Can NET load and parse a properties file equivalent to Java Properties class

Question

Is there an easy way in C  to read a properties file that has each property on a separate line followed by an equals sign and the value  such as the following   ServerName prod-srv1 Port 8888 CustomProperty Any value   In Java  the Properties class handles this parsing easily   Properties myProperties new Properties    FileInputStream fis   new FileInputStream  new File  CustomProps properties     myProperties load fis   System out println myProperties getProperty  ServerName     System out println myProperties getProperty  CustomProperty       I can easily load the file in C  and parse each line  but is there a built in way to easily get a property without having to parse out the key name and equals sign myself   The C  information I have found seems to always favor XML  but this is an existing file that I don t control and I would prefer to keep it in the existing format as it will require more time to get another team to change it to XML than parsing the existing file

User · Accepted Answer

No there is no built-in support for this.

You have to make your own "INIFileReader". Maybe something like this?

var data = new Dictionary<string, string>();
foreach (var row in File.ReadAllLines(PATH_TO_FILE))
  data.Add(row.Split('=')[0], string.Join("=",row.Split('=').Skip(1).ToArray()));

Console.WriteLine(data["ServerName"]);

Edit: Updated to reflect Paul's comment.

User · Answer

There are several NuGet packages for this  but all are currently in pre-release version    Capgemini Cauldron Core JavaProperties 2 0 39-beta Kajabity Tools Java 0 2 6638 28124    Update  As of June 2018  Capgemini Cauldron Core JavaProperties is now in a stable version  version 2 1 0 and 3 0 20

User · Answer

Most Java   properties  files can be split by assuming the     is the separator - but the format is significantly more complicated than that and allows for embedding spaces  equals  newlines and any Unicode characters in either the property name or value   I needed to load some Java properties for a C  application so I have implemented JavaProperties cs to correctly read and write   properties  formatted files using the same approach as the Java version - you can find it at http   www kajabity com index php 2009 06 loading-java-properties-files-in-csharp    There  you will find a zip file containing the C  source for the class and some sample properties files I tested it with   Enjoy

User · Answer

C  generally uses xml-based config files rather than the   ini-style file like you said  so there s nothing built-in to handle this   However  google returns a number of promising results

User · Answer

You can also use C  automatic property syntax with default values and a restrictive set   The advantage here is that you can then have any kind of data type in your properties  file   now actually a class    The other advantage is that you can use C  property syntax to invoke the properties   However  you just need a couple of lines for each property  one in the property declaration and one in the constructor  to make this work   using System  namespace ReportTester      class TestProperties              internal String ReportServerUrl   get  private set            internal TestProperties                         ReportServerUrl    http   myhost ReportServer ReportExecution2005 asmx wsdl

User · Answer

C  generally uses xml-based config files rather than the   ini-style file like you said  so there s nothing built-in to handle this   However  google returns a number of promising results

User · Answer

The real answer is no  at least not by itself    You can still write your own code to do it

User · Answer

Final class  Thanks  eXXL   public class Properties       private Dictionary lt String  String gt  list      private String filename       public Properties String file                reload file              public String get String field  String defValue                return  get field     null     defValue     get field              public String get String field                return  list ContainsKey field    list field    null              public void set String field  Object value                if   list ContainsKey field               list Add field  value ToString             else             list field    value ToString               public void Save                 Save this filename              public void Save String filename                this filename   filename           if   System IO File Exists filename               System IO File Create filename            System IO StreamWriter file   new System IO StreamWriter filename            foreach String prop in list Keys ToArray                if   String IsNullOrWhiteSpace list prop                    file WriteLine prop         list prop             file Close               public void reload                 reload this filename              public void reload String filename                this filename   filename          list   new Dictionary lt String  String gt              if  System IO File Exists filename               loadFromFile filename           else             System IO File Create filename              private void loadFromFile String file                foreach  String line in System IO File ReadAllLines file                         if    String IsNullOrEmpty line    amp  amp                    line StartsWith        amp  amp                    line StartsWith        amp  amp                    line StartsWith        amp  amp                   line Contains                                      int index   line IndexOf                       String key   line Substring 0  index  Trim                    String value   line Substring index   1  Trim                     if   value StartsWith        amp  amp  value EndsWith                                value StartsWith       amp  amp  value EndsWith                                              value   value Substring 1  value Length - 2                                      try                                         ignore dublicates                     list Add key  value                                     catch                                         Sample use     load Properties config   new Properties fileConfig     get value whith default value com port Text   config get  com port    1      set value config set  com port   com port Text     save config Save

