`spring.data.rest.base-uri` doesn't work

After Spring Boot 1.3.0.M1, the following property doesn't work:

spring.data.rest.base-uri=/api

You have to use the following property:

spring.data.rest.base-path=/api

This is corresponding to Spring Data REST change.

Handle keys having dots in JsonPath

When you handle keys having dots in JsonPath,

you can use one of the followings:

// NOTE: 1L doesn't work. Why?
assertThat(JsonPath.<Long> read(metrics, "['counter.test']"), is(1));
assertThat(JsonPath.<Long> read(metrics, "$['counter.test']"), is(1));
assertThat(JsonPath.<Long> read(metrics, "$.['counter.test']"), is(1));

I'm not sure why `<Long>` doesn't work as expected.

It's converted into `Integer`.

You can see a sample in the following:

https://github.com/izeye/samples-spring-boot-branches/blob/rest-and-actuator/src/test/java/samples/springboot/counter/web/CounterControllerTests.java

Reference:
http://stackoverflow.com/questions/19726859/jsonpath-junit-escape-character-for-dots

Get detailed stack traces of failed tests in Gradle

When a test failed in Gradle,

you will get the following stack trace:

com.izeye.test.SomeTests > test FAILED
    java.lang.IllegalStateException                                                    
        Caused by: org.springframework.beans.factory.BeanCreationException              
            Caused by: java.lang.NoClassDefFoundError                                  
                Caused by: java.lang.ClassNotFoundException

But it's sometimes not useful.

When you want to get a detailed stack trace,

add the following configuration:

    test {
        testLogging {
            exceptionFormat = 'full'
        }
    }

Now you will get the following output:

com.izeye.test.SomeTests > test FAILED  
    java.lang.IllegalStateException: Failed to load ApplicationContext                  
                                                                                       
        Caused by:                                                                      
        org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sqlSessionFactory' defined in class path resource [com/izeye/test/config/PersistenceConfig.class]: Invocation of init method failed; nested exception is java.lang.NoClassDefF
oundError: org/w3c/dom/ElementTraversal
                                                                                       
            Caused by:                                                                  
            java.lang.NoClassDefFoundError: org/w3c/dom/ElementTraversal                
                                                                                       
                Caused by:                                                              
                java.lang.ClassNotFoundException: org.w3c.dom.ElementTraversal      

Now you can see that the culprit was `org.w3c.dom.ElementTraversal `.

Reference:
http://java.dzone.com/articles/gradle-goodness-show-more

Caused by: java.lang.NoSuchFieldException: $jacocoAccess

When you run the following command:

gradle clean test

you might get the following exception:

Caused by: java.lang.NoSuchFieldException: $jacocoAccess

JaCoCo default version (0.6.2.201302030002) doesn't work with Java 8.

You can check your JaCoCo version with the following configuration:

    jacoco {
        println toolVersion
    }

and you will get the following output:

0.6.2.201302030002

You can fix with the following configuration:

    jacoco {
        toolVersion = "0.7.1.201405082137"
    }

Reference:
https://github.com/jacoco/jacoco/issues/74

Missing `datasource.xxx.active` and `datasource.xxx.usage` in `metrics` endpoint in Spring Boot Actuator

In Spring Boot Actuator's `metrics` endpoint,

if you can't see `datasource.xxx.active` and `datasource.xxx.usage`,

you might have the following configuration:

@SpringBootApplication(exclude = {
    DataSourceAutoConfiguration.class,
    DataSourceTransactionManagerAutoConfiguration.class
})

Showing the metrics needs `DataSourcePoolMetadataProvidersConfiguration`

which is included in `DataSourceAutoConfiguration`.

So you have to use the following if you don't use `DataSourceAutoConfiguration`:

@Import(DataSourcePoolMetadataProvidersConfiguration.class)

It would be nice to separate them because `DataSourceAutoConfiguration` doesn't work

when having multiple `DataSource`s.

`java.lang.StackOverflowError` in Spring Data MongoDB

You might encounter the following error suddenly:

