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How to disable fatal error showing in java?

I would like to know if it is possible to disable the [Fatal Error]:1:50: White spaces are required between publicId and systemId. error in my java program.
Im using java built-in DOM parser api to parse an XML document. The xml document is deliberately incorrect because I want to learn how to handle exceptions related to xml parsing. I also want to say that when the xml document is correct, no exception occurs.
I have already tried with the following :
try {
Document doc = documentBuilder.parse(xmlDocument)
} catch (Throwable t){
System.out.println("An error occur when parsing");
}
The code inside the catch block is displayed correctly but the fatal error message is still showing.
If anyone has a solution, I would be delighted, thanks.

The problem is that by default the error handler for the XML parser prints the errors to the output. You can install your own handler to capture or ignore the errors:
class NullErrorHandler implements ErrorHandler {
#Override
public void fatalError(SAXParseException e) {
// do nothing
}
#Override
public void error(SAXParseException e) {
// do nothing
}
#Override
public void warning(SAXParseException e) {
// do nothing
}
}
Use it as follows:
documentBuilder.setErrorHandler(new NullErrorHandler());
You could also have an error handler that, for example, stored the exceptions in lists in member variables, so you could access them and examine them after parsing the document.
Here's a fully worked-out example:
import javax.xml.parsers.*;
import org.xml.sax.*;
String xml = """
<?xml version="1.0"?>
<!DOCTYPE whatsupdoc PUBLIC
"http://example.com/bugs""http://example.com/bunny">
""";
InputSource getXmlInput(String xml) {
InputSource is = new InputSource();
is.setCharacterStream(new StringReader(xml));
return is;
}
var documentBuilder = DocumentBuilderFactory.newInstance().newDocumentBuilder();
documentBuilder.parse(getXmlInput(xml)); // prints the error and throws
documentBuilder.setErrorHandler(new NullErrorHandler());
documentBuilder.parse(getXmlInput(xml)); // only throws, does not print

JUnit Test: Unable to unmarshall element

I have encountered the following difficulty for close to a week now after trying countless solutions across the net. The specific problem relates to NullPointerException being thrown after calling the method Configuration.getUnmarshallerFactory().getUnmarshaller(Element) in my JUnit test.
The following is the dependency information for opensaml library imported into my project:
<dependency>
<groupId>org.opensaml</groupId>
<artifactId>opensaml</artifactId>
<version>2.6.4</version>
</dependency>
The following is the implementation. During normal execution of the program/project, it is able to execute and return the Response object successfully.
private Response a(String text) throws ConfigurationException, SAXException {
DefaultBootstrap.bootstrap();
Schema s = SAMLSchemaBuilder.getSAML11Schema();
BasicParserPool bpp = new BasicParserPool();
bpp.setNamespaceAware(true);
bpp.setIgnoreElementContentWhitespace(true);
bpp.setSchema(schema);
InputStream is= new ByteArrayInputStream(Base64.decode(samlContent).getBytes());
Response res= null;
try {
Document doc = bpp.parse(is);
Element elmt= doc.getDocumentElement();
try {
QName qn = new QName(elmt.getNamespaceURI(), elmt.getLocalName(), elmt.getPrefix());
Unmarshaller um = Configuration.getUnmarshallerFactory().getUnmarshaller(qn); <== NullPointerException thrown at this line during JUnit Test**
samlResponse = (Response) unmarshaller.unmarshall(elmt);
} catch (XMLParserException e) {
logger.debug(e.getMessage());
} catch (UnmarshallingException e) {
logger.debug(e.getMessage());
}
return res;
}
The following is JUnit Test:
(I got a sample samlp:Response string from the following website: https://www.samltool.com/generic_sso_res.php)
#Test
public void test() throws Exception {
PowerMockito.mockStatic(DefaultBootstrap.class);
PowerMockito.doNothing().when(DefaultBootstrap.class, "bootstrap");
Response result = classInstance.a(Base64.encode(responseStringFromWebsite));
assertNotNull(result);
}
I would greatly appreciate any help or sharing of knowledge if any of you have encountered similar errors before.

By mocking method DefaultBootstrap # bootstrap, you've skiped initialization of required fields, I guess. Check up the source code of DefaultBootstrap.bootstrap(), it will clarify the reason of NPE.