User · Answer

I realize that this isn t exactly what you re asking  but just in case   When you want to load an actual Java properties file  you ll need to accomodate its encoding   The Java docs indicate that the encoding is ISO 8859-1  which contains some escape sequences that you might not correctly interpret   For instance look at this SO answer to see what s necessary to turn UTF-8 into ISO 8859-1  and vice versa   When we needed to do this  we found an open-source PropertyFile cs and made a few changes to support the escape sequences   This class is a good one for read write scenarios   You ll need the supporting PropertyFileIterator cs class as well   Even if you re not loading true Java properties  make sure that your prop file can express all the characters you need to save  UTF-8 at least

User · Answer

You can also use C  automatic property syntax with default values and a restrictive set   The advantage here is that you can then have any kind of data type in your properties  file   now actually a class    The other advantage is that you can use C  property syntax to invoke the properties   However  you just need a couple of lines for each property  one in the property declaration and one in the constructor  to make this work   using System  namespace ReportTester      class TestProperties              internal String ReportServerUrl   get  private set            internal TestProperties                         ReportServerUrl    http   myhost ReportServer ReportExecution2005 asmx wsdl

User · Answer

Yet another answer  in January 2018  to the old question  in January 2009    The specification of Java properties file is described in the JavaDoc of java util Properties load java io Reader   One problem is that the specification is a bit complicated than the first impression we may have  Another problem is that some answers here arbitrarily added extra specifications - for example    and   are regarded as starters of comment lines but they should not be  Double single quotations around property values are removed but they should not be   The following are points to be considered    There are two kinds of line  natural lines and logical lines  A natural line is terminated by  n   r   r n or the end of the stream  A logical line may be spread out across several adjacent natural lines by escaping the line terminator sequence with a backslash character    Any white space at the start of the second and following natural lines in a logical line are discarded  White spaces are space     u0020   tab   t   u0009  and form feed   f   u000C   As stated explicitly in the specification   it is not sufficient to only examine the character preceding a line terminator sequence to decide if the line terminator is escaped  there must be an odd number of contiguous backslashes for the line terminator to be escaped  Since the input is processed from left to right  a non-zero even number of 2n contiguous backslashes before a line terminator  or elsewhere  encodes n backslashes after escape processing     is used as the separator between a key and a value    is used as the separator between a key and a value  too  The separator between a key and a value can be omitted  A comment line has   or   as its first non-white space characters  meaning leading white spaces before   or   are allowed  A comment line cannot be extended to next natural lines even its line terminator is preceded by    As stated explicitly in the specification       and white spaces can be embedded in a key if they are escaped by backslashes  Even line terminator characters can be included using  r and  n escape sequences  If a value is omitted  an empty string is used as a value   uxxxx is used to represent a Unicode character  A backslash character before a non-valid escape character is not treated as an error  it is silently dropped    So  for example  if test properties has the following content     A comment line that starts with           This is a comment line having leading white spaces    A comment line that starts with       key1 value1   key2   value2     key3 value3 key    4 value      4  u006B u0065 u00795  u0076 u0061 u006c u0075 u00655  k e y 6  v a lu e 6             colon  space  equal   it should be interpreted as the following key-value pairs    ------ --------------------    KEY    VALUE                 ------ --------------------    key1   value1                 key2   value2                 key3   value3                 key4   value4                 key5   value5                 key6   value6                         colon space equal    ------ --------------------    PropertiesLoader class in Authlete Authlete NuGet package can interpret the format of the specification  The example code below   using System  using System IO  using System Collections Generic  using Authlete Util   namespace MyApp       class Program               public static void Main string   args                        string file    test properties               IDictionary lt string  string gt  properties               using  TextReader reader   new StreamReader file                                 properties   PropertiesLoader Load reader                              foreach  var entry in properties                                Console WriteLine    entry Key     entry Value                                       will generate this output   key1   value1 key2   value2 key3   value3 key4   value4 key5   value5 key6   value6        colon space equal   An equivalent example in Java is as follows   import java util    import java io     public class Program       public static void main String   args  throws IOException               String file    test properties           Properties properties   new Properties             try  Reader reader   new FileReader file                          properties load reader                      for  Map Entry lt Object  Object gt  entry   properties entrySet                          System out format   s    s n   entry getKey    entry getValue                             The source code  PropertiesLoader cs  can be found in authlete-csharp  xUnit tests for PropertiesLoader are written in PropertiesLoaderTest cs

