<ROOT>

<EMPLOYEE>

<id></id>

<nm></nm>

….

</EMPLOYEE>

<EMPLOYEE>

<id></id>

<nm></nm>

….

</EMPLOYEE>

</ROOT>

package spring;

import java.util.ArrayList;
import java.util.List;

import javax.xml.bind.annotation.XmlAccessType;
import javax.xml.bind.annotation.XmlAccessorType;
import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlRootElement;

@XmlRootElement(name="ROOT")
@XmlAccessorType(XmlAccessType.FIELD)
public class Root {
   
    @XmlElement(name="EMPLOYEE")
    private List<Employee> employees;

    public Root() {
        employees = new ArrayList<Employee>();
    }

    public List<Employee> getEmployees() {
        return employees;
    }

    public void setEmployees(List<Employee> employees) {
        this.employees = employees;
    }

}

package test;

public class Employee {

private String id;
private String nm;

….

… // set, get

}

public class XEmployee {

    private static List<String> employeeList;
    public static List<String> getEmployeeList() {
        return employeeList;
    }
    static {
        employeeList = new ArrayList<String>();

        employeeList.add("aaa");
         employeeList.add("bbb");
         employeeList.add("ccc");

…

    }
}

<?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:oxm="http://www.springframework.org/schema/oxm"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
           http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
           http://www.springframework.org/schema/oxm
           http://www.springframework.org/schema/oxm/spring-oxm-3.0.xsd">

    <oxm:jaxb2-marshaller id="jaxb2Marshaller">
        <oxm:class-to-be-bound name="spring.Root" />
    </oxm:jaxb2-marshaller>
   
    <!-- oxm:jaxb2-marshaller 에서 사용했던 것과 동일한 효과(예전 방식) 
    <bean id="jaxb2Marshaller" class="org.springframework.oxm.jaxb.Jaxb2Marshaller">
        <property name="classesToBeBound">
            <list>
                <value>spring.Root</value>
            </list>
        </property>
    </bean>
    -->

    <bean id="application" class="spring.CheckEmp">
        <property name="marshaller" ref="jaxb2Marshaller" />
        <property name="unmarshaller" ref="jaxb2Marshaller" />
    </bean>

</beans>

package spring;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.UnsupportedEncodingException;
import java.io.Writer;

import javax.annotation.Resource;
import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBException;
import javax.xml.transform.stream.StreamSource;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.springframework.oxm.Marshaller;
import org.springframework.oxm.Unmarshaller;

public class CheckEmp {
    @Resource(name = "jaxb2Marshaller")
    Unmarshaller unmarshaller;

    @Resource(name = "jaxb2Marshaller")
    Marshaller marshaller;
   
    public void setMarshaller(Marshaller marshaller) {
        this.marshaller = marshaller;
    }

    public void setUnmarshaller(Unmarshaller unmarshaller) {
        this.unmarshaller = unmarshaller;
    }
   
    public static final boolean isSaved = false;
    public static final String URL = "http://aaaaaaaaa";
    public static JAXBContext jaxbContext;
    static {
        try {
            jaxbContext = JAXBContext
                    .newInstance(new Class[] { test.Root.class });
        } catch (JAXBException e) {
            e.printStackTrace();
        }
    }

       public static void main(String[] args) throws Exception {
        ApplicationContext appContext = new ClassPathXmlApplicationContext("applicationContext.xml");
        CheckEmp application = (CheckEmp) appContext.getBean("application");
        application.start();
    }

    private void start() throws Exception {
        BufferedReader reader = connectURL();
        if (isSaved) {
            saveFile(reader);
        }

        Root root = getRoot(reader);

         for (String retiredEmpID : XEmployee.getEmployeeList()) {
            boolean found = false;
            for (Employee emp : root.getEmployees()) {
                if (emp.getID().trim().equalsIgnoreCase(retiredEmpID)) {
                      found = true;
                }
            }
            if (found == false) {
                System.out.println(retiredEmpID);
            }
        }
    }

    private Root getRoot(BufferedReader reader) throws Exception {
        StreamSource source = new StreamSource(reader);
        Root root = (Root) unmarshaller.unmarshal(source);
        return root;
    }

    private BufferedReader connectURL() throws IOException,
            ClientProtocolException, UnsupportedEncodingException {
        HttpGet httpget = new HttpGet(URL);
        HttpClient httpclient = new DefaultHttpClient();
        httpclient.getParams().setParameter("http.socket.timeout", 999000);

