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POJava ResultSet already closed exception while querying user data
 

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  1. POJava ResultSet already closed exception while querying user data
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    <p>As I've started in the title, while I'm querying for user data in my java application, I get following message: <em>"Operation not allowed after ResultSet closed"</em>.</p> <p>I know that this is happens if you try to have more ResultSets opened at the same time.</p> <p>Here is my current code:</p> <p>App calls getProject("..."), other 2 methods are there just for help. I'm using 2 classes because there is much more code, this is just one example of exception I get.</p> <p><em>Please note that I've translated variable names, etc. for better understanding, I hope I didn't miss anything.</em></p> <pre><code>/* Class which reads project data */ public Project getProject(String name) { ResultSet result = null; try { // executing query for project data // SELECT * FROM Project WHERE name=name result = statement.executeQuery(generateSelect(tProject.tableName, "*", tProject.name, name)); // if cursor can't move to first place, // that means that project was not found if (!result.first()) return null; return user.usersInProject(new Project(result.getInt(1), result .getString(2))); } catch (SQLException e) { e.printStackTrace(); return null; } catch (BadAttributeValueExpException e) { e.printStackTrace(); return null; } finally { // closing the ResultSet try { if (result != null) result.close(); } catch (SQLException e) { } } } /* End of class */ /* Class which reads user data */ public Project usersInProject(Project p) { ResultSet result = null; try { // executing query for users in project // SELECT ID_User FROM Project_User WHERE ID_Project=p.getID() result = statement.executeQuery(generateSelect( tProject_User.tableName, tProject_User.id_user, tProject_User.id_project, String.valueOf(p.getID()))); ArrayList&lt;User&gt; alUsers = new ArrayList&lt;User&gt;(); // looping through all results and adding them to array while (result.next()) { // here java gets ResultSet closed exception int id = result.getInt(1); if (id &gt; 0) alUsers.add(getUser(id)); } // if no user data was read, project from parameter is returned // without any new user data if (alUsers.size() == 0) return p; // array of users is added to the object, // then whole object is returned p.addUsers(alUsers.toArray(new User[alUsers.size()])); return p; } catch (SQLException e) { e.printStackTrace(); return p; } finally { // closing the ResultSet try { if (result != null) result.close(); } catch (SQLException e) { } } } public User getUser(int id) { ResultSet result = null; try { // executing query for user: // SELECT * FROM User WHERE ID=id result = statement.executeQuery(generateSelect(tUser.tableName, "*", tUser.id, String.valueOf(id))); if (!result.first()) return null; // new user is constructed (ID, username, email, password) User usr = new user(result.getInt(1), result.getString(2), result.getString(3), result.getString(4)); return usr; } catch (SQLException e) { e.printStackTrace(); return null; } catch (BadAttributeValueExpException e) { e.printStackTrace(); return null; } finally { // closing the ResultSet try { if (result != null) result.close(); } catch (SQLException e) { } } } /* End of class */ </code></pre> <p>Statements from both classes are added in constructor, calling connection.getStatement() when constructing each of the classes.</p> <p>tProject and tProject_User are my enums, I'm using it for easier name handling. generateSelect is my method and should work as expected. I'm using this because I've found out about prepared statements after I have written most of my code, so I left it as it is. </p> <p>I am using latest java MySQL connector (5.1.21). </p> <p>I don't know what else to try. Any advice will be appreciated.</p>
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    1. PO
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    1. This table or related slice is empty.
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    1. USMarko Grešak
    1. USMarko Grešak
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    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
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    1. VO
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      1. POJava ResultSet already closed exception while querying user data
      1. This table or related slice is empty.
      1. VTUpMod
    1. CODo you have more than one class accessing the DB?
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      1. POJava ResultSet already closed exception while querying user data
      1. USRedandwhite
    2. COYes, as I've described in the example of how it should work, there is one class, which is reading project data and another, which is reading user data.
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      1. POJava ResultSet already closed exception while querying user data
      1. USMarko Grešak
    3. COOK. First off, I know it sounds dumb, but are all the resources on the other class being closed? If you can, try to use the same connection objects for both classes. Also, are you running them in Threads? I doubt, just asking
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      1. POJava ResultSet already closed exception while querying user data
      1. USRedandwhite
 

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