I'm working with Apache Accumulo and I need to create a iterator that every minor compaction scans all whole row and create a MD5 of two column and save it as another column of my row...
Example:
I insert this data:
|| Row || colFam || colQual || value ||
||=====||========||=========||=======||
|| A || person || name || Bob ||
|| A || person || surname || Smith ||
|| A || work || place || Bank ||
|| B || person || name || Jhon ||
|| B || person || surname || Allen ||
|| B || work || place || Pub ||
...
...
I need a iterator that every time I write a row (A or B with all its colFam e colQual) it get the value of two column (name and surname) and calculate the MD5 of the resulting string (name + surname) and save it as a column of my row.
The result should be like that:
|| Row || colFam || colQual || value ||
||=====||========||=========||==============||
|| A || person || name || Bob ||
|| A || person || surname || Smith ||
|| A || work || place || Bank ||
|| A || MD5 || MD5 || <MD5 result> || <--
|| B || person || name || Jhon ||
|| B || person || surname || Allen ||
|| B || work || place || Pub ||
|| B || MD5 || MD5 || <MD5 result> || <--
....
....
I think that I can put this iterator on a minor(/major) compaction of a table.
Any idea? Which one of the Built-In iterator I have to extend to do that?
Thank you so much
Check out the TransformingIterator. This iterator tries to hide some of the complexities behind row-level operations.
The general strategy is that, when iterating over a row, you have to buffer the row in memory, perform your computation, and then write out the row in the correct sorted order.
Related
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PrintWriter append method not appending
(5 answers)
How to append text to an existing file in Java?
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I need HELP. I tried to separate the valid serial keys from invalid ones. I got the output correctly. but then when i tried to write it in a file, ONLY the last line is being written.
the output is:
1A000000
1A000001
1A000002
1A000003
1A000004
1A000005
2B200012
3C343455
4D342423
5E324344
6F435435
7G245347
and I want to write this to a file. But ONLY 7G245347 is being written.
import java.util.*;`
import java.io.*;
public class ValidSerialKey {
public static void main(String[] args) throws IOException {
String keys = "";
File file = new File("serialkeys.txt");
try{
Scanner scan = new Scanner(file);
while (scan.hasNext()){
keys = scan.nextLine();
if ((keys.charAt(0) == '1' || keys.charAt(0) == '2' || keys.charAt(0) == '3' || keys.charAt(0) == '4' || keys.charAt(0) == '5' ||
keys.charAt(0) == '6' || keys.charAt(0) == '7' || keys.charAt(0) == '8' || keys.charAt(0) == '9' ) &&
(keys.charAt(1) == 'A' || keys.charAt(1) == 'B' || keys.charAt(1) == 'C' || keys.charAt(1) == 'D' || keys.charAt(1) == 'E' ||
keys.charAt(1) == 'F' || keys.charAt(1) == 'G' || keys.charAt(1) == 'H' || keys.charAt(1) == 'I' || keys.charAt(1) == 'J' ||
keys.charAt(1) == 'K' || keys.charAt(1) == 'L' || keys.charAt(1) == 'M' || keys.charAt(1) == 'N' || keys.charAt(1) == 'O' ||
keys.charAt(1) == 'P' || keys.charAt(1) == 'Q' || keys.charAt(1) == 'R' || keys.charAt(1) == 'S' || keys.charAt(1) == 'T' ||
keys.charAt(1) == 'U' || keys.charAt(1) == 'V' || keys.charAt(1) == 'W' || keys.charAt(1) == 'X' || keys.charAt(1) == 'Y' ||
keys.charAt(1) == 'Z' )){
System.out.println(keys);
File filein = new File("ValidKeys.txt");
try{
try
(PrintWriter pw = new PrintWriter(filein)){
pw.print(keys);
pw.close();
}
}catch (FileNotFoundException ex){
System.out.println(ex.getMessage());
}
}//end of if
}//end of while
scan.close();
}catch (FileNotFoundException exp){
System.out.println(exp.getMessage());
}
}
}
You want to keep the PrintWriter opened to write other things during the next iterations of the loop
So don't create a new one at each iteration.
As a side note, you don't need to close explicitly the PrintWriter instance when you use try with resources.
You should replace this logic :
loop
try
(PrintWriter pw = new PrintWriter(uniqueFile)){
pw.print(keys);
}//end of inner try
end loop
by a logic where you include the whole logic in the try with resources statement :
try(PrintWriter pw = new PrintWriter(uniqueFile)){
loop
pw.print(keys);
end loop
}
catch (IOException e){
... // exception handling
}
Why is the first if statement always true?
private String setDepartment (){
int code = Integer.parseInt(JOptionPane.showInputDialog("Enter The Department Code:\n" +
"1:Sales\n" +
"2:Development\n" +
"3:Accounting\n" +
"4:None"));
/*Why this if statement is always true? How do i solve it? */
if (code !=1 || code !=2 || code !=3 || code !=4)
{
JOptionPane.showMessageDialog(null, "Invalid Number.Enter a number between 1-4");
setDepartment();
}
if (code==1){
return "Sales";
}
else if (code==2){
return "Development";
}
else if (code==3){
return "Accounting";
}
else
return "";
}
Replace || with &&:
if (code !=1 && code !=2 && code !=3 && code !=4)
You need to use AND instead of OR.
If the user enters 1 then it's automatically different than 2,3 and 4.
You can therefore use :
if (code !=1 && code !=2 && code !=3 && code !=4)
OR
if (code ==1 || code ==2 || code ==3 || code ==4)
From first principles, picking code = 1:
code !=1 || code !=2 || code !=3 || code !=4
= 1 !=1 || 1 !=2 || 1 !=3 || 1 !=4
= false || true || true || true
= true
You probably meant && rather than ||.