java.lang.StackOverflowError
at java.lang.String.<init>(String.java:201)
at java.lang.String.substring(String.java:1956)
at sun.reflect.misc.ReflectUtil.isNonPublicProxyClass(ReflectUtil.java:288)
at sun.reflect.misc.ReflectUtil.checkPackageAccess(ReflectUtil.java:165)
at sun.reflect.misc.ReflectUtil.isPackageAccessible(ReflectUtil.java:195)
at java.beans.MethodRef.get(MethodRef.java:72)
at java.beans.PropertyDescriptor.getReadMethod(PropertyDescriptor.java:206)
at org.springframework.data.mapping.model.AbstractPersistentProperty.getGetter(AbstractPersistentProperty.java:159)
at org.springframework.data.mapping.model.BeanWrapper.getProperty(BeanWrapper.java:127)
at org.springframework.data.mapping.model.BeanWrapper.getProperty(BeanWrapper.java:100)
at org.springframework.data.mongodb.core.convert.MappingMongoConverter$3.doWithPersistentProperty(MappingMongoConverter.java:419)
at org.springframework.data.mongodb.core.convert.MappingMongoConverter$3.doWithPersistentProperty(MappingMongoConverter.java:412)
at org.springframework.data.mapping.model.BasicPersistentEntity.doWithProperties(BasicPersistentEntity.java:307)
at org.springframework.data.mongodb.core.convert.MappingMongoConverter.writeInternal(MappingMongoConverter.java:412)
at org.springframework.data.mongodb.core.convert.MappingMongoConverter.writeInternal(MappingMongoConverter.java:386)
at org.springframework.data.mongodb.core.convert.MappingMongoConverter.writeCollectionInternal(MappingMongoConverter.java:622)
at org.springframework.data.mongodb.core.convert.MappingMongoConverter.createCollection(MappingMongoConverter.java:546)
at org.springframework.data.mongodb.core.convert.MappingMongoConverter.writePropertyInternal(MappingMongoConverter.java:457)
at org.springframework.data.mongodb.core.convert.MappingMongoConverter$3.doWithPersistentProperty(MappingMongoConverter.java:424)
at org.springframework.data.mongodb.core.convert.MappingMongoConverter$3.doWithPersistentProperty(MappingMongoConverter.java:412)
at org.springframework.data.mapping.model.BasicPersistentEntity.doWithProperties(BasicPersistentEntity.java:307)

I didn't dig into the problem due to lack of time

but the culprit was `Logger` in a MongoDB document as follows:

  private final Logger log = LoggerFactory.getLogger(getClass());

It could be fixed with `org.springframework.data.annotation.Transient` as follows:

  @Transient
  private final Logger log = LoggerFactory.getLogger(getClass());

but it doesn't make sense that every document has its own field for the logger

although the logger will be singleton.

Using `static` is much better as follows:

  private static final Logger log = LoggerFactory.getLogger(NaboxImpressionLog.class);

Reference:
http://stackoverflow.com/questions/21734785/mongodb-spring-saving-an-object-causes-stackoverflowerror

Error:Cause: net.rubygrapefruit.platform.internal.jni.WindowsHandleFunctions.markStandardHandlesUninheritable(Lnet/rubygrapefruit/platform/internal/FunctionResult;)V

I encountered the following error in IntelliJ when I tried to run a Gradle task:

Error:Cause: net.rubygrapefruit.platform.internal.jni.WindowsHandleFunctions.markStandardHandlesUninheritable(Lnet/rubygrapefruit/platform/internal/FunctionResult;)V

I can run a Gradle task in a terminal but I can't run a Gradle task in IntelliJ any more.

I'll update if I find any.

Any hint to solve this problem will be appreciatied.

---

UPDATED:

Restarting IntelliJ solved the problem :-)

java.lang.IllegalArgumentException: Cannot locate declared field class org.apache.http.impl.client.HttpClientBuilder.sslcontext

When you try to use `HtmlUnit`,

you might encounter the following exception:

java.lang.IllegalArgumentException: Cannot locate declared field class org.apache.http.impl.client.HttpClientBuilder.sslcontext

You're using httpcomponents 4.5.

If you don't need the version,

downgrade it to 4.4.1 as follows:

    testCompile("org.apache.httpcomponents:httpclient:4.4.1")
    testCompile("org.apache.httpcomponents:httpmime:4.4.1")

References:
http://htmlunit.10904.n7.nabble.com/HtmlUnit-htmlunit-bugs-1692-Update-to-HttpComponents-4-5-td36318.html

Show all indexes in MongoDB

To show all indexes in MongoDB,

you can use the following command:

db.someCollection.getIndexes()

Reference:
http://docs.mongodb.org/manual/tutorial/list-indexes/

Relocate MongoDB storage location in CentOS

To relocate MongoDB storage location in CentOS,

stop MongoDB server with the following command:

sudo /sbin/service mongod stop

Modify MongoDB configuration as follows:

sudo vi /etc/mongod.conf

#dbpath=/var/lib/mongo
dbpath=/home/izeye/mongo

Start MongoDB server with the following command:

sudo /sbin/service mongod start

Note that the directory should be owned by `mongod` user.

