Java tutorial
/* * To change this license header, choose License Headers in Project Properties. * To change this template file, choose Tools | Templates * and open the template in the editor. */ package com.oracle.products; import java.io.PrintWriter; import java.io.StringReader; import static java.lang.Integer.parseInt; import static java.lang.Integer.parseInt; import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import java.util.ArrayList; import java.util.LinkedHashMap; import java.util.Map; import javax.json.Json; import javax.json.stream.JsonParser; import javax.ws.rs.Consumes; import javax.ws.rs.DELETE; import javax.ws.rs.DefaultValue; import javax.ws.rs.GET; import javax.ws.rs.POST; import javax.ws.rs.PUT; import javax.ws.rs.Path; import javax.ws.rs.PathParam; import javax.ws.rs.Produces; import javax.ws.rs.QueryParam; import javax.ws.rs.core.Context; import javax.ws.rs.core.MediaType; import javax.ws.rs.core.UriInfo; import jdk.nashorn.internal.parser.JSONParser; import org.json.simple.JSONArray; import org.json.simple.JSONObject; /** * REST Web Service * * @author Ganesh */ @Path("products") public class ProductResource { MyConnection con = new MyConnection(); Connection conn = null; @Context private UriInfo context; /** * Creates a new instance of ProductResource */ public ProductResource() { conn = con.getConnection(); } /** * Retrieves representation of an instance of com.oracle.products.ProductResource * @return an instance of java.lang.String */ @GET @Produces(MediaType.APPLICATION_JSON) public String getAllProducts() throws SQLException { if (conn == null) { return "not connected"; } else { String query = "Select * from product"; PreparedStatement pstmt = conn.prepareStatement(query); ResultSet rs = pstmt.executeQuery(); String result = ""; JSONArray productArr = new JSONArray(); while (rs.next()) { Map productMap = new LinkedHashMap(); productMap.put("productID", rs.getInt("product_id")); productMap.put("name", rs.getString("name")); productMap.put("description", rs.getString("description")); productMap.put("quantity", rs.getInt("quantity")); productArr.add(productMap); } result = productArr.toString(); return result.replace("},", "},\n"); } } @GET @Path("{id}") @Produces(MediaType.APPLICATION_JSON) public String getproduct(@PathParam("id") int id) throws SQLException { if (conn == null) { return "not connected"; } else { String query = "Select * from product where product_id = ?"; PreparedStatement pstmt = conn.prepareStatement(query); pstmt.setInt(1, id); ResultSet rs = pstmt.executeQuery(); String result = ""; JSONArray productArr = new JSONArray(); while (rs.next()) { Map productMap = new LinkedHashMap(); productMap.put("productID", rs.getInt("product_id")); productMap.put("name", rs.getString("name")); productMap.put("description", rs.getString("description")); productMap.put("quantity", rs.getInt("quantity")); productArr.add(productMap); } result = productArr.toString(); return result; } } @POST @Consumes(MediaType.APPLICATION_JSON) @Produces(MediaType.TEXT_PLAIN) public String postProduct(String str) throws SQLException { JsonParser parser = Json.createParser(new StringReader(str)); Map<String, String> productMap = new LinkedHashMap<String, String>(); String key = ""; String val = ""; while (parser.hasNext()) { JsonParser.Event event = parser.next(); switch (event) { case KEY_NAME: key = parser.getString(); break; case VALUE_STRING: val = parser.getString(); productMap.put(key, val); break; case VALUE_NUMBER: val = parser.getString(); productMap.put(key, val); break; default: break; } } if (conn == null) { return "Not connected"; } else { String query = "INSERT INTO product (product_id,name,description,quantity) VALUES (?,?,?,?)"; PreparedStatement pstmt = conn.prepareStatement(query); pstmt.setInt(1, Integer.parseInt(productMap.get("product_id"))); pstmt.setString(2, productMap.get("name")); pstmt.setString(3, productMap.get("description")); pstmt.setInt(4, Integer.parseInt(productMap.get("quantity"))); pstmt.executeUpdate(); return "row has been inserted into the database"; } } @PUT @Path("{id}") @Consumes(MediaType.APPLICATION_JSON) public String putProduct(@PathParam("id") int id, String str) throws SQLException { JsonParser parser = Json.createParser(new StringReader(str)); Map<String, String> productMap = new LinkedHashMap<>(); String key = ""; String val = ""; while (parser.hasNext()) { JsonParser.Event event = parser.next(); switch (event) { case KEY_NAME: key = parser.getString(); break; case VALUE_STRING: val = parser.getString(); productMap.put(key, val); break; case VALUE_NUMBER: val = parser.getString(); productMap.put(key, val); break; default: break; } } if (conn == null) { return "Not connected"; } else { String query = "UPDATE product SET name = ?, description = ?, quantity = ? WHERE product_id =?"; PreparedStatement pstmt = conn.prepareStatement(query); pstmt.setString(1, productMap.get("name")); pstmt.setString(2, productMap.get("description")); pstmt.setInt(3, Integer.parseInt(productMap.get("quantity"))); pstmt.setInt(4, id); pstmt.executeUpdate(); return "row has been updated into the database"; } } @DELETE @Path("{id}") @Consumes(MediaType.APPLICATION_JSON) @Produces(MediaType.TEXT_PLAIN) public String deleteProduct(@PathParam("id") int id) throws SQLException { if (conn == null) { return "not connected"; } else { String query = "DELETE FROM product WHERE product_id = ?"; PreparedStatement pstmt = conn.prepareStatement(query); pstmt.setInt(1, id); pstmt.executeUpdate(); return "The specified row is deleted"; } } }