I have a text widget that contains a numeric value representaion for a port (TCP). I validate the value, because the maximum port size is 65535.
Problem:
The field initially contains the value 8001. Now, if the user doublclicks the text widget, the whole text will be selected. The wants to enter a new port like 7002.
For the validation On VerifyListener's - verifyText method i use the current value of the text widget (8001) and the typed in char (7).
-> 80017 is invalid
textField.addVerifyListener(new VerifyListener() {
#Override
public void verifyText(VerifyEvent e) {
String text = ((Text) e.widget).getText();
try {
if(Integer.parseInt(text+e.character) > 65535) {
MessageBox.openError( composite.getShell(),
"Invalid value",
"Invalid value" );
e.doit = false;
}
} catch (Exception e2) {/*ignore*/}
}
});
Ok, i did it. :)
textField.addVerifyListener(new VerifyListener() {
#Override
public void verifyText(VerifyEvent e) {
String text = ((Text) e.widget).getText();
try {
/*-------------------------------------------------------------------------*/
String newText = text.substring(0, e.start) + e.text + text.substring(e.end);
/*-------------------------------------------------------------------------*/
if(Integer.parseInt(newText) > 65535) {
MessageBox.openError( composite.getShell(),
"Invalid value",
"Invalid value" );
e.doit = false;
}
} catch (Exception e2) {/*ignore*/}
}
});
I have this account creation program I'm working on, and would love to save the persons name, last name, email and password to a text file. The following snippet should do just that, but the error message I'm getting when I put a String variable in the .write method is, "no suitable method found for write(JTextFeild)".
private void signupActionPerformed(java.awt.event.ActionEvent evt) {
fname.getText();
lname.getText();
email.getText();
reemail.getText();
password.getText();
repassword.getText();
if(male.equals(true)) {
males = true;
}
if(female.equals(true)) {
females = true;
}
BufferedWriter writer = null;
try {
writer = new BufferedWriter( new FileWriter("UserPass.txt"));
writer.write(fname);
}
catch ( IOException e) {
}
finally {
try {
if ( writer != null) {
writer.close( );
}
}
catch ( IOException e) {
}
}
}
Any ideas on how to fix this?
From the documentation of getText() in javax.swing.text.JTextComponent:
public String getText()
JTextField is just the GUI element, getText() doesn't change it.
You should store the result in a String variable and then use it to write().
I want to make website blocker in my web browser, so I made a database which contain the names of website. Now I want to check the string from database with indexOf method, but it is giving me an error while I am trying to check. Please tell me where my mistake is. Rest of the code is correct and working only database part is not working.
public void loadURL(final String url) {
try {
Connection myconnection;
myconnection = DriverManager.getConnection("jdbc:mysql://localhost/bookmarks", "roo t", "");
try {
String q = "select * from block where url=?";
PreparedStatement mysat = myconnection.prepareStatement(q);
ResultSet myresult = mysat.executeQuery();
int index1;
while (myresult.next()) {
String s2 = myresult.setString("url");
String s1 = txtURL.getText();
index1 = s1.indexOf(s2);
}
if (index1 == -1) {
JOptionPane.showMessageDialog(rootPane, "You Cannot access this website", "Error", JOptionPane.ERROR_MESSAGE);
} else {
Platform.runLater(new Runnable() {
#Override
public void run() {
String tmp = toURL(url);
if (tmp == null) {
tmp = toURL("http://" + url);
}
engine.load(tmp);
}
});
}
} catch (Exception e) {
e.printStackTrace();
} finally {
myconnection.close();
}
} catch (Exception e) {
e.printStackTrace();
}
}
if you use PreparedStatement you have to set a
value for each ? marker:
String q="select * from block where url=?";
PreparedStatement mysat=myconnection.prepareStatement(q);
mysat.setString(1,"www.google.com");
without you have an invalid sql syntax.
I want to open XHTML file which resides in resources. I tried with HTMLComponent of LWUIT. But it is opening only HTML files only. What would be correct way to open XHTML file using any LWUIT component.?
I tried with below code. Its working for HTML files with simple tags. Not working for all tags and attributes.
