/*@jsxRuntime automatic @jsxImportSource react*/
const {Fragment: _Fragment, jsx: _jsx, jsxs: _jsxs} = arguments[0];
function _createMdxContent(props) {
  const _components = Object.assign({
    p: "p",
    a: "a",
    code: "code",
    pre: "pre",
    span: "span",
    h2: "h2"
  }, props.components), {Link} = _components;
  if (!Link) _missingMdxReference("Link", true);
  return _jsxs(_Fragment, {
    children: [_jsxs(_components.p, {
      children: ["Now that ", _jsx(Link, {
        href: "/blog/eclipse-vert-x-3-6-0-released/",
        passHref: true,
        children: _jsx(_components.a, {
          href: "",
          children: "Vert.x 3.6.0 has been re­leased"
        })
      }), ", it’s the per­fect time to con­clude our ", _jsx(Link, {
        href: "/docs/vertx-cassandra-client/java/",
        passHref: true,
        children: _jsx(_components.a, {
          href: "",
          children: "Vert.x Cas­san­dra Client"
        })
      }), " tu­to­r­ial!"]
    }), "\n", _jsxs(_components.p, {
      children: ["In ", _jsx(Link, {
        href: "/blog/the-rss-reader-tutorial-step-2/",
        passHref: true,
        children: _jsx(_components.a, {
          href: "",
          children: "the pre­vi­ous step"
        })
      }), ", we have suc­cess­fully im­ple­mented the sec­ond end­point\nof the RSS reader app."]
    }), "\n", _jsxs(_components.p, {
      children: ["The RSS reader ex­am­ple as­sumes im­ple­ment­ing three end­points. This ar­ti­cle is ded­i­cated to im­ple­ment­ing the last ", _jsx(_components.code, {
        children: "GET /articles/by_rss_link?link={rss_link}"
      }), " end­point."]
    }), "\n", _jsxs(_components.p, {
      children: ["Be­fore com­plet­ing this step, make sure your are in the ", _jsx(_components.code, {
        children: "step_3"
      }), " git branch:"]
    }), "\n", _jsx(_components.pre, {
      children: _jsxs(_components.code, {
        className: "hljs language-better-shell",
        children: [_jsx(_components.span, {
          className: "hljs-meta",
          children: "$"
        }), _jsx(_components.span, {
          className: "bash",
          children: " git checkout step_3"
        }), "\n"]
      })
    }), "\n", _jsxs(_components.h2, {
      id: "implementing-the-3rd-endpoint",
      children: [_jsx(_components.a, {
        "aria-hidden": true,
        tabIndex: "-1",
        className: "heading-anchor",
        href: "#implementing-the-3rd-endpoint"
      }), "Implementing the 3rd endpoint"]
    }), "\n", _jsx(_components.p, {
      children: "The 3rd end­point serves a list of ar­ti­cles re­lated to a spe­cific RSS chan­nel. In a re­quest, we spec­ify RSS chan­nel by pro­vid­ing a link. On the ap­pli­ca­tion side, after re­ceiv­ing a re­quest we ex­e­cute the fol­low­ing query:"
    }), "\n", _jsx(_components.pre, {
      children: _jsxs(_components.code, {
        className: "hljs language-sql",
        children: [_jsx(_components.span, {
          className: "hljs-keyword",
          children: "SELECT"
        }), " title, article_link, description, pubDate ", _jsx(_components.span, {
          className: "hljs-keyword",
          children: "FROM"
        }), " articles_by_rss_link ", _jsx(_components.span, {
          className: "hljs-keyword",
          children: "WHERE"
        }), " rss_link ", _jsx(_components.span, {
          className: "hljs-operator",
          children: "="
        }), " RSS_LINK_FROM_REQUEST ;\n"]
      })
    }), "\n", _jsxs(_components.h2, {
      id: "implementation",
      children: [_jsx(_components.a, {
        "aria-hidden": true,
        tabIndex: "-1",
        className: "heading-anchor",
        href: "#implementation"
      }), "Implementation"]
    }), "\n", _jsxs(_components.p, {
      children: ["For ob­tain­ing ar­ti­cles by RSS link we need to pre­pare a re­lated state­ment first. Change ", _jsx(_components.code, {
        children: "AppVerticle#prepareSelectArticlesByRssLink"
      }), " in this way:"]
    }), "\n", _jsx(_components.pre, {