How to copy a resource to a file in another location in Java

I'm trying to copy a resource in my project onto another location on the disk. So far, I have this code:
if (!file.exists()){
try {
file.createNewFile();
Files.copy(new InputSupplier<InputStream>() {
public InputStream getInput() throws IOException {
return Main.class.getResourceAsStream("/" + name);
}
}, file);
} catch (IOException e) {
file = null;
return null;
}
}
And it works fine, but the InputSupplier class is deprecated, so I was wondering if there was a better way to do what I'm trying to do.

See the documentation for the Guava InputSupplier class:
For InputSupplier<? extends InputStream>, use ByteSource instead. For InputSupplier<? extends Reader>, use CharSource. Implementations of InputSupplier that don't fall into one of those categories do not benefit from any of the methods in common.io and should use a different interface. This interface is scheduled for removal in December 2015.
So in your case, you're looking for ByteSource:
Resources.asByteSource(url).copyTo(Files.asByteSink(file));
See this section of the Guava Wiki for more information.
If you're looking for a pure Java (no external libraries) version, you can do the following:
try (InputStream is = this.getClass().getClassLoader().getResourceAsStream("/" + name)) {
Files.copy(is, Paths.get("C:\\some\\file.txt"));
} catch (IOException e) {
// An error occurred copying the resource
}
Note that this is only valid for Java 7 and higher.

java.lang.IllegalArgumentException: 'hello' does not contain an equals sign

I am currently using the Apache commons configuration library to write and read data from a file. I am able to save the key value pair colors=hello to the user..properties file, but when i try to read the value is get the below exception.
Exception in thread "main" java.lang.IllegalArgumentException: 'hello' does not contain an equals sign
at org.apache.commons.configuration.AbstractConfiguration.getProperties(AbstractConfiguration.java:625)
at org.apache.commons.configuration.AbstractConfiguration.getProperties(AbstractConfiguration.java:579)
at com.code.prep.CommonsMain.readProperties(CommonsMain.java:21)
at com.code.prep.CommonsMain.main(CommonsMain.java:12)
The code is as below
package com.code.prep;
import org.apache.commons.configuration.ConfigurationException;
import org.apache.commons.configuration.PropertiesConfiguration;
public class CommonsMain {
public static void main(String[] args) {
CommonsMain main = new CommonsMain();
main.readProperties();
// main.writeProperties();
}
public void readProperties(){
PropertiesConfiguration config = new PropertiesConfiguration();
try {
config.load("user.properties");
System.out.println(config.getProperties("colors"));
} catch (ConfigurationException e) {
e.printStackTrace();
}
}
public void writeProperties(){
PropertiesConfiguration config = new PropertiesConfiguration();
try {
config.load("user.properties");
config.setProperty("colors", "hello");
config.save("user.properties");
} catch (ConfigurationException e) {
e.printStackTrace();
}
}
}
The Jars in the class path are:
commons-configuration-1.9.jar
commons-lang-2.4.jar
commons-logging-1.1.1.jar
user.properties contains
colors = hello
user = thejavamonk

You should not be using
config.getProperties("colors")
but
config.getProperty("colors")
"getProperties(code)" is looking for (multiple) lines in your user.properties file of the form:
code key=val
so it's expecting your code as it stands to have lines like :
colors foreground=black
colors background=white
etc.

This does not look like library issue. Open your file and check whether the data is actually available. From you code it looks like you are doing -
main.readProperties();
// main.writeProperties();
Why would there be any data unless you write it? Call writeProperties() method first and then read it back.