If not, change it by the following command:

sudo chown mongod /home/izeye/mongo/

Caused by: com.mongodb.WriteConcernException: { "serverUsed" : "1.2.3.4:27017" , "ok" : 1 , "n" : 0 , "err" : "new file allocation failure" , "code" : 12520}

You might encounter the following exception:

Caused by: com.mongodb.WriteConcernException: { "serverUsed" : "1.2.3.4:27017" , "ok" : 1 , "n" : 0 , "err" : "new file allocation failure" , "code" : 12520}

You can check your MongoDB server log with the following command:

sudo vi /var/log/mongodb/mongod.log

The log will have the following lines:

2015-06-10T20:19:19.311+0900 I -        [conn7] Assertion: 12520:new file allocation failure
2015-06-10T20:19:19.313+0900 I STORAGE  [FileAllocator] allocating new datafile /var/lib/mongo/test.6, filling with zeroes...
2015-06-10T20:19:19.316+0900 I -        [conn7] Assertion: 12520:new file allocation failure
2015-06-10T20:19:19.316+0900 I STORAGE  [FileAllocator] FileAllocator: posix_fallocate failed: errno:28 No space left on device falling back
2015-06-10T20:19:19.317+0900 I STORAGE  [FileAllocator] error: failed to allocate new file: /var/lib/mongo/test.6 size: 2146435072 failure creating new datafile; lseek failed for fd 22 with errno: errno:2 No such file or directory.  will try again in 10 seconds
2015-06-10T20:19:19.322+0900 I -        [conn7] Assertion: 12520:new file allocation failure

You can notice there is not enough space.

So you can clean up your disk

or relocate MongoDB storage location

to a directory mounted on a different partition or disk.

Caused by: java.lang.NoClassDefFoundError: org/w3c/dom/ElementTraversal

You can encounter the following error after upgrading to Spring Boot 1.3.0.M1:

Caused by: java.lang.NoClassDefFoundError: org/w3c/dom/ElementTraversal
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:760)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:455)
at java.net.URLClassLoader.access$100(URLClassLoader.java:73)
at java.net.URLClassLoader$1.run(URLClassLoader.java:367)
at java.net.URLClassLoader$1.run(URLClassLoader.java:361)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:360)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
at org.apache.xerces.parsers.AbstractDOMParser.startDocument(Unknown Source)
at org.apache.xerces.impl.dtd.XMLDTDValidator.startDocument(Unknown Source)
at org.apache.xerces.impl.XMLDocumentScannerImpl.startEntity(Unknown Source)
at org.apache.xerces.impl.XMLVersionDetector.startDocumentParsing(Unknown Source)
at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
at org.apache.xerces.parsers.XMLParser.parse(Unknown Source)
at org.apache.xerces.parsers.DOMParser.parse(Unknown Source)
at org.apache.xerces.jaxp.DocumentBuilderImpl.parse(Unknown Source)
at org.apache.ibatis.parsing.XPathParser.createDocument(XPathParser.java:254)
at org.apache.ibatis.parsing.XPathParser.<init>(XPathParser.java:125)
at org.apache.ibatis.builder.xml.XMLConfigBuilder.<init>(XMLConfigBuilder.java:75)
at org.mybatis.spring.SqlSessionFactoryBean.buildSqlSessionFactory(SqlSessionFactoryBean.java:358)
at org.mybatis.spring.SqlSessionFactoryBean.afterPropertiesSet(SqlSessionFactoryBean.java:340)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1637)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1574)

With the hint from StackOverflow and the following command:

gradle dependencies

I can figure out that `xml-apis-1.4.01` has been changed to `xml-apis-1.3.04` as follows:

Before upgrading to Spring Boot 1.3.0.M1:

+--- net.sourceforge.nekohtml:nekohtml:1.9.22
|    \--- xerces:xercesImpl:2.11.0
|         \--- xml-apis:xml-apis:1.4.01

After upgrading to Spring Boot 1.3.0.M1:

+--- net.sourceforge.nekohtml:nekohtml:1.9.22
|    \--- xerces:xercesImpl:2.11.0
|         \--- xml-apis:xml-apis:1.4.01 -> 1.3.04

With the following command:

gradle dependencyInsight --dependency xml-apis

you will get the following result:

:dependencyInsight                                                                                                                                              
xml-apis:xml-apis:1.3.04 (selected by rule)
                                 
xml-apis:xml-apis:1.4.01 -> 1.3.04
\--- xerces:xercesImpl:2.11.0    
     \--- net.sourceforge.nekohtml:nekohtml:1.9.22
          \--- compile

