i want to print error log and skip the invalid json when it parse wrong in flink sql. i know there is configuration like :
'json.ignore-parse-errors' = 'true'
but it doesnt match what i want. i can use try catch method when i parse json in java like this
try {
return GSON.fromJson(json, element.class);
} catch (Exception e) {
LOG.warn("parse error, json: {}, error: {}", json, e);
return null;
}
but i really dont know how to do it in flink sql.
is there any way to do this?
thanks all.
I'm trying to generate random int and check if the integer is exists in Firebase database, and do this infinitly until the integer is not exist inside database.
Below my code:
while (true) {
_changeRandomInt()
firebaseFirestore.collection("myCollection").doc(_randomInt).get().then((DocumentSnapshot documentSnapshot) {
if (getFromFirebase(documentSnapshot) == null) {
break;
}
});
}
But I cannot even run this code. Error: A break statement can't be used outside of a loop or switch statement. Try removing the break statement. I have my break inside while loop, then why I'm getting this error? How to fix this?
A break statement can't be used outside of a loop or switch statement. Try removing the break statement.
This is self explanatory. You can't use break outside of a loop. Which in your case is inside a future.
Do something like this:
_changeRandomInt();
firebaseFirestore.collection("myCollection").doc(_randomInt).get()
.then((DocumentSnapshot documentSnapshot) {
while (getFromFirebase(documentSnapshot) != null){
//the body of this loop will only execute as long as the value isn't null
//will break out of the loop as soon as the value is null
}
}
The break you have used is inside then(), which means no loop is available immediately above `break. You can refactor your code in this manner to get it working.
while (true) {
_changeRandomInt()
final documentSnapshot = await firebaseFirestore.collection("myCollection").doc(_randomInt).get();
if (getFromFirebase(documentSnapshot) == null) {
break;
}
}
If getFromFirebase is also a future, then await that as well inside if block.
You want to do something like this:
void functionName() async {
try{
var ans;
while(getFromFirebae(ans)== null){
ans = await firebaseFirestore.collection("myCollection").doc(_randomInt).get();
}
} catch(e){
//error
}
}
However, this is not the correct way. A good practice is to create a loading widget, that would show an animation while the future is loading. An even better way - to load everything in the background without stalling the overall app.
Some people have been saying that you're using "break inside a Future", but that's not quite right. Your problem is that you're using break inside of a separate function body. This is equivalent to writing:
void f() {
break;
}
which doesn't make sense since break is not used directly within a local loop or switch statement. It doesn't matter that you're creating your function within a loop; break and continue statements perform local control flow (within a function), not across functions.
In general, instead of using Future.then, you should prefer using async/await which will have the compiler generate the callback function with appropriate code transformations for you:
while (true) {
_changeRandomInt()
var documentSnapshot =
await firebaseFirestore.collection("myCollection").doc(_randomInt).get();
if (getFromFirebase(documentSnapshot) == null) {
break;
}
}
Note that performing an asynchronous operation continuously in a loop isn't very efficient, so you probably should consider alternative approaches if possible, however.
As soon as my code gets to my while(rs.next()) loop it produces the ResultSet is closed exception. What causes this exception and how can I correct for it?
EDIT: I notice in my code that I am nesting while(rs.next()) loop with another (rs2.next()), both result sets coming from the same DB, is this an issue?
Sounds like you executed another statement in the same connection before traversing the result set from the first statement. If you're nesting the processing of two result sets from the same database, you're doing something wrong. The combination of those sets should be done on the database side.
This could be caused by a number of reasons, including the driver you are using.
a) Some drivers do not allow nested statements. Depending if your driver supports JDBC 3.0 you should check the third parameter when creating the Statement object. For instance, I had the same problem with the JayBird driver to Firebird, but the code worked fine with the postgres driver. Then I added the third parameter to the createStatement method call and set it to ResultSet.HOLD_CURSORS_OVER_COMMIT, and the code started working fine for Firebird too.
static void testNestedRS() throws SQLException {
Connection con =null;
try {
// GET A CONNECTION
con = ConexionDesdeArchivo.obtenerConexion("examen-dest");
String sql1 = "select * from reportes_clasificacion";
Statement st1 = con.createStatement(
ResultSet.TYPE_SCROLL_INSENSITIVE,
ResultSet.CONCUR_READ_ONLY,
ResultSet.HOLD_CURSORS_OVER_COMMIT);
ResultSet rs1 = null;
try {
// EXECUTE THE FIRST QRY
rs1 = st1.executeQuery(sql1);
while (rs1.next()) {
// THIS LINE WILL BE PRINTED JUST ONCE ON
// SOME DRIVERS UNLESS YOU CREATE THE STATEMENT
// WITH 3 PARAMETERS USING
// ResultSet.HOLD_CURSORS_OVER_COMMIT
System.out.println("ST1 Row #: " + rs1.getRow());
String sql2 = "select * from reportes";
Statement st2 = con.createStatement(
ResultSet.TYPE_SCROLL_INSENSITIVE,
ResultSet.CONCUR_READ_ONLY);
// EXECUTE THE SECOND QRY. THIS CLOSES THE FIRST
// ResultSet ON SOME DRIVERS WITHOUT USING
// ResultSet.HOLD_CURSORS_OVER_COMMIT
st2.executeQuery(sql2);
st2.close();
}
} catch (SQLException e) {
e.printStackTrace();
} finally {
rs1.close();
st1.close();
}
} catch (SQLException e) {
} finally {
con.close();
}
}
b) There could be a bug in your code. Remember that you cannot reuse the Statement object, once you re-execute a query on the same statement object, all the opened resultsets associated with the statement are closed. Make sure you are not closing the statement.
