Develop Reference

Creating a Search Button (Double cannot converted to String)

private void searchProduct()
{
try {
Product p = new Product();
//Read data
p.setId(Double.parseDouble(textID.getText()));
//Display data
textDescription.setText(String.valueOf(p.getDescription()));
textPrice.setText(String.valueOf(p.getUnitPrice()));
textUOM.setText(String.valueOf(p.getUnitOfMeasurement()));
}
catch(NumberFormatException e)
{
JOptionPane.showMessageDialog(this.frame, "ID must be number", "Error",JOptionPane.ERROR_MESSAGE);
}
}
Hello recently I tried to put a button "Search" to find a product than equals to ID, but I don't know how to parse the ID than comes from the product class, I have a error.

Does the textID.getText() actually is a parseable double string? For instance "10.1" do but "10.1 " no.
Always I did this kind of conversion I use trim() to remove this extra white spaces as follow:
String stringValue = textID.getText();
if(stringValue != null) {
stringValue = stringValue.trim();
}
double doubleValue = Double.parseDouble(stringValue);
Se here http://docs.oracle.com/javase/8/docs/api/java/lang/Double.html#valueOf-java.lang.String- how to avoid NumberFormatException using a regular expression to text you string before try to convert it to double.

Java/Mysql: Get all resulted lines from a stored procedure and not only the last

I have a stored procedure in mysql that returns more than one lines.
My java code to execute it is:
preparedStmt = conn.prepareCall(queryString);
preparedStmt.setString(1, String.valueOf(patient_id));
//System.out.print("select patient data java file 1 ");
boolean results = preparedStmt.execute();
int rowsAffected = 0;
// Protects against lack of SET NOCOUNT in stored procedure
while (results || rowsAffected != -1) {
if (results) {
rs = preparedStmt.getResultSet();
break;
} else {
rowsAffected = preparedStmt.getUpdateCount();
}
results = preparedStmt.getMoreResults();
}
int i = 0;
obj = new JSONObject();
while (rs.next()) {
JSONArray alist = new JSONArray();
alist.put(rs.getString("patient_id"));
alist.put(rs.getString("allergy"));
alist.put(rs.getString("allergy_description"));
alist.put(rs.getString("allergy_onset_date"));
alist.put(rs.getString("agent_description"));
alist.put(rs.getString("agent"));
alist.put(rs.getString("severity"));
obj.put("ps_allergies", alist);
i++;
}
conn.close();
At the end, ps_allergies json object contains only the last line of the query. This is the print output:
["1","week",null,"2017-07-07","vacation home","test2","mobile contact"]
I want ps_allergies to contain something similar to
[["1","hydrogen peroxide","Nuts","2017-07-04","Nursing profressionals","43","Paramedical practinioners"],["1","week",null,"2017-07-07","vacation home","test2","mobile contact"]...]
Do you know how to fix this?

Not exactly knowing what library you use, but it might have something to do with this line:
obj.put("ps_allergies", alist);
A put method in general associates the specified value with the specified key in a map. Since you are constantly overwriting you key 'ps_allergies' in the loop it will only retain the last value.
You might want to associate a list/array to ps_allergies and you then add every alist object in this list/array.

I found the solution. Instead of put I'm using append method.
obj.append("ps_allergies", alist);
The resulted output now is:
[["1","hydrogen peroxide","Nuts","2017-07-04","Nursing professionals","43","Paramedical practitioners"],["1","chlorhexidine","test123","2017-07-15","mobile contact","test232","pager"],["1","Resistance to unspecified antibiotic","Feb3","2017-03-02","mobile contact","test232","pager"],["1","week",null,"2017-07-07","vacation home","test2","mobile contact"]]

