I have a sample program as follows
public static void enterText(WebElement loc, String value) {
try {
loc.clear();
System.out.println("Text cleared successfully");
} catch (Exception e) {
// exception handling
}
}
On executing loc.clear(), a runtime exception occurs.
Is there a way I can get the method name with parameters after exception happens.
I need to get this enterText(WebElement loc, String value).
You shall print the trace of the exception via this call: e.printStackTrace() inside catch block.
You just need to add a "print" statement in the catch block.
public static void enterText(WebElement loc, String value) {
try {
loc.clear();
System.out.println("Text cleared successfully");
}
catch (Exception e) {
System.out.printf("ERROR: enterText( %s , %s )%n", loc, value);
e.printStackTrace();
}
}
Related
I have a string variable that has a full qualified exception name. I want to check in catch block if exceptions occur whether it is an instance of exception that mentioned in string or not. How to solve that
String stringEx = "org.hibernate.StaleStateException";
try {
// program
} catch (Exception ex) {
if (e instanceof stringEx) { //<-- How to convert string to exception class
// do specific process
}
}
Maybe you need this:
String stringEx = "org.hibernate.StaleStateException";
try {
// program
} catch (Exception ex) {
if (Class.forName(stringEx).isInstance(ex)) {
// do specific process
}
}
I would like to know what the exception instance was in this situation:
try {
// some risky actions
} catch (Exception e) {
System.out.println("Get instance name there");
}
How can I achieve this?
Here you go:
try {
throw new ArithmeticException();
} catch (Exception e) {
System.out.println( e.getClass().getCanonicalName());
}
Output:
java.lang.ArithmeticException
The type of the exception is shown as part of the output of:
e.printStackTrace();
To get it programmatically you can use:
String exceptionClassName = e.getClass().getName();
It is poor form to have logic depending on exception sub types within a catch block. Sonar will flag this as a code violation (squid S1193).
Instead you should add multiple catch blocks to catch different types of exceptions:
try {
readFile(fileName);
}
catch (java.io.IOException e) {
LOG.error("Error accessing file {}", fileName, e);
}
catch (java.lang.IllegalArgumentException e) {
LOG.error("Invalid file name {}", fileName, e);
}
Note: Since Log4j 2 (and SLF4J 1.6+) you can add a throwable as the last parameter and it will be recognized as such. So the above will work!
Since Java 7 you can also do a multi-catch:
}
catch (java.io.IOException | java.lang.IllegalArgumentException e) {
LOG.error("Could not read the file {}", fileName, e);
}
The benefit of the multi-catch is that you can handle multiple exception types within a single catch block without having to revert to a common super class (like java.lang.Exception) that would include exception types you didn't want to handle.
Default exception logging is something like
try
{
//
}
catch (Exception e)
{
e.printStackTrace();
}
This will print the stacktrace of the exception to system.err
If you are looking to add some contextual information, you can take a look at Apache Commons ContextedRuntimeException
public static void main(String[] args) {
try {
doSomething();
} catch (ContextedRuntimeException e) {
System.out.println(e.getMessage());
System.out.println(e.getContextEntries());
}
}
private static void doSomething() {
int divisor = 0;
int dividend = 100;
int result;
try {
result = dividend / divisor; // Just throw an exception to test things....
System.out.print("DIVISION RESULT: "+result);
} catch (ArithmeticException e) {
throw new ContextedRuntimeException("Oops..division by zero not allowed", e)
.addContextValue("Divisor", divisor)
.addContextValue("Dividend", dividend);
}
}
would output:
Oops..division by zero not allowed
Exception Context:
[1:Divisor=0]
[2:Dividend=100]
---------------------------------
[(Divisor,0), (Dividend,100)]
I want to get error message using java when exception are generated.
now I have java code with following scenario:
method first(){
try{
second();
}catch(Exception e){
System.out.println("Error:> "+e)
}
}
method second(){
try{
my code
}catch(Exception e){
throw new Exception("Exception generate in second method",e);
}
}
now when the first method execute then I get only "Exception generate in second method" message but there is some other message printed on console by java so how to get that console error message.
Note: I have already try with e.getMessage(); and e.printStackTrace();
Every exception has a cause that you can get with getCause(). You can go recursively down them until you get to the root cause. Here is your example with a utility that dumps the exception with all its causes like the console does.
private void first() {
try {
second();
} catch (Exception ex) {
Log.e("CATCH", getExceptionDump(ex));
}
}
private void second() {
try {
throw new UnsupportedOperationException("We don't do this.");
} catch (Exception ex) {
throw new RuntimeException("Exception in second()", ex);
}
}
private String getExceptionDump(Exception ex) {
StringBuilder result = new StringBuilder();
for (Throwable cause = ex; cause != null; cause = cause.getCause()) {
if (result.length() > 0)
result.append("Caused by: ");
result.append(cause.getClass().getName());
result.append(": ");
result.append(cause.getMessage());
result.append("\n");
for (StackTraceElement element: cause.getStackTrace()) {
result.append("\tat ");
result.append(element.getMethodName());
result.append("(");
result.append(element.getFileName());
result.append(":");
result.append(element.getLineNumber());
result.append(")\n");
}
}
return result.toString();
}
The message in the Exception constructor argument is not printed in the exception detail.
