Java Posts

A Simple Thousand Separator using Java

Trying to create a quick and simple solution for formatting an Integer into a formatted string with thousand separator,

	class Main
	{
		public static void main (String[] args) throws java.lang.Exception
		{
			String s = (String.format("%,d", 10000000)).replace(",",".");
			System.out.println(s);
		}
	}

The output will be, 10.000.000. (H)

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Error java.sql.SQLException: Numeric Overflow when Connect to Oracle using Hibernate

Got weird error today, here is the complere stacktrace

2018-01-31 12:14:56 WARN  SqlException: - SQL Error: 17026, SQLState: 99999
2018-01-31 12:14:56 ERROR SqlException: - Numeric Overflow

Caused by: java.sql.SQLException: Numeric Overflow
	at oracle.jdbc.driver.NumberCommonAccessor.throwOverflow(NumberCommonAccessor.java:4136)
	at oracle.jdbc.driver.NumberCommonAccessor.getInt(NumberCommonAccessor.java:103)
	at oracle.jdbc.driver.GeneratedStatement.getInt(GeneratedStatement.java:197)
	at oracle.jdbc.driver.GeneratedScrollableResultSet.getInt(GeneratedScrollableResultSet.java:244)
	at oracle.jdbc.driver.GeneratedResultSet.getInt(GeneratedResultSet.java:554)
	at org.apache.tomcat.dbcp.dbcp.DelegatingResultSet.getInt(DelegatingResultSet.java:275)
	at org.apache.tomcat.dbcp.dbcp.DelegatingResultSet.getInt(DelegatingResultSet.java:275)
	at org.hibernate.type.descriptor.sql.IntegerTypeDescriptor$2.doExtract(IntegerTypeDescriptor.java:66)
	at org.hibernate.type.descriptor.sql.BasicExtractor.extract(BasicExtractor.java:64)
	at org.hibernate.type.AbstractStandardBasicType.nullSafeGet(AbstractStandardBasicType.java:265)
	at org.hibernate.type.AbstractStandardBasicType.nullSafeGet(AbstractStandardBasicType.java:261)
	at org.hibernate.type.AbstractStandardBasicType.nullSafeGet(AbstractStandardBasicType.java:251)
	at org.hibernate.type.AbstractStandardBasicType.hydrate(AbstractStandardBasicType.java:336)
	at org.hibernate.persister.entity.AbstractEntityPersister.hydrate(AbstractEntityPersister.java:2924)
	at org.hibernate.loader.Loader.loadFromResultSet(Loader.java:1695)
	at org.hibernate.loader.Loader.instanceNotYetLoaded(Loader.java:1627)
	at org.hibernate.loader.Loader.getRow(Loader.java:1509)
	at org.hibernate.loader.Loader.getRowFromResultSet(Loader.java:719)
	at org.hibernate.loader.Loader.processResultSet(Loader.java:949)
	at org.hibernate.loader.Loader.doQuery(Loader.java:917)
	at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:348)
	at org.hibernate.loader.Loader.doList(Loader.java:2550)
	... 75 more	

And here is my java class,

public class Class {
   private Integer value;

   // other setter and getter
}

How to solve the issue is actually quite simple, it’s all happen because im having a data on database which is bigger than Integer’s max value. Updating my bean from Integer to BigDecimal solve the problem,

public class Class {
   private BigDecimal value;

   // other setter and getter
}
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Create a Simple Autocomplete Textfield using Spring MVC, JQuery, EasyAutocomplete and Hibernate

Several weeks ago i got a request from one of my student, Albi Dwi Haryono. He was asking how to create an autocomplete textbox on JSP page using Spring MVC. So i create this tutorial for helping him and who knows, perhaps also helping other people.

First as usual, create a table Test

CREATE TABLE `test` (
  `field1` varchar(40) NOT NULL,
  PRIMARY KEY (`field1`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1;

create a simple maven file which consist of Spring MVC library, json, MySql and Hibernate,

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.edw</groupId>
    <artifactId>SpringAutoComplete</artifactId>
    <version>1.0.0</version>
    <packaging>war</packaging>

    <name>SpringAutoComplete</name>

    <properties>
        <endorsed.dir>${project.build.directory}/endorsed</endorsed.dir>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>
    
    <dependencies>
        <dependency>
            <groupId>javax</groupId>
            <artifactId>javaee-web-api</artifactId>
            <version>7.0</version>
            <scope>provided</scope>
        </dependency>
        
        <!-- Spring dependencies -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-core</artifactId>
            <version>4.3.10.RELEASE</version>
        </dependency> 
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-web</artifactId>
            <version>4.3.10.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>4.3.10.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-tx</artifactId>
            <version>4.3.10.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-orm</artifactId>
            <version>4.3.10.RELEASE</version>
        </dependency>
        
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>4.3.10.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context-support</artifactId>
            <version>4.3.10.RELEASE</version>
        </dependency>  
        