        HttpResponse response = httpclient.execute(httpget);
        HttpEntity entity = response.getEntity();
        if (entity == null) {
            throw new RuntimeException("url error");
        }
        InputStream instream = entity.getContent();
        BufferedReader reader = new BufferedReader(new InputStreamReader(
                instream, "utf-8"));
        return reader;
    }

    private static void saveFile(BufferedReader reader) throws IOException {
        Writer fstream = new BufferedWriter(new OutputStreamWriter(
                new FileOutputStream("aaa.txt"), "utf-8"));
        BufferedWriter out = new BufferedWriter(fstream);
        char[] a = new char[1024];
        while (reader.read(a) > 0) {
            out.write(a);
        }
        out.flush();
        System.out.println("File created successfully.");
    }

}

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE log4j:configuration SYSTEM "log4j.dtd">

<log4j:configuration xmlns:log4j='http://jakarta.apache.org/log4j/'>
    <appender name="STDOUT" class="org.apache.log4j.ConsoleAppender">
        <param name="Threshold" value="DEBUG"/>
        <layout class="org.apache.log4j.PatternLayout">
         <param name="ConversionPattern" value="%d{yyyy-MM-dd HH:mm:ss} [%-5p](%F:%L) %m%n"/>
        </layout>
    </appender>
    <appender name="general" class="org.apache.log4j.ConsoleAppender">
       <layout class="org.apache.log4j.PatternLayout">
         <param name="ConversionPattern" value="%d{yyyy-MM-dd HH:mm:ss} [%-5p](%F:%L) %m%n"/>
       </layout>
    </appender>

    <logger name="com" additivity="false">
        <level value="DEBUG"/>
        <appender-ref ref="general"/>
    </logger>

    <logger name="org.springframework" additivity="false">
        <level value="DEBUG"/>
        <appender-ref ref="general"/>
    </logger>

    <root>
        <level value="WARN"/>
        <appender-ref ref="STDOUT"/>
    </root>
</log4j:configuration>

<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>test1123</groupId>
    <artifactId>teswt1</artifactId>
    <version>0.0.1-SNAPSHOT</version>

    <properties>
        <spring-version>3.1.0.RELEASE</spring-version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.apache.httpcomponents</groupId>
            <artifactId>httpclient</artifactId>
            <version>4.1.2</version>
        </dependency>
        <dependency>
            <groupId>javax.xml.bind</groupId>
            <artifactId>jaxb-api</artifactId>
            <version>2.2</version>
        </dependency>
        <dependency>
            <groupId>com.sun.xml.bind</groupId>
            <artifactId>jaxb-xjc</artifactId>
            <version>2.2</version>
        </dependency>
        <dependency>
            <groupId>com.sun.xml.bind</groupId>
            <artifactId>jaxb-impl</artifactId>
            <version>2.2</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-core</artifactId>
            <version>${spring-version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-beans</artifactId>
            <version>${spring-version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-oxm</artifactId>
            <version>${spring-version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-test</artifactId>
            <version>${spring-version}</version>
        </dependency>
        <dependency>
            <groupId>javax.annotation</groupId>
            <artifactId>jsr250-api</artifactId>
            <version>1.0</version>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.10</version>
        </dependency>

        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.16</version>
        </dependency>
    </dependencies>

</project>

<ROOT>

<EMPLOYEE>

<id></id>

<nm></nm>

….

</EMPLOYEE>

<EMPLOYEE>

<id></id>

<nm></nm>

….

</EMPLOYEE>

</ROOT>

package test;

import java.util.ArrayList;
import java.util.List;

import javax.xml.bind.annotation.XmlAccessType;
import javax.xml.bind.annotation.XmlAccessorType;
import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlRootElement;

@XmlRootElement(name = "ROOT")
@XmlAccessorType(XmlAccessType.FIELD)
public class Root {
   
    @XmlElement(name="EMPLOYEE")
    private List<Employee> employees;

    public Root() {
        employees = new ArrayList<Employee>();
    }

    public List<Employee> getEmployees() {
        return employees;
    }

    public void setEmployees(List<Employee> employees) {
        this.employees = employees;
    }

}

package test;

public class Employee {

private String id;
private String nm;

….