User · Answer

I don t know of any built-in way to do this   However  it would seem easy enough to do  since the only delimiters you have to worry about are the newline character and the equals sign   It would be very easy to write a routine that will return a NameValueCollection  or an IDictionary given the contents of the file

User · Answer

Yeah there s no built in classes to do this that I m aware of   But that shouldn t really be an issue should it  It looks easy enough to parse just by storing the result of Stream ReadToEnd   in a string  splitting based on new lines and then splitting each record on the   character  What you d be left with is a bunch of key value pairs which you can easily toss into a dictionary   Here s an example that might work for you   public static Dictionary lt string  string gt  GetProperties string path        string fileData           using  StreamReader sr   new StreamReader path                 fileData   sr ReadToEnd   Replace   r                  Dictionary lt string  string gt  Properties   new Dictionary lt string  string gt         string   kvp      string   records   fileData Split   n  ToCharArray         foreach  string record in records                kvp   record Split     ToCharArray             Properties Add kvp 0   kvp 1              return Properties      Here s an example of how to use it   Dictionary lt string string gt  Properties   GetProperties  data txt    Console WriteLine  Hello      Properties  Hello     Console ReadKey

User · Answer

I realize that this isn t exactly what you re asking  but just in case   When you want to load an actual Java properties file  you ll need to accomodate its encoding   The Java docs indicate that the encoding is ISO 8859-1  which contains some escape sequences that you might not correctly interpret   For instance look at this SO answer to see what s necessary to turn UTF-8 into ISO 8859-1  and vice versa   When we needed to do this  we found an open-source PropertyFile cs and made a few changes to support the escape sequences   This class is a good one for read write scenarios   You ll need the supporting PropertyFileIterator cs class as well   Even if you re not loading true Java properties  make sure that your prop file can express all the characters you need to save  UTF-8 at least

User · Answer

There are several NuGet packages for this  but all are currently in pre-release version    Capgemini Cauldron Core JavaProperties 2 0 39-beta Kajabity Tools Java 0 2 6638 28124    Update  As of June 2018  Capgemini Cauldron Core JavaProperties is now in a stable version  version 2 1 0 and 3 0 20

User · Answer

I ve written a method that allows emty lines  outcommenting and quoting within the file   Examples   var1  value1   var2  value2    var3 outcommented   var4 outcommented  too  Here s the method   public static IDictionary ReadDictionaryFile string fileName        Dictionary lt string  string gt  dictionary   new Dictionary lt string  string gt         foreach  string line in File ReadAllLines fileName                 if    string IsNullOrEmpty line    amp  amp                line StartsWith        amp  amp                line StartsWith        amp  amp                line StartsWith        amp  amp               line Contains                              int index   line IndexOf                   string key   line Substring 0  index  Trim                string value   line Substring index   1  Trim                 if   value StartsWith        amp  amp  value EndsWith                            value StartsWith       amp  amp  value EndsWith                                      value   value Substring 1  value Length - 2                             dictionary Add key  value                        return dictionary