      children: _jsxs(_components.code, {
        className: "hljs language-java",
        children: [_jsx(_components.span, {
          className: "hljs-keyword",
          children: "private"
        }), " Future<Void> ", _jsx(_components.span, {
          className: "hljs-title function_",
          children: "prepareSelectArticlesByRssLink"
        }), _jsx(_components.span, {
          className: "hljs-params",
          children: "()"
        }), " {\n    ", _jsx(_components.span, {
          className: "hljs-keyword",
          children: "return"
        }), " Util.prepareQueryAndSetReference(client,\n            ", _jsx(_components.span, {
          className: "hljs-string",
          children: "\"SELECT title, article_link, description, pubDate FROM articles_by_rss_link WHERE rss_link = ? ;\""
        }), ",\n            selectArticlesByRssLink\n    );\n}\n"]
      })
    }), "\n", _jsxs(_components.p, {
      children: ["And now, we can im­ple­ment the ", _jsx(_components.code, {
        children: "AppVerticle#getArticles"
      }), " method. Ba­si­cally, it will use the ", _jsx(_components.code, {
        children: "selectArticlesByRssLink"
      }), " state­ment for find­ing ar­ti­cles by the given link. Here’s the im­ple­men­ta­tion:"]
    }), "\n", _jsx(_components.pre, {
      children: _jsxs(_components.code, {
        className: "hljs language-java",
        children: [_jsx(_components.span, {
          className: "hljs-keyword",
          children: "private"
        }), " ", _jsx(_components.span, {
          className: "hljs-keyword",
          children: "void"
        }), " ", _jsx(_components.span, {
          className: "hljs-title function_",
          children: "getArticles"
        }), _jsx(_components.span, {
          className: "hljs-params",
          children: "(RoutingContext ctx)"
        }), " {\n    ", _jsx(_components.span, {
          className: "hljs-type",
          children: "String"
        }), " ", _jsx(_components.span, {
          className: "hljs-variable",
          children: "link"
        }), " ", _jsx(_components.span, {
          className: "hljs-operator",
          children: "="
        }), " ctx.request().getParam(", _jsx(_components.span, {
          className: "hljs-string",
          children: "\"link\""
        }), ");\n    ", _jsx(_components.span, {
          className: "hljs-keyword",
          children: "if"
        }), " (link == ", _jsx(_components.span, {
          className: "hljs-literal",
          children: "null"
        }), ") {\n        responseWithInvalidRequest(ctx);\n    } ", _jsx(_components.span, {
          className: "hljs-keyword",
          children: "else"
        }), " {\n        client.executeWithFullFetch(selectArticlesByRssLink.bind(link), handler -> {\n            ", _jsx(_components.span, {
          className: "hljs-keyword",
          children: "if"
        }), " (handler.succeeded()) {\n                List<Row> rows = handler.result();\n\n                ", _jsx(_components.span, {
          className: "hljs-type",
          children: "JsonObject"
        }), " ", _jsx(_components.span, {
          className: "hljs-variable",
          children: "responseJson"
        }), " ", _jsx(_components.span, {
          className: "hljs-operator",
          children: "="
        }), " ", _jsx(_components.span, {
          className: "hljs-keyword",
          children: "new"
        }), " ", _jsx(_components.span, {
          className: "hljs-title class_",
          children: "JsonObject"
        }), "();\n                ", _jsx(_components.span, {
          className: "hljs-type",
          children: "JsonArray"
        }), " ", _jsx(_components.span, {
          className: "hljs-variable",
          children: "articles"
        }), " ", _jsx(_components.span, {
          className: "hljs-operator",
          children: "="
        }), " ", _jsx(_components.span, {
          className: "hljs-keyword",
          children: "new"
        }), " ", _jsx(_components.span, {
