#环境
sts (这里用的是IDDEA,STS在老师博客里)
Maven:
更新依赖不成功:远程仓库(阿里)和中央仓库切换着下载即可.
在IDEA中 File—Settings----搜索maven

1. 指向maven安装的目录中的maven软件 没有指定是用的内置的Maven
2.指向maven中的settings.xml的配置文件 (配置镜像仓库,下载依赖: 打开就是阿里的,关闭就是中央仓库)
如果依赖还下载不行:复制别人下载好的依赖到本地仓库.
3.本地仓库的位置: 没有指定默认位置,指定了就用指定仓库的位置.
默认位置:

lombak插件:
最好更新成最新版本

安装2个插件:

spring cloud 介绍

spring cloud 是一系列框架的集合。它利用 spring boot 的开发便利性巧妙地简化了分布式系统基础设施的开发，如服务发现注册、配置中心、消息总线、负载均衡、断路器、数据监控等，都可以用 spring boot 的开发风格做到一键启动和部署。spring cloud 并没有重复制造轮子，它只是将目前各家公司开发的比较成熟、经得起实际考验的服务框架组合起来，通过 spring boot 风格进行再封装屏蔽掉了复杂的配置和实现原理，最终给开发者留出了一套简单易懂、易部署和易维护的分布式系统开发工具包。

spring cloud 对于中小型互联网公司来说是一种福音，因为这类公司往往没有实力或者没有足够的资金投入去开发自己的分布式系统基础设施，使用 spring cloud == 一站式解决方案能在从容应对业务发展的同时大大减少开发成本==。同时，随着近几年微服务架构和 docker 容器概念的火爆，也会让 spring cloud 在未来越来越“云”化的软件开发风格中立有一席之地，尤其是在目前五花八门的分布式解决方案中提供了标准化的、一站式的技术方案，意义可能会堪比当年 servlet 规范的诞生，有效推进服务端软件系统技术水平的进步。

spring cloud 技术组成

eureka
微服务治理，服务注册和发现

ribbon
负载均衡、请求重试

hystrix
断路器，服务降级、熔断

feign
ribbon + hystrix 集成，并提供声明式客户端

hystrix dashboard 和 turbine
hystrix 数据监控

zuul
API 网关，提供微服务的统一入口，并提供统一的权限验证

config
配置中心

bus
消息总线, 配置刷新

sleuth+zipkin
链路跟踪

Spring Cloud 对比 Dubbo

Dubbo

Dubbo只是一个远程调用(RPC)框架
默认基于长连接,支持多种序列化格式

Spring Cloud

框架集
提供了一整套微服务解决方案(全家桶)
基于http调用, Rest API

一、service - 服务

商品服务 item service，端口 8001
用户服务 user service，端口 8101
订单服务 order service，端口 8201

这个项目都是demo数据写死的, 没有数据库等.这个项目主要是为了springcloud工具的使用.

二、commons 通用项目

新建 maven 项目

1.File–new --project(新建工程)—Empty Project 即工作空间
或者直接在D盘建一个目录,然后再File–open–打开这个目录

2.新建项目
File–new–Model(模块) —Maven 或则直接在工作空间上右键model
注意指定路径即可.

pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"><modelVersion>4.0.0</modelVersion><groupId>cn.tedu</groupId><artifactId>sp01-commons</artifactId><version>0.0.1-SNAPSHOT</version><name>sp01-commons</name><dependencies><dependency><groupId>com.fasterxml.jackson.module</groupId><artifactId>jackson-module-parameter-names</artifactId><version>2.9.8</version></dependency><dependency><groupId>com.fasterxml.jackson.datatype</groupId><artifactId>jackson-datatype-jdk8</artifactId><version>2.9.8</version></dependency><dependency><groupId>com.fasterxml.jackson.datatype</groupId><artifactId>jackson-datatype-jsr310</artifactId><version>2.9.8</version></dependency><dependency><groupId>com.fasterxml.jackson.datatype</groupId><artifactId>jackson-datatype-guava</artifactId><version>2.9.8</version></dependency><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId><version>1.18.6</version></dependency><dependency><groupId>javax.servlet</groupId><artifactId>javax.servlet-api</artifactId><version>3.1.0</version></dependency><dependency><groupId>org.slf4j</groupId><artifactId>slf4j-api</artifactId><version>1.7.26</version></dependency><dependency><groupId>org.apache.commons</groupId><artifactId>commons-lang3</artifactId><version>3.9</version></dependency></dependencies><build><plugins><plugin><groupId>org.apache.maven.plugins</groupId><artifactId>maven-compiler-plugin</artifactId><version>3.8.0</version><configuration><source>1.8</source><target>1.8</target></configuration></plugin></plugins></build>
</project>

