Search Results

Search found 24935 results on 998 pages for 'double click'.

Page 153/998 | < Previous Page | 149 150 151 152 153 154 155 156 157 158 159 160  | Next Page >

• C# is there a problem with division?

  - by Tom

  This is a piece of my code, it is called every second, after about 10 seconds the values start to become weird (see below): double a; double b; for (int i = 0; i < currAC.Length; i++ ) { a = currAC[i]; b = aveACValues[i]; divisor = (a/b); Console.WriteLine("a = " + a.ToString("N2") + "\t" + "b = " + b.ToString("N2")); Console.WriteLine("divisor = " + divisor); Console.WriteLine("a+b = " + (a+b)); } and the output: a = -0.05 b = 0.00 divisor = 41 a+b = -0.0524010372273268 currAC and aveACValues are double[] what on earth is going on???? The addition result is correct every time, but the division value is wrong, yet it is reading a and b correctly?? EDIT: '41' is the value of the first calculation, ie when a = currAC[0], but this should not remain???

  Read the article

• Define and return a struct in c

  - by nevan

  I'm trying to convert some code from Javascript to c. The function creates an array (which always has a fixed number of items) and then returns the array. I've learned that in c it's not straightforward to return an array, so I'd like to return this as a struct instead. My c is not all that great, so I'd like to check that returning a struct is the right thing to do in this situation, and that I'm doing it the right way. Thanks. typedef struct { double x; double y; double z; } Xyz; Xyz xyzPlusOne(Xyz addOne) { Xyz xyz; xyz.x = addOne.x + 1; xyz.y = addOne.y + 1; xyz.z = addOne.z + 1; return xyz; }

  Read the article

• problem while converting object into datetime in c#

  - by Lalit

  Hi, I am getting string value in object let say "28/05/2010". While i am converting it in to DateTime it is throwing exception as : String was not recognized as a valid DateTime. The Code is: object obj = ((Excel.Range)worksheet.Cells[iRowindex, colIndex_q17]).Value2; Type type = obj.GetType(); string strDate3 = string.Empty; double dbl = 0.0; if (type == typeof(System.Double)) { dbl = Convert.ToDouble(((Excel.Range)worksheet.Cells[iRowindex, colIndex_q17]).Value2); strDate3 = DateTime.FromOADate(dbl).ToShortDateString(); } else { DateTime dt = new DateTime().Date; //////////dt = DateTime.Parse(Convert.ToString(obj)); **dt = Convert.ToDateTime(obj).Date;** strDate3 = dt.ToShortDateString(); } The double star "**" line gets exception.

  Read the article

• Array::ConvertAll in managed C++

  - by danny.lesnik

  This is a continuation from this post. I'm trying to parse this string in managed C++: String ^ rgba = "[0.09019608,0.5176471,0.9058824,1]"; cli::array<System::Double> ^ RGB = System::Array::ConvertAll<String,cli::array<System::Double> >((rgba->Substring(1,rgba->Length-2)->Split(',')),double::Parse); Compiler throws me the following error: Error 15 error C2770: invalid explicit generic argument(s) for 'cli::array<Type,dimension> ^System::Array::ConvertAll(cli::array<TInput,1> ^,System::Converter<TInput,TOutput> ^)' What am I doing wrong?

  Read the article

• Haskell: Why is it saying my function type is off?

  - by linkmaster03

  I wrote a little Haskell program to find the area of a triangle, primarily to practice custom types, but it keeps throwing the following error on compile: areafinder.hs:7:4: Couldn't match expected type 'Triangle' against inferred type 'm b' In a stmt of a 'do' expression: putStr "Base: " In the expression: do { putStr "Base: "; baseStr I'm not sure where 'm b' comes from, so I'm at a loss here. Why is it throwing this error, and what can I do to fix it? Here is my code: module Main where data Triangle = Triangle Double Double -- base, height getTriangle :: Triangle getTriangle = do putStr "Base: " baseStr Double calcTriangle (Triangle base height) = base * height main = putStrLn ("Area = " ++ show (calcTriangle getTriangle)) Thanks. :)

  Read the article

• Make the Enter key act like the submit button

  - by Michael Quiles

  How can I make it where some one presses the enter key on my form it will submit this code ? Ive tried the ligtning bolt events etc... but I can't seem to figure it out. private void xTripSubmitButton_Click(object sender, EventArgs e) { // Calculates the numbers from the input and output boxes/labels Miles = double.Parse(this.xTripDestinationTextBox.Text); Mpg = double.Parse(this.xTripMpgTextBox.Text); Price = double.Parse(this.xTripPricepgTextBox.Text); Output = Miles / Mpg; Coutput = Output * Price; //displays a message and the result for the numbers the user inputs this.xTripOutputLabel.Text = "Total gallons you would use: " + Output.ToString("0") + Environment.NewLine + "Total amount it will cost you: " + Coutput.ToString("C"); }