`spring-boot-dependencies` enforces `1.3.04` as follows:

<xml-apis.version>1.3.04</xml-apis.version>

You can resolve the problem by using `xml-apis:1.4.01` as follows:

compile("xml-apis:xml-apis:1.4.01")

I created a PR to upgrade `xml-apis as follows:

https://github.com/spring-projects/spring-boot/pull/3226

References:
http://stackoverflow.com/questions/10234201/appengine-error-java-lang-noclassdeffounderror-org-w3c-dom-elementtraversal
https://github.com/spring-projects/spring-boot/blob/master/spring-boot-dependencies/pom.xml

Error creating bean with name 'mbeanExporter' defined in class path resource [org/springframework/boot/autoconfigure/jmx/JmxAutoConfiguration.class]

When you have the following JMX configuration with Spring Boot,

  @Bean
  public MBeanServerFactoryBean mBeanServer() {
    MBeanServerFactoryBean mBeanServerFactoryBean = new MBeanServerFactoryBean();
    mBeanServerFactoryBean.setLocateExistingServerIfPossible(true);
    return mBeanServerFactoryBean;
  }

you can encounter the following exception:

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'mbeanExporter' defined in class path resource [org/springframework/boot/autoconfigure/jmx/JmxAutoConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.jmx.export.annotation.AnnotationMBeanExporter]: Factory method 'mbeanExporter' threw exception; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No bean named 'mbeanServer' is defined
at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:599)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1119)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1014)

If you should keep your own `MBeanServer`,

set the following property in `application.properties`:

spring.jmx.server=mBeanServer

If you don't have to keep your own `MBeanServer`,

drop your own JMX configuration for `MBeanServer`

and use one provided by Spring Boot.

Reference:
http://docs.spring.io/spring-boot/docs/current-SNAPSHOT/reference/htmlsingle/

List all indexes in MongoDB

To list all indexes in MongoDB,

you can do the following:

> db.someCollection.getIndexes()                                                                                
[
        {
                "v" : 1,
                "key" : {
                        "_id" : 1
                },
                "name" : "_id_",
                "ns" : "test.someCollection"
        },
        {
                "v" : 1,
                "key" : {
                        "someIndexProperty" : 1
                },
                "name" : "someIndexProperty_1",
                "ns" : "test.someCollection"
        }
]
>

Reference:
http://docs.mongodb.org/manual/tutorial/list-indexes/

Create an index in MongoDB

To create an index in MongoDB,

you can do the following:

> db.someCollection.createIndex({someIndexProperty: 1})
{
        "createdCollectionAutomatically" : false,
        "numIndexesBefore" : 1,
        "numIndexesAfter" : 2,
        "ok" : 1
}
>

Reference:
http://docs.mongodb.org/manual/tutorial/create-an-index/

Oracle VARCHAR2's length is BYTE or CHAR?

Oracle VARCHAR2's length is BYTE or CHAR?

It depends on an option you used when creating a column as follows:

VARCHAR2(20 BYTE)

VARCHAR2(20 CHAR)

What if you omit the option as follows?

VARCHAR2(20)

It depends on the global setting for length semantics.

You can check the setting as follows:

SELECT VALUE FROM NLS_DATABASE_PARAMETERS WHERE PARAMETER = 'NLS_LENGTH_SEMANTICS';

BYTE

References:
http://docs.oracle.com/cd/B28359_01/server.111/b28318/datatype.htm#CNCPT1824
http://oracleschools.blogspot.kr/2013/01/how-to-check-nlslengthsemantics.html

How to use `sort` in Spring Data REST

To use `sort` in Spring Data REST,

you can use as follows:

http://localhost:{port}/api/customers?sort=firstName,desc

You can reference the following sample project:

https://github.com/izeye/samples-spring-boot-branches/tree/jpa-and-data-rest

Reference:
http://docs.spring.io/spring-data/rest/docs/current/reference/html/

MongoDB installation location in Windows

MongoDB installation location in Windows is as follows:

C:\Program Files\MongoDB\Server\3.0\bin

Allow all interfaces to listen for MongoDB in CentOS 6.6

To allow all interfaces to listen for MongoDB in CentOS 6.6,

comment out the `bind_ip` as follows:

sudo vi /etc/mongod.conf

# Listen to local interface only. Comment out to listen on all interfaces.
#bind_ip=127.0.0.1

Restart the MongoDB server (mongod) as follows:

sudo /sbin/service mongod start

Change MongoDB server port in CentOS 6.6

To change MongoDB server port in CentOS 6.6,

edit the following configuration:

sudo vi /etc/mongod.conf

port=10000

Restart the MongoDB server (mongod) as follows:

sudo /sbin/service mongod start

Reference:
http://docs.mongodb.org/manual/reference/configuration-options/

Install MongoDB on CentOS 6.6

To install MongoDB on CentOS 6.6,

you add MongoDB repository as follows:

sudo vi /etc/yum.repos.d/mongodb-org-3.0.repo

[mongodb-org-3.0]
name=MongoDB Repository
baseurl=http://repo.mongodb.org/yum/redhat/$releasever/mongodb-org/3.0/x86_64/
gpgcheck=0
enabled=1