java 源文件

pojo

Item

package cn.tedu.sp01.pojo;import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;@Data
@NoArgsConstructor
@AllArgsConstructor
public class Item {private Integer id;private String name;private Integer number;
}

User

package cn.tedu.sp01.pojo;import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;@Data
@NoArgsConstructor
@AllArgsConstructor
public class User {private Integer id;private String username;private String password;
}

Order

package cn.tedu.sp01.pojo;import java.util.List;import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;@Data
@NoArgsConstructor
@AllArgsConstructor
public class Order {private String id;private User user;private List<Item> items;
}

service

ItemService

package cn.tedu.sp01.service;import java.util.List;import cn.tedu.sp01.pojo.Item;public interface ItemService {//根据商品id,获取商品列表List<Item> getItems(String orderId);//减少商品库存void decreaseNumbers(List<Item> list);
}

UserService

package cn.tedu.sp01.service;import cn.tedu.sp01.pojo.User;public interface UserService {
//根据用户id获取用户信息User getUser(Integer id);//增加用户积分void addScore(Integer id, Integer score);
}

OrderService

package cn.tedu.sp01.service;import cn.tedu.sp01.pojo.Order;public interface OrderService {
//获取订单信息Order getOrder(String orderId);//保存订单void addOrder(Order order);
}

Util

CookieUtil

package cn.tedu.web.util;import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;public class CookieUtil {/*** @param response* @param name* @param value* @param maxAge*/public static void setCookie(HttpServletResponse response,String name, String value, String domain, String path, int maxAge) {Cookie cookie = new Cookie(name, value);if(domain != null) {cookie.setDomain(domain);}cookie.setPath(path);cookie.setMaxAge(maxAge);response.addCookie(cookie);}public static void setCookie(HttpServletResponse response, String name, String value, int maxAge) {setCookie(response, name, value, null, "/", maxAge);}public static void setCookie(HttpServletResponse response, String name, String value) {setCookie(response, name, value, null, "/", 3600);}public static void setCookie(HttpServletResponse response, String name) {setCookie(response, name, "", null, "/", 3600);}/*** @param request* @param name* @return*/public static String getCookie(HttpServletRequest request, String name) {String value = null;Cookie[] cookies = request.getCookies();if (null != cookies) {for (Cookie cookie : cookies) {if (cookie.getName().equals(name)) {value = cookie.getValue();}}}return value;}/*** @param response* @param name* @return*/public static void removeCookie(HttpServletResponse response, String name, String domain, String path) {setCookie(response, name, "", domain, path, 0);}}