  Read the article

• F# operator over-loading question

  - by jyoung

  The following code fails in 'Evaluate' with: "This expression was expected to have type Complex but here has type double list" Am I breaking some rule on operator over-loading on '(+)'? Things are OK if I change '(+)' to 'Add'. open Microsoft.FSharp.Math /// real power series [kn; ...; k0] => kn*S^n + ... + k0*S^0 type Powers = double List let (+) (ls:Powers) (rs:Powers) = let rec AddReversed (ls:Powers) (rs:Powers) = match ( ls, rs ) with | ( l::ltail, r::rtail ) -> ( l + r ) :: AddReversed ltail rtail | ([], _) -> rs | (_, []) -> ls ( AddReversed ( ls |> List.rev ) ( rs |> List.rev) ) |> List.rev let Evaluate (ks:Powers) ( value:Complex ) = ks |> List.fold (fun (acc:Complex) (k:double)-> acc * value + Complex.Create(k, 0.0) ) Complex.Zero

  Read the article

• There is more then one Point class

  - by Dmitry

  Today I hit something very annoying while working with one of my colleagues. It seems there are two Point classes in .NET and by mistake we were trying for a good few minutes to figure out why our "Point(x,y)" wouldn’t take double, but only Int. Turns out we were using the wrong one since the XAML element in question needed the version with Double. So, based on what you actually want to do, make sure you’re using the right namespace. Please see below for MSDN reference links for each namespace version of Point, hope this saves you some time. System.Windows Point (MSDN Ref - Double version) System.Dawing Point (MSDN Ref - Int version)

  Read the article

• why this with excel sheet reading?

  - by Lalit

  Hi, I am reading the excel sheet from c# interop services cell by cell. where as my excel sheet have Date cells. It generates some double values , I am converting them in date by : double dbl = Convert.ToDouble(((Excel.Range)worksheet.Cells[iRowindex, colIndex_q17]).Value2); string strDate3 = DateTime.FromOADate(dbl).ToShortDateString(); drRow[dtSourceEXLData.Columns[constants.VisualDate]] = strDate3; ok? but some time happening the value of ((Excel.Range)worksheet.Cells[iRowindex,colIndex_q17]).Value2 getting date formate.why this is happeing? plaease guide me. it throws excepion of "input string not in correct format".why it is not generating double value like other cell of same column?

  Read the article

• Measuring execution time of a call to system() in C++

  - by jm1234567890

  I have found some code on measuring execution time here http://www.dreamincode.net/forums/index.php?showtopic=24685 However, it does not seem to work for calls to system(). I imagine this is because the execution jumps out of the current process. clock_t begin=clock(); system(something); clock_t end=clock(); cout<<"Execution time: "<<diffclock(end,begin)<<" s."<<endl; Then double diffclock(clock_t clock1,clock_t clock2) { double diffticks=clock1-clock2; double diffms=(diffticks)/(CLOCKS_PER_SEC); return diffms; } However this always returns 0 seconds... Is there another method that will work? Also, this is in Linux. Thanks!

  Read the article

• Why this friend function can't access a private member of the class?

  - by Alceu Costa

  I am getting the following error when I try to access bins private member of the GHistogram class from within the extractHistogram() implementation: error: 'QVector<double> MyNamespace::GHistogram::bins' is private error: within this context Where the 'within this context' error points to the extractHistogram() implementation. Does anyone knows what's wrong with my friend function declaration? Here's the code: namespace MyNamespace{ class GHistogram { public: GHistogram(qint32 numberOfBins); qint32 getNumberOfBins(); /** * Returns the frequency of the value i. */ double getValueAt(qint32 i); friend GHistogram * Gbdi::extractHistogram(GImage *image, qint32 numberOfBins); private: QVector<double> bins; }; GHistogram * extractHistogram(GImage * image, qint32 numberOfBins); }

  Read the article

• Strange calculation problem in C multiply by 1.2 fails

  - by DoomStone

  I have this c code, where i need to calculate a dobule from a long. double result; long t2_value; t2_value = 72; result = t2_value * 1.2; Now this code crashes at "result = t2_value * 1.2;" only with the error "Vector 0000000006". Here is the strange thing, if i replace result = t2_value * 1.2; with result = 72 * 1.2; evything works just as it should, i have tryed type casting t2_value as an double result = ((double)t2_value * 1.2); or making it an int istead of a long, but nothing helps.

  Read the article

• Convert Decimal number into Fraction

  - by alankrita

  I am trying to convert decimal number into its fraction. Decimal numbers will be having a maximum 4 digits after the decimal place. example:- 12.34 = 1234/100 12.3456 = 123456/10000 my code :- #include <stdio.h> int main(void) { double a=12.34; int c=10000; double b=(a-floor(a))*c; int d=(int)floor(a)*c+(int)b; while(1) { if(d%10==0) { d=d/10; c=c/10; } else break; } printf("%d/%d",d,c); return 0; } but I am not getting correct output, Decimal numbers will be of double precision only.Please guide me what I should do.

