From: Slim S. <zia...@gm...> - 2010-02-17 22:43:46
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Hello everybody! I've some questions about Geotools. Please be forgiven with me. 1) How can I show data which are coming from PostGIS? 2) How can I write queries to extract geometrical data from PostGIS? 3) I want add a menu to my application to change features style. For this, I saw *StyleLab* class, but I didn't find on which moment "Simple style maker" JFrame has been created! If you have some examples or some explanations about this questions, please show them to me. Thank you a lot. |
From: Michael B. <mic...@gm...> - 2010-02-18 05:24:55
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Hi, > I've some questions about Geotools. Please be forgiven with me. Everyone is nice here :) > 1) How can I show data which are coming from PostGIS? > 2) How can I write queries to extract geometrical data from PostGIS? Have a look at this example app (note to self: create a postgis lab web page !) http://svn.osgeo.org/geotools/branches/2.6.x/demo/example/src/main/java/org/geotools/demo/PostGIS2Example.java It doesn't draw a map but it shows you how to connect to PostGIS and query feature data. > 3) I want add a menu to my application to change features style. For this, I > saw StyleLab class, but I didn't find on which moment "Simple style maker" > JFrame has been created! Oops - sounds like the example text is out of date, sorry about that. Have a look here: http://geotools.org/javadocs/org/geotools/swing/styling/JSimpleStyleDialog.html Hope this helps, Michael |
From: Michael B. <mic...@gm...> - 2010-02-18 13:09:38
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Hi Ziad, You're using an old repository that is no longer updated. Edit you pom.xml file to use this one instead... <repository> <id>osgeo</id> <name>Open Source Geospatial Foundation Repository</name> <url>http://download.osgeo.org/webdav/geotools/</url> </repository> (see http://geotools.org/quickstart.html for details on GeoTools-specific parts of the pom.xml) Then the dependency should be... <dependency> <groupId>org.geotools</groupId> <artifactId>gt2-postgis</artifactId> <version>2.6.1</version> </dependency> Hope this helps. Michael |
From: Michael B. <mic...@gm...> - 2010-02-19 00:51:27
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Hi Ziad, > I have already this repository on my pom, but I didn't find the artifact > gt2-postgis-2.6.1 : >From GeoTools 2.5 onwards, all of the modules use the "gt" prefix rather than "gt2". I'm afraid there are probably lots of wiki pages etc that refer to gt2 to confuse you though. Michael |
From: Michael B. <mic...@gm...> - 2010-03-02 01:17:49
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Hi Ziad, I'm forwarding your question to the list. It's best for you to post there, rather than contacting any of us directly, so that you get the benefit of the GeoTools hive mind :) Please see my responses below. > I found some difficulties, when I test this example : PostGIS2Example.java > and specially I get this exception in the console: > Wizard completed with:Exception in thread "main" > java.lang.ArrayIndexOutOfBoundsException: 0 > at org.geotools.demo.PostGIS2Example.main(PostGIS2Example.java:53) Can you tell me what version of GeoTools you're using ? The line number in the error message doesn't seem to match the source code in GeoTools 2.6.x. > I think that I didn't fill some areatext, or I wrote something wrong. > All what I do, is I fill database areatext, user areatext and passwd > areatext. That should be fine (assuming that postgis is running on your local machine and listening to the default port number 5432). You don't need to fill in schema if your db is in the public schema. > And I confess that I didn't understand the meaning of those > areatext : > > namespace? > Namespaces can be used to organize your database and avoid conflicts between names of tables etc. I don't actually know much about postgis / postgresql so I'll defer to someone else to give a better explanation or leave you to google it. > after clicking on next > > wkb enabled? > loose bbox? > estimated extent? > > Please could you explain me the meaning of those aretexts. Have a look at this page in the GeoServer docs which defines these parameters in a bit more detail that the text on the wizard page... http://geoserver.org/display/GEOSDOC/PostGIS+DataStore I've just run PostGIS2Example and successfully connected to a database so I think the (not very helpful) error you're getting is probably from your inputs (assuming that your PostGIS server is running). You might like to try connecting to this public database to confirm that the example app is working... host: www.refractions.net port: 5432 database: demo-bc user: demo password: demo Michael |
From: Slim S. <zia...@gm...> - 2010-03-02 11:56:38
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Hi, I'm forwarding your question to the list. It's best for you to post > there, rather than contacting any of us directly, so that you get the > benefit of the GeoTools hive mind :) > I'm really sorry about that, I didn't pay attention to the receiver mail when I clicked on send button :) > Please see my responses below. > > > I found some difficulties, when I test this example : > PostGIS2Example.java > > and specially I get this exception in the console: > > Wizard completed with:Exception in thread "main" > > java.lang.ArrayIndexOutOfBoundsException: 0 > > at org.geotools.demo.PostGIS2Example.main(PostGIS2Example.java:53) > > Can you tell me what version of GeoTools you're using ? The line > number in the error message doesn't seem to match the source code in > GeoTools 2.6.x. > I'm using 2.6.1 version. I don't think that's a version problem, because I tested PostGIS2Example.java class with connection parameters that you gave me, and it works. > I think that I didn't fill some areatext, or I wrote something wrong. > > All what I do, is I fill database areatext, user areatext and passwd > > areatext. > > That should be fine (assuming that postgis is running on your local > machine and listening to the default port number 5432). You don't need > to fill in schema if your db is in the public schema. > > > And I confess that I didn't understand the meaning of those > > areatext : > > > > namespace? > > > > Namespaces can be used to organize your database and avoid conflicts > between names of tables etc. I don't actually know much about postgis > / postgresql so I'll defer to someone else to give a better > explanation or leave you to google it. > > > after clicking on next > > > > wkb enabled? > > loose bbox? > > estimated extent? > > > > Please could you explain me the meaning of those aretexts. > > Have a look at this page in the GeoServer docs which defines these > parameters in a bit more detail that the text on the wizard page... > > http://geoserver.org/display/GEOSDOC/PostGIS+DataStore > > I've just run PostGIS2Example and successfully connected to a database > so I think the (not very helpful) error you're getting is probably > from your inputs (assuming that your PostGIS server is running). > > You might like to try connecting to this public database to confirm > that the example app is working... > > host: www.refractions.net > port: 5432 > database: demo-bc > user: demo > password: demo > > Michael > I'm very thankful for your explanations. Perhaps I didn't detailed perfectly what I want to do. Simply put, I want to retrieve geometrical data by applying Pl/pgsql queries like : SELECT ST_Extent(the_geom) FROM towns WHERE town = 'BOSTON'; So, for this I should establish a connexion to a data base, and from my IHM write queries. Do you have any class model for this? Thank you in advance. |
From: Michael B. <mic...@gm...> - 2010-03-02 03:12:14
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Hi Ziad, > My purpose is to extract geometrical forms from a table named > geometry_columns, founded in postgres database named template_postgis. How > it can be done? > > Thank you in advance. > Perhaps that's not really what you really want to do (?) The geometry_columns table only holds the details of the geometry type, geometry field name, spatial reference system etc used in your other tables. It is the other table(s) that hold the actual geometries. 'template_postgis' is a template (blank database) that you can copy when creating a new database. You don't usually store anything in it. Please let the list know if you managed to solve the connection problems that you were having before, then we can talk about retrieving features from the database. Hope this helps. Michael |