java - connecting to a database through JDBC -

-

this question has answer here:

i trying follow tutorial in book on connecting program database jdbc. confused on first block of code doing in class. whan run code error saying java.sql.sqlexception: no suitable driver found jdbc:mysql://localhost:8889/book_store

and code throwing exception in first block inside class. need add sort of dependency or library project?

as can tell first attempt @ using db...

package com.apress.books.dao;  import com.apress.books.model.author; import com.apress.books.model.book; import com.apress.books.model.category;  import java.sql.*; import java.util.arraylist; import java.util.list;  public class bookdaoimpl implements bookdao {  static {     try {         class.forname("com.mysql.jdbc.driver");     } catch (classnotfoundexception ex) {     } }  private connection getconnection() throws sqlexception {     return drivermanager.getconnection("jdbc:mysql://localhost:8889/book_store",             "root", "password"); }  private void closeconnection(connection connection) {     if (connection == null)         return; try {         connection.close();     } catch (sqlexception ex) {     } } @override public void insert(book book) {  }  @override public void update(book book) {  }  @override public void delete(long bookid) {  } }

in essence classnotfoundexception. first catch clause empty , thus, although exception being caught, not acting upon it. in least, this:

static {     try {         class.forname("com.mysql.jdbc.driver");     } catch (classnotfoundexception ex) {         throw ex;     } }

this see better causing troubles.

moving on solution:

if using maven, need add following dependency in pom.xml:

<dependency>     <groupid>mysql</groupid>     <artifactid>mysql-connector-java</artifactid>     <version>5.1.35</version> </dependency>

and if want, change version 1 found here.

otherwise, need download jar same link , include in project dependencies.


Comments

Post a Comment

Popular posts from this blog

python - How to create jsonb index using GIN on SQLAlchemy? -

-
here's current code creating index jsonb. index("mytable_data_idx_id_key", mytable.data['id'].astext, postgresql_using='gin') but got error. sqlalchemy.exc.programmingerror: (psycopg2.programmingerror) data type text has no default operator class access method "gin" hint: must specify operator class index or define default operator class data type. [sql: "create index event_data_idx_id_key on event using gin ((data ->> 'id'))"] is there way create index on sqlalchemy? the postgresql specific sqlalchemy docs @ http://docs.sqlalchemy.org/en/latest/dialects/postgresql.html#operator-classes mention postgresql_ops dictionary provide "operator class" used postgresql, , provide example illustrating use: index('my_index', my_table.c.id, my_table.c.data, postgresql_ops={ 'data': 'text_pattern_ops', ...
Read more

PHP DOM loadHTML() method unusual warning -

-
i had following code works fine on localhost: $document = new domdocument(); $document->loadhtml($p_result); $form = $document->getelementsbytagname('form')->item(0); // code continues using $form variable after same code updated on outside server, loadhtml() failed , issued warning. warning: domdocument::loadhtml() expects parameter 1 valid path, string given in path/name/to/script.php returned null instead of object code pretty gets fatal error. note contents of $p_result absolutely same on outside server , on localhost. but why displays kind of warning , why not work? doesn't loadhtml() expects argument 1 string in first place? why method expects parameter 1 valid path ? just make clear i'm not calling loadhtmlfile() , i'm calling loadhtml() . thanks. you're affected one of php bugs . issue present in php 5.6.8 , 5.6.9. have affected php version on server, , bug-free version on localhost. the bug forbids null ...
Read more

c# - TransactionScope not rolling back although no complete() is called -

-
i'm using transactionscope rollback transaction fail bool errorreported = false; action<importerrorlog> newerrorcallback = e => { errorreported = true; errorcallback(e); }; using (var transaction = new transactionscope()) { foreach (importtaskdefinition task in taskdefinition) { loader.load(streamfile, newerrorcallback, task.destinationtable, processingtaskid); } if (!errorreported) transaction.complete(); } i'm sure there no transactionscope started ahead or after code. i'm using entity framework insert in db. regardless state of errorreported transaction never rolled in case of error. what missing ? transactionscope sets transaction.current . that's does. wants transacted must @ property. i believe ef each time connection opened reason. probably, connection open when scope installed. open connection inside of scope or enlist manually. ef has nasty "design decision": default opens ...
Read more