Install MongoDB by `yum` as follows:

sudo yum install -y mongodb-org

Start MongoDB by `service` as follows:

sudo /sbin/service mongod start

Check listening port as follows:

sudo vi /var/log/mongodb/mongod.log

2015-06-08T21:14:23.908+0900 I NETWORK  [initandlisten] waiting for connections on port 27017

Run MongoDB client as follows:

mongo

Reference:
http://docs.mongodb.org/manual/tutorial/install-mongodb-on-red-hat/

java.lang.IllegalArgumentException: Cannot subclass final class class com.sun.proxy.$Proxy52

When you are using Spring Data MongoDB,

you can encounter the following exception:

Caused by: java.lang.IllegalArgumentException: Cannot subclass final class class com.sun.proxy.$Proxy52
at org.springframework.cglib.proxy.Enhancer.generateClass(Enhancer.java:446)
at org.springframework.cglib.transform.TransformingClassGenerator.generateClass(TransformingClassGenerator.java:33)

It happened by adding `@Repository` accidentally as follows:

@Repository
public interface SomethingRepository extends MongoRepository<Something, String> {
}

Removing `@Repository` fixes the problem.

It would be better to have an exception having better explanation if possible.

Reference:
https://github.com/spring-projects/spring-boot/issues/1929

Hotfix KB2731284 or later update is not installed, will zero-out data files

When you run a MongoDB server (mongod) in Windows,

you can encounter the following error:

C:\Program Files\MongoDB\Server\3.0\bin>mongod
2015-06-08T20:29:47.485+0900 I CONTROL  Hotfix KB2731284 or later update is not installed, will zero-out data files
2015-06-08T20:29:47.565+0900 I STORAGE  [initandlisten] exception in initAndListen: 29 Data directory C:\data\db\ not found., terminating
2015-06-08T20:29:47.565+0900 I CONTROL  [initandlisten] dbexit:  rc: 100

You can fix it by creating the following directory:

C:\data\db

Unfortunately I can't understand why it fixed the problem.

Anyone who explains why?

Reference:
http://stackoverflow.com/questions/29316482/mongo-error-on-i-control-hotfix

Show all sub-projects' dependencies in Gradle

In Gradle, to show all sub-projects' dependencies,

add the following to `build.gradle`.

subprojects {
    task allDependencies(type: DependencyReportTask) {}
}

Now you can use the following command:

gradle allDependencies

Reference:
https://solidsoft.wordpress.com/2014/11/13/gradle-tricks-display-dependencies-for-all-subprojects-in-multi-project-build/

Caused by: java.lang.NoSuchMethodError: org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry.hasMappingForPattern(Ljava/lang/String;)Z

You can encounter the following error:

Caused by: java.lang.NoSuchMethodError: org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry.hasMappingForPattern(Ljava/lang/String;)Z
at org.springframework.boot.autoconfigure.web.WebMvcAutoConfiguration$WebMvcAutoConfigurationAdapter.addResourceHandlers(WebMvcAutoConfiguration.java:256)
at org.springframework.web.servlet.config.annotation.WebMvcConfigurerComposite.addResourceHandlers(WebMvcConfigurerComposite.java:102)

Using `gradle dependencies` didn't help me much.

It showed the right dependency I expected:

org.springframework:spring-webmvc:4.1.6.RELEASE

It's one of Gradle sub-projects.

It is caused by another sub-project which it depends on.

The sub-project has a dependency having the following transitive dependency:

org.springframework.mobile:spring-mobile-device:1.1.3.RELEASE

And it has the following transitive dependency:

org.springframework:spring-webmvc:3.2.11.RELEASE

So the conflict occurred.

I solved it as follows:

    compile("xxx:xxx:1.0.0") {
        exclude module: 'spring-mobile-device'
    }

But I can't understand why the latest dependency doesn't win.

Show disk usages of all directories in Windows

If you want to know disk usages of all directories in Windows,

you can use `WinDirStat`.

I used it to find directories using a lot of space and it nicely worked.

Reference:
http://windirstat.info/