NullPointerException in invokeLater while running through Java Webstart

After upgraded from JRE 1.7.0_21 to 1.7.0_25-b15 my application started to throw NullPointerException in SwingUtilities.invokeLater(...) when it is run from Java WebStart. Surprisingly when it is executed as a standalone application (outside JWS), it works great.
Here is the top of the stack:
Exception in thread "AWT-EventQueue-2" java.lang.NullPointerException
at sun.awt.SunToolkit.getSystemEventQueueImplPP(SunToolkit.java:1011)
at sun.awt.SunToolkit.getSystemEventQueueImplPP(SunToolkit.java:1007)
at sun.awt.SunToolkit.getSystemEventQueueImpl(SunToolkit.java:1002)
at java.awt.Toolkit.getEventQueue(Toolkit.java:1730)
at java.awt.EventQueue.invokeLater(EventQueue.java:1217)
at javax.swing.SwingUtilities.invokeLater(SwingUtilities.java:1290)
at AppletView$8.setBaseUnits(AppletView.java:536)
(...)
To get you full picture: the method setBaseUnits(..) is called as a callback from RMI by remote server. The full stack trace is quite long.
Is there something in security model that changed in RMI or JWS that could break things ? If so I would expect some security exception, but it could be something that is not correctly detected in JRE and leads to NPE.
Any suggestions are appreciated.
---- Update1:
There are similar issues with JRE 1.7.0_25 update probably regarding some security changes and AppContext objects:
https://forums.oracle.com/message/11080621
https://forums.oracle.com/thread/2552799 .
I tried suggested fix: https://forums.oracle.com/message/11082162#11082162 but without any success.
I can see 3 AWT-EventQueue threads in my application with numbers from 0 to 2. It looks like JRE creates additional event queues for different application contexts if program is started by JWS. There are 3 AppContext and 3 EVTs in JWS and there is only one context and EVT if program is executed from IDE.
---- Update2:
There is a workaround as suggested by guruman below (thanks a lot). Unfortunately all the calls to the SwingUtilities.invokeLater(..) from RMI threads must be replaced, and the program starts to depend on Sun JRE internal API.
I am still looking for more general approach not specific to Sun JRE. I think it is a JRE bug. Maybe it could be patched somehow: AppContext should not be null in RMI thread.
---- Update3:
I've made a simple test case to show the problem. It consists 4 files. To run this test case one need to sign the destination jar (TestCase.jar). First of all specify correct codebase in launch.jnlp, then run the server by Java Web Start (eg. using javaws launch.jnlp). A following frame should appear on the screen:
Then the RMI client could be executed. After successful execution the frame should consist:
but if You try to execute the server using JWS You will get the following exception in the client program (the exception is propagated from RMI server to RMI client):
Exception in thread "main" java.lang.NullPointerException
at sun.awt.SunToolkit.getSystemEventQueueImplPP(SunToolkit.java:1011)
at sun.awt.SunToolkit.getSystemEventQueueImplPP(SunToolkit.java:1007)
at sun.awt.SunToolkit.getSystemEventQueueImpl(SunToolkit.java:1002)
at java.awt.Toolkit.getEventQueue(Toolkit.java:1730)
at java.awt.EventQueue.invokeLater(EventQueue.java:1217)
at javax.swing.SwingUtilities.invokeLater(SwingUtilities.java:1290)
at testcase.RmiServiceImpl.callBack(RmiServiceImpl.java:70)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:322)
at sun.rmi.transport.Transport$1.run(Transport.java:177)
at sun.rmi.transport.Transport$1.run(Transport.java:174)
at java.security.AccessController.doPrivileged(Native Method)
at sun.rmi.transport.Transport.serviceCall(Transport.java:173)
at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:553)
