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Monthly Archives: November 2012

REST clients for Java, MySQL and JSON Restful Web Services

This is the second part of the tutorial which demonstrates Restful web service using Java, MySQL and JSON. In this tutorial we are going to create several REST clients for our web service. You can download each REST client project. Each REST client is going to parse the JSON response and display output.

Java REST client
Download
We use Java SE application as our client. To parse JSON, gson library is added to project /lib folder Also it is included in project build path as an external JAR.

Course.java – data bound model class

public class Course
{
private int id;
private String name;
private String duration;
private double fee;

public Course()
{

}

public Course(int id, String name, String duration, double fee)
{
super();
this.id = id;
this.name = name;
this.duration = duration;
this.fee = fee;
}

public int getId()
{
return id;
}

public void setId(int id)
{
this.id = id;
}

public String getName()
{
return name;
}

public void setName(String name)
{
this.name = name;
}

public String getDuration()
{
return duration;
}

public void setDuration(String duration)
{
this.duration = duration;
}

public double getFee()
{
return fee;
}

public void setFee(double fee)
{
this.fee = fee;
}

@Override
public String toString()
{
return "Course [id=" + id + ", name=" + name + ", duration=" + duration
+ ", fee=" + fee + "]";
}

}

Main.java

package com;

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;

import com.google.gson.Gson;
import com.google.gson.JsonArray;
import com.google.gson.JsonElement;
import com.google.gson.JsonParser;

public class Main
{

/**
* @param args
* @throws Exception
*/
public static void main(String[] args) throws Exception
{
String json = readUrl("http://localhost:8080/RestProject/Rest/courseService/courses");
Gson gson = new Gson();
JsonParser jsonParser = new JsonParser();
JsonArray courseArray = jsonParser.parse(json).getAsJsonArray();
List<Course> coursesList = new ArrayList<Course>();
for (JsonElement course : courseArray)
{
Course courseObj = gson.fromJson(course, Course.class);
coursesList.add(courseObj);
}

for (Course courseObj : coursesList)
{
System.out.println("ID : " + courseObj.getId());
System.out.println("Course Name : " + courseObj.getName());
System.out.println("Duration : " + courseObj.getDuration());
System.out.println("Course fee : " + courseObj.getFee());
}

}

private static String readUrl(String urlString) throws Exception
{
BufferedReader reader = null;
try
{
URL url = new URL(urlString);
reader = new BufferedReader(new InputStreamReader(url.openStream()));
StringBuffer buffer = new StringBuffer();
int read;
char[] chars = new char[1024];
while ((read = reader.read(chars)) != -1)
buffer.append(chars, 0, read);

return buffer.toString();
} finally
{
if (reader != null)
reader.close();
}

}
}

PHP REST client
CURL or file_get_contents() can be used to get JSON  from the web service URL.

$json = file_get_contents("http://localhost:8080/RestProject/Rest/courseService/courses");
$json_o = json_decode($json);

$msg .= "";
foreach($json_o as $item)
{
$msg .= "Course ID : ". $item->id. "<br>";
$msg .= "Course Name : ". $item->name. "<br>";
$msg .= "Duration  : ". $item->duration. "<br>";
$msg .= "Course fee : ". $item->fee. "<br><br>";
}
echo $msg;

$ch = curl_init();
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_URL, "http://localhost:8080/RestProject/Rest/courseService/courses");
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 2);
$json = curl_exec($ch);
$json_o = json_decode($json);

$msg .= "";
foreach($json_o as $item)
{
$msg .= "Course ID : ". $item->id. "<br>";
$msg .= "Course Name : ". $item->name. "<br>";
$msg .= "Duration  : ". $item->duration. "<br>";
$msg .= "Course fee : ". $item->fee. "<br><br>";
}
echo $msg;

Android REST client

Download


 
3 Comments

Posted by on November 28, 2012 in C#.Net, Java, PHP

 

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Search People Using Pipl API

If you are a Facebook user or Twitter user like me, you already know how to find a particular person. Facebook Friends Finder is a great tool. It is so intelligent that it can find mutual relationships and many more. Several weeks ago, I wanted some methodology to develop a web solution to allow someone to find his interested people. It should not be limited to Facebook. The user may wish to see search results from different social networks. Obviously, it ‘s very difficult to integrate several social networks and develop a combined solution. The easiest way is to find a good API that provides reliable information. There comes Pipl. It ‘s highly sophisticated.

So you know what I gonna explore today. The Pipl Search API. This is a Restful API that can generate response in xml as well as json format for a given user information. There are huge amount of query parameters. You can use any of them as you wish. In this tutorial, I show you how to find a person when we know his first name and last name. Very simple. Just a matter of decoding json/xml response.

