Java Regex Matcher IllegalStateException
I am trying to use a matcher and am getting an IllegalStateException: no matches problem
public static final Pattern PATTERN= Pattern.compile("(d+)(|)(d+)((*)(d+)(|)(d+))?");
I then use it on the following input string
Matcher matcher = PATTERN.matcher("20150220|10");
According to RegexPlanet, this should match the pattern:
http://www.regexplanet.com/advanced/java/index.html
Basically my pattern should match both of the following strings:
"20150120|10"
AND
"20150120|10*20150121|15"
Any ideas?
I get this exception when calling matcher.group(1)
java.lang.IllegalStateException: No match found
at java.util.regex.Matcher.group(Matcher.java:485)
at java.util.regex.Matcher.group(Matcher.java:445)
at com.myproject.handle(handler.java:128)
at com.myproject.handle(handlerTest.java:195)
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 org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:271)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:70)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)
at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
at org.mockito.internal.runners.JUnit45AndHigherRunnerImpl.run(JUnit45AndHigherRunnerImpl.java:37)
at org.mockito.runners.MockitoJUnitRunner.run(MockitoJUnitRunner.java:62)
at org.gradle.api.internal.tasks.testing.junit.JUnitTestClassExecuter.runTestClass(JUnitTestClassExecuter.java:86)
at org.gradle.api.internal.tasks.testing.junit.JUnitTestClassExecuter.execute(JUnitTestClassExecuter.java:49)
at org.gradle.api.internal.tasks.testing.junit.JUnitTestClassProcessor.processTestClass(JUnitTestClassProcessor.java:69)
at org.gradle.api.internal.tasks.testing.SuiteTestClassProcessor.processTestClass(SuiteTestClassProcessor.java:48)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.gradle.messaging.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:35)
at org.gradle.messaging.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:24)
at org.gradle.messaging.dispatch.ContextClassLoaderDispatch.dispatch(ContextClassLoaderDispatch.java:32)
at org.gradle.messaging.dispatch.ProxyDispatchAdapter$DispatchingInvocationHandler.invoke(ProxyDispatchAdapter.java:93)
at com.sun.proxy.$Proxy2.processTestClass(Unknown Source)
at org.gradle.api.internal.tasks.testing.worker.TestWorker.processTestClass(TestWorker.java:105)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.gradle.messaging.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:35)
at org.gradle.messaging.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:24)
at org.gradle.messaging.remote.internal.hub.MessageHub$Handler.run(MessageHub.java:360)
at org.gradle.internal.concurrent.DefaultExecutorFactory$StoppableExecutorImpl$1.run(DefaultExecutorFactory.java:64)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:745)
After looking at this post apparently I need to call .matches() first if I want to match the full string
Doing this before calling group worked for me:
http://ideone.com/cjV5rc
/* package whatever; // don't place package name! */
import java.util.*;
import java.lang.*;
import java.io.*;
import java.util.regex.Pattern;
import java.util.regex.Matcher;
/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
public static void main (String[] args) throws java.lang.Exception
{
Pattern PATTERN= Pattern.compile("(d+)(|)(d+)((*)(d+)(|)(d+))?");
Matcher matcher = PATTERN.matcher("20150220|10");
matcher.matches();
System.out.println(matcher.group(1));
}
}
"No match Found" when using matcher's group method
I usually call the group method in a if block, and the conditions is matcher.matches() or matcher.find() to prevent the exception you got, although there is some difference between these two methods. For more information, please refer to the document.
Matcher matcher = PATTERN.matcher("20150220|10");
if(matcher.matches())
{
System.out.println(matcher.group(1) + ","
+ matcher.group(2) + ","
+ matcher.group(3) + ",
+ matcher.group(4) + ","
+ matcher.group(5) + ","
+ matcher.group(6) + ","
+ matcher.group(7) + ","
+ matcher.group(8));
}
matcher = PATTERN.matcher("20150120|10*20150121|15");
if(matcher.find())
{
System.out.println(matcher.group(1) + ","
+ matcher.group(2) + ","
+ matcher.group(3) + ","
+ matcher.group(4) + ","
+ matcher.group(5) + ","
+ matcher.group(6) + ","
+ matcher.group(7) + ","
+ matcher.group(8)
);
}
Additionally, the index can use in group method should equals the pairs of parentheses in your pattern.
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