Because at any point of time code value would be any of 1-4. And 3 of 4 conditions would always be true. Change your if condition to
If( !( code ==1 || code == 2 || code == 3 || code == 4))
I create Hospital Management System for School projects and I think i am at 35% of the system and here at Patient Registration where I struggle a lot here is the `JFrame1 I have at First Page
First Page
St First Page I have this Past Medical History and Review Symptoms with other options so if I don't check any of the JCheckBox controls including the None check box but I click the next Button it will pop up the option if you don't have any Past Medical History the codes like this
if(!jCheckBox1.isSelected() || !jCheckBox2.isSelected() || !jCheckBox3.isSelected() || !jCheckBox4.isSelected() || !jCheckBox5.isSelected() || !jCheckBox6.isSelected() || !jCheckBox7.isSelected() || !jCheckBox8.isSelected() || !jCheckBox9.isSelected() || !jCheckBox10.isSelected() || !jCheckBox11.isSelected() || !jCheckBox12.isSelected()|| !jCheckBox13.isSelected() || !jCheckBox14.isSelected() || !jCheckBox15.isSelected() || !jCheckBox16.isSelected() || !jCheckBox17.isSelected() ||
!jCheckBox18.isSelected() || !jCheckBox19.isSelected() || !jCheckBox20.isSelected() || !jCheckBox21.isSelected() || !jCheckBox104.isSelected() || !jCheckBox102.isSelected() || !jCheckBox100.isSelected() || !jCheckBox98.isSelected() || !jCheckBox111.isSelected() || !jCheckBox94.isSelected() || !jCheckBox95.isSelected() || !jCheckBox99.isSelected() || !jCheckBox109.isSelected() || !jCheckBox112.isSelected() || !jCheckBox110.isSelected() || !jCheckBox97.isSelected() ||
!jCheckBox107.isSelected() || !jCheckBox101.isSelected() || !jCheckBox106.isSelected() || !jCheckBox96.isSelected() || !jCheckBox105.isSelected() || !jCheckBox92.isSelected() || !jCheckBox103.isSelected()|| !jCheckBox93.isSelected() || !jCheckBox105.isSelected() || !jCheckBox115.isSelected() || !jCheckBox114.isSelected() || !jCheckBox113.isSelected() || !jCheckBox121.isSelected() || !jCheckBox120.isSelected() || !jCheckBox119.isSelected() || !jCheckBox118.isSelected() ||
!jCheckBox117.isSelected()|| !jCheckBox116.isSelected() || !jCheckBox127.isSelected()){
//JOptionPane.showMessageDialog(null, "Medical History is empty","Error",JOptionPane.WARNING_MESSAGE);
int yesOrno = JOptionPane.showConfirmDialog(null, "No medical History?", "Proceed",JOptionPane.YES_NO_OPTION);
if(yesOrno == 0){
jCheckBox127.setSelected(true);
PARENTPANEL.removeAll();
PARENTPANEL.add(ALLERGIES);
PARENTPANEL.repaint();
PARENTPANEL.revalidate();
jCheckBox1.setEnabled(false);
jCheckBox1.setSelected(false);
jCheckBox2.setEnabled(false);
jCheckBox2.setSelected(false);
jCheckBox3.setEnabled(false);
jCheckBox3.setSelected(false);
JOptionPane Popup even when I already select one
I already checked the check boxes and click next but pop up always showed up.
changing || into && in the if clause may save you.
This question already has answers here:
Scanner NoSuchElementException when calling .next() method
(3 answers)
Closed 5 years ago.
if (charIte.next()=='{' || charIte.next()=='}'
|| charIte.next()=='[' || charIte.next()==']'
|| charIte.next()=='(' || charIte.next()==')'
|| charIte.next()=='*' || charIte.next()=='"'
|| charIte.next()=='/'){
}
The program returns:
Exception in thread "main" java.util.NoSuchElementException at line
|| charIte.next()=='(' || charIte.next()==')'
What is the problem?
Each invocation of next() consumes one token. Call it once, and save and then compare with the result. Like,
char ch = charIte.next();
if (ch == '{' || ch == '}' || ch == '[' || ch == ']' || ch == '('
|| ch == ')' || ch == '*' || ch == '"' || ch == '/') {
// ...
}
Each time you do charIte.next() you're asking to read the next token.
I think what you should do to ischar ite = charIte.next.chartAt(0) and then use ite in your if statement
if (ite next()=='{' || next()=='}'
|| ite.next()=='[' || ite.next()==']'
|| ite.next()=='(' || ite.next()==')'
|| ite.next()=='*' || ite.next()=='"'
|| ite.next()=='/'){
Info on Scanner
This loop keeps giving me my error message even when I enter a valid input and I can't find what is wrong with it. It's the same as my other loops in the program which all work fine. Does anyone know the problem? Here is the loop:
System.out.println("Male or Female (M/F)");
gender = userInput.next().charAt(0);
gender = Character.toLowerCase(gender);
while((gender != 'm') || (gender != 'f')) {
System.out.println("ERROR Please enter a valid age");
System.out.println("Male or Female (M/F)");
gender = userInput.next().charAt(0);
gender = Character.toLowerCase(gender);
}//end while
Now if I type 'm' or 'f' it will give me the error message? ??? ???
while((gender != 'm') || (gender != 'f')) {
should really be
while((gender != 'm') && (gender != 'f')) {
The condition (gender != 'm') || (gender != 'f') always evaluates to true. To understand why, consider one case - gender = 'm'...
(gender != 'm') || (gender != 'f')
('m' != 'm') || ('m' != 'f')
false || true
true
Basically, java doesn't know the common English idiom if gender isn't (either) male or female.