  Read the article

• C++ return type overload hack

  - by aaa

  I was bored and came up with such hack (pseudocode): 1 struct proxy { 2 operator int(); // int function 3 operator double(); // double function 4 proxy(arguments); 5 arguments &arguments_; 6 }; 7 8 proxy function(arguments &args) { 9 return proxy(args); 10 } 11 int v = function(...); 12 double u = function(...); is it evil to use in real code?

  Read the article

• Is it possible to write a generic +1 method for numeric box types in Java?

  - by polygenelubricants

  This is NOT homework. Part 1 Is it possible to write a generic method, something like this: <T extends Number> T plusOne(T num) { return num + 1; // DOESN'T COMPILE! How to fix??? } Short of using a bunch of instanceof and casts, is this possible? Part 2 The following 3 methods compile: Integer plusOne(Integer num) { return num + 1; } Double plusOne(Double num) { return num + 1; } Long plusOne(Long num) { return num + 1; } Is it possible to write a generic version that bound T to only Integer, Double, or Long?

  Read the article

• How to rewrite the following?(C#3.0)

  - by Newbie

  I am trying to write the following double sum_res = 0.0; double yhat = 0; double res = 0; int n = 0; for(int i=0;i<x.Count;i++) { yhat = inter + (slp*x[i]); res = yhat - y[i]; n++; } using lambda but somehow not able to get it work(compile time error) Enumerable.Range(0, x.Count).Select(i => { yhat = inter + (slp * x[i]); res = yhat - y[i]; sum_res += res * res; n++; }); Error: The type arguments for method 'System.Linq.Enumerable.Select(System.Collections.Generic.IEnumerable, System.Func)' cannot be inferred from the usage. Try specifying the type arguments explicitly. Help needed. Thanks

  Read the article

• How to add up amount of data from an external file in C# (Stream Reader)

  - by user2985995

  I'm new to this site, and pretty new to programming, at the moment I'm trying to display a count amount for the users names on my donation list, and then I also want to have a sum to work out the total amount of money the donation list contains, If someone could help me with creating a way to add up amount of donors on the donations.txt file that would be great help, I have no idea where to start, but so far this is my coding: string sName; double dAmount; string sTotalNames; double dAmountTotal; double dAmountAverage; using (StreamReader sr = new StreamReader("Donations.txt")) { while (sr.Peek() != -1) { sName = sr.ReadLine(); Console.WriteLine(sName); dAmount = Convert.ToDouble(sr.ReadLine()); Console.WriteLine(dAmount); } Console.WriteLine("Press any key to close"); Console.ReadKey(); }

  Read the article

• Referencing an array to a pointer

  - by james

  I want to refer a pointer to an array by another pointer. Example: void exp() { double var[2]; exp1(&var[0]); printf("\n varvalue is %lf\n",var[0]); } void exp1(double *var) { //updating the value *var[0]=4.0; exp2(&var[0]); } void exp2(double *var) { *var[0]=7.0; } This should update the value as 7.0(the last update).I am getting an array like invalid argument type of unary(*) . How can i correct this?where i am going wrong here?

  Read the article

• Exception for java Swing application?

  - by Rich Fluckiger

  For some reason this is locking up the java application. Did I handle the exception correctly? private void submitButtonActionPerformed(java.awt.event.ActionEvent evt) { double amount, interest,rateCalc, a, b, c, payment; int years, months; while (true){ try{ amount = Double.valueOf(loanAmount.getText()); interest = Double.valueOf(interestRate.getText()); years = Integer.valueOf(loanYears.getText()); rateCalc = (interest/12); months = (years*12); a = Math.pow((1+rateCalc),months); b = (a*rateCalc); c = (a-1); payment = (amount *(b/c)); monthlyPayment.setText("Mortgage Payment $ = " + payment); } catch (NumberFormatException nfe){ javax.swing.JOptionPane.showMessageDialog(null, "Please enter numbers and not letters"); return; } } } monthlyPayment returns to the java app.

  Read the article

• Changing the values of a class returned by the array [] operator

  - by devdept

  The question is: at the end of this code the value of ptArray[0].X is 3.33 or 1.11? Thanks. class MyPoint { public double X, Y; public MyPoint(double x, double y) { X = x; Y = y; } } MyPoint[] ptArray = new MyPoint[2]; ptArray[0] = new MyPoint(1.11, 2.22); MyPoint first = ptArray[0]; // Am I changing ptArray[0] here or not? first.X = 3.33; first.Y = 4.44;

  Read the article

• c++ constructors

  - by aharont

  i wrote this code: class A { public: A(){d=2.2;cout<<d;} A(double d):d(d){cout<<d;} double getD(){return d;} private: double d; }; class Bing { public: Bing(){a=A(5.3);} void f(){cout<<a.getD();} private: A a; }; int main() { Bing b; b.f(); } i get the output: 2.2 5.3 5.3 instead of 5.3 5.3. it's something in the constructor.... wahy am i getting this? how can i fix it?