You can simply use this code to print the message :
method first(){
try{
second();
}catch(Exception e){
System.out.println("Error:> "+e.getMessage())
}
}
Hope this solves your problem
Why you cannot use print stack trace ?
Because A throwable contains a snapshot of the execution stack of its thread at the time it was created. (see Throwable)
It implies that, if you want to print the stack trace you need to use the printStackTrace() method BUT in your second method !
method second(){
try {
my code
} catch(Exception e) {
e.printStackTrace();
throw new Exception("Exception generate in second method",e);
}
}
Or using a the tricky method setStackTrace and using the printStackTrace() in first
method second(){
try {
my code
} catch(Exception e) {
Exception ex = new Exception("Exception generate in second method",e);
ex.setStackTrace(e);
throw ex;
}
}
method first(){
try {
second();
} catch(Exception e) {
e.printStackTrace();
}
}
You can print the cause of the exception you get. Try this:
method first(){
try{
second();
}catch(Exception e){
System.out.println("Error:> "+e);
if (e.getCause() != null) {
System.out.println("Cause:> " + e.getCause());
}
}
}
I believe this is the console message you want to achieve:
Error:> java.lang.Exception: Exception generate in second method
Try this code, when the catch block of the second method throws an exception the second method should declare it as throws or put a nested try catch within the catch block.
The exception is propagated to the first() method which is handled by its catch block.
public class Test {
public void first() {
try {
second();
} catch (Exception e) {
System.out.println("Error:> " + e);
}
}
public void second() throws Exception {
try {
throw new Exception();
} catch (Exception e) {
throw new Exception("Exception generate in second method", e);
}
}
public static void main(String ars[]) {
Test test = new Test();
test.first();
}
}
I have helper class in which I have written this function.
public static String createProject(Map<String, String> params,String projectName, String projectPrefix) {
String createdProject = null;
try {
createdProject=//logic for creating createdProject string which may throw two exception mentioned below
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (TestLinkAPIException t) {
t.printStackTrace();
}
return createdProject;
}
now I am calling this function from GUI part where I have written
String createProject=//called above function.
now If error occur in above code I want to show error to the user.
my question is how I get back the created string and error message if some Exception occur
Create a Custom Exception
Add your String value as an instance field of that Custom Exception.
Throw the custom exception with the String values passed in.
Now you have the exception and the String as well.
If you have a Java 7, then you can use Multi-Catch exception block.
public static String createProject(Map<String, String> params,String projectName, String projectPrefix) throws Exception {
String createdProject = null;
try {
createdProject=//logic for creating createdProject string which may throw two exception mentioned below
} catch (MalformedURLException | TestLinkAPIException e) {
e.printStackTrace();
throw new Exception("Error creating createdProject", e);
}
return createdProject;
}
If exception occurs, createdProject is never set.
You should throw the exception from this method and catch it in block where you calling this method.
public static String createProject(Map<String, String> params,String projectName, String projectPrefix) throws Exception {
String createdProject = null;
try {
createdProject = doSomething();
} catch (Exception e) {
throw new Exception("Error creating Project");
}
return createdProject;
}
and where you calling this method you will have something like this.
try {
String str = createProject();
displayTheProjectCreated(str);
} catch (Exception e) {
// Oops something went wrong
displayErrorMessage(e);
}
when I debug the below code, there is an SmbException and goes catch block line sb.append(pLogger.reportError(pStr, e));, but it does not go into the method reportError().
what is the reason behind this. please advise if any changes.
try {
sfos = new SmbFileOutputStream(sFile);
} catch (SmbException e) {
sb.append(pLogger.rError(pathStr, e));
}
below is rError() method
public String rError(String pxString,Exception e){
String errorToMailStr=null;
abcd="Verifying # "+pxString+"::Error ["+e.getMessage()+"]";
logger.debug("Error when verifying # "+pxString+":Error ["+gMsg(e)+"]");
return abcd;
}
at line logger.debug("Issue "+pxString+":Error ["+gMsg(e)+"]");
is going to below method and ends.
public abstract class ReflectiveCallable {
public Object run() throws Throwable {
try {
return runReflectiveCall();
} catch (InvocationTargetException e) {
throw e.getTargetException();
}
}
Based on what you have revealed here, there is a problem in getExceptionMsg()