1. 增加Post支持；2.补充说明

README.md

+# 获取签名
+通过SignApplication启动程序（或者打包成jar）。
+* 启动后GET或POST访问[http://localhost:8080/sign]()获取签名
+* 传递参数和实际传递给接口的参数一致（除sign参数）
\ No newline at end of file

src/main/java/com/lylb/epw/sign/SignController.java

@@ -13,12 +13,13 @@ public class SignController {
 
     /**
      * 对请求进行签名
+     *
      * @param query request query
-     * @param body request body
+     * @param body  request body
      * @return 签名值
      */
-    @GetMapping
-    public String sign(@RequestParam Map<String,?> query, @Nullable @RequestBody Object body){
-        return computeSign(query,body);
+    @RequestMapping(method = {RequestMethod.GET, RequestMethod.POST})
+    public String sign(@RequestParam Map<String, ?> query, @Nullable @RequestBody Object body) {
+        return computeSign(query, body);
     }
 }