Java - Parse delimited file and find column datatypes

Is it possible to parse a delimited file and find column datatypes? e.g
Delimited file:
Email,FirstName,DOB,Age,CreateDate
test#test1.com,Test User1,20/01/2001,24,23/02/2015 14:06:45
test#test2.com,Test User2,14/02/2001,24,23/02/2015 14:06:45
test#test3.com,Test User3,15/01/2001,24,23/02/2015 14:06:45
test#test4.com,Test User4,23/05/2001,24,23/02/2015 14:06:45
Output:
Email datatype: email
FirstName datatype: Text
DOB datatype: date
Age datatype: int
CreateDate datatype: Timestamp
The purpose of this is to read a delimited file and construct a table creation query on the fly and insert data into that table.
I tried using apache validator, I believe we need to parse the complete file in order to determine each column data type.
EDIT: The code that I've tried:
CSVReader csvReader = new CSVReader(new FileReader(fileName),',');
String[] row = null;
int[] colLength=(int[]) null;
int colCount = 0;
String[] colDataType = null;
String[] colHeaders = null;
String[] header = csvReader.readNext();
if (header != null) {
colCount = header.length;
}
colLength = new int[colCount];
colDataType = new String[colCount];
colHeaders = new String[colCount];
for (int i=0;i<colCount;i++){
colHeaders[i]=header[i];
}
int templength=0;
String tempType = null;
IntegerValidator intValidator = new IntegerValidator();
DateValidator dateValidator = new DateValidator();
TimeValidator timeValidator = new TimeValidator();
while((row = csvReader.readNext()) != null) {
for(int i=0;i<colCount;i++) {
templength = row[i].length();
colLength[i] = templength > colLength[i] ? templength : colLength[i];
if(colHeaders[i].equalsIgnoreCase("email")){
logger.info("Col "+i+" is Email");
} else if(intValidator.isValid(row[i])){
tempType="Integer";
logger.info("Col "+i+" is Integer");
} else if(timeValidator.isValid(row[i])){
tempType="Time";
logger.info("Col "+i+" is Time");
} else if(dateValidator.isValid(row[i])){
tempType="Date";
logger.info("Col "+i+" is Date");
} else {
tempType="Text";
logger.info("Col "+i+" is Text");
}
logger.info(row[i].length()+"");
}
Not sure if this is the best way of doing this, any pointers in the right direction would be of help

If you wish to write this yourself rather than use a third party library then probably the easiest mechanism is to define a regular expression for each data type and then check if all fields satisfy it. Here's some sample code to get you started (using Java 8).
public enum DataType {
DATETIME("dd/dd/dddd dd:dd:dd"),
DATE("dd/dd/dddd",
EMAIL("\\w+#\\w+"),
TEXT(".*");
private final Predicate<String> tester;
DateType(String regexp) {
tester = Pattern.compile(regexp).asPredicate();
}
public static Optional<DataType> getTypeOfField(String[] fieldValues) {
return Arrays.stream(values())
.filter(dt -> Arrays.stream(fieldValues).allMatch(dt.tester)
.findFirst();
}
}
Note that this relies on the order of the enum values (e.g. testing for datetime before date).

Yes it is possible and you do have to parse the entire file first. Have a set of rules for each data type. Iterate over every row in the column. Start of with every column having every data type and cancel of data types if a row in that column violates a rule of that data type. After iterating the column check what data type is left for the column. Eg. Lets say we have two data types integer and text... rules for integer... well it must only contain numbers 0-9 and may begin with '-'. Text can be anything.
Our column:
345
-1ab
123
The integer data type would be removed by the second row so it would be text. If row two was just -1 then you would be left with integer and text so it would be integer because text would never be removed as our rule says text can be anything... you dont have to check for text basically if you left with no other data type the answer is text. Hope this answers your question

I have slight similar kind of logic needed for my project. Searched lot but did not get right solution. For me i need to pass string object to the method that should return datatype of the obj. finally i found post from #sprinter, it looks similar to my logic but i need to pass string instead of string array.
Modified the code for my need and posted below.
public enum DataType {
DATE("dd/dd/dddd"),
EMAIL("#gmail"),
NUMBER("[0-9]+"),
STRING("^[A-Za-z0-9? ,_-]+$");
private final String regEx;
public String getRegEx() {
return regEx;
}
DataType(String regEx) {
this.regEx = regEx;
}
public static Optional<DataType> getTypeOfField(String str) {
return Arrays.stream(DataType.values())
.filter(dt -> {
return Pattern.compile(dt.getRegEx()).matcher(str).matches();
})
.findFirst();
}
}
For example:
Optional<DataType> dataType = getTypeOfField("Bharathiraja");
System.out.println(dataType);
System.out.println(dataType .get());
Output:
Optional[STRING]
STRING
Please note, regular exp pattern is vary based on requirements, so modify the pattern as per your need don't take as it is.
Happy Coding !

Split the getString result into multiple values according to columns

<%
st = con.createStatement();
rs = st.executeQuery("select pf_nm from portfolio");
while(rs.next())
{
out.print(rs.getString(1)); //divide the result into multiple values
}
%>
The result in above code may vary according to data fetched. Example of result is as below:
Google Facebook
or
Google
or
Google Facebook Apple

If I understood your question and comment correctly then you can do something like this
ArrayList<String> cols = new ArrayList<String>();
while(rs.next())
{
cols.add(rs.getString(1));
// Do something..
}
Edit : What I understood from your previous question
String result = rs.getString(1); // gives "Google Facebook Apple AT&T" as result
String[] names = result.split("\\s"); // Split the line by whitespace
If you want you can also make use of ArrayList. You can also use hashMap if you required key values assoiciation (I am not sure thats what you want). Following are some useful links
1. Splitting string in java
2. How to use ArrayList in Java
3. HashMap example in Java
Here is complete pseudo code for you.
public class StringSplit {
public static void main(String [] sm){
String str = "Google Facebook Apple AT&T";
// If you have more than one whitespace then better use \\s+
String[] names = str.split("\\s");
for(int i =0; i<names.length; i++){
System.out.println(i +" : " + names[i]);
}
}
}
I hope this helps you.