at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:808)
at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:667)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:724)
at sun.rmi.transport.StreamRemoteCall.exceptionReceivedFromServer(StreamRemoteCall.java:273)
at sun.rmi.transport.StreamRemoteCall.executeCall(StreamRemoteCall.java:251)
at sun.rmi.server.UnicastRef.invoke(UnicastRef.java:160)
at java.rmi.server.RemoteObjectInvocationHandler.invokeRemoteMethod(RemoteObjectInvocationHandler.java:194)
at java.rmi.server.RemoteObjectInvocationHandler.invoke(RemoteObjectInvocationHandler.java:148)
at com.sun.proxy.$Proxy0.callBack(Unknown Source)
at testcase.RmiClient.main(RmiClient.java:22)
So here they are the test case files:
1) JNLP file definition launch.jnlp:
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<jnlp codebase="file:/home/user/NetBeansProjects/TestCase/dist/" href="launch.jnlp" spec="1.0+">
<information>
<title>TestCase</title>
<vendor>digital_infinity</vendor>
<homepage href=""/>
<description>TestCase</description>
<description kind="short">TestCase</description>
</information>
<security>
<all-permissions/>
</security>
<update check="always"/>
<resources>
<j2se version="1.7+"/>
<jar href="TestCase.jar" main="true"/>
</resources>
<application-desc main-class="testcase.RmiServiceImpl">
</application-desc>
</jnlp>
2) RMI interface definition (RmiService.java):
package testcase;
public interface RmiService extends java.rmi.Remote {
void callBack() throws java.rmi.RemoteException;
}
3) RMI service code and the service main class:
package testcase;
import java.rmi.RemoteException;
import java.rmi.registry.LocateRegistry;
import java.rmi.registry.Registry;
import javax.swing.JFrame;
import javax.swing.JTextField;
import javax.swing.SwingUtilities;
/**
*/
public class RmiServiceImpl extends java.rmi.server.UnicastRemoteObject
implements RmiService {
final static int PORT = 1099;
static JFrame frame;
static JTextField textField;
public RmiServiceImpl() throws RemoteException {
super(PORT);
}
/**
* #param args the command line arguments
*/
public static void main(String[] args) throws Exception {
Registry reg;
RmiServiceImpl service = new RmiServiceImpl();
try {
reg = LocateRegistry.getRegistry(PORT);
reg.rebind("test", service);
} catch (RemoteException ex) {
reg = LocateRegistry.createRegistry(PORT);
reg.rebind("test", service);
}
SwingUtilities.invokeAndWait(new Runnable() {
#Override
public void run() {
frame = new JFrame("Test App");
textField = new JTextField("Before call to callBack");
frame.getContentPane().add(textField);
frame.pack();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
}
});
}
/** RMI callback */
public void callBack() {
Runnable rn = new Runnable() {
public void run() {
textField.setText("CallBack succesfully called.");
frame.pack();
}
};
SwingUtilities.invokeLater(rn);
}
}
4) Simple client code:
package testcase;
import java.rmi.registry.LocateRegistry;
import java.rmi.registry.Registry;
public class RmiClient {
public static void main(String[] args) throws Exception {
//now we trying to communicate with object through RMI
Registry reg = LocateRegistry.getRegistry(RmiServiceImpl.PORT);
//after got the registry, lookup the object and finally do call
RmiService serv = (RmiService) reg.lookup("test");
serv.callBack();
}
}
---- Update4:
JRE Bug I submitted: http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=8019272
Other related bugs:
http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=8019274
http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=8028290
http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=8017770
http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=8021370

