It's always good to keep functions smaller and focused on one behavior. So is this safe:
Java Code:
public Unit findBySql(int id){
Unit unit=null;
DbConnectionPool dbPool = DbConnectionPool.getInstance();
HashMap<String, String> conditions = new HashMap<String, String>();
conditions.put("id", String.valueOf(id));
String sql = buildSelect("units", "*", conditions);
[Code] ......
As you can see a pass ResultSet to a function which populates the item. But I also make sure that the ResultSet that the passed object is pointing to is closed, so it doesn't leak resources.
I came across a code where the exceptions can be thrown from catch and finally block too. I never gave a thought on what scenarios that can be required. Some practical examples when/where it can be required to throw the exception from catch and finally blocks.
is my current exercise.so far i have gotten the code to create a file, and ask the user to input their age.what should i use to save what the user writes into the file?
Java Code:
package assignment7; import java.io.*; import java.util.*; public class Exercise2 { public static void main ( String [ ] args ) throws IOException { Scanner scan = new Scanner(System.in);
Ok here i am trying to pull out all the items in my Product table but all it does it last the row in the table. I have tried using do while but it still does not retrieve the information
Here the the Bean
public class Pageitem { private int id; private String name; private double price; private String description; private Date modifyDate; private int category;}//Has getter Setters and ToString methods for the items
The below method shows that a JOptionPane should display when the result is null, meaning it has not found what I was trying to look for. However only the if statement that finds the query runs:
public void find(Person person) { String query = "SELECT * from employee WHERE last LIKE'" + lastName + "'"; try { statement = connection.createStatement(); resultSet = statement.executeQuery(query); Â [Code] ....
query ="Select major_career.Major_Title, career.ISCOTitle,career.FS.... " //only partial, // I swear the query is correct resultSet = statement.executeQuery(query); //this executes it relArr = new ArrayList<String>(); //don't worry it is intialized
In the code below I tried to store the resultset components into the arraylist
int j = 1; while (resultSet.next()) { while(j<=numberOfColumns){ relArr.add(resultSet.getObject(j).toString()); j++; } } // end while
I am not sure whether the arraylist is able to store the result set because when i try to display it like show below it only shows some rows and only the first column
Iterator it = relArr.iterator(); while (it.hasNext()) { System.out.println(it.next());
I want to manipulate the resultset results in my program by copying the resultset values to other datastructures.
I've been trying to get a handle on how to populate a jtable with data from my resultset and have found out that using DBUtils is probably the easiest method but unfortunately its not working for me at all. The program runs but the jtable remains empty as ever. I don't understand where I'm going wrong with it. I have import net.proteanit.sql.DbUtils; imported at the top and the jar added in class path. Here is my code:
private void jPanel3FocusGained(java.awt.event.FocusEvent evt) { // TODO add your handling code here: // JDBC driver name and database URL String JDBC_DRIVER = "com.mysql.jdbc.Driver"; String DB_URL = "jdbc:mysql://localhost/new";
I have retrieve the data in listbox from my database already and now again i want to select the data from this listbox and query on it , is it possible?
For Ex i have listbox as follows
<h4>Models For Selected Pattern:</h4> </br> <select Name="drop_model" multiple="true"> <%
There is no permission for me that I can change SQL query(or anything like this), and I've to return the modified ResultSet(not TableModel). I googled a lot to implement AbstractResultSet, but no luck for me. How can I achieve this ?
I am trying to use a custom class in a .jsp page, as part of a course I am taking on Web Technologies.The original version of the jsp page was working fine, until I moved part of the Java code to a separate class.Here is the original .jsp code that is working:
I'm want to call another statement within the same resultSet. But it gives an error that the result set is closed.
public static void updateAlarmStatus(int status) { ResultSet rs = null; database.restartDatabase(); try { rs = database .executeQuery("Select alarmId from alarms where alarmDate = '"
[Code] ....
I googled it and came to know that resultSet is automatically closed if we call another statement within in. I've also tried creating the connection again before the second statement but of no use.