User · Answer

I don t know of any built-in way to do this   However  it would seem easy enough to do  since the only delimiters you have to worry about are the newline character and the equals sign   It would be very easy to write a routine that will return a NameValueCollection  or an IDictionary given the contents of the file

User · Answer

I don t know of any built-in way to do this   However  it would seem easy enough to do  since the only delimiters you have to worry about are the newline character and the equals sign   It would be very easy to write a routine that will return a NameValueCollection  or an IDictionary given the contents of the file

User · Answer

Yeah there s no built in classes to do this that I m aware of   But that shouldn t really be an issue should it  It looks easy enough to parse just by storing the result of Stream ReadToEnd   in a string  splitting based on new lines and then splitting each record on the   character  What you d be left with is a bunch of key value pairs which you can easily toss into a dictionary   Here s an example that might work for you   public static Dictionary lt string  string gt  GetProperties string path        string fileData           using  StreamReader sr   new StreamReader path                 fileData   sr ReadToEnd   Replace   r                  Dictionary lt string  string gt  Properties   new Dictionary lt string  string gt         string   kvp      string   records   fileData Split   n  ToCharArray         foreach  string record in records                kvp   record Split     ToCharArray             Properties Add kvp 0   kvp 1              return Properties      Here s an example of how to use it   Dictionary lt string string gt  Properties   GetProperties  data txt    Console WriteLine  Hello      Properties  Hello     Console ReadKey

User · Answer

The real answer is no  at least not by itself    You can still write your own code to do it

User · Answer

Final class  Thanks  eXXL   public class Properties       private Dictionary lt String  String gt  list      private String filename       public Properties String file                reload file              public String get String field  String defValue                return  get field     null     defValue     get field              public String get String field                return  list ContainsKey field    list field    null              public void set String field  Object value                if   list ContainsKey field               list Add field  value ToString             else             list field    value ToString               public void Save                 Save this filename              public void Save String filename                this filename   filename           if   System IO File Exists filename               System IO File Create filename            System IO StreamWriter file   new System IO StreamWriter filename            foreach String prop in list Keys ToArray                if   String IsNullOrWhiteSpace list prop                    file WriteLine prop         list prop             file Close               public void reload                 reload this filename              public void reload String filename                this filename   filename          list   new Dictionary lt String  String gt              if  System IO File Exists filename               loadFromFile filename           else             System IO File Create filename              private void loadFromFile String file                foreach  String line in System IO File ReadAllLines file                         if    String IsNullOrEmpty line    amp  amp                    line StartsWith        amp  amp                    line StartsWith        amp  amp                    line StartsWith        amp  amp                   line Contains                                      int index   line IndexOf                       String key   line Substring 0  index  Trim                    String value   line Substring index   1  Trim                     if   value StartsWith        amp  amp  value EndsWith                                value StartsWith       amp  amp  value EndsWith                                              value   value Substring 1  value Length - 2                                      try                                         ignore dublicates                     list Add key  value                                     catch                                         Sample use     load Properties config   new Properties fileConfig     get value whith default value com port Text   config get  com port    1      set value config set  com port   com port Text     save config Save

User · Answer

Yeah there s no built in classes to do this that I m aware of   But that shouldn t really be an issue should it  It looks easy enough to parse just by storing the result of Stream ReadToEnd   in a string  splitting based on new lines and then splitting each record on the   character  What you d be left with is a bunch of key value pairs which you can easily toss into a dictionary   Here s an example that might work for you   public static Dictionary lt string  string gt  GetProperties string path        string fileData           using  StreamReader sr   new StreamReader path                 fileData   sr ReadToEnd   Replace   r                  Dictionary lt string  string gt  Properties   new Dictionary lt string  string gt         string   kvp      string   records   fileData Split   n  ToCharArray         foreach  string record in records                kvp   record Split     ToCharArray             Properties Add kvp 0   kvp 1              return Properties      Here s an example of how to use it   Dictionary lt string string gt  Properties   GetProperties  data txt    Console WriteLine  Hello      Properties  Hello     Console ReadKey