  Read the article

• Simple Java library for storing statistical observations and calculating statistics such as stddev,

  - by knorv

  For logging purposes I want to collect the response times of an external system, and periodically fetch various statistics (such as min/max/stddev) of the response times. I'm looking for a pure in-memory solution. What Java library can help me with this simple task? I'm looking for an API that would ideally look something along the lines of: StatisticsCollector s = new StatisticsCollector(); while (...) { double responseTime = ...; s.addObservation(responseTime); } double stddev = s.getStandardDeviation(); double mean = s.getMean();

  Read the article

• How to use composition from another class to set Name?

  - by user1874549

  I have some of the code here. I am trying to use one class to reference another so I may obtain the first name of the person. I want the firstName in main class to work but IDE mentions the variable isn't found. Will replacing 'first' with 'firstName' work? Main class: public BasePlusCommissionEmployee( String first, String last, String ssn, double sales, double rate, double salary) { cE = new CommissionEmployee( first, last, ssn, sales, rate ); setBaseSalary( salary ); } public void setFirstName(String firstName) { // Trying to get this to work... cE.setFirstName(first); } SubClass: private String firstName; public void setFirstName( String first ) { firstName = first; }

  Read the article

• SOA Suite 11g Native Format Builder Complex Format Example

  - by bob.webster

  This rather long posting details the steps required to process a grouping of fixed length records using Format Builder.   If it’s 10 pm and you’re feeling beat you might want to leave this until tomorrow.  But if it’s 10 pm and you need to get a Format Builder Complex template done, read on… The goal is to process individual orders from a file using the 11g File Adapter and Format Builder Sample Data =========== 001Square Widget            0245.98 102Triagular Widget         1120.00 403Circular Widget           0099.45 ORD8898302/01/2011 301Hexagon Widget         1150.98 ORD6735502/01/2011 The records are fixed length records representing a number of logical Order records. Each order record consists of a number of item records starting with a 3 digit number, followed by a single Summary Record which starts with the constant ORD. How can this file be processed so that the first poll returns the first order? 001Square Widget            0245.98 102Triagular Widget         1120.00 403Circular Widget           0099.45 ORD8898302/01/2011 And the second poll returns the second order? 301Hexagon Widget           1150.98 ORD6735502/01/2011 Note: if you need more than one order per poll, that’s also possible, see the “Multiple Messages” field in the “File Adapter Step 6 of 9” snapshot further down.   To follow along with this example you will need - Studio Edition Version 11.1.1.4.0    with the   - SOA Extension for JDeveloper 11.1.1.4.0 installed Both can be downloaded from here:  http://www.oracle.com/technetwork/middleware/soasuite/downloads/index.html You will not need a running WebLogic Server domain to complete the steps and Format Builder tests in this article.     Start with a SOA Composite containing a File Adapter The Format Builder is part of the File Adapter so start by creating a new SOA Project and Composite. Here is a quick summary for those not familiar with these steps - Start JDeveloper - From the Main Menu choose File->New - In the New Gallery window that opens Expand the “General” category and Select the Applications node.   Then choose SOA Application from the Items section on the right.  Finally press the OK button. - In Step 1 of the “Create SOA Application wizard” that appears enter an Application Name and an Directory of your     choice,   then press the Next button. - In Step 2 of the “Create SOA Application wizard”, press the Next button leaving all entries as defaulted. - In Step 3 of the “Create SOA Application wizard”, Enter a composite name of your choice and Press the Finish   Button These steps result in a new Application and SOA Project. The SOA Project contains a composite.xml file which is opened and shown below. For our example we have not defined a Mediator or a BPEL process to minimize the steps, but one or the other would eventually be needed to use the File Adapter we are about to create. Drag and drop the File Adapter icon from the Component Pallette onto either the LEFT side of the diagram under “Exposed Services” or the right side under “External References”.  (See the Green Circle in the image below).  Placing the adapter on the left side would indicate the file being processed is inbound to the composite, if the adapter is placed on the right side then the data is outbound to a file.     Note that the same Format Builder definition can be used in both directions.  For example we could use the format with a File Adapter on the left side of the composite to parse fixed data into XML, modify the data in our Composite or BPEL process and then use the same Format Builder definition with a File adapter on the right side of the composite to write the data back out in the same fixed data format When the File Adapter is dropped on the Composite the File Adapter Wizard Appears. Skip Past the first page, Step 1 of 9 by pressing the Next button. In Step 2 enter a service name of your choice as shown below, then press Next   When the Native Format Builder appears, skip the welcome page by pressing next. Also press the Next button to accept the settings on Step 3 of 9 On Step 4, select Read File and press the Next button as shown below.   On Step 5 enter a directory that will contain a file with the input data, then  Press the Next button as shown below. In step 6, enter *.txt or another file format to select input files from the input directory mentioned in step 5. ALSO check the “Files contain Multiple Messages” checkbox and set the “Publish Messages in Batches of” field to 1.  The value can be set higher to increase the number of logical order group records returned on each poll of the file adapter.  In other words, it determines the number of Orders that will be sent to each instance of a Mediator or Composite processing using the File Adapter.   Skip Step 7 by pressing the Next button In Step 8 press the Gear Icon on the right side to load the Native Format Builder.       