writer = new BufferedWriter(new FileWriter(tempfile, true));
If I understand your question correctly.
try this code:
String id = filedda.getText();
String pass= filedda1.getText();
try {
File inputFile = new File("E:/yoo.txt");
File tempfile = new File("E:/mytempfile.txt");
BufferedReader reader = new BufferedReader(new FileReader(inputFile));
BufferedWriter writer = new BufferedWriter(new FileWriter(tempfile));
String CurrentLine;
while((CurrentLine = reader.readLine())!=null){
if(CurrentLine.contains(id+pass)){
CurrentLine= CurrentLine.replace(id+pass, "");
}
}
writer.write(CurrentLine);
reader.close();
writer.close();
inputFile.delete();
tempfile.renameTo(inputFile);
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
i write ArrayLists into a file. I read it with FileInputStream. But always just the "first" ArrayList is appears by reading. I tried it with readInt() / wirteInt(), and loops, but there were always thrown exceptions, by calling readInt() --> EOF
I want to read all ArrayList from this File into an ArrayList. My application needs to be persistent, so i serialized the ArrayLists.
write into file:
try {
FileOutputStream fos = new FileOutputStream(_cache, true);
ObjectOutputStream os = new ObjectOutputStream(fos);
// os.writeInt(newValueList.size()); // Save size first
os.writeObject(newValueList);
os.flush();
os.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
read from file:
List cachedValueList = new ArrayList<String>();
ObjectInputStream o = new ObjectInputStream(new FileInputStream("caching.io"));
// int count = o.readInt(); // Get the number of regions
try {
cachedValueList.add(o.readObject());
} catch (EOFException e) {
o.close();
e.printStackTrace();
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
If you are writing the same list many times, it will only write the list once. After that it will use the same reference but the contents will be the same (this is true of any object)
If you call reset() between writeObject() it will send a fresh copy of the list each time.