User · Answer

Most Java   properties  files can be split by assuming the     is the separator - but the format is significantly more complicated than that and allows for embedding spaces  equals  newlines and any Unicode characters in either the property name or value   I needed to load some Java properties for a C  application so I have implemented JavaProperties cs to correctly read and write   properties  formatted files using the same approach as the Java version - you can find it at http   www kajabity com index php 2009 06 loading-java-properties-files-in-csharp    There  you will find a zip file containing the C  source for the class and some sample properties files I tested it with   Enjoy

User · Answer

No there is not   But I have created one easy class to help     public class PropertiesUtility       private static Hashtable ht   new Hashtable        public void loadProperties string path                string   lines   System IO File ReadAllLines path           bool readFlag   false          foreach  string line in lines                        string text   Regex Replace line     s                     readFlag    checkSyntax text               if  readFlag                                string   splitText   text Split                       ht Add splitText 0  ToLower    splitText 1                                       private bool checkSyntax string line                if  String IsNullOrEmpty line     line 0  Equals                             return false                     if  line Contains       amp  amp   String IsNullOrEmpty line Split      0    amp  amp   String IsNullOrEmpty line Split      1                          return true                    else                       throw new Exception  Can not Parse Properties file please verify the syntax                         public string getProperty string key                if  ht Contains key                         return ht key  ToString                      else                       throw new Exception  Property     key    Does not exist                         Hope this helps

User · Answer

Yet another answer  in January 2018  to the old question  in January 2009    The specification of Java properties file is described in the JavaDoc of java util Properties load java io Reader   One problem is that the specification is a bit complicated than the first impression we may have  Another problem is that some answers here arbitrarily added extra specifications - for example    and   are regarded as starters of comment lines but they should not be  Double single quotations around property values are removed but they should not be   The following are points to be considered    There are two kinds of line  natural lines and logical lines  A natural line is terminated by  n   r   r n or the end of the stream  A logical line may be spread out across several adjacent natural lines by escaping the line terminator sequence with a backslash character    Any white space at the start of the second and following natural lines in a logical line are discarded  White spaces are space     u0020   tab   t   u0009  and form feed   f   u000C   As stated explicitly in the specification   it is not sufficient to only examine the character preceding a line terminator sequence to decide if the line terminator is escaped  there must be an odd number of contiguous backslashes for the line terminator to be escaped  Since the input is processed from left to right  a non-zero even number of 2n contiguous backslashes before a line terminator  or elsewhere  encodes n backslashes after escape processing     is used as the separator between a key and a value    is used as the separator between a key and a value  too  The separator between a key and a value can be omitted  A comment line has   or   as its first non-white space characters  meaning leading white spaces before   or   are allowed  A comment line cannot be extended to next natural lines even its line terminator is preceded by    As stated explicitly in the specification       and white spaces can be embedded in a key if they are escaped by backslashes  Even line terminator characters can be included using  r and  n escape sequences  If a value is omitted  an empty string is used as a value   uxxxx is used to represent a Unicode character  A backslash character before a non-valid escape character is not treated as an error  it is silently dropped    So  for example  if test properties has the following content     A comment line that starts with           This is a comment line having leading white spaces    A comment line that starts with       key1 value1   key2   value2     key3 value3 key    4 value      4  u006B u0065 u00795  u0076 u0061 u006c u0075 u00655  k e y 6  v a lu e 6             colon  space  equal   it should be interpreted as the following key-value pairs    ------ --------------------    KEY    VALUE                 ------ --------------------    key1   value1                 key2   value2                 key3   value3                 key4   value4                 key5   value5                 key6   value6                         colon space equal    ------ --------------------    PropertiesLoader class in Authlete Authlete NuGet package can interpret the format of the specification  The example code below   using System  using System IO  using System Collections Generic  using Authlete Util   namespace MyApp       class Program               public static void Main string   args                        string file    test properties               IDictionary lt string  string gt  properties               using  TextReader reader   new StreamReader file                                 properties   PropertiesLoader Load reader                              foreach  var entry in properties                                Console WriteLine    entry Key     entry Value                                       will generate this output   key1   value1 key2   value2 key3   value3 key4   value4 key5   value5 key6   value6        colon space equal   An equivalent example in Java is as follows   import java util    import java io     public class Program       public static void main String   args  throws IOException               String file    test properties           Properties properties   new Properties             try  Reader reader   new FileReader file                          properties load reader                      for  Map Entry lt Object  Object gt  entry   properties entrySet                          System out format   s    s n   entry getKey    entry getValue                             The source code  PropertiesLoader cs  can be found in authlete-csharp  xUnit tests for PropertiesLoader are written in PropertiesLoaderTest cs

