Implemented rest api utils

LoadBalancerWeb/src/main/java/ru/dragonestia/loadbalancer/web/config/RestApiConfig.java

@@ -0,0 +1,23 @@
+package ru.dragonestia.loadbalancer.web.config;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.web.client.RestTemplateBuilder;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.web.client.RestTemplate;
+
+import java.util.function.Supplier;
+
+@Configuration
+public class RestApiConfig {
+
+    @Bean
+    RestTemplateBuilder restTemplateBuilder() {
+        return new RestTemplateBuilder();
+    }
+
+    @Bean
+    Supplier<RestTemplate> restTemplate(@Autowired RestTemplateBuilder builder) {
+        return builder::build;
+    }
+}

LoadBalancerWeb/src/main/java/ru/dragonestia/loadbalancer/web/repository/impl/RestUtil.java

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+package ru.dragonestia.loadbalancer.web.repository.impl;
+
+import lombok.RequiredArgsConstructor;
+import org.springframework.stereotype.Component;
+import org.springframework.web.client.RestTemplate;
+
+import java.net.URI;
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Objects;
+import java.util.function.Consumer;
+import java.util.function.Supplier;
+
+@Component
+@RequiredArgsConstructor
+public class RestUtil {
+
+    private final URI serverUrl;
+    private final Supplier<RestTemplate> restTemplate;
+
+    public <T> T get(URI uri, Class<T> responseType) {
+        var template = restTemplate.get();
+        return Objects.requireNonNull(template.getForObject(serverUrl.resolve(uri), responseType));
+    }
+
+    public <T> T get(URI uri, Class<T> responseType, Consumer<Map<String, String>> paramsConsumer) {
+        var params = new HashMap<String, String>();
+        paramsConsumer.accept(params);
+
+        var template = restTemplate.get();
+        return Objects.requireNonNull(template.getForObject(buildPath(uri, params.keySet()),
+                responseType,
+                params));
+    }
+
+    public <T> T post(URI uri, Class<T> responseType, Consumer<Map<String, String>> paramsConsumer) {
+        var params = new HashMap<String, String>();
+        paramsConsumer.accept(params);
+
+        var template = restTemplate.get();
+        return Objects.requireNonNull(template.postForObject(buildPath(uri, params.keySet()),
+                null,
+                responseType,
+                params));
+    }
+
+    public void put(URI uri, Consumer<Map<String, String>> paramsConsumer) {
+        var params = new HashMap<String, String>();
+        paramsConsumer.accept(params);
+
+        var template = restTemplate.get();
+        template.put(buildPath(uri, params.keySet()), params);
+    }
+
+    public void delete(URI uri, Consumer<Map<String, String>> paramsConsumer) {
+        var params = new HashMap<String, String>();
+        paramsConsumer.accept(params);
+
+        var template = restTemplate.get();
+        template.delete(buildPath(uri, params.keySet()), params);
+    }
+
+    private String buildPath(URI uri, Collection<String> paramKeys) {
+        var path = new StringBuilder(serverUrl.resolve(uri) + "?");
+        int left = paramKeys.size();
+        for (var key: paramKeys) {
+            path.append(key);
+            path.append("={");
+            path.append(key);
+            path.append("}");
+            if (--left > 0) {
+                path.append("&");
+            }
+        }
+        return path.toString();
+    }
+}