Combine for loop and sql in java

I have 2 input dates: myStartDate,myEndDate and a table TEST_TABLE with columns
TEST_ID, TEST_USER,TEST_START, TEST_END
I need to check if the range of dates between myStartDate and myEndDate have corresponding records in the TEST_TABLE.
I also need to ensure that I don't retrieve duplicate records.
Here's a sample of the logic I have so far:
Assuming,
myStartDate=06/06/2012;myEndDate=06/09/2012
int diff = myEndDate - myStartDate; //In this case = 3
String myQuery = "SELECT * FROM TEST_TABLE WHERE"+ myStartDate +"BETWEEN TEST_START AND TEST_END OR "+ (myStartDate +1) +" BETWEEN TEST_START AND TEST_END OR"+ (myStartDate+2)+"BETWEEN TEST_START AND TEST_END OR"+(myStartDate+3)+"BETWEEN TEST_START AND TEST_END";
List <TestTableData> myList = new List();
//Exceute query & save results into myList using add method
Want to know if there's any way to test the range of dates between myStartDate &myEndDate using a for loop in java code, instead of the approach used above in myQuery.Also, how can I avoid duplicates.
New to Java so any help would be appreciated!

Use a ResultSet to iterate over the output, like the code below.
while (res.next()) {
String col1= res.getString("col1");
String col2 = res.getString("col2");
}
If you use an Array implementation , it does not allow for duplicate elements and hence there is no need to check for one.
But if you must use a list then , you could use the following code to remove any duplicate elements.
public static void removeDuplicates(List list)
{
Set set = new HashSet();
List newList = new ArrayList();
for (Iterator iter = list.iterator(); iter.hasNext(); ) {
Object element = iter.next();
if (set.add(element))
newList.add(element);
}
list.clear();
list.addAll(newList);
}

I think what you are asking are some generic questions about how to read a database and how to handle dates in java. I will give you some sample code below. But I suggest you look at the java database tutorial http://docs.oracle.com/javase/tutorial/jdbc/index.html and the java.util.Date api doc http://docs.oracle.com/javase/1.5.0/docs/api/java/sql/Date.html for more info.
Here is some sample code that specifically demonstrates how to implement your question:
// get the input dates
// they are hard coded in this example
// but would probably normally be passed in
String startDateStr = "2/3/03";
String endDateStr = "3/1/03";
// unfortunately, there are 2 "Date" classes in this code and you need to differentiate
// java.util.Date is the standard java class for manipulating dates
// java.sql.Date is used to handle dates in the database
// name conflicts like this are rare in Java
SimpleDateFormat dateFmt = new SimpleDateFormat("M/d/yy");
java.util.Date myStartDate = dateFmt.parse(startDateStr);
java.util.Date myEndDate = dateFmt.parse(endDateStr);
// conneect to the database
// I am using mysql and its driver class is "com.mysql.jdbc.Driver"
// if using a different database, you would use its driver instead
// make sure the jar containing the driver is in your classpath (library list)
// you also have to know the url string that connects to your database
Class.forName("com.mysql.jdbc.Driver").newInstance(); // loads the driver
Connection dbConn = DriverManager.getConnection(
"jdbc:mysql://localhost/testdb", "(db user)", "(db password)"
);
// get the database rows from the db table
// my table is named "testtable"
// my columns are named "DateStart" and "DateEnd"
Statement st = dbConn.createStatement();
String sqlStr = "Select * from testtable";
ResultSet rs = st.executeQuery(sqlStr);
// loop through the rows until you find a row with the right date range
boolean foundRange = false;
while (rs.next()) {
java.util.Date dbStartDate = rs.getDate("DateStart");
java.util.Date dbEndDate = rs.getDate("DateEnd");
if (myStartDate.before(dbStartDate)) continue;
if (myEndDate.after(dbEndDate)) continue;
foundRange = true;
break;
}
if (foundRange) {
// code that executes when range is found in db
} else {
// code that executes if range not found in db
}
dbConn.close();
Hope this helps you get started.