String htmlFileName = "index.html";
HTMLComponent htmlC = new HTMLComponent(new FileRequestHandler(HtmlScreen.this));
htmlC.setHTMLCallback(new SimpleHTMLCallback(this));
htmlC.setPage("jar://"+"/res/"+htmlFileName.trim());
FileRequestHandler.java:
class FileRequestHandler implements com.divaa.app.DocumentRequestHandler {
HtmlScreen htmlDemo;
static final String DEFAULT_RES = "images";
public FileRequestHandler(HtmlScreen htmlDemo) {
this.htmlDemo=htmlDemo;
}
public InputStream resourceRequested(DocumentInfo docInfo) {
String url=docInfo.getUrl();
// If a from was submitted on a local file, just display the parameters
if ((docInfo.getParams()!=null) && (!docInfo.getParams().equals(""))) {
String method="GET";
if (docInfo.isPostRequest()) {
method="POST";
}
String params=docInfo.getParams();
String newParams="";
if (params!=null) {
for(int i=0;i<params.length();i++) {
char c=params.charAt(i);
if (c=='&') {
newParams+=", ";
} else {
newParams+=c;
}
}
}
return getStream("<h2>Form submitted locally.</h2><b>Method:</b> "+method+"<br><br><b>Parameters:</b><br>"+newParams+"<hr>Continue to local URL","Form Results");
}
url=url.substring(6); // Cut the jar://
byte[] buf;
try {
buf = getBuffer(Display.getInstance().getResourceAsStream(getClass(), url));
if (url.endsWith(".html")) { //only set source to HTML files (not images)
htmlDemo.setSource(new String(getBuffer(new ByteArrayInputStream(buf))));
}
return new ByteArrayInputStream(buf);
} catch (Exception ex) {
System.out.println("ex.toString exception........ "+ex.toString());
ex.printStackTrace();
}
return null;
}
SimpleHTMLCallBack.java:
class SimpleHTMLCallback extends DefaultHTMLCallback {
HtmlScreen htmlDemo;
public SimpleHTMLCallback(HtmlScreen htmlDemo) {
this.htmlDemo=htmlDemo;
}
public boolean linkClicked(HTMLComponent htmlC, String url) {
return true; // Signals the HTMLComponent to prcoess this link as usual (i.e. call DocumentRequestHandler.resourceRequested)
}
public void titleUpdated(HTMLComponent htmlC, String title) {
htmlDemo.setTitle(title);
}
}
Thanks...
I want to write a Object into CSV file.
For XML we have XStream like this
So if i want to convert object to CSV do we have any such library ?
EDIT:
I want to pass my list of Bean to a method which should write all the fields of bean to CSV.
First, serialization is writing the object to a file 'as it is'. AFAIK, you cannot choose file formats and all. The serialized object (in a file) has its own 'file format'
If you want to write the contents of an object (or a list of objects) to a CSV file, you can do it yourself, it should not be complex.
Looks like Java CSV Library can do this, but I have not tried this myself.
EDIT: See following sample. This is by no way foolproof, but you can build on this.
//European countries use ";" as
//CSV separator because "," is their digit separator
private static final String CSV_SEPARATOR = ",";
private static void writeToCSV(ArrayList<Product> productList)
{
try
{
BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(new FileOutputStream("products.csv"), "UTF-8"));
for (Product product : productList)
{
StringBuffer oneLine = new StringBuffer();
oneLine.append(product.getId() <=0 ? "" : product.getId());
oneLine.append(CSV_SEPARATOR);
oneLine.append(product.getName().trim().length() == 0? "" : product.getName());
oneLine.append(CSV_SEPARATOR);
oneLine.append(product.getCostPrice() < 0 ? "" : product.getCostPrice());
oneLine.append(CSV_SEPARATOR);
oneLine.append(product.isVatApplicable() ? "Yes" : "No");
bw.write(oneLine.toString());
bw.newLine();
}
bw.flush();
bw.close();
}
catch (UnsupportedEncodingException e) {}
catch (FileNotFoundException e){}
catch (IOException e){}
}
This is product (getters and setters hidden for readability):
class Product
{
private long id;
private String name;
private double costPrice;
private boolean vatApplicable;
}
And this is how I tested:
public static void main(String[] args)
{
ArrayList<Product> productList = new ArrayList<Product>();
productList.add(new Product(1, "Pen", 2.00, false));
productList.add(new Product(2, "TV", 300, true));
productList.add(new Product(3, "iPhone", 500, true));
writeToCSV(productList);
}
Hope this helps.
Cheers.
For easy CSV access, there is a library called OpenCSV. It really ease access to CSV file content.
EDIT
According to your update, I consider all previous replies as incorrect (due to their low-levelness). You can then go a completely diffferent way, the hibernate way, in fact !
By using the CsvJdbc driver, you can load your CSV files as JDBC data source, and then directly map your beans to this datasource.