        <!-- json request -->        
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-core</artifactId>
            <version>2.6.3</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>2.6.3</version>
        </dependency>
        
        <!-- log4j -->   
        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.17</version>
        </dependency>
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-log4j12</artifactId>
            <version>1.7.12</version>
        </dependency> 
        
        <!-- Hibernate -->
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-core</artifactId>
            <version>5.1.8.Final</version>
        </dependency>
        
        <!-- MySQL database driver --> 
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.10</version>
        </dependency>
        
        <!-- dbcp2 -->   
        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-dbcp2</artifactId>
            <version>2.1.1</version>
        </dependency>
        
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.1</version>
                <configuration>
                    <source>1.7</source>
                    <target>1.7</target>
                    <compilerArguments>
                        <endorseddirs>${endorsed.dir}</endorseddirs>
                    </compilerArguments>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-war-plugin</artifactId>
                <version>2.3</version>
                <configuration>
                    <failOnMissingWebXml>false</failOnMissingWebXml>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-dependency-plugin</artifactId>
                <version>2.6</version>
                <executions>
                    <execution>
                        <phase>validate</phase>
                        <goals>
                            <goal>copy</goal>
                        </goals>
                        <configuration>
                            <outputDirectory>${endorsed.dir}</outputDirectory>
                            <silent>true</silent>
                            <artifactItems>
                                <artifactItem>
                                    <groupId>javax</groupId>
                                    <artifactId>javaee-endorsed-api</artifactId>
                                    <version>7.0</version>
                                    <type>jar</type>
                                </artifactItem>
                            </artifactItems>
                        </configuration>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>
</project>

Next is create configuration file, applicationContext.xml, dispatcher-servlet.xml and registering all thos files on web.xml. I wont explain too much here, just see my github pages for a much more detailed code.

As for java files, i have a java bean Test, as representation for table Test

package com.edw.springautocomplete.bean;

import java.io.Serializable;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;

@Entity
@Table(name = "test")
public class Test implements Serializable {

    @Id
    public String field1;

    public String getField1() {
        return field1;
    }

    public void setField1(String field1) {
        this.field1 = field1;
    }
}

And finally a simple controller file, for serving default index page, and also for serving json file for autocomplete purpose.

package com.edw.springautocomplete.controller;

import com.edw.springautocomplete.bean.Test;
import java.util.List;
import org.hibernate.SessionFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.transaction.annotation.Transactional;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.ResponseBody;

@Controller
public class IndexController {

    @Autowired
    private SessionFactory sessionFactory;
    
    @RequestMapping(value = "/", method = RequestMethod.GET)
    public String index() {
        return "index";
    }

    @Transactional
    @RequestMapping(value = "/field1", method = RequestMethod.GET)
    public @ResponseBody List<Test> field1() {
        return sessionFactory.openSession()
                .createQuery("from Test")
                .list();
    }
}

But, the most important file is the jsp page,

<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
        <title>JSP Page</title>
        
        <link href="https://cdnjs.cloudflare.com/ajax/libs/easy-autocomplete/1.3.5/easy-autocomplete.min.css" rel="stylesheet" type="text/css">
        <script src="//code.jquery.com/jquery-1.11.2.min.js"></script>
        <script src="https://cdnjs.cloudflare.com/ajax/libs/easy-autocomplete/1.3.5/jquery.easy-autocomplete.min.js" type="text/javascript" ></script>
        
    </head>
    <body>
        <input id="field1"/>
        
        <script>
        var options = {
                url: "${pageContext.request.contextPath}/field1",
                getValue: "field1",
                list: {
                        match: {
                                enabled: true
                        }
                }
        };
        $("#field1").easyAutocomplete(options);
        </script>
    </body>
</html>

The result would be like this,
autcomplete1

For the complete sourcecode, can be downloaded here.

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Error “Can not write a field name, expecting a value;” while Writing JSON on Spring MVC

The error started since i upgraded my jackson library, somehow it never happen before. This is my full stacktrace