I am trying to get resultset into a string and then use split method to store it in an array but it is not working. i tried to work it seperately as java program but it throws exception "could not find or load main class java."
String ar = "This.is.a.split.method"; String[] temp = ar.split("."); for(int i=0;i<temp.length;i++){
I am building an online quiz. I created a database , bean , controller and jsp. I connected database, wrote query , put resultset in arraylist of object and passed it to jsp. My program runs but arraylist size increases everytime and same question get displayed repeatedly . i cant find the error. Everytime i run the program arraylist size increases. I think it is adding same rows again ang again. here is my code for controller and jsp.
I have a my result set object which has data as shown by the attached image.What i am trying to do is traverse these results and do certain operations. I want my program to do this, if I
I am very new to multithreading thus the code below reeks of ignorance,but i guess thats a place to start from.I am trying to obtain values that are already in my db and send them to a database by creating a new thread as follows:
//ADDED JUL 15 2014 12:07, LISTITEMS SO public void getList() throws SQLException { String sql = "select * from PRODUCTS"; out.print(m_Stmt); ResultSet rs = m_Stmt.executeQuery(sql); ExecutorService es=Executors.newCachedThreadPool(); es.execute(new Runnable(){ @Override
I have observed a strange behaviour from Resultset object. My application fetches 400 records from a table and processes these records every 10secs. By default the resultset has a fetchsize of 10 from the database cursor. As I understand if the query returns 400records, the resultset will fetch 40times, in multiple of 10 to get all these 400 records from database cursor.
Query : SELECT * FROM ( SELECT * FROM TestTable WHERE STATE_ACTION = 0 ORDER BY ROP_TIME DESC ) WHERE ROWNUM <= 250
Observation : Under a normal operation, the resultset fetches all the 400 records on query execution from database cursor, but under unknown conditions the same resultset object fetches only 10 records from the database cursor and exits. Please refer page 297 in document below for the result fetch size details. JDBC developer guide for oracle 10g : [URL] .... This condition self-heals itself in few hours or restarting the database or restarting the server. The root cause of this behavior is unknown.
In the following piece of code Iam confused as to where the InputMismatchException in the catch block is thrown on the first place? Is the InputMismatchException thrown automatically with declaring to throw the exception?
import java.util.*;
public class InputMismatchExceptionDemo { public static void main(String[] args) { Scanner input = new Scanner(System.in); boolean continueInput = true;
Is it a best practice to return from try block or place return statement after try-catch when we intend to return a value from a method(* Catch block is being also used to rethrow the exception)??
I'm doing project in area of "Cryptography and Network security". I'm having a file with binary Unicode (mean file contain Unicode value of corresponding data (text file)), want to divide that as blocks with the size of 144bits.
Regarding return statements within methods. So I have a method containing try and catch block (as required) and much like when you have an if else statement... I noted you have to return an object for both the try and catch blocks. Now in my case my method should return a List object.
The way I have tried to overcome this:
- I've initialised a List object to null as an attribute of the class I'm working in. - Therefore in the catch block would just simply return the null List object, where as the try block would return the non-empty List (which is what I want). - I then just test to see if the List != null, when the method is invoked... and that is that.
However the method always seems to return null (when it shouldn't).
Modify the program in Assign4 to synchronize access to the instance variable, balance. Save the program as SyncBank.java. Because balance is a double and not an object, it cannot be used as the monitor. Use synchronized methods or synchronized blocks of code as appropriate. Simultaneously test two threads as was done in Assign4. Because the threads can complete too quickly to determine if they are interfering with each other, delay the adding of a deposit by inserting the following code within the synchronized block or method:
I am developing a Client/Server java application, where CSMessage is sent through socket.CSMessage has some data like String type and HashMap<String, String> type.the Client send message:
private ObjectInputStream in; private ObjectOutputStream out; out = new ObjectOutputStream(socket.getOutputStream()); in = new ObjectInputStream(socket.getInputStream());
[code]....
When this happen, the only way to make the system to work is to kill the process and restart it, that's bad!