I would have talked to you about CSVObjects, but as the site seems broken, I fear the lib is unavailable nowadays.
Two options I just ran into:
http://sojo.sourceforge.net/
http://supercsv.sourceforge.net/
It would be interesting to have a csv serializer as it would take up the minimal space compared to other serializing method.
The closest support for java object to csv is stringutils provided by spring utils project
arrayToCommaDelimitedString(Object[] arr) but it is far from being a serializer.
Here is a simple utility which uses reflection to serialize value objects
public class CSVWriter
{
private static String produceCsvData(Object[] data) throws IllegalArgumentException, IllegalAccessException, InvocationTargetException
{
if(data.length==0)
{
return "";
}
Class classType = data[0].getClass();
StringBuilder builder = new StringBuilder();
Method[] methods = classType.getDeclaredMethods();
for(Method m : methods)
{
if(m.getParameterTypes().length==0)
{
if(m.getName().startsWith("get"))
{
builder.append(m.getName().substring(3)).append(',');
}
else if(m.getName().startsWith("is"))
{
builder.append(m.getName().substring(2)).append(',');
}
}
}
builder.deleteCharAt(builder.length()-1);
builder.append('\n');
for(Object d : data)
{
for(Method m : methods)
{
if(m.getParameterTypes().length==0)
{
if(m.getName().startsWith("get") || m.getName().startsWith("is"))
{
System.out.println(m.invoke(d).toString());
builder.append(m.invoke(d).toString()).append(',');
}
}
}
builder.append('\n');
}
builder.deleteCharAt(builder.length()-1);
return builder.toString();
}
public static boolean generateCSV(File csvFileName,Object[] data)
{
FileWriter fw = null;
try
{
fw = new FileWriter(csvFileName);
if(!csvFileName.exists())
csvFileName.createNewFile();
fw.write(produceCsvData(data));
fw.flush();
}
catch(Exception e)
{
System.out.println("Error while generating csv from data. Error message : " + e.getMessage());
e.printStackTrace();
return false;
}
finally
{
if(fw!=null)
{
try
{
fw.close();
}
catch(Exception e)
{
}
fw=null;
}
}
return true;
}
}
Here is an example value object
public class Product {
private String name;
private double price;
private int identifier;
private boolean isVatApplicable;
public Product(String name, double price, int identifier,
boolean isVatApplicable) {
super();
this.name = name;
this.price = price;
this.identifier = identifier;
this.isVatApplicable = isVatApplicable;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public double getPrice() {
return price;
}
public void setPrice(long price) {
this.price = price;
}
public int getIdentifier() {
return identifier;
}
public void setIdentifier(int identifier) {
this.identifier = identifier;
}
public boolean isVatApplicable() {
return isVatApplicable;
}
public void setVatApplicable(boolean isVatApplicable) {
this.isVatApplicable = isVatApplicable;
}
}
and the code to run the util
public class TestCSV
{
public static void main(String... a)
{
Product[] list = new Product[5];
list[0] = new Product("dvd", 24.99, 967, true);
list[1] = new Product("pen", 4.99, 162, false);
list[2] = new Product("ipad", 624.99, 234, true);
list[3] = new Product("crayons", 4.99,127, false);
list[4] = new Product("laptop", 1444.99, 997, true);
CSVWriter.generateCSV(new File("C:\\products.csv"),list);
}
}
Output:
Name VatApplicable Price Identifier
dvd true 24.99 967
pen false 4.99 162
ipad true 624.99 234
crayons false 4.99 127
laptop true 1444.99 997
I wrote a simple class that uses OpenCSV and has two static public methods.
static public File toCSVFile(Object object, String path, String name) {
File pathFile = new File(path);
pathFile.mkdirs();
File returnFile = new File(path + name);
try {
CSVWriter writer = new CSVWriter(new FileWriter(returnFile));
writer.writeNext(new String[]{"Member Name in Code", "Stored Value", "Type of Value"});
for (Field field : object.getClass().getDeclaredFields()) {
writer.writeNext(new String[]{field.getName(), field.get(object).toString(), field.getType().getName()});
}
writer.flush();
writer.close();
return returnFile;
} catch (IOException e) {
Log.e("EasyStorage", "Easy Storage toCSVFile failed.", e);
return null;
} catch (IllegalAccessException e) {
Log.e("EasyStorage", "Easy Storage toCSVFile failed.", e);
return null;
}
}
static public void fromCSVFile(Object object, File file) {
try {
CSVReader reader = new CSVReader(new FileReader(file));
String[] nextLine = reader.readNext(); // Ignore the first line.
