Spring on paper.archive

calling a spring jpa namedQuery directly

Fri, 13 Nov 2015 17:57:00 +0000

As in Test.java, you can execute a NamedQuery defined in orm.xml directly with the EntityManager..

Calling it through a repository seems to only run as getResultList. Called it like below to get the number of updated rows.

Test.java

@PersistenceContext private EntityManager em;

public void test() {
    int cnt = em.createNamedQuery("Order.clearOrder").executeUpdate();
    logger.info("Order.clearOrder updated={}", cnt);
}

About @PersistenceContext private EntityManager em; ..
Both @PersistenceContext and @Autowired seem to work. Not sure about the difference yet.

spring redis integration

Tue, 10 Nov 2015 17:36:00 +0000

Add the following to pom.xml.

<dependency>
    <groupId>org.springframework.data</groupId>
    <artifactId>spring-data-redis</artifactId>
    <version>1.1.0.RELEASE</version>
</dependency>
<dependency>
    <groupId>redis.clients</groupId>
    <artifactId>jedis</artifactId>
    <version>2.1.0</version>
</dependency>

Match the versions carefully. Otherwise some classes are missing and you get errors.

context-redis.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:p="http://www.springframework.org/schema/p"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
    http://www.springframework.org/schema/beans/spring-beans-3.2.xsd">

    <bean id="jedisConnFactory"
          class="org.springframework.data.redis.connection.jedis.JedisConnectionFactory"
          p:usePool="true"
          p:hostName="172.xxx.xxx.xxx"
          p:port="6379"
    />

    <!-- redis template definition -->
    <bean id="redisTemplate"
          class="org.springframework.data.redis.core.RedisTemplate"
          p:connectionFactory-ref="jedisConnFactory"
    />
</beans>

6379 is the redis default port. Can be changed at install time.

building a website with spring + sitemesh

Wed, 28 Oct 2015 17:08:00 +0000

Let’s set up sitemesh.

pom.xml

<dependency>
    <groupId>opensymphony</groupId>
    <artifactId>sitemesh</artifactId>
    <version>2.4.2</version>
</dependency>

Add the following to WEB-INF/web.xml.

<filter>
    <filter-name>sitemesh</filter-name>
    <filter-class>com.opensymphony.module.sitemesh.filter.PageFilter</filter-class>
</filter>
<filter-mapping>
    <filter-name>sitemesh</filter-name>
    <url-pattern>/*</url-pattern>
</filter-mapping>

WEB-INF/sitemesh.xml

<?xml version="1.0" encoding="UTF-8"?>
<sitemesh>
    <property name="decorators-file" value="/WEB-INF/decorators.xml" />
    <excludes file="${decorators-file}" />

    <page-parsers>
        <parser content-type="text/html"
                class="com.opensymphony.module.sitemesh.parser.HTMLPageParser" />
        <parser content-type="text/html;charset=UTF-8"
                class="com.opensymphony.module.sitemesh.parser.HTMLPageParser" />
    </page-parsers>

    <decorator-mappers>
        <mapper class="com.opensymphony.module.sitemesh.mapper.PrintableDecoratorMapper">
            <param name="decorator" value="printable" />
            <param name="parameter.name" value="printable" />
            <param name="parameter.value" value="true" />
        </mapper>

        <mapper class="com.opensymphony.module.sitemesh.mapper.PageDecoratorMapper" >
            <param name="property" value="meta.decorator" />
        </mapper>

        <mapper class="com.opensymphony.module.sitemesh.mapper.ConfigDecoratorMapper">
            <param name="config" value="${decorators-file}" />
        </mapper>
    </decorator-mappers>
</sitemesh>

There’s almost nothing to change in sitemesh.xml (just the decorators.xml file path)

spring jpa save

Wed, 21 Oct 2015 16:20:00 +0000

In jpa you save with the repository.save method

Like the Member class, @OneToMany or @ManyToOne fields can be saved together.