com.fasterxml.jackson.core.JsonGenerationException: Can not write a field name, expecting a value
	com.fasterxml.jackson.core.JsonGenerator._reportError(JsonGenerator.java:1649)
	com.fasterxml.jackson.core.json.UTF8JsonGenerator.writeFieldName(UTF8JsonGenerator.java:186)
	com.edw.test.jackson.TestSerializer.serialize(TestSerializer.java:27)
	com.edw.test.jackson.TestSerializer.serialize(TestSerializer.java:19)
	com.fasterxml.jackson.databind.ser.DefaultSerializerProvider.serializeValue(DefaultSerializerProvider.java:130)
	com.fasterxml.jackson.databind.ObjectWriter$Prefetch.serialize(ObjectWriter.java:1387)
	com.fasterxml.jackson.databind.ObjectWriter.writeValue(ObjectWriter.java:889)
	org.springframework.http.converter.json.AbstractJackson2HttpMessageConverter.writeInternal(AbstractJackson2HttpMessageConverter.java:292)
	org.springframework.http.converter.AbstractGenericHttpMessageConverter.write(AbstractGenericHttpMessageConverter.java:106)
	org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodProcessor.writeWithMessageConverters(AbstractMessageConverterMethodProcessor.java:231)
	org.springframework.web.servlet.mvc.method.annotation.RequestResponseBodyMethodProcessor.handleReturnValue(RequestResponseBodyMethodProcessor.java:174)
	org.springframework.web.method.support.HandlerMethodReturnValueHandlerComposite.handleReturnValue(HandlerMethodReturnValueHandlerComposite.java:81)
	org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:113)
	org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:827)
	org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:738)
	org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)
	org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:967)
	org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:901)
	org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)
	org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:861)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:622)
	org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
	org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
	org.netbeans.modules.web.monitor.server.MonitorFilter.doFilter(MonitorFilter.java:393)

Looks like this error happen on my custom json serializer,

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:p="http://www.springframework.org/schema/p"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:mvc="http://www.springframework.org/schema/mvc"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
        http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd">
    
    <mvc:annotation-driven>
        <mvc:message-converters register-defaults="false">
            <bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter" p:objectMapper-ref="testObjectMapper"/>
        </mvc:message-converters>
    </mvc:annotation-driven>
    
    <context:component-scan base-package="com.edw.test.jackson"/>
</beans>

And this is the content of my objectMapper java class,

package com.edw.test.jackson;

import com.edw.test.jackson.bean.Test;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.SerializationFeature;
import com.fasterxml.jackson.databind.module.SimpleModule;
import org.springframework.stereotype.Component;

@Component
public class TestObjectMapper extends ObjectMapper {
    public TestObjectMapper() {
        super();
        
        SimpleModule module = new SimpleModule();
        module.addSerializer(Test.class, new TestSerializer());
        registerModule(module);
        configure(SerializationFeature.INDENT_OUTPUT, false);
    }
}

And as you can see, the main culprit is on class TestSerializer

package com.edw.test.jackson;

import com.edw.test.jackson.bean.Test;
import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.JsonSerializer;
import com.fasterxml.jackson.databind.SerializerProvider;
import java.io.IOException;

public class TestSerializer extends JsonSerializer<Test> {

    @Override
    public void serialize(Test t, JsonGenerator jgen, SerializerProvider sp) throws IOException, JsonProcessingException {
        jgen.writeStartObject();
        jgen.writeRaw("{");
        jgen.writeFieldName("test01");
        jgen.writeRaw(t.getTest01());
        jgen.writeFieldName("test02");
        jgen.writeRaw(t.getTest02());
        jgen.writeRaw("}");
        jgen.writeEndObject();
    }
}

replacing writeFieldName method with writeRaw method solve my problem.

package com.edw.test.jackson;

import com.edw.test.jackson.bean.Test;
import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.JsonSerializer;
import com.fasterxml.jackson.databind.SerializerProvider;
import java.io.IOException;

public class TestSerializer extends JsonSerializer<Test> {
    @Override
    public void serialize(Test t, JsonGenerator jgen, SerializerProvider sp) throws IOException, JsonProcessingException {
        jgen.writeStartObject();
        jgen.writeRaw("test01");
        jgen.writeRaw(t.getTest01());
        jgen.writeRaw("test02");
        jgen.writeRaw(t.getTest02());
        jgen.writeEndObject();
    }
}

Hope it helps :)

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[Netbeans] Error NoClassDefFoundError when Building Java Project using Maven

I got this error when trying to build my maven project on Netbeans,

java.lang.NoClassDefFoundError: org/apache/commons/lang/StringUtils

Here is my complete stacktrace,

Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/commons/lang/StringUtils
	at org.apache.maven.wagon.providers.file.FileWagon.resolveDestinationPath(FileWagon.java:206)
	at org.apache.maven.wagon.providers.file.FileWagon.resourceExists(FileWagon.java:265)
	at org.sonatype.aether.connector.wagon.WagonRepositoryConnector$GetTask.run(WagonRepositoryConnector.java:577)
	at org.sonatype.aether.util.concurrency.RunnableErrorForwarder$1.run(RunnableErrorForwarder.java:60)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
	at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.ClassNotFoundException: org.apache.commons.lang.StringUtils
	at org.codehaus.plexus.classworlds.strategy.SelfFirstStrategy.loadClass(SelfFirstStrategy.java:50)
	at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClass(ClassRealm.java:244)
	at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClass(ClassRealm.java:230)
	... 7 more

Looks like it happen because my maven doesnt have a StringUtils class, from apache-commons-lang library. Adding commons-lang-2.6.jar to my Netbeans maven folder (E:\Program\NetBeans 8.2\java\maven\lib\ext) solves this issue.

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