while ((nextLine = reader.readNext()) != null) {
if (nextLine.length >= 2) {
try {
Field field = object.getClass().getDeclaredField(nextLine[0]);
Class<?> rClass = field.getType();
if (rClass == String.class) {
field.set(object, nextLine[1]);
} else if (rClass == int.class) {
field.set(object, Integer.parseInt(nextLine[1]));
} else if (rClass == boolean.class) {
field.set(object, Boolean.parseBoolean(nextLine[1]));
} else if (rClass == float.class) {
field.set(object, Float.parseFloat(nextLine[1]));
} else if (rClass == long.class) {
field.set(object, Long.parseLong(nextLine[1]));
} else if (rClass == short.class) {
field.set(object, Short.parseShort(nextLine[1]));
} else if (rClass == double.class) {
field.set(object, Double.parseDouble(nextLine[1]));
} else if (rClass == byte.class) {
field.set(object, Byte.parseByte(nextLine[1]));
} else if (rClass == char.class) {
field.set(object, nextLine[1].charAt(0));
} else {
Log.e("EasyStorage", "Easy Storage doesn't yet support extracting " + rClass.getSimpleName() + " from CSV files.");
}
} catch (NoSuchFieldException e) {
Log.e("EasyStorage", "Easy Storage fromCSVFile failed.", e);
} catch (IllegalAccessException e) {
Log.e("EasyStorage", "Easy Storage fromCSVFile failed.", e);
}
} // Close if (nextLine.length >= 2)
} // Close while ((nextLine = reader.readNext()) != null)
} catch (FileNotFoundException e) {
Log.e("EasyStorage", "Easy Storage fromCSVFile failed.", e);
} catch (IOException e) {
Log.e("EasyStorage", "Easy Storage fromCSVFile failed.", e);
} catch (IllegalArgumentException e) {
Log.e("EasyStorage", "Easy Storage fromCSVFile failed.", e);
}
}
I think with some simple recursion these methods could be modified to handle any Java object, but for me this was adequate.
Though its very late reply, I have faced this problem of exporting java entites to CSV, EXCEL etc in various projects, Where we need to provide export feature on UI.
I have created my own light weight framework. It works with any Java Beans, You just need to add annotations on fields you want to export to CSV, Excel etc.
Link: https://github.com/abhisoni96/dev-tools
Worth mentioning that the handlebar library https://github.com/jknack/handlebars.java can trivialize many transformation tasks include toCSV.
You can use gererics to work for any class
public class FileUtils<T> {
public String createReport(String filePath, List<T> t) {
if (t.isEmpty()) {
return null;
}
List<String> reportData = new ArrayList<String>();
addDataToReport(t.get(0), reportData, 0);
for (T k : t) {
addDataToReport(k, reportData, 1);
}
return !dumpReport(filePath, reportData) ? null : filePath;
}
public static Boolean dumpReport(String filePath, List<String> lines) {
Boolean isFileCreated = false;
String[] dirs = filePath.split(File.separator);
String baseDir = "";
for (int i = 0; i < dirs.length - 1; i++) {
baseDir += " " + dirs[i];
}
baseDir = baseDir.replace(" ", "/");
File base = new File(baseDir);
base.mkdirs();
File file = new File(filePath);
try {
if (!file.exists())
file.createNewFile();
} catch (Exception e) {
e.printStackTrace();
return isFileCreated;
}
try (BufferedWriter writer = new BufferedWriter(
new OutputStreamWriter(new FileOutputStream(file), System.getProperty("file.encoding")))) {
for (String line : lines) {
writer.write(line + System.lineSeparator());
}
} catch (IOException e) {
e.printStackTrace();
return false;
}
return true;
}
void addDataToReport(T t, List<String> reportData, int index) {
String[] jsonObjectAsArray = new Gson().toJson(t).replace("{", "").replace("}", "").split(",\"");
StringBuilder row = new StringBuilder();
for (int i = 0; i < jsonObjectAsArray.length; i++) {
String str = jsonObjectAsArray[i];
str = str.replaceFirst(":", "_").split("_")[index];
if (i == 0) {
if (str != null) {
row.append(str.replace("\"", ""));
} else {
row.append("N/A");
}
} else {
if (str != null) {
row.append(", " + str.replace("\"", ""));
} else {
row.append(", N/A");
}
}
}
reportData.add(row.toString());
}