Member.java

@Entity 
@Table(name = "tb_member")
public class Member {
    @Id 
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name = "member_seq")
    public Integer memberSeq;

    @Column
    public String nickname;
    
    @Expose
    @OneToMany(
            targetEntity = MemberInter.class
            , cascade = CascadeType.ALL
            , fetch = FetchType.EAGER
            , mappedBy = "memberSeq")
    public List<MemberInter> memberInterList;
}

MemberInter.java

@Entity 
@Table(name="tb_member_inter") 
@IdClass(value = MemberInterPk.class)
public class MemberInter {
    @Id 
    @Column(name = "member_seq")
    public Integer memberSeq;
    
    @Id 
    @Column(name = "inter_seq")
    public Integer interSeq;
    
    @ManyToOne(
            targetEntity = Inter.class
            ,cascade = CascadeType.ALL
            ,fetch = FetchType.LAZY
            ,optional = false
    )
    @JoinColumn(name = "inter_seq", referencedColumnName = "inter_seq"
            , insertable = false, updatable = false)
    public Inter inter;
}

Added insertable, updateable to @JoinColumn and set them to false

practicing spring jpa @NamedQuery, @NamedNativeQuery

Thu, 08 Oct 2015 01:32:00 +0000

In jpa.. you can query data through a repository with findAll or the findOneBy…. series, but you can also write specific queries directly like below.

/classes/META-INF/orm.xml

<?xml version="1.0" encoding="UTF-8"?>
<entity-mappings xmlns="http://java.sun.com/xml/ns/persistence/orm"
                 version="2.0">

    <named-query name="Inter.findByAlal2">
        <query>select i from Inter i where i.internameko = ?1</query>
    </named-query>

    <named-native-query name="Inter.findByAlal" result-class="sample.jpa.Inter">
        <query>select a.inter_seq, a.inter_name_ko, a.inter_name_en from tb_inter a where a.inter_name_ko = ?</query>
    </named-native-query>

</entity-mappings>

Or.. you can declare it on the Entity class like below

spring jpa query practice

Wed, 07 Oct 2015 18:04:00 +0000

Tested entity mapping plus queries..

Given table relationships like this

`1`	`tb_member -< tb_member_inter >- tb_inter`

Query conditions

When fetching a Member.. also fetch the member’s images… and the list of inters
Inter details live in tb_inter (join when fetching..)

Quick notes on the classes below

MemberInter has two PKs, so you need to make a separate class and specify @IdClass as shown
@Expose is a Gson option for choosing which fields to render. Nothing to do with jpa.
MemberInter.class confused me a lot. (@ManyToOne)
- You also need.. @JoinColumn.
- optional=true makes the join an outer join. (false is inner join)

FetchType

spring jpa setup and test (maven config)

Mon, 05 Oct 2015 00:41:00 +0000

I develop with mybatis most of the time..

But JPA is supposedly the trend, so I wired it into a small project.

1. Import the libraries…. maven pom.xml

<dependency>
   <groupId>org.springframework.data</groupId>
   <artifactId>spring-data-jpa</artifactId>
   <version>1.9.0.RELEASE</version>
</dependency>
<dependency>
   <groupId>org.hibernate</groupId>
   <artifactId>hibernate-entitymanager</artifactId>
   <version>4.3.8.Final</version>
</dependency>

2. Create the Entity class.

Note that SerializedName and Expose are not directly related to jpa.. (used when rendering the object as-is with JsonView)

using spring batch

Thu, 27 Aug 2015 22:44:00 +0000

Tried spring-batch recently.. worked out well. Being able to set the transaction commit size and read size separately seems especially nice.
The config below matters more than the queries or other logic, so I’m keeping it here as a record.

To sum up the job:
the reader reads data, the processor handles it, and the writer records the result.

Besides the config above, it also provides things like listeners that catch events at each stage.

hadoop + spring integration test 2 - hadoop 2.6.x with spring 4.0 (MapReduce WordCount example)

Wed, 15 Apr 2015 00:39:00 +0000

Add the following to context-hadoop.xml.