Native Format Builder  appears Before diving into the format, here is an overview of the process. Approach - Bottom up Assuming an Order is a grouping of item records and a summary record…. - Define a separate  Complex Type for each Record Type found in the group.    (One for itemRecord and one for summaryRecord) - Define a Complex Type to contain the Group of Record types defined above   (LogicalOrderRecord) - Define a top level element to represent an order.  (order)   The order element will be of type LogicalOrderRecord   Defining the Format In Step 1 select   “Create new”  and  “Complex Type” and “Next”   In Step two browse to and select a file containing the test data shown at the start of this article. A link is provided at the end of this article to download a file containing the test data. Press the Next button     In Step 3 Complex types must be define for each type of input record. Select the Root-Element and Click on the Add Complex Type icon This creates a new empty complex type definition shown below. The fastest way to create the definition is to highlight the first line of the Sample File data and drag the line onto the  <new_complex_type> Format Builder introspects the data and provides a grid to define additional fields. Change the “Complex Type Name” to  “itemRecord” Then click on the ruler to indicate the position of fixed columns.  Drag the red triangle icons to the exact columns if necessary. Double click on an existing red triangle to remove an unwanted entry. In the case below fields are define in columns 0-3, 4-28, 29-eol When the field definitions are correct, press the “Generate Fields” button. Field entries named C1, C2 and C3 will be created as shown below. Click on the field names and rename them from C1->itemNum, C2->itemDesc and C3->itemCost  When all the fields are correctly defined press OK to save the complex type.        Next, the process is repeated to define a Complex Type for the SummaryRecord. Select the Root-Element in the schema tree and press the new complex type icon Then highlight and drag the Summary Record from the sample data onto the <new_complex_type>   Change the complex type name to “summaryRecord” Mark the fixed fields for Order Number and Order Date. Press the Generate Fields button and rename C1 and C2 to itemNum and orderDate respectively.   The last complex type to be defined is a type to hold the group of items and the summary record. Select the Root-Element in the schema tree and click the new complex type icon Select the “<new_complex_type>” entry and click the pencil icon   On the Complex Type Details page change the name and type of each input field. Change line 1 to be named item and set the Type  to “itemRecord” Change line 2 to be named summary and set the Type to “summaryRecord” We also need to indicate that itemRecords repeat in the input file. Click the pencil icon at the right side of the item line. On the Edit Details page change the “Max Occurs” entry from 1 to UNBOUNDED. We also need to indicate how to identify an itemRecord.  Since each item record has “.” in column 32 we can use this fact to differentiate an item record from a summary record. Change the “Look Ahead” field to value 32 and enter a period in the “Look For” field Press the OK button to save entry.     Finally, its time to create a top level element to represent an order. Select the “Root-Element” in the schema tree and press the New element icon Click on the <new_element> and press the pencil icon.   Set the Element Name to “order” and change the Data Type to “logicalOrderRecord” Press the OK button to save the element definition.   The final definition should match the screenshot below. Press the Next Button to view the definition source.     Press the Test Button to test the definition   Press the Green Triangle Icon to run the test.   And we are presented with an unwelcome error. The error states that the processor ran out of data while working through the definition. The processor was unable to differentiate between itemRecords and summaryRecords and therefore treated the entire file as a list of itemRecords.  At end of file, the “summary” portion of the logicalOrderRecord remained unprocessed but mandatory.   This root cause of this error is the loss of our “lookAhead” definition used to identify itemRecords. This appears to be a bug in the  Native Format Builder 11.1.1.4.0 Luckily, a simple workaround exists. Press the Cancel button and return to the “Step 4 of 4” Window. Manually add    nxsd:lookAhead="32" nxsd:lookFor="."   attributes after the maxOccurs attribute of the item element. as shown in the highlighted text below.   When the lookAhead and lookFor attributes have been added Press the Test button and on the Test page press the Green Triangle. The test is now successful, the first order in the file is returned by the File Adapter.     Below is a complete listing of the Result XML from the right column of the screen above   Try running it The downloaded input test file and completed schema file can be used for testing without following all the Native Format Builder steps in this example. Use the following link to download a file containing the sample data. Download Sample Input Data This is the best approach rather than cutting and pasting the input data at the top of the article.  Since the data is fixed length it’s very important to watch out for trailing spaces in the data and to ensure an eol character at the end of every line. The download file is correctly formatted. The final schema definition can be downloaded at the following link Download Completed Schema Definition   - Save the inputData.txt file to a known location like the xsd folder in your project. - Save the inputData_6.xsd file to the xsd folder in your project. - At step 1 in the Native Format Builder wizard  (as shown above) check the “Edit existing” radio button,    then browse and select the inputData_6.xsd file - At step 2 of the Format Builder configuration Wizard (as shown above) supply the path and filename for    the inputData.txt file. - You can then proceed to the test page and run a test. - Remember the wizard bug will drop the lookAhead and lookFor attributes,  you will need to manually add   nxsd:lookAhead="32" nxsd:lookFor="."    after the maxOccurs attribute of the item element in the   LogicalOrderRecord Complex Type.  (as shown above)   Good Luck with your Format Project

