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.
[sourcecode language="java"]
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 + "]";
}
}
[/sourcecode]
Database.java
[sourcecode language="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;
}
}
}
[/sourcecode]
Access.java
[sourcecode language="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;
}
}
[/sourcecode]
AccessManager.java
[sourcecode language="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;
}
}
[/sourcecode]
CourseService.java
[sourcecode language="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;
}
}
[/sourcecode]
web.xml
[sourcecode language="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>
[/sourcecode]
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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