<hdp:configuration id="hdConf">
    fs.default.name=hdfs://localhost:9000
</hdp:configuration>

<hdp:job id="wordCountJob"
        input-path="/input/"
        output-path="/output/"
        configuration-ref="hdConf"
        mapper="delim.app.service.WordCount$TokenizerMapper"
        reducer="delim.app.service.WordCount$IntSumReducer"
        >
</hdp:job>

<hdp:job-runner id="wordCountJobRunner" job-ref="wordCountJob" run-at-startup="false">
</hdp:job-runner>

WordCount.java

import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.hadoop.mapreduce.Reducer;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.IOException;
import java.util.StringTokenizer;

public class WordCount {
    private static final Logger logger = LoggerFactory.getLogger(WordCount.class);

    public static class TokenizerMapper
            extends Mapper<Object, Text, Text, IntWritable> {

        private final static IntWritable one = new IntWritable(1);
        private Text word = new Text();

        @Override
        public void map(Object key, Text value, Context context) throws IOException, InterruptedException {
            logger.info("map key={}, value={}", key, value);

            StringTokenizer itr = new StringTokenizer(value.toString());
            while (itr.hasMoreTokens()) {
                word.set(itr.nextToken());
                context.write(word, one);
            }
        }
    }


    public static class IntSumReducer
            extends Reducer<Text, IntWritable, Text, IntWritable> {
        private IntWritable result = new IntWritable();

        @Override
        public void reduce(Text key, Iterable<IntWritable> values, Context context) throws IOException, InterruptedException {
            logger.info("reduce key={}", key);

            int sum = 0;
            for (IntWritable val : values) {
                sum += val.get();
            }
            result.set(sum);
            context.write(key, result);
        }
    }
}

Test.java

@Autowired
private org.apache.hadoop.conf.Configuration hdConf;

@Autowired
private JobRunner wordCountJobRunner;

@Before
public void beforeCopyFile() throws IOException {
    String file = "/Users/paper/Desktop/4/14/debug.2015-04-09.log";

    Path srcFilePath = new Path(file);
    Path dstFilePath = new Path("/input/debug.2015-04-09.log");

    FileSystem hdfs = FileSystem.get(dstFilePath.toUri(), hdConf);
    hdfs.copyFromLocalFile(false, true, srcFilePath, dstFilePath);

    hdfs.delete(new Path("/output/"), true);
}

@Test
public void testRunJob() throws Exception {
    wordCountJobRunner.call();
}

In Before, copy the local debug.log file into hdfs.
Run the job.
Once it runs, you can see the debug.log file being read line by line. (WordCount$TokenizerMapper)

hadoop + spring integration test - hadoop 2.6.x with spring 4.0

Sun, 12 Apr 2015 19:46:00 +0000

Hadoop install and setup as below (osx Yosemite.) https://hadoop.apache.org/releases.html#Download ( 2.6.x version )

Installed following this blog http://iamhereweare.blogspot.kr/2014/05/hadoop.html

Add the dependency below to pom.xml.

<dependency>
  <groupid>org.springframework.data</groupId>
  <artifactid>spring-data-hadoop</artifactId>
  <version>2.1.1.RELEASE</version>
</dependency>

Add context-hadoop.xml to the spring config

<?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:hdp="http://www.springframework.org/schema/hadoop"
      xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/hadoop http://www.springframework.org/schema/hadoop/spring-hadoop.xsd">

    <hdp:configuration id="hdConf">
        fs.default.name=hdfs://localhost:9000
    </hdp:configuration>
</beans>

Write the test code like below.

writing spring junit testcases

Tue, 24 Mar 2015 22:42:00 +0000

Add the following to pom.xml.

<dependency>
   <groupId>org.springframework</groupId>
   <artifactId>spring-test</artifactId>
   <version>4.0.5.RELEASE</version>
   <scope>test</scope>
</dependency>

Test java code MemberServiceTest.java

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration( {
  "classpath:servlet-context.xml",
  "classpath:config/context-datasource.xml"
}
)
public class MemberServiceTest {

    @Autowired
    MemberService memberService;


    @Test
    public void testSr2002() throws Exception {
        RequestData req = new RequestData(null, new DbMap());
        ResponseData res = new ResponseData(new DbMap());

        memberService.sr2002(req, res);
    }

}

Since the DB uses jndi-lookup, I put test/resources/config/context-datasource.xml in place to override the existing bean id like below.

spring-rabbitmq integration

Tue, 10 Mar 2015 18:55:00 +0000

Install is just rpm

# 서버 시작.
sbin/rabbitmq-server start

# 서버 중지
sbin/rabbitmqctl stop

spring-rabbit pom.xml

<dependency>
  <groupid>org.springframework.amqp</groupId>
  <artifactid>spring-rabbit</artifactId>
  <version>1.4.1.RELEASE</version>
</dependency>

context-rabbitmq.xml

<!-- A reference to the org.springframework.amqp.rabbit.connection.ConnectionFactory -->
<rabbit:connection-factory id="connectionFactory" host="localhost" username="worker" password="workerpassword" />

