add doc

README.md

+# demo 工程说明
+
+### 工程结构
+![](gic-demo-helper/src/main/resources/snapshot_01.png)
+
+### 生成 mybatis model mapper xml 
+gic-demo-helper工程，配置generatorConfig_test.xml。
+```xml
+<context id="testTables" targetRuntime="MyBatis3">
+
+	<!-- 配置数据库连接 -->
+	<jdbcConnection driverClass="com.mysql.jdbc.Driver"
+					connectionURL="jdbc:mysql://xxxx:6634/test?characterEncoding=utf-8"
+					userId="userId"
+					password="password">
+	</jdbcConnection>
+	
+	<!-- 配置Model生成 -->
+	<javaModelGenerator targetPackage="com.gic.demo.project.service.entity" targetProject="src/main/java">
+		<property name="enableSubPackages" value="true"/>
+	</javaModelGenerator>
+	
+	<!-- 配置 mapper xml 生成 -->
+	<sqlMapGenerator targetPackage="mapper" targetProject="src/main/resources">
+	    <property name="enableSubPackages" value="true"/>
+	</sqlMapGenerator>
+	
+	<!-- 配置 mapper 对应接口 -->
+	<javaClientGenerator type="XMLMAPPER"
+						 targetPackage="com.gic.demo.project.service.dao.mapper" targetProject="src/main/java">
+		<property name="enableSubPackages" value="true"/>
+	</javaClientGenerator>
+
+	<!-- 指定数据库表 -->
+	<table tableName="tab_gic_demo_enterprise" enableSelectByExample="false" enableDeleteByExample="false" enableCountByExample="false" enableUpdateByExample="false" selectByExampleQueryId="false"/>
+	<table tableName="tab_gic_demo_store" enableSelectByExample="false" enableDeleteByExample="false" enableCountByExample="false" enableUpdateByExample="false" selectByExampleQueryId="false"/>
+	
+</context>
+
+```
+生成代码
+```java
+public class GeneratorStartUp {
+    public static void main(String[] args) {
+        try {
+            List<String> warnings = new ArrayList<>();
+            ClassLoader classloader = Thread.currentThread().getContextClassLoader();
+            InputStream is = classloader.getResourceAsStream("generatorConfig_test.xml");
+            ConfigurationParser cp = new ConfigurationParser(warnings);
+            Configuration config = cp.parseConfiguration(is);
+            DefaultShellCallback callback = new DefaultShellCallback(true);
+            MyBatisGenerator myBatisGenerator = new MyBatisGenerator(config, callback, warnings);
+            myBatisGenerator.generate(null);
+        } catch (Exception e) {
+            e.printStackTrace();
+        }
+    }
+}
+```
+
+### 生成雪花id
+未来 UniqueIdUtils 会集成到 gic-commons 4.x 里
+```java
+public class TestRun {
+	public static void main(String[] args) {
+	    // 生成long型id
+	    UniqueIdUtils.uniqueLong();
+	    // 生成hex字符串型id
+	    UniqueIdUtils.uniqueLongHex();
+	}
+}
+```
+
+### sharding-jdbc 配置
+1. 参照 sharding-jdbc 配置说明配置分表，保存到mongodb
+2. 修改 Apollo配置 COMMON.sharding sharding.shardingId
+3. 配置xml
+```xml
+<bean id="dataSource" class="com.gic.sharding.sdk.ShardingDatasource" init-method="init">
+    <property name="shardingId" value="${sharding.shardingId}"/>
+    <property name="maxSize" value="${jdbc.maxsize}"/>
+    <property name="urlType" value="${sharding.urlType:inner}"/>
+</bean>
+```
+
+### dubbo 服务
+参考 gic 3.x，com.alibaba.dubbo.container.Main 替换为 com.gic.commons.DubboMain 。
+
+### web rest 服务
+使用 spring boot 内嵌 tomcat 启动
+```java
+/**
+ * Spring Boot Web 启动类
+ *
+ * @author zhurz
+ */
+@SpringBootApplication
+@ImportResource(value = {
+        // spring 配置初始化xml
+        "classpath*:gic-demo-init.xml",
+        // 通用 dubbo 配置
+        "classpath*:dubbo-setting.xml",
+        // dubbo api 配置
+        "classpath*:dubbo-gic-demo-web.xml",
+        // 拦截器配置
+        "classpath*:spring-interceptor.xml"
+})
+public class Main {
+    public static void main(String[] args) {
+        ConfigurableApplicationContext context = SpringApplication.run(Main.class, args);
+        DubboContextUtil.setApplicationContext(context.getParent());
+    }
+}
+```
+