Java – How do RESTful and SOAP Web Services differ in practice

javanetnusoapPHPweb services

I am implementing web services for a PHP application and am trying to understand what both standard web services and RESTful web services have to offer.
My intent is to write wrapper code to abstract away the web service details so that developers can just "instantiate remote objects" and use them.
Here are my thoughts, perhaps some of you could add your experience and expand this:

RESTful Web Servcies

are basically just "XML feeds on demand", so e.g. you could write wrapper code for a client application so it could query the server application in this way:

$users = Users::getUsers("state = 'CO'");

this would in turn get an XML feed form a remote URL
$users could be made into a collection of full User objects, or
left as XML, or
turned into an array, etc.
the query script ("state = 'CO'") would be translated into SQL on the server side
RESTful Web Services are in general read-only from the view of the client, although you could write code which could use POST or GET to make changes on the server, e.g. passing an encrypted token for security, e.g.:

$users = Users::addUser($encryptedTrustToken, 'jim',$encryptedPassword, 'James', 'Taylor');

and this would create a new user on the server application.

Standard Web Services

Standard Web Servcies in the end basically do the same thing. The one advantage they have is that client can discover their details via WSDL. But other than that, if I want to write wrapper code which allows a developer to instantiate, edit and save objects remotely, I still need to implement the wrapper code. SOAP doesn't do any of that for me, it can do this:

$soap = new nusoap_client('http://localhost/test/webservice_user.php?wsdl', true);
$user = $soap->getProxy(); 
$lastName = $user->lastName();

but if I want to edit and save:

$user->setLastName('Jones');
$user->save();

then I need to e.g. handle all of the state on the server side, SOAP doesn't seem to hold that object on the server side for each client.

Perhaps there are limitations in the PHP SOAP implementation I am using (nusoap). Perhaps Java and .NET implementations do much more.

Will enjoy hearing your feedback to clear up some of these clouds.

Best Answer

They are different models... REST is data-centric, where-as SOAP is operation-centric. i.e. with SOAP you tend to have discrete operations "SubmitOrder", etc; but with REST you are typically a lot more fluid about how you are querying the data.

SOAP also tends to be associated with a lot more complexity (which is sometimes necessary) - REST is back to POX etc, and YAGNI.

In terms of .NET, tools like "wsdl.exe" will give you a full client-side proxy library to represent a SOAP service (or "svcutil.exe" for a WCF service):

var someResult = proxy.SubmitOrder(...);

For REST with .NET, I guess ADO.NET Data Services is the most obvious player. Here, the tooling (datasvcutil.exe) will give you a full client-side data-context with LINQ support. LINQ is .NET's relatively new way of forming complex queries. So something like (with strong/static type checking and intellisense):

var qry = from user in ctx.Users
          where user.State == 'CO'
          select user;

(this will be translated to/from the appropriate REST syntax for ADO.NET Data Services)

Related Solutions

C# – How to create an Excel (.XLS and .XLSX) file in C# without installing Microsoft Office

You can use a library called ExcelLibrary. It's a free, open source library posted on Google Code:

ExcelLibrary

This looks to be a port of the PHP ExcelWriter that you mentioned above. It will not write to the new .xlsx format yet, but they are working on adding that functionality in.

It's very simple, small and easy to use. Plus it has a DataSetHelper that lets you use DataSets and DataTables to easily work with Excel data.

ExcelLibrary seems to still only work for the older Excel format (.xls files), but may be adding support in the future for newer 2007/2010 formats.

You can also use EPPlus, which works only for Excel 2007/2010 format files (.xlsx files). There's also NPOI which works with both.

There are a few known bugs with each library as noted in the comments. In all, EPPlus seems to be the best choice as time goes on. It seems to be more actively updated and documented as well.

Also, as noted by @АртёмЦарионов below, EPPlus has support for Pivot Tables and ExcelLibrary may have some support (Pivot table issue in ExcelLibrary)

Here are a couple links for quick reference:
ExcelLibrary - GNU Lesser GPL
EPPlus - GNU (LGPL) - No longer maintained
EPPlus 5 - Polyform Noncommercial - Starting May 2020
NPOI - Apache License

Here some example code for ExcelLibrary:

Here is an example taking data from a database and creating a workbook from it. Note that the ExcelLibrary code is the single line at the bottom:

//Create the data set and table
DataSet ds = new DataSet("New_DataSet");
DataTable dt = new DataTable("New_DataTable");

//Set the locale for each
ds.Locale = System.Threading.Thread.CurrentThread.CurrentCulture;
dt.Locale = System.Threading.Thread.CurrentThread.CurrentCulture;

//Open a DB connection (in this example with OleDB)
OleDbConnection con = new OleDbConnection(dbConnectionString);
con.Open();

//Create a query and fill the data table with the data from the DB
string sql = "SELECT Whatever FROM MyDBTable;";
OleDbCommand cmd = new OleDbCommand(sql, con);
OleDbDataAdapter adptr = new OleDbDataAdapter();

adptr.SelectCommand = cmd;
adptr.Fill(dt);
con.Close();

//Add the table to the data set
ds.Tables.Add(dt);

//Here's the easy part. Create the Excel worksheet from the data set
ExcelLibrary.DataSetHelper.CreateWorkbook("MyExcelFile.xls", ds);

Creating the Excel file is as easy as that. You can also manually create Excel files, but the above functionality is what really impressed me.

Java – How to declare and initialize an array in Java

You can either use array declaration or array literal (but only when you declare and affect the variable right away, array literals cannot be used for re-assigning an array).

For primitive types:

int[] myIntArray = new int[3];
int[] myIntArray = {1, 2, 3};
int[] myIntArray = new int[]{1, 2, 3};

// Since Java 8. Doc of IntStream: https://docs.oracle.com/javase/8/docs/api/java/util/stream/IntStream.html

int [] myIntArray = IntStream.range(0, 100).toArray(); // From 0 to 99
int [] myIntArray = IntStream.rangeClosed(0, 100).toArray(); // From 0 to 100
int [] myIntArray = IntStream.of(12,25,36,85,28,96,47).toArray(); // The order is preserved.
int [] myIntArray = IntStream.of(12,25,36,85,28,96,47).sorted().toArray(); // Sort

For classes, for example String, it's the same:

String[] myStringArray = new String[3];
String[] myStringArray = {"a", "b", "c"};
String[] myStringArray = new String[]{"a", "b", "c"};

The third way of initializing is useful when you declare an array first and then initialize it, pass an array as a function argument, or return an array. The explicit type is required.

String[] myStringArray;
myStringArray = new String[]{"a", "b", "c"};

Best Answer

Related Solutions

C# – How to create an Excel (.XLS and .XLSX) file in C# without installing Microsoft Office

Java – How to declare and initialize an array in Java

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