<!-- Creates a org.springframework.amqp.rabbit.core.RabbitTemplate for access to the broker -->
<rabbit:template id="amqpTemplate" connection-factory="connectionFactory" />

<!-- Creates a org.springframework.amqp.rabbit.core.RabbitAdmin  to manage exchanges, queues and bindings -->
<rabbit:admin connection-factory="connectionFactory" />

<!-- Creates a queue for consumers to retrieve messages -->
<rabbit:queue name="simple_queue" />

<rabbit:listener-container  connection-factory="connectionFactory">
    <rabbit:listener queues="simple_queue" ref="mqService" />
</rabbit:listener-container>

MqService.java

@Service
public class MqService implements MessageListener {
    private static final Logger logger = LoggerFactory.getLogger(MqService.class);
    private static final String TASK_QUEUE_NAME = "simple_queue";

    @Autowired
    private RabbitTemplate rabbitTemplate;

    public void send(String message) throws IOException {
        rabbitTemplate.convertAndSend(TASK_QUEUE_NAME, message);

        logger.info("send message={}", message);
    }

    @Override
    public void onMessage(Message message) {
        String msg = null;
        try {
            msg = new String(message.getBody(), "UTF-8");
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }

        logger.info("recv message=" + msg );
    }
}

spring map to xml viewresolver

Thu, 05 Feb 2015 17:16:00 +0000

A Spring view class I made when I had to return xml instead of the usual json.
Only works when the result is a map.

Set up the config below…

applicationServlet.xml

    <beans:bean id="xmlView2" class="org.springframework.web.servlet.view.XmlViewResolver">
        <beans:property name="order" value="1"/>
        <beans:property name="location" value="classpath:xml-views.xml"/>
    </beans:bean>

Contents of xml-views.xml.

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN"
        "http://www.springframework.org/dtd/spring-beans.dtd">
<beans>
    <bean name="xmlView"  class="com.xxxxx.view.AjaxResponseXMLView">
        <property name="contentType">
            <value>text/xml;charset=utf-8</value>
        </property>
    </bean>
</beans>

AjaxResponseXMLView.java — use the class below

public class AjaxResponseXMLView extends AbstractView {

    @Override
    protected void renderMergedOutputModel(Map map, HttpServletRequest request,
                                           HttpServletResponse response) throws Exception {
        String xmlHeader = "\r\n";

        StringBuffer xmlSb = new StringBuffer();
        xmlSb.append(xmlHeader);
        xmlSb.append("");
        writeFromMap(xmlSb, map);
        xmlSb.append("");

        response.setContentType("application/xml");
        response.setCharacterEncoding("utf-8");
        response.setHeader("Cache-Control", "no-cache");
        response.setContentLength(xmlSb.toString().getBytes("utf-8").length);
        response.getWriter().print(xmlSb.toString());
    }

    private void writeFromMap(StringBuffer sb, Map map) {

        for(Object str : map.keySet()) {
            Object v = map.get(str);
            sb.append("<" + str + ">");
            if(v instanceof Map) {
                writeFromMap(sb, (Map) v);
            }
            else if(v instanceof List) {
                writeFromList(sb, (List) v);
            }
            else {
                writeFromData(sb, v);
            }
            sb.append("</" + str + ">");
        }
    }

    private void writeFromList(StringBuffer sb, List list) {

        for(Object v : list) {
            sb.append("");
            if(v instanceof Map) {
                writeFromMap(sb, (Map)v);
            }
            else if(v instanceof List) {
                writeFromList(sb, (List) v);
            }
            else {
                writeFromData(sb, v);
            }
            sb.append("");
        }
    }

    private void writeFromData(StringBuffer sb, Object data) {
        sb.append(escapeXml(data+""));
    }

    private String escapeXml(String src) {
//        "   "
//        <   <
//        >   >
//        &   &
        src = src.replace("\"", """);
        src = src.replace("<", "<");
        src = src.replace(">", ">");
        src = src.replace("&", "&");

        return src;
    }
}