Also, you can only have one result set open from each statement. So if you are iterating through two result sets at the same time, make sure they are executed on different statements. Opening a second result set on one statement will implicitly close the first.
http://java.sun.com/javase/6/docs/api/java/sql/Statement.html
The exception states that your result is closed. You should examine your code and look for all location where you issue a ResultSet.close() call. Also look for Statement.close() and Connection.close(). For sure, one of them gets called before rs.next() is called.
You may have closed either the Connection or Statement that made the ResultSet, which would lead to the ResultSet being closed as well.
Proper jdbc call should look something like:
try {
Connection conn;
Statement stmt;
ResultSet rs;
try {
conn = DriverManager.getConnection(myUrl,"","");
stmt = conn.createStatement();
rs = stmt.executeQuery(myQuery);
while ( rs.next() ) {
// process results
}
} catch (SqlException e) {
System.err.println("Got an exception! ");
System.err.println(e.getMessage());
} finally {
// you should release your resources here
if (rs != null) {
rs.close();
}
if (stmt != null) {
stmt.close();
}
if (conn != null) {
conn.close();
}
}
} catch (SqlException e) {
System.err.println("Got an exception! ");
System.err.println(e.getMessage());
}
you can close connection (or statement) only after you get result from result set. Safest way is to do it in finally block. However close() could also throe SqlException, hence the other try-catch block.
I got same error everything was correct only i was using same statement interface object to execute and update the database.
After separating i.e. using different objects of statement interface for updating and executing query i resolved this error. i.e. do get rid from this do not use same statement object for both updating and executing the query.
Check whether you have declared the method where this code is executing as static. If it is static there may be some other thread resetting the ResultSet.
make sure you have closed all your statments and resultsets before running rs.next. Finaly guarantees this
public boolean flowExists( Integer idStatusPrevious, Integer idStatus, Connection connection ) {
LogUtil.logRequestMethod();
PreparedStatement ps = null;
ResultSet rs = null;
try {
ps = connection.prepareStatement( Constants.SCRIPT_SELECT_FIND_FLOW_STATUS_BY_STATUS );
ps.setInt( 1, idStatusPrevious );
ps.setInt( 2, idStatus );
rs = ps.executeQuery();
Long count = 0L;
if ( rs != null ) {
while ( rs.next() ) {
count = rs.getLong( 1 );
break;
}
}
LogUtil.logSuccessMethod();
return count > 0L;
} catch ( Exception e ) {
String errorMsg = String
.format( Constants.ERROR_FINALIZED_METHOD, ( e.getMessage() != null ? e.getMessage() : "" ) );
LogUtil.logError( errorMsg, e );
throw new FatalException( errorMsg );
} finally {
rs.close();
ps.close();
}
A ResultSetClosedException could be thrown for two reasons.
1.) You have opened another connection to the database without closing all other connections.
2.) Your ResultSet may be returning no values. So when you try to access data from the ResultSet java will throw a ResultSetClosedException.
It happens also when using a ResultSet without being in a #Transactional method.
ScrollableResults results = getScrollableResults("select e from MyEntity e");
while (results.next()) {
...
}
results.close();
if MyEntity has eager relationships with other entities. the second time results.next() is invoked the ResultSet is closed exception is raised.
so if you use ScrollableResults on entities with eager relationships make sure your method is run transactionally.
"result set is closed" happened to me when using tag <collection> in MyBatis nested (one-to-many) xml <select> statement
A Spring solution could be to have a (Java) Spring #Service layer, where class/methods calling MyBatis select-collection statements are annotated with
#Transactional(propagation = Propagation.REQUIRED)
annotations being:
import org.springframework.transaction.annotation.Propagation;
import org.springframework.transaction.annotation.Transactional;
this solution does not require to set the following datasource properties (i.e., in JBoss EAP standalone*.xml):
<xa-datasource-property name="downgradeHoldCursorsUnderXa">**true**\</xa-datasource-property>
<xa-datasource-property name="resultSetHoldability">**1**</xa-datasource-property>
I'm currently finding the current url with
expect(browser.getCurrentUrl()).toEqual("example.com");
I want to make it into an if statement that would the url as the condition. How could I do that?
if(browser.driver.getCurrentUrl().toEqual("example.com") == "example.com"){
//do stuff
}
This is what I tried and it did not work
getCurrentUrl() is a promise, so you need to resolve it yourself to use the value as a conditional.
browser.getCurrentUrl().then((url) => {
if(~url.indexOf('example.com')) {
// code
}
else {
// code
}
})
Finally, Jasmine methods like toEqual should be used strictly with test assertions. I wouldn't use them outside of an expect statement like you have above.
Suppose "doc" is some document I want to insert into a MongoDB collection and "collection" is the collection I am inserting the document into.
I have something like the following:
try
{
WriteConcern wc = new WriteConcern();
wc.W = 1;
wc.Journal = true;
WriteConcernResult wcResult = collection.Insert(doc, wc);
if (!string.IsNullOrWhiteSpace(wcResult.ErrorMessage) || !wcResult.Ok)
{
return ErrorHandler(...);
}
else
{
return SuccessFunction(...);
}
}
catch (Exception e)
{
return e.Message;
}
Basically, if the insertion fails for any reason (other than hardware no longer working properly) I want to handle it (through the ErrorHandler function or the catch clause), while if it succeeds I want to call SuccessFunction.
My question: Is the above code sufficient for error checking purposes? In other words, will all failed insertions be caught, so that SuccessFunction is never called in those situations?
You don't even need to do any checking. collection.Insert will throw an exception if the write was not successful when you are using any write concern other than unacknowledged.
If you want to know if an error occured, you need to catch a WriteConcernException.