JsonUtil

package cn.tedu.web.util;import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Writer;
import java.math.BigDecimal;
import java.math.BigInteger;
import java.net.URL;
import java.nio.charset.StandardCharsets;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.List;import org.apache.commons.lang3.StringUtils;import com.fasterxml.jackson.annotation.JsonInclude;
import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.core.type.TypeReference;
import com.fasterxml.jackson.databind.DeserializationFeature;
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.SerializationFeature;
import com.fasterxml.jackson.databind.node.ObjectNode;
import com.fasterxml.jackson.datatype.guava.GuavaModule;
import com.fasterxml.jackson.datatype.jdk8.Jdk8Module;
import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;
import com.fasterxml.jackson.module.paramnames.ParameterNamesModule;import lombok.extern.slf4j.Slf4j;@Slf4j
public class JsonUtil {private static ObjectMapper mapper;private static JsonInclude.Include DEFAULT_PROPERTY_INCLUSION = JsonInclude.Include.NON_DEFAULT;private static boolean IS_ENABLE_INDENT_OUTPUT = false;private static String CSV_DEFAULT_COLUMN_SEPARATOR = ",";static {try {initMapper();configPropertyInclusion();configIndentOutput();configCommon();} catch (Exception e) {log.error("jackson config error", e);}}private static void initMapper() {mapper = new ObjectMapper();}private static void configCommon() {config(mapper);}private static void configPropertyInclusion() {mapper.setSerializationInclusion(DEFAULT_PROPERTY_INCLUSION);}private static void configIndentOutput() {mapper.configure(SerializationFeature.INDENT_OUTPUT, IS_ENABLE_INDENT_OUTPUT);}private static void config(ObjectMapper objectMapper) {objectMapper.enable(JsonGenerator.Feature.WRITE_BIGDECIMAL_AS_PLAIN);objectMapper.enable(DeserializationFeature.ACCEPT_EMPTY_STRING_AS_NULL_OBJECT);objectMapper.enable(DeserializationFeature.ACCEPT_SINGLE_VALUE_AS_ARRAY);objectMapper.enable(DeserializationFeature.FAIL_ON_READING_DUP_TREE_KEY);objectMapper.enable(DeserializationFeature.FAIL_ON_NUMBERS_FOR_ENUMS);objectMapper.disable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES);objectMapper.disable(DeserializationFeature.FAIL_ON_NULL_FOR_PRIMITIVES);objectMapper.disable(SerializationFeature.FAIL_ON_EMPTY_BEANS);objectMapper.enable(JsonParser.Feature.ALLOW_COMMENTS);objectMapper.disable(JsonGenerator.Feature.ESCAPE_NON_ASCII);objectMapper.enable(JsonGenerator.Feature.IGNORE_UNKNOWN);objectMapper.enable(JsonParser.Feature.ALLOW_UNQUOTED_FIELD_NAMES);objectMapper.disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS);objectMapper.setDateFormat(new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"));objectMapper.enable(JsonParser.Feature.ALLOW_SINGLE_QUOTES);objectMapper.registerModule(new ParameterNamesModule());objectMapper.registerModule(new Jdk8Module());objectMapper.registerModule(new JavaTimeModule());objectMapper.registerModule(new GuavaModule());}public static void setSerializationInclusion(JsonInclude.Include inclusion) {DEFAULT_PROPERTY_INCLUSION = inclusion;configPropertyInclusion();}public static void setIndentOutput(boolean isEnable) {IS_ENABLE_INDENT_OUTPUT = isEnable;configIndentOutput();}public static <V> V from(URL url, Class<V> c) {try {return mapper.readValue(url, c);} catch (IOException e) {log.error("jackson from error, url: {}, type: {}", url.getPath(), c, e);return null;}}public static <V> V from(InputStream inputStream, Class<V> c) {try {return mapper.readValue(inputStream, c);} catch (IOException e) {log.error("jackson from error, type: {}", c, e);return null;}}public static <V> V from(File file, Class<V> c) {try {return mapper.readValue(file, c);} catch (IOException e) {log.error("jackson from error, file path: {}, type: {}", file.getPath(), c, e);return null;}}public static <V> V from(Object jsonObj, Class<V> c) {try {return mapper.readValue(jsonObj.toString(), c);} catch (IOException e) {log.error("jackson from error, json: {}, type: {}", jsonObj.toString(), c, e);return null;}}public static <V> V from(String json, Class<V> c) {try {return mapper.readValue(json, c);} catch (IOException e) {log.error("jackson from error, json: {}, type: {}", json, c, e);return null;}}public static <V> V from(URL url, TypeReference<V> type) {try {return mapper.readValue(url, type);} catch (IOException e) {log.error("jackson from error, url: {}, type: {}", url.getPath(), type, e);return null;}}public static <V> V from(InputStream inputStream, TypeReference<V> type) {try {return mapper.readValue(inputStream, type);} catch (IOException e) {log.error("jackson from error, type: {}", type, e);return null;}}public static <V> V from(File file, TypeReference<V> type) {try {return mapper.readValue(file, type);} catch (IOException e) {log.error("jackson from error, file path: {}, type: {}", file.getPath(), type, e);return null;}}public static <V> V from(Object jsonObj, TypeReference<V> type) {try {return mapper.readValue(jsonObj.toString(), type);} catch (IOException e) {log.error("jackson from error, json: {}, type: {}", jsonObj.toString(), type, e);return null;}}public static <V> V from(String json, TypeReference<V> type) {try {return mapper.readValue(json, type);} catch (IOException e) {log.error("jackson from error, json: {}, type: {}", json, type, e);return null;}}public static <V> String to(List<V> list) {try {return mapper.writeValueAsString(list);} catch (JsonProcessingException e) {log.error("jackson to error, obj: {}", list, e);return null;}}public static <V> String to(V v) {try {return mapper.writeValueAsString(v);} catch (JsonProcessingException e) {log.error("jackson to error, obj: {}", v, e);return null;}}public static <V> void toFile(String path, List<V> list) {try (Writer writer = new FileWriter(new File(path), true)) {mapper.writer().writeValues(writer).writeAll(list);writer.flush();} catch (Exception e) {log.error("jackson to file error, path: {}, list: {}", path, list, e);}}public static <V> void toFile(String path, V v) {try (Writer writer = new FileWriter(new File(path), true)) {mapper.writer().writeValues(writer).write(v);writer.flush();} catch (Exception e) {log.error("jackson to file error, path: {}, obj: {}", path, v, e);}}public static String getString(String json, String key) {if (StringUtils.isEmpty(json)) {return null;}try {JsonNode node = mapper.readTree(json);if (null != node) {return node.get(key).toString();} else {return null;}} catch (IOException e) {log.error("jackson get string error, json: {}, key: {}", json, key, e);return null;}}public static Integer getInt(String json, String key) {if (StringUtils.isEmpty(json)) {return null;}try {JsonNode node = mapper.readTree(json);if (null != node) {return node.get(key).intValue();} else {return null;}} catch (IOException e) {log.error("jackson get int error, json: {}, key: {}", json, key, e);return null;}}public static Long getLong(String json, String key) {if (StringUtils.isEmpty(json)) {return null;}try {JsonNode node = mapper.readTree(json);if (null != node) {return node.get(key).longValue();} else {return null;}} catch (IOException e) {log.error("jackson get long error, json: {}, key: {}", json, key, e);return null;}}public static Double getDouble(String json, String key) {if (StringUtils.isEmpty(json)) {return null;}try {JsonNode node = mapper.readTree(json);if (null != node) {return node.get(key).doubleValue();} else {return null;}} catch (IOException e) {log.error("jackson get double error, json: {}, key: {}", json, key, e);return null;}}public static BigInteger getBigInteger(String json, String key) {if (StringUtils.isEmpty(json)) {return new BigInteger(String.valueOf(0.00));}try {JsonNode node = mapper.readTree(json);if (null != node) {return node.get(key).bigIntegerValue();} else {return null;}} catch (IOException e) {log.error("jackson get biginteger error, json: {}, key: {}", json, key, e);return null;}}public static BigDecimal getBigDecimal(String json, String key) {if (StringUtils.isEmpty(json)) {return null;}try {JsonNode node = mapper.readTree(json);if (null != node) {return node.get(key).decimalValue();} else {return null;}} catch (IOException e) {log.error("jackson get bigdecimal error, json: {}, key: {}", json, key, e);return null;}}public static boolean getBoolean(String json, String key) {if (StringUtils.isEmpty(json)) {return false;}try {JsonNode node = mapper.readTree(json);if (null != node) {return node.get(key).booleanValue();} else {return false;}} catch (IOException e) {log.error("jackson get boolean error, json: {}, key: {}", json, key, e);return false;}}public static byte[] getByte(String json, String key) {if (StringUtils.isEmpty(json)) {return null;}try {JsonNode node = mapper.readTree(json);if (null != node) {return node.get(key).binaryValue();} else {return null;}} catch (IOException e) {log.error("jackson get byte error, json: {}, key: {}", json, key, e);return null;}}public static <T> ArrayList<T> getList(String json, String key) {if (StringUtils.isEmpty(json)) {return null;}String string = getString(json, key);return from(string, new TypeReference<ArrayList<T>>() {});}public static <T> String add(String json, String key, T value) {try {JsonNode node = mapper.readTree(json);add(node, key, value);return node.toString();} catch (IOException e) {log.error("jackson add error, json: {}, key: {}, value: {}", json, key, value, e);return json;}}private static <T> void add(JsonNode jsonNode, String key, T value) {if (value instanceof String) {((ObjectNode) jsonNode).put(key, (String) value);} else if (value instanceof Short) {((ObjectNode) jsonNode).put(key, (Short) value);} else if (value instanceof Integer) {((ObjectNode) jsonNode).put(key, (Integer) value);} else if (value instanceof Long) {((ObjectNode) jsonNode).put(key, (Long) value);} else if (value instanceof Float) {((ObjectNode) jsonNode).put(key, (Float) value);} else if (value instanceof Double) {((ObjectNode) jsonNode).put(key, (Double) value);} else if (value instanceof BigDecimal) {((ObjectNode) jsonNode).put(key, (BigDecimal) value);} else if (value instanceof BigInteger) {((ObjectNode) jsonNode).put(key, (BigInteger) value);} else if (value instanceof Boolean) {((ObjectNode) jsonNode).put(key, (Boolean) value);} else if (value instanceof byte[]) {((ObjectNode) jsonNode).put(key, (byte[]) value);} else {((ObjectNode) jsonNode).put(key, to(value));}}public static String remove(String json, String key) {try {JsonNode node = mapper.readTree(json);((ObjectNode) node).remove(key);return node.toString();} catch (IOException e) {log.error("jackson remove error, json: {}, key: {}", json, key, e);return json;}}public static <T> String update(String json, String key, T value) {try {JsonNode node = mapper.readTree(json);((ObjectNode) node).remove(key);add(node, key, value);return node.toString();} catch (IOException e) {log.error("jackson update error, json: {}, key: {}, value: {}", json, key, value, e);return json;}}public static String format(String json) {try {JsonNode node = mapper.readTree(json);return mapper.writerWithDefaultPrettyPrinter().writeValueAsString(node);} catch (IOException e) {log.error("jackson format json error, json: {}", json, e);return json;}}public static boolean isJson(String json) {try {mapper.readTree(json);return true;} catch (Exception e) {log.error("jackson check json error, json: {}", json, e);return false;}}private static InputStream getResourceStream(String name) {return JsonUtil.class.getClassLoader().getResourceAsStream(name);}private static InputStreamReader getResourceReader(InputStream inputStream) {if (null == inputStream) {return null;}return new InputStreamReader(inputStream, StandardCharsets.UTF_8);}
}