  Read the article

• Quick guide to Oracle IRM 11g: Configuring SSL

  - by Simon Thorpe

  Quick guide to Oracle IRM 11g index So far in this guide we have an IRM Server up and running, however I skipped over SSL configuration in the previous article because I wanted to focus in more detail now. You can, if you wish, not bother with setting up SSL, but considering this is a security technology it is worthwhile doing. Contents Setting up a one way, self signed SSL certificate in WebLogic Setting up an official SSL certificate in Apache 2.x Configuring Apache to proxy traffic to the IRM server There are two common scenarios in which an Oracle IRM server is configured. For a development or evaluation system, people usually communicate directly to the WebLogic Server running the IRM service. However in a production environment and for some proof of concept evaluations that require a setup reflecting a production system, the traffic to the IRM server travels via a web server proxy, commonly Apache. In this guide we are building an Oracle Enterprise Linux based IRM service and this article will go over the configuration of SSL in WebLogic and also in Apache. Like in the past articles, we are going to use two host names in the configuration below,irm.company.com will refer to the public Apache server irm.company.internal will refer to the internal WebLogic IRM server Setting up a one way, self signed SSL certificate in WebLogic First lets look at creating just a simple self signed SSL certificate to be used in WebLogic. This is a quick and easy way to get SSL working in your environment, however the downside is that no browsers are going to trust this certificate you create and you'll need to manually install the certificate onto any machine's communicating with the server. This is fine for development or when you have only a few users evaluating the system, but for any significant use it's usually better to have a fully trusted certificate in use and I explain that in the next section. But for now lets go through creating, installing and testing a self signed certificate. We use a library in Java to create the certificates, open a console and running the following commands. Note you should choose your own secure passwords whenever you see password below. [oracle@irm /] source /oracle/middleware/wlserver_10.3/server/bin/setWLSEnv.sh [oracle@irm /] cd /oracle/middleware/user_projects/domains/irm_domain/config/fmwconfig/ [oracle@irm /] java utils.CertGen -selfsigned -certfile MyOwnSelfCA.cer -keyfile MyOwnSelfKey.key -keyfilepass password -cn "irm.oracle.demo" [oracle@irm /] java utils.ImportPrivateKey -keystore MyOwnIdentityStore.jks -storepass password -keypass password -alias trustself -certfile MyOwnSelfCA.cer.pem -keyfile MyOwnSelfKey.key.pem -keyfilepass password [oracle@irm /] keytool -import -trustcacerts -alias trustself -keystore TrustMyOwnSelf.jks -file MyOwnSelfCA.cer.der -keyalg RSA We now have two Java Key Stores, MyOwnIdentityStore.jks and TrustMyOwnSelf.jks. These contain keys and certificates which we will use in WebLogic Server. Now we need to tell the IRM server to use these stores when setting up SSL connections for incoming requests. Make sure the Admin server is running and login into the WebLogic Console at http://irm.company.intranet:7001/console and do the following; In the menu on the left, select the + next to Environment to expose the submenu, then click on Servers. You will see two servers in the list, AdminServer(admin) and IRM_server1. If the IRM server is running, shut it down either by hitting CONTROL + C in the console window it was started from, or you can switch to the CONTROL tab, select IRM_server1 and then select the Shutdown menu and then Force Shutdown Now. In the Configuration tab select IRM_server1 and switch to the Keystores tab. By default WebLogic Server uses it's own demo identity and trust. We are now going to switch to the self signed one's we've just created. So select the Change button and switch to Custom Identity and Custom Trust and hit save. Now we have to complete the resulting fields, the setting's i've used in my evaluation server are below. IdentityCustom Identity Keystore: /oracle/middleware/user_projects/domains/irm_domain/config/fmwconfig/MyOwnIdentityStore.jks Custom Identity Keystore Type: JKS Custom Identity Keystore Passphrase: password Confirm Custom Identity Keystore Passphrase: password TrustCustom Trust Keystore: /oracle/middleware/user_projects/domains/irm_domain/config/fmwconfig/TrustMyOwnSelf.jks Custom Trust Keystore Type: JKS Custom Trust Keystore Passphrase: password Confirm Custom Trust Keystore Passphrase: password Now click on the SSL tab for the IRM_server1 and enter in the alias and passphrase, in my demo here the details are; IdentityPrivate Key Alias: trustself Private Key Passphrase: password Confirm Private Key Passphrase: password And hit save. Now lets test a connection to the IRM server over HTTPS using SSL. Go back to a console window and start the IRM server, a quick reminder on how to do this is... [oracle@irm /] cd /oracle/middleware/user_projects/domains/irm_domain/bin [oracle@irm /] ./startManagedWeblogic IRM_server1 Once running, open a browser and head to the SSL port of the server. By default the IRM server will be listening on the URL https://irm.company.intranet:16101/irm_rights. Note in the example image on the right the port is 7002 because it's a system that has the IRM services installed on the Admin server, this isn't typical (or advisable). Your system is going to have a separate managed server which will be listening on port 16101. Once