concat_ws2

src/main/java/com/winhc/bigdata/udf/Concat_ws2.java

@@ -0,0 +1,35 @@
+package com.winhc.bigdata.udf;
+
+import com.aliyun.odps.udf.UDF;
+import com.aliyun.odps.utils.StringUtils;
+
+import java.util.regex.Pattern;
+
+/**
+ * @Author: Yan Yongnian
+ * @Date: 2020/8/5
+ * @Description: 包容null的字符串连接函数，类似spark sql里的对应函数
+ */
+public class Concat_ws2 extends UDF {
+    public String evaluate(String seperator,String...args) {
+        StringBuilder sb = new StringBuilder();
+        for(String arg : args) {//当作数组用foreach遍历
+            if(arg!=null){
+                sb.append(arg);
+                sb.append(seperator);
+            }
+        }
+        int sepLen = seperator.length();
+        int sbLen = sb.length();
+        if(seperator==null || sepLen==0){
+            return sb.toString();
+        }
+        else {
+            return sbLen > 0 ? sb.delete(sbLen - sepLen, sbLen).toString() : null;
+        }
+    }
+    public static void main(String[] args) {
+        String res = new Concat_ws2().evaluate("_","100336476","94126f32c17495ad45ef1e8bb51d2ac4");
+        System.out.println(res);
+    }
+}