          className: "hljs-title class_",
          children: "JsonArray"
        }), "();\n\n                rows.forEach(eachRow -> articles.add(\n                        ", _jsx(_components.span, {
          className: "hljs-keyword",
          children: "new"
        }), " ", _jsx(_components.span, {
          className: "hljs-title class_",
          children: "JsonObject"
        }), "()\n                                .put(", _jsx(_components.span, {
          className: "hljs-string",
          children: "\"title\""
        }), ", eachRow.getString(", _jsx(_components.span, {
          className: "hljs-number",
          children: "0"
        }), "))\n                                .put(", _jsx(_components.span, {
          className: "hljs-string",
          children: "\"link\""
        }), ", eachRow.getString(", _jsx(_components.span, {
          className: "hljs-number",
          children: "1"
        }), "))\n                                .put(", _jsx(_components.span, {
          className: "hljs-string",
          children: "\"description\""
        }), ", eachRow.getString(", _jsx(_components.span, {
          className: "hljs-number",
          children: "2"
        }), "))\n                                .put(", _jsx(_components.span, {
          className: "hljs-string",
          children: "\"pub_date\""
        }), ", eachRow.getTimestamp(", _jsx(_components.span, {
          className: "hljs-number",
          children: "3"
        }), ").getTime())\n                ));\n\n                responseJson.put(", _jsx(_components.span, {
          className: "hljs-string",
          children: "\"articles\""
        }), ", articles);\n                ctx.response().end(responseJson.toString());\n            } ", _jsx(_components.span, {
          className: "hljs-keyword",
          children: "else"
        }), " {\n                log.error(", _jsx(_components.span, {
          className: "hljs-string",
          children: "\"failed to get articles for \""
        }), " + link, handler.cause());\n                ctx.response().setStatusCode(", _jsx(_components.span, {
          className: "hljs-number",
          children: "500"
        }), ").end(", _jsx(_components.span, {
          className: "hljs-string",
          children: "\"Unable to retrieve the info from C*\""
        }), ");\n            }\n        });\n    }\n}\n"]
      })
    }), "\n", _jsxs(_components.h2, {
      id: "conclusion",
      children: [_jsx(_components.a, {
        "aria-hidden": true,
        tabIndex: "-1",
        className: "heading-anchor",
        href: "#conclusion"
      }), "Conclusion"]
    }), "\n", _jsxs(_components.p, {
      children: ["Dur­ing the se­ries, we have shown how the RSS reader app can be im­ple­mented with the ", _jsx(_components.a, {
        href: "https://github.com/vert-x3/vertx-cassandra-client",
        children: "Vert.x Cas­san­dra client"
      }), "."]
    }), "\n", _jsxs(_components.p, {
      children: ["Thanks for read­ing this. I hope you en­joyed this se­ries. See you soon on our ", _jsx(_components.a, {
        href: "https://gitter.im/eclipse-vertx/vertx-users",
        children: "Git­ter chan­nel"
      }), "!"]
    })]
  });
}
function MDXContent(props = {}) {
  const {wrapper: MDXLayout} = props.components || ({});
  return MDXLayout ? _jsx(MDXLayout, Object.assign({}, props, {
    children: _jsx(_createMdxContent, props)
  })) : _createMdxContent(props);
}
return {
  default: MDXContent
};
function _missingMdxReference(id, component) {
  throw new Error("Expected " + (component ? "component" : "object") + " `" + id + "` to be defined: you likely forgot to import, pass, or provide it.");
}


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Eclipse Vert.x 3.6.0 released!

Blog

The RSS reader tutorial (Step 3)

Next post

HTTP response validation with the Vert.x Web Client

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Eclipse Vert.x 3.6.0 released!

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