[FLINK-16094][docs-zh] Translate /dev/table/functions/udfs.zh.md into…

… Chinese

This closes apache#11191

docs/dev/table/functions/udfs.md

@@ -215,6 +215,30 @@ tableEnv.sqlQuery("SELECT a, word, length FROM MyTable LEFT JOIN LATERAL TABLE(s
 {% endhighlight %}
 </div>
 
+Please note that POJO types do not have a deterministic field order. Therefore, you cannot rename the fields of POJO returned by a table function using `AS`.
+
+By default the result type of a `TableFunction` is determined by Flink’s automatic type extraction facilities. This works well for basic types and simple POJOs but might be wrong for more complex, custom, or composite types. In such a case, the type of the result can be manually specified by overriding `TableFunction#getResultType()` which returns its `TypeInformation`.
+
+The following example shows an example of a `TableFunction` that returns a `Row` type which requires explicit type information. We define that the returned table type should be `RowTypeInfo(String, Integer)` by overriding `TableFunction#getResultType()`.
+
+{% highlight java %}
+public class CustomTypeSplit extends TableFunction<Row> {
+    public void eval(String str) {
+        for (String s : str.split(" ")) {
+            Row row = new Row(2);
+            row.setField(0, s);
+            row.setField(1, s.length());
+            collect(row);
+        }
+    }
+
+    @Override
+    public TypeInformation<Row> getResultType() {
+        return Types.ROW(Types.STRING(), Types.INT());
+    }
+}
+{% endhighlight %}
+
 <div data-lang="scala" markdown="1">
 In order to define a table function one has to extend the base class `TableFunction` in `org.apache.flink.table.functions` and implement (one or more) evaluation methods. The behavior of a table function is determined by its evaluation methods. An evaluation method must be declared `public` and named `eval`. The `TableFunction` can be overloaded by implementing multiple methods named `eval`. The parameter types of the evaluation methods determine all valid parameters of the table function. Evaluation methods can also support variable arguments, such as `eval(String... strs)`. The type of the returned table is determined by the generic type of `TableFunction`. Evaluation methods emit output rows using the protected `collect(T)` method.
 
@@ -250,6 +274,30 @@ tableEnv.sqlQuery("SELECT a, word, length FROM MyTable, LATERAL TABLE(split(a))
 tableEnv.sqlQuery("SELECT a, word, length FROM MyTable LEFT JOIN LATERAL TABLE(split(a)) as T(word, length) ON TRUE")
 {% endhighlight %}
 **IMPORTANT:** Do not implement TableFunction as a Scala object. Scala object is a singleton and will cause concurrency issues.
+
+Please note that POJO types do not have a deterministic field order. Therefore, you cannot rename the fields of POJO returned by a table function using `AS`.
+
+By default the result type of a `TableFunction` is determined by Flink’s automatic type extraction facilities. This works well for basic types and simple POJOs but might be wrong for more complex, custom, or composite types. In such a case, the type of the result can be manually specified by overriding `TableFunction#getResultType()` which returns its `TypeInformation`.
+
+The following example shows an example of a `TableFunction` that returns a `Row` type which requires explicit type information. We define that the returned table type should be `RowTypeInfo(String, Integer)` by overriding `TableFunction#getResultType()`.
+
+{% highlight scala %}
+class CustomTypeSplit extends TableFunction[Row] {
+  def eval(str: String): Unit = {
+    str.split(" ").foreach({ s =>
+      val row = new Row(2)
+      row.setField(0, s)
+      row.setField(1, s.length)
+      collect(row)
+    })
+  }
+
+  override def getResultType: TypeInformation[Row] = {
+    Types.ROW(Types.STRING, Types.INT)
+  }
+}
+{% endhighlight %}
+
 </div>
 
 <div data-lang="python" markdown="1">
@@ -288,59 +336,6 @@ Please refer to the [Python Table Function]({{ site.baseurl }}/dev/table/python/
 </div>
 </div>
 
-<div class="codetabs" markdown="1">
-<div data-lang="java" markdown="1">
-Please note that POJO types do not have a deterministic field order. Therefore, you cannot rename the fields of POJO returned by a table function using `AS`.
-
-By default the result type of a `TableFunction` is determined by Flink’s automatic type extraction facilities. This works well for basic types and simple POJOs but might be wrong for more complex, custom, or composite types. In such a case, the type of the result can be manually specified by overriding `TableFunction#getResultType()` which returns its `TypeInformation`.
-
-The following example shows an example of a `TableFunction` that returns a `Row` type which requires explicit type information. We define that the returned table type should be `RowTypeInfo(String, Integer)` by overriding `TableFunction#getResultType()`.
-
-{% highlight java %}
-public class CustomTypeSplit extends TableFunction<Row> {
-    public void eval(String str) {
-        for (String s : str.split(" ")) {
-            Row row = new Row(2);
-            row.setField(0, s);
-            row.setField(1, s.length());
-            collect(row);
-        }
-    }
-
-    @Override
-    public TypeInformation<Row> getResultType() {
-        return Types.ROW(Types.STRING(), Types.INT());
-    }
-}
-{% endhighlight %}
-</div>
-
-<div data-lang="scala" markdown="1">
-Please note that POJO types do not have a deterministic field order. Therefore, you cannot rename the fields of POJO returned by a table function using `AS`.
-
-By default the result type of a `TableFunction` is determined by Flink’s automatic type extraction facilities. This works well for basic types and simple POJOs but might be wrong for more complex, custom, or composite types. In such a case, the type of the result can be manually specified by overriding `TableFunction#getResultType()` which returns its `TypeInformation`.
-
-The following example shows an example of a `TableFunction` that returns a `Row` type which requires explicit type information. We define that the returned table type should be `RowTypeInfo(String, Integer)` by overriding `TableFunction#getResultType()`.
-
-{% highlight scala %}
-class CustomTypeSplit extends TableFunction[Row] {
-  def eval(str: String): Unit = {
-    str.split(" ").foreach({ s =>
-      val row = new Row(2)
-      row.setField(0, s)
-      row.setField(1, s.length)
-      collect(row)
-    })
-  }
-
-  override def getResultType: TypeInformation[Row] = {
-    Types.ROW(Types.STRING, Types.INT)
-  }
-}
-{% endhighlight %}
-</div>
-</div>
-
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