JsonResult

package cn.tedu.web.util;import lombok.Getter;
import lombok.Setter;@Getter
@Setter
public class JsonResult<T> {/** 成功 */public static final int SUCCESS = 200;/** 没有登录 */public static final int NOT_LOGIN = 400;/** 发生异常 */public static final int EXCEPTION = 401;/** 系统错误 */public static final int SYS_ERROR = 402;/** 参数错误 */public static final int PARAMS_ERROR = 403;/** 不支持或已经废弃 */public static final int NOT_SUPPORTED = 410;/** AuthCode错误 */public static final int INVALID_AUTHCODE = 444;/** 太频繁的调用 */public static final int TOO_FREQUENT = 445;/** 未知的错误 */public static final int UNKNOWN_ERROR = 499;private int code;private String msg;private T data;public static JsonResult build() {return new JsonResult();}public static JsonResult build(int code) {return new JsonResult().code(code);}public static JsonResult build(int code, String msg) {return new JsonResult<String>().code(code).msg(msg);}public static <T> JsonResult<T> build(int code, T data) {return new JsonResult<T>().code(code).data(data);}public static <T> JsonResult<T> build(int code, String msg, T data) {return new JsonResult<T>().code(code).msg(msg).data(data);}public JsonResult<T> code(int code) {this.code = code;return this;}public JsonResult<T> msg(String msg) {this.msg = msg;return this;}public JsonResult<T> data(T data) {this.data = data;return this;}public static JsonResult ok() {return build(SUCCESS);}public static JsonResult ok(String msg) {return build(SUCCESS, msg);}public static <T> JsonResult<T> ok(T data) {return build(SUCCESS, data);}public static JsonResult err() {return build(EXCEPTION);}public static JsonResult err(String msg) {return build(EXCEPTION, msg);}@Overridepublic String toString() {return JsonUtil.to(this);}
}

三、item service 商品服务