I found what I believe to be a better solution to this bug.
I just added the following code before calling SwingUtilities or any Swing related component method. It create a new AppContext for the RMI Thread (RMI thread must be the current Thread when running the code below).
if(AppContext.getAppContext() == null){
SunToolkit.createNewAppContext();
}
Due to the needs of my application I was able to add it on a single method that was using SwingUtilities, but you may need to add it to every method on your RMI Callable Object.
The code needs to run only once, so check the behavior of your application.

The problem occurs in the Webstart environment. Before Webstart version of Java 7u25 the AppContext was set on the system thread group. Yet it is set on the main thread group.
If you have a thread based on a thread group where its parent or grandparent is not the main thread group it has no sun.awt.AppContext.
You should create your thread based on the thread group of the security manager if one exists.
Runnable task = ....
ThreadGroup threadGroup = System.getSecurityManager() != null
? System.getSecurityManager().getThreadGroup()
: Thread.currentThread().getThreadGroup();
Thread t = new Thread(threadGroup, task, "my thread", 0);

Here is a workaround for JDK-8019274, packaged in a utility class.
For us, invokeAndWait() was still an issue. This example has the
existing fix for invokeLater() and a new fix for invokeAndWait().
Notes:
You'll need to include the jnlp.jar in your project.
Call init() early in your main() method, before calling invokeLater()
Replace all your calls to SwingUtilities invokeLater() and invokeAndWait() with these calls
(Disclaimer: This is from our product. Some aspects of this solution may not apply to you.)
public class JreFix {
private static String badVersionInfo = null;
private static AppContext awtEventDispatchContext = null;
private static AppContext mainThreadContext = null;
private static Boolean isWebStart = null;
private static BasicService basicService = null;
private static IntegrationService integrationService = null;
/**
* Call this early in main().
*/
public static void init() {
if (isWebstart() && isApplicableJvmType()) {
String javaVersion = System.getProperty("java.version");
if ("1.7.0_25".equals(javaVersion)) {
badVersionInfo = "7u25";
}
else if ("1.7.0_40".equals(javaVersion)) {
badVersionInfo = "7u40";
}
else if (javaVersion != null && "1.6.0_51".equals(javaVersion.substring(0,8))) {
badVersionInfo = "6u51";
}
else if ("javaws-10.25.2.16".equals(System.getProperty("javawebstart.version"))) {
badVersionInfo = "Web Start 10.25.2.16";
}
}
if (badVersionInfo != null) {
mainThreadContext = AppContext.getAppContext();
try {
SwingUtilities.invokeAndWait(new Runnable() {
public void run() {
awtEventDispatchContext = AppContext.getAppContext();
}
});
}
catch (Exception e) {
displayErrorAndExit(null);
}
if (mainThreadContext == null || awtEventDispatchContext == null) {
displayErrorAndExit(null);
}
}
}
public static void invokeNowOrLater(Runnable runnable) {
if (hasAppContextBug()) {
invokeLaterOnAwtEventDispatchThreadContext(runnable);
}
else {
SwingUtilities.invokeLater(runnable);
}
}
public static void invokeNowOrWait(Runnable runnable) {
if (hasAppContextBug()) {
fixThreadAppContext(null);
}
try {
SwingUtilities.invokeAndWait(runnable);
}
catch (Exception e) {
// handle it
}
}
public static boolean hasAppContextBug() {
return isJreWithAppContextBug() && AppContext.getAppContext() == null;
}
public static void invokeLaterOnAwtEventDispatchThreadContext(Runnable runnable) {
sun.awt.SunToolkit.invokeLaterOnAppContext(awtEventDispatchContext, runnable);
}
public static void fixThreadAppContext(Component parent) {
try {
final Field field = AppContext.class.getDeclaredField("threadGroup2appContext");
field.setAccessible(true);
Map<ThreadGroup, AppContext> threadGroup2appContext = (Map<ThreadGroup, AppContext>)field.get(null);
final ThreadGroup currentThreadGroup = Thread.currentThread().getThreadGroup();
threadGroup2appContext.put(currentThreadGroup, mainThreadContext);
}
catch (Exception e) {
displayErrorAndExit(parent);
}
if (AppContext.getAppContext() == null) {
displayErrorAndExit(parent);
}
}
private static boolean isJreWithAppContextBug() {
return badVersionInfo != null;
}
private static void displayErrorAndExit(Component parent) {
JLabel msgLabel = new JLabel("<html>" +
"Our application cannot run using <b>Web Start</b> with this version of Java.<p><p>" +
"Java " + badVersionInfo + " contains a bug acknowledged by Oracle (JDK-8019274).");
JOptionPane.showMessageDialog(parent, msgLabel, "Java Version Error", JOptionPane.ERROR_MESSAGE);
System.exit(1);
}
private static boolean isApplicableJvmType() {
String vendor = System.getProperty("java.vendor");
String vmName = System.getProperty("java.vm.name");
if (vendor != null && vmName != null) {
return vmName.contains("Java HotSpot") &&
(vendor.equals("Oracle Corporation") ||
vendor.equals("Sun Microsystems Inc."));
}
return false;
}
private static boolean isWebstart() {
if (isWebStart == null) {
try {
basicService = (BasicService) ServiceManager.lookup("javax.jnlp.BasicService");
isWebStart = true;
}
catch (UnavailableServiceException e) {
isWebStart = false;
}
try {
integrationService = (IntegrationService) ServiceManager.lookup("javax.jnlp.IntegrationService");
}
catch (UnavailableServiceException e) {
}
}
return isWebStart;
}
}

Java 7u65 which came out yesterday (2014-07-15) claims to have fixed this or a very similar issue, in JDK-8019724. I'm testing right now to find out - a driver from one of our vendors doesn't function under Java Web Start, and it has been keeping us on Java 6.
ETA: Yes, it looks like this resolves our problems!

This is still happening on Mac Sierra. But I'm able to workaround it by calling:
if (sun.awt.AppContext.getAppContext() == null) {
sun.awt.SunToolkit.createNewAppContext();
}
just before my first SwingUtilities.invokeLater(...) call.