you open this address you will notice that your browser is going to complain that the server certificate is untrusted. The images on the right show how Firefox displays this error. You are going to be prompted every time you create a new SSL session with the server, both from the browser and more annoyingly from the IRM Desktop. If you plan on always using a self signed certificate, it is worth adding it to the Windows certificate store so that when you are accessing sealed content you do not keep being informed this certificate is not trusted. Follow these instructions (which are for Internet Explorer 8, they may vary for your version of IE.) Start Internet Explorer and open the URL to your IRM server over SSL, e.g. https://irm.company.intranet:16101/irm_rights. IE will complain that about the certificate, click on Continue to this website (not recommended). From the IE Tools menu select Internet Options and from the resulting dialog select Security and then click on Trusted Sites and then the Sites button. Add to the list of trusted sites a URL which mates the server you are accessing, e.g. https://irm.company.intranet/ and select OK. Now refresh the page you were accessing and next to the URL you should see a red cross and the words Certificate Error. Click on this button and select View Certificates. You will now see a dialog with the details of the self signed certificate and the Install Certificate... button should be enabled. Click on this to start the wizard. Click next and you'll be asked where you should install the certificate. Change the option to Place all certificates in the following store. Select browse and choose the Trusted Root Certification Authorities location and hit OK. You'll then be prompted to install the certificate and answer yes. You also need to import the root signed certificate into the same location, so once again select the red Certificate Error option and this time when viewing the certificate, switch to the Certification Path tab and you should see a CertGenCAB certificate. Select this and then click on View Certificate and go through the same process as above to import the certificate into the store. Finally close all instances of the IE browser and re-access the IRM server URL again, this time you should not receive any errors. Setting up an official SSL certificate in Apache 2.x At this point we now have an IRM server that you can communicate with over SSL. However this certificate isn't trusted by any browser because it's path of trust doesn't end in a recognized certificate authority (CA). Also you are communicating directly to the WebLogic Server over a non standard SSL port, 16101. In a production environment it is common to have another device handle the initial public internet traffic and then proxy this to the WebLogic server. The diagram below shows a very simplified view of this type of deployment. What i'm going to walk through next is configuring Apache to proxy traffic to a WebLogic server and also to use a real SSL certificate from an official CA. First step is to configure Apache to handle incoming requests over SSL. In this guide I am configuring the IRM service in Oracle Enterprise Linux 5 update 3 and Apache 2.2.3 which came with OpenSSL and mod_ssl components. Before I purchase an SSL certificate, I need to generate a certificate request from the server. Oracle.com uses Verisign and for my own personal needs I use cheaper certificates from GoDaddy. The following instructions are specific to Apache, but there are many references out there for other web servers. For Apache I have OpenSSL and the commands are; [oracle@irm /] cd /usr/bin [oracle@irm bin] openssl genrsa -des3 -out irm-apache-server.key 2048 Generating RSA private key, 2048 bit long modulus ............................+++ .........+++ e is 65537 (0x10001) Enter pass phrase for irm-apache-server.key: Verifying - Enter pass phrase for irm-apache-server.key: [oracle@irm bin] openssl req -new -key irm-apache-server.key -out irm-apache-server.csr Enter pass phrase for irm-apache-server.key: You are about to be asked to enter information that will be incorporated into your certificate request. What you are about to enter is what is called a Distinguished Name or a DN. There are quite a few fields but you can leave some blank For some fields there will be a default value, If you enter '.', the field will be left blank. ----- Country Name (2 letter code) [GB]:US State or Province Name (full name) [Berkshire]:CA Locality Name (eg, city) [Newbury]:San Francisco Organization Name (eg, company) [My Company Ltd]:Oracle Organizational Unit Name (eg, section) []:Security Common Name (eg, your name or your server's hostname) []:irm.company.com Email Address []:[email protected] Please enter the following 'extra' attributes to be sent with your certificate request A challenge password []:testing An optional company name []: You must make sure to remember the pass phrase you used in the initial key generation, you will need this when later configuring Apache. In the /usr/bin directory there are now two new files. The irm-apache-server.csr contains our certificate request and is what you cut and paste, or upload, to your certificate authority when you purchase and validate your SSL certificate. In response you will typically get two files. Your server certificate and another certificate file that will likely contain a set of certificates from your CA which validate your certificate's trust. Next we need to configure Apache to use these files. Typically there is an ssl.conf file which is where all the SSL configuration is