… // set, get

}

public class XEmployee {

    private static List<String> employeeList;
   
    public static List<String> getEmployeeList() {
        return employeeList;
    }
   
    static {
        employeeList = new ArrayList<String>();

        employeeList.add("aaa");
         employeeList.add("bbb");
         employeeList.add("ccc");

…

    }
}

package test;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.UnsupportedEncodingException;
import java.io.Writer;

import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBException;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;

public class CheckEmp {
    public static final boolean isSaved = false;
    public static final String URL = "http://xxxxxxxx";
    public static JAXBContext jaxbContext;
    static {
        try {
            jaxbContext = JAXBContext
                    .newInstance(new Class[] { test.Root.class });
        } catch (JAXBException e) {
            e.printStackTrace();
        }
    }

        public static void main(String[] args) throws Exception {

        // connect url
        BufferedReader reader = connectURL();

        // save file
        if (isSaved) {
            saveFile(reader);
        }
       

        // get object
        Root root = getRoot(reader);

        // find
        for (String retiredEmpID : XEmployee.getEmployeeList()) {
            boolean found = false;
            for(Employee emp : root.getEmployees()) {
                if (emp.getID().trim().equalsIgnoreCase(retiredEmpID)) {
                    found = true;
                }
            }
            if (found == false) {
                System.out.println(retiredEmpID);
            }
        }
    }

    private static Root getRoot(BufferedReader reader) throws JAXBException {
        Root root = (Root) jaxbContext.createUnmarshaller().unmarshal(reader);
        return root;
    }

    private static BufferedReader connectURL() throws IOException,
            ClientProtocolException, UnsupportedEncodingException {

        HttpGet httpget = new HttpGet(URL);
        HttpClient httpclient = new DefaultHttpClient();
        httpclient.getParams().setParameter("http.socket.timeout", 999000);
       
        HttpResponse response = httpclient.execute(httpget);
        HttpEntity entity = response.getEntity();
        if (entity == null) {
            throw new RuntimeException("url error");
        }
        InputStream instream = entity.getContent();
        BufferedReader reader = new BufferedReader(new InputStreamReader(instream, "utf-8"));
        return reader;
    }

    private static void saveFile(BufferedReader reader) throws IOException {
        Writer fstream = new BufferedWriter(new OutputStreamWriter(new FileOutputStream("aaa.txt"), "utf-8"));
        BufferedWriter out = new BufferedWriter(fstream);
        char[] a = new char[1024] ;
        while (reader.read(a) > 0) {
            out.write(a);
        }
        out.flush();
        System.out.println("File created successfully.");
    }

}

public class test {
    public static void main(String[] args) throws Exception {
        String[] s = new String[] { "aaa" };
        String clName = s.getClass().getName();
        Class c = Class.forName(clName,false,Thread.currentThread().getContextClassLoader());
        System.out.println(c);
    }
}

class [Ljava.lang.String;

public class test {
    public static void main(String[] args) throws Exception {
        String[] objs = new String[10];
        objs[0] = new String();
        String[] objs2 = (String[]) cloneObject(objs,
                test.class.getClassLoader());
    }

    public static Object cloneObject(Object toClone,
            final ClassLoader classLoader) throws Exception {
        ByteArrayOutputStream bOut = new ByteArrayOutputStream();
        ObjectOutputStream oOut = new ObjectOutputStream(bOut);
        oOut.writeObject(toClone);
        oOut.close();
        ByteArrayInputStream bIn = new ByteArrayInputStream(bOut.toByteArray());
        bOut.close();
        ObjectInputStream oIn = new ObjectInputStream(bIn) {
            protected Class resolveClass(ObjectStreamClass desc)
                    throws IOException, ClassNotFoundException {
                System.out
                        .println("Attempting to load class " + desc.getName());
                return classLoader.loadClass(desc.getName());
            }
        };
        bIn.close();
        Object copy = oIn.readObject();
        oIn.close();
        return copy;
    }