HTML Form

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>Untitled Document</title>
</head>

<body>
<form method="get">
First <input name="first" type="text" value="asantha">
Last <input name="last" type="text" value="prasad">
<input name="btn" type="submit">
</form>
</body>
</html>

PHP Script


 if(isset($_GET['first']) && isset($_GET['last']))
 {
 $first = $_GET['first'];
$last = $_GET['last'];</pre>
$json = file_get_contents("http://apis.pipl.com/search/v2/json/?first_name=$first&last_name=$last&key=h6cbvuu8mkj97vbrztanvptp");

$json_o = json_decode($json);

$count = 0;
 foreach($json_o->results->records as $rec)
 {
 echo ++$count." ".$rec->names[0]->display ."<br>";
 echo "Domain : " .$rec->source->domain."<br>";

$url =  $rec->source->url;
 echo "<a href='$url'>URL</a><br>";

$img =  $rec->images[0]->url;
 echo "<img src='$img' width='125px' height='125px'>";
 echo "<hr><br>";
 }

echo "<hr><h3>suggestions</h3>";
 $suggest =  $json_o->suggested_searches[0]->source->url."h6cbvuu8mkj97vbrztanvptp";
 echo "<a href='$suggest'>visit</a>";
 }

 
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Posted by on November 10, 2012 in PHP

 

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Restful Web Services Java, MySQL and JSON

Today we are going to build another restful web service in eclipse using gson library. When client makes a request, the application queries the database and produces response in JSON format. This JSON can be parsed with most of the programming languages.
We will see how various clients can consume this web service in the second part of the tutorial.

Download Source Code

Download Source Code
Project Architecture

Create a new dynamic web project in Eclipse and add jersy, gson library to WEB-INF/lib.

course.java
We utilize this class when we wanna bind data after querying database.

package dto;

public class Course
{
private int id;
private String name;
private String duration;
private double fee;

public Course()
{

}

public Course(int id, String name, String duration, double fee)
{
super();
this.id = id;
this.name = name;
this.duration = duration;
this.fee = fee;
}

public int getId()
{
return id;
}

public void setId(int id)
{
this.id = id;
}

public String getName()
{
return name;
}

public void setName(String name)
{
this.name = name;
}

public String getDuration()
{
return duration;
}

public void setDuration(String duration)
{
this.duration = duration;
}

public double getFee()
{
return fee;
}

public void setFee(double fee)
{
this.fee = fee;
}

@Override
public String toString()
{
return "Course [id=" + id + ", name=" + name + ", duration=" + duration
+ ", fee=" + fee + "]";
}

}

 

Database.java

package dao;

import java.sql.Connection;
import java.sql.DriverManager;

public class Database
{
public Connection getConnection() throws Exception
{
try
{
String connectionURL = "jdbc:mysql://localhost:3306/codezone4";
Connection connection = null;
Class.forName("com.mysql.jdbc.Driver").newInstance();
connection = DriverManager.getConnection(connectionURL, "root", "");
return connection;
} catch (Exception e)
{
throw e;
}

}

}

Access.java

package dao;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;

import dto.Course;

public class Access
{
public ArrayList<Course> getCourses(Connection con) throws SQLException
{
ArrayList<Course> courseList = new ArrayList<Course>();
PreparedStatement stmt = con.prepareStatement("SELECT * FROM courses");
ResultSet rs = stmt.executeQuery();
try
{
while(rs.next())
{
Course courseObj = new Course();
courseObj.setId(rs.getInt("id"));
courseObj.setName(rs.getString("name"));
courseObj.setDuration(rs.getString("duration"));
courseObj.setFee(rs.getDouble("fee"));
courseList.add(courseObj);
}
} catch (SQLException e)
{
e.printStackTrace();
}
return courseList;

}
}

AccessManager.java

package model;

import java.sql.Connection;
import java.sql.SQLException;
import java.util.ArrayList;

import dao.Access;
import dao.Database;
import dto.Course;

public class AccessManager
{
public ArrayList<Course> getCourses() throws Exception
{
ArrayList<Course> courseList = new ArrayList<Course>();
Database db = new Database();
Connection con = db.getConnection();
Access access = new Access();
courseList = access.getCourses(con);
return courseList;
}
}

CourseService.java

package webService;

import java.util.ArrayList;

import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;

import com.google.gson.Gson;

import model.AccessManager;

import dto.Course;

@Path("/courseService")
public class CourseService
{
@GET
@Path("/courses")
@Produces("application/json")
public String courses()
{
String courses = null;
ArrayList<Course> courseList = new ArrayList<Course>();
try
{
courseList = new AccessManager().getCourses();
Gson gson = new Gson();
courses = gson.toJson(courseList);
} catch (Exception e)
{
e.printStackTrace();
}
return courses;
}
}

web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID" version="2.5">
<display-name>RestProject</display-name>
<welcome-file-list>
<welcome-file>index.html</welcome-file>
<welcome-file>index.htm</welcome-file>
<welcome-file>index.jsp</welcome-file>
<welcome-file>default.html</welcome-file>
<welcome-file>default.htm</welcome-file>
<welcome-file>default.jsp</welcome-file>
</welcome-file-list>
<servlet>
<servlet-name>Course Service</servlet-name>
<servlet-class>com.sun.jersey.server.impl.container.servlet.ServletAdaptor</servlet-class>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>Course Service</servlet-name>
<url-pattern>/Rest/*</url-pattern>
</servlet-mapping>
</web-app>

Run the application in server.
visit following URL :
http://localhost:8440/RestProject/Rest/courseService/courses
The port number in the URL depends on your server settings.
You will see the JSON response.

 

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56 Comments

Posted by on November 8, 2012 in J2EE, Java

 

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