restTemplate template

        // create restTemplate
        SimpleClientHttpRequestFactory factory = new SimpleClientHttpRequestFactory();
        InetSocketAddress address = new InetSocketAddress(proxySettings.getHost(), proxySettings.getPort());
        Proxy proxy = new Proxy(Proxy.Type.HTTP, address);
        factory.setProxy(proxy);
        RestTemplate restTemplate = restTemplateBuilder.requestFactory(factory).build();

        // set headers
        HttpHeaders httpHeaders = new HttpHeaders();
        httpHeaders.add("User-Agent", "hogeclient");
        httpHeaders.add("Content-Type", "application/json; charset=utf-8");

        // set body as JSON
        ObjectMapper mapper = new ObjectMapper();
        ObjectNode objectNode = mapper.createObjectNode();
        objectNode.put("key", body);

        // set uri
        try {
            uri = new URI("http://hoge.io/");
        } catch (URISyntaxException e) {
            e.printStackTrace();
        }

        // create requestEntity
        RequestEntity<?> requestEntity = new RequestEntity<>(httpHeaders, HttpMethod.GET, uri);

        // request
        ResponseEntity<?> responseEntity = restTemplate.exchange(requestEntity, String.class);

参考

• https://github.com/FasterXML/jackson-databind
• http://blog.kymmt.com/entry/jackson