}

// a single header file is required
  #include <ev.h>

  #include <stdio.h> // for puts

  // every watcher type has its own typedef'd struct
  // with the name ev_TYPE
  ev_io stdin_watcher;
  ev_timer timeout_watcher;

  // all watcher callbacks have a similar signature
  // this callback is called when data is readable on stdin
  static void
  stdin_cb (EV_P_ ev_io *w, int revents)
  {
    puts ("stdin ready");
    // for one-shot events, one must manually stop the watcher
    // with its corresponding stop function.
    ev_io_stop (EV_A_ w);

    // this causes all nested ev_run's to stop iterating
    ev_break (EV_A_ EVBREAK_ALL);
  }

  // another callback, this time for a time-out
  static void
  timeout_cb (EV_P_ ev_timer *w, int revents)
  {
    puts ("timeout");
    // this causes the innermost ev_run to stop iterating
    ev_break (EV_A_ EVBREAK_ONE);
  }

  int
  main (void)
  {
    // use the default event loop unless you have special needs
    struct ev_loop *loop = EV_DEFAULT;

    // initialise an io watcher, then start it
    // this one will watch for stdin to become readable
    ev_io_init (&stdin_watcher, stdin_cb, /*STDIN_FILENO*/ 0, EV_READ);
    ev_io_start (loop, &stdin_watcher);

    // initialise a timer watcher, then start it
    // simple non-repeating 5.5 second timeout
    ev_timer_init (&timeout_watcher, timeout_cb, 5.5, 0.);
    ev_timer_start (loop, &timeout_watcher);

    // now wait for events to arrive
    ev_run (loop, 0);

    // break was called, so exit
    return 0;
  }

Libev is an event loop: you register interest in certain events (such as a file descriptor being readable or a timeout occurring), and it will manage these event sources and provide your program with events.

To do this, it must take more or less complete control over your process (or thread) by executing the event loop handler, and will then communicate events via a callback mechanism.

You register interest in certain events by registering so-called event watchers, which are relatively small C structures you initialise with the details of the event, and then hand it over to libev by starting the watcher.

Libev supports select, poll, the Linux-specific epoll, the BSD-specific kqueue and the Solaris-specific event port mechanisms for file descriptor events (ev_io), the Linux inotify interface (for ev_stat), Linux eventfd/signalfd (for faster and cleaner inter-thread wakeup (ev_async)/signal handling (ev_signal)) relative timers (ev_timer), absolute timers with customised rescheduling (ev_periodic), synchronous signals (ev_signal), process status change events (ev_child), and event watchers dealing with the event loop mechanism itself (ev_idle, ev_embed, ev_prepare and ev_check watchers) as well as file watchers (ev_stat) and even limited support for fork events (ev_fork).

It also is quite fast (see this benchmark comparing it to libevent for example).

static struct ev_loop *loop;
static ev_idle repeat_watcher;
static ev_async ready_watcher;

/* idle watcher callback, only used when eio_poll */
/* didn't handle all results in one call */
static void
repeat (EV_P_ ev_idle *w, int revents)
{
  if (eio_poll () != -1)
    ev_idle_stop (EV_A_ w);
}

/* eio has some results, process them */
static void
ready (EV_P_ ev_async *w, int revents)
{
  if (eio_poll () == -1)
    ev_idle_start (EV_A_ &repeat_watcher);
}

/* wake up the event loop */
static void
want_poll (void)
{
  ev_async_send (loop, &ready_watcher)
}

void
my_init_eio ()
{
  loop = EV_DEFAULT;

  ev_idle_init (&repeat_watcher, repeat);
  ev_async_init (&ready_watcher, ready);
  ev_async_start (loop &watcher);

  eio_init (want_poll, 0);
}

This library provides fully asynchronous versions of most POSIX functions dealing with I/O. Unlike most asynchronous libraries, this not only includes read and write, but also open, stat, unlink and similar functions, as well as less rarely ones such as mknod, futime or readlink.

It also offers wrappers around sendfile (Solaris, Linux, HP-UX and FreeBSD, with emulation on other platforms) and readahead (Linux, with emulation elsewhere>).

The goal is to enable you to write fully non-blocking programs. For example, in a game server, you would not want to freeze for a few seconds just because the server is running a backup and you happen to call readdir.