done. On my Oracle Enterprise Linux server this file is located in /etc/httpd/conf.d/ssl.conf and i've added the following lines. <VirtualHost irm.company.com> # Setup SSL for irm.company.com ServerName irm.company.com SSLEngine On SSLCertificateFile /oracle/secure/irm.company.com.crt SSLCertificateKeyFile /oracle/secure/irm.company.com.key SSLCertificateChainFile /oracle/secure/gd_bundle.crt </VirtualHost> Restarting Apache (apachectl restart) and I can now attempt to connect to the Apache server in a web browser, https://irm.company.com/. If all is configured correctly I should now see an Apache test page delivered to me over HTTPS. Configuring Apache to proxy traffic to the IRM server Final piece in setting up SSL is to have Apache proxy requests for the IRM server but do so securely. So the requests to Apache will be over HTTPS using a legitimate certificate, but we can also configure Apache to proxy these requests internally across to the IRM server using SSL with the self signed certificate we generated at the start of this article. To do this proxying we use the WebLogic Web Server plugin for Apache which you can download here from Oracle. Download the zip file and extract onto the server. The file extraction reveals a set of zip files, each one specific to a supported web server. In my instance I am using Apache 2.2 32bit on an Oracle Enterprise Linux, 64 bit server. If you are not sure what version your Apache server is, run the command /usr/sbin/httpd -V and you'll see version and it its 32 or 64 bit. Mine is a 32bit server so I need to extract the file WLSPlugin1.1-Apache2.2-linux32-x86.zip. The from the resulting lib folder copy the file mod_wl.so into /usr/lib/httpd/modules/. First we want to test that the plug in will work for regular HTTP traffic. Edit the httpd.conf for Apache and add the following section at the bottom. LoadModule weblogic_module modules/mod_wl.so <IfModule mod_weblogic.c>    WebLogicHost irm.company.internal    WebLogicPort 16100    WLLogFile /tmp/wl-proxy.log </IfModule> <Location /irm_rights>    SetHandler weblogic-handler </Location> <Location /irm_desktop>    SetHandler weblogic-handler </Location> <Location /irm_sealing>    SetHandler weblogic-handler </Location> <Location /irm_services>    SetHandler weblogic-handler </Location> Now restart Apache again (apachectl restart) and now open a browser to http://irm.company.com/irm_rights. Apache will proxy the HTTP traffic from the port 80 of your Apache server to the IRM service listening on port 16100 of the WebLogic Managed server. Note above I have included all four of the Locations you might wish to proxy. http://irm.company.internalirm_rights is the URL to the management website, /irm_desktop is the URL used for the IRM Desktop to communicate. irm_sealing is for web services based document sealing and irm_services is for IRM server web services. The last two are typically only used when you have the IRM server integrated with another application and it is unlikely you'd be accessing these resources from the public facing Apache server. However, just in case, i've mentioned them above. Now let's enable SSL communication from Apache to WebLogic. In the ZIP file we extracted were some more modules we need to copy into the Apache folder. Looking back in the lib that we extracted, there are some more files. Copy the following into the /usr/lib/httpd/modules/ folder. libwlssl.so libnnz11.so libclntsh.so.11.1 Now the documentation states that should only need to do this, but I found that I also needed to create an environment variable called LD_LIBRARY_PATH and point this to the folder /usr/lib/httpd/modules/. If I didn't do this, starting Apache with the WebLogic module configured to SSL would throw the error. [crit] (20014)Internal error: WL SSL Init failed for server: (null) on 0 So I had to edit the file /etc/profile and add the following lines at the bottom. You may already have the LD_LIBRARY_PATH variable defined, therefore simply add this path to it. LD_LIBRARY_PATH=/usr/lib/httpd/modules/ export LD_LIBRARY_PATH Now the WebLogic plug in uses an Oracle Wallet to store the required certificates.You'll need to copy the self signed certificate from the IRM server over to the Apache server. Copy over the MyOwnSelfCA.cer.der into the same folder where you are storing your public certificates, in my example this is /oracle/secure. It's worth mentioning these files should ONLY be readable by root (the user Apache runs as). Now lets create an Oracle Wallet and import the self signed certificate from the IRM server. The file orapki was included in the bin folder of the Apache 1.1 plugin zip you extracted. orapki wallet create -wallet /oracle/secure/my-wallet -auto_login_only orapki wallet add -wallet /oracle/secure/my-wallet -trusted_cert -cert MyOwnSelfCA.cer.der -auto_login_only Finally change the httpd.conf to reflect that we want the WebLogic Apache plug-in to use HTTPS/SSL and not just plain HTTP. <IfModule mod_weblogic.c>    WebLogicHost irm.company.internal    WebLogicPort 16101    SecureProxy ON    WLSSLWallet /oracle/secure/my-wallet    WLLogFile /tmp/wl-proxy.log </IfModule> Then restart Apache once more and you can go back to the browser to test the communication. Opening the URL https://irm.company.com/irm_rights will proxy your request to the WebLogic server at https://irm.company.internal:16101/irm_rights. At this point you have a fully functional Oracle IRM service, the next step is to create a sealed document and test the entire system.

  Read the article

< Previous Page | 149 150 151 152 153 154 155 156 157 158 159 160  | Next Page >