User · Answer

No there is not   But I have created one easy class to help     public class PropertiesUtility       private static Hashtable ht   new Hashtable        public void loadProperties string path                string   lines   System IO File ReadAllLines path           bool readFlag   false          foreach  string line in lines                        string text   Regex Replace line     s                     readFlag    checkSyntax text               if  readFlag                                string   splitText   text Split                       ht Add splitText 0  ToLower    splitText 1                                       private bool checkSyntax string line                if  String IsNullOrEmpty line     line 0  Equals                             return false                     if  line Contains       amp  amp   String IsNullOrEmpty line Split      0    amp  amp   String IsNullOrEmpty line Split      1                          return true                    else                       throw new Exception  Can not Parse Properties file please verify the syntax                         public string getProperty string key                if  ht Contains key                         return ht key  ToString                      else                       throw new Exception  Property     key    Does not exist                         Hope this helps

User · Answer

Yeah there s no built in classes to do this that I m aware of   But that shouldn t really be an issue should it  It looks easy enough to parse just by storing the result of Stream ReadToEnd   in a string  splitting based on new lines and then splitting each record on the   character  What you d be left with is a bunch of key value pairs which you can easily toss into a dictionary   Here s an example that might work for you   public static Dictionary lt string  string gt  GetProperties string path        string fileData           using  StreamReader sr   new StreamReader path                 fileData   sr ReadToEnd   Replace   r                  Dictionary lt string  string gt  Properties   new Dictionary lt string  string gt         string   kvp      string   records   fileData Split   n  ToCharArray         foreach  string record in records                kvp   record Split     ToCharArray             Properties Add kvp 0   kvp 1              return Properties      Here s an example of how to use it   Dictionary lt string string gt  Properties   GetProperties  data txt    Console WriteLine  Hello      Properties  Hello     Console ReadKey

User · Answer

I ve written a method that allows emty lines  outcommenting and quoting within the file   Examples   var1  value1   var2  value2    var3 outcommented   var4 outcommented  too  Here s the method   public static IDictionary ReadDictionaryFile string fileName        Dictionary lt string  string gt  dictionary   new Dictionary lt string  string gt         foreach  string line in File ReadAllLines fileName                 if    string IsNullOrEmpty line    amp  amp                line StartsWith        amp  amp                line StartsWith        amp  amp                line StartsWith        amp  amp               line Contains                              int index   line IndexOf                   string key   line Substring 0  index  Trim                string value   line Substring index   1  Trim                 if   value StartsWith        amp  amp  value EndsWith                            value StartsWith       amp  amp  value EndsWith                                      value   value Substring 1  value Length - 2                             dictionary Add key  value                        return dictionary

User · Answer

C  generally uses xml-based config files rather than the   ini-style file like you said  so there s nothing built-in to handle this   However  google returns a number of promising results

User · Answer

C  generally uses xml-based config files rather than the   ini-style file like you said  so there s nothing built-in to handle this   However  google returns a number of promising results

User · Answer

I don t know of any built-in way to do this   However  it would seem easy enough to do  since the only delimiters you have to worry about are the newline character and the equals sign   It would be very easy to write a routine that will return a NameValueCollection  or an IDictionary given the contents of the file

[c#] Can .NET load and parse a properties file equivalent to Java Properties class?

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