refactor: simplify code. (#1165)

dlink-executor/src/main/java/com/dlink/executor/SqlManager.java

@@ -37,7 +37,7 @@ import org.apache.flink.types.Row;
 import org.apache.flink.util.StringUtils;
 
 import java.util.ArrayList;
-import java.util.Arrays;
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.Iterator;
 import java.util.List;
@@ -53,8 +53,9 @@ import java.util.regex.Pattern;
  **/
 public final class SqlManager {
 
-    private Map<String, String> sqlFragments;
+    public static final String FRAGMENT = "fragment";
     static final String SHOW_FRAGMENTS = "SHOW FRAGMENTS";
+    private final Map<String, String> sqlFragments;
 
     public SqlManager() {
         sqlFragments = new HashMap<>();
@@ -78,14 +79,11 @@ public final class SqlManager {
      *                          But at the moment, with CatalogException, not SqlException
      */
     public void registerSqlFragment(String sqlFragmentName, String sqlFragment) {
-        checkArgument(
-            !StringUtils.isNullOrWhitespaceOnly(sqlFragmentName),
-            "sql fragment name cannot be null or empty.");
+        checkArgument(!StringUtils.isNullOrWhitespaceOnly(sqlFragmentName), "sql fragment name cannot be null or empty.");
         checkNotNull(sqlFragment, "sql fragment cannot be null");
 
         if (sqlFragments.containsKey(sqlFragmentName)) {
-            throw new CatalogException(
-                format("The fragment of sql %s already exists.", sqlFragmentName));
+            throw new CatalogException(format("The fragment of sql %s already exists.", sqlFragmentName));
         }
 
         sqlFragments.put(sqlFragmentName, sqlFragment);
@@ -114,15 +112,12 @@ public final class SqlManager {
      *                          failed. But at the moment, with CatalogException, not SqlException
      */
     public void unregisterSqlFragment(String sqlFragmentName, boolean ignoreIfNotExists) {
-        checkArgument(
-            !StringUtils.isNullOrWhitespaceOnly(sqlFragmentName),
-            "sql fragmentName name cannot be null or empty.");
+        checkArgument(!StringUtils.isNullOrWhitespaceOnly(sqlFragmentName), "sql fragmentName name cannot be null or empty.");
 
         if (sqlFragments.containsKey(sqlFragmentName)) {
             sqlFragments.remove(sqlFragmentName);
         } else if (!ignoreIfNotExists) {
-            throw new CatalogException(
-                format("The fragment of sql %s does not exist.", sqlFragmentName));
+            throw new CatalogException(format("The fragment of sql %s does not exist.", sqlFragmentName));
         }
     }
 
@@ -134,26 +129,22 @@ public final class SqlManager {
      *                          failed. But at the moment, with CatalogException, not SqlException
      */
     public String getSqlFragment(String sqlFragmentName) {
-        checkArgument(
-            !StringUtils.isNullOrWhitespaceOnly(sqlFragmentName),
-            "sql fragmentName name cannot be null or empty.");
+        checkArgument(!StringUtils.isNullOrWhitespaceOnly(sqlFragmentName), "sql fragmentName name cannot be null or empty.");
 
         if (sqlFragments.containsKey(sqlFragmentName)) {
             return sqlFragments.get(sqlFragmentName);
-        } else {
-            throw new CatalogException(
-                format("The fragment of sql %s does not exist.", sqlFragmentName));
         }
+
+        throw new CatalogException(format("The fragment of sql %s does not exist.", sqlFragmentName));
     }
 
     public TableResult getSqlFragmentResult(String sqlFragmentName) {
         if (Asserts.isNullString(sqlFragmentName)) {
-            return CustomTableResultImpl.buildTableResult(new ArrayList<>(Arrays.asList(new TableSchemaField("fragment", DataTypes.STRING()))), new ArrayList<>());
+            return CustomTableResultImpl.buildTableResult(Collections.singletonList(new TableSchemaField(FRAGMENT, DataTypes.STRING())), new ArrayList<>());
         }
+
         String sqlFragment = getSqlFragment(sqlFragmentName);
-        List<Row> rows = new ArrayList<>();
-        rows.add(Row.of(sqlFragment));
-        return CustomTableResultImpl.buildTableResult(new ArrayList<>(Arrays.asList(new TableSchemaField("fragment", DataTypes.STRING()))), rows);
+        return CustomTableResultImpl.buildTableResult(Collections.singletonList(new TableSchemaField(FRAGMENT, DataTypes.STRING())), Collections.singletonList(Row.of(sqlFragment)));
     }
 
     /**
@@ -171,7 +162,7 @@ public final class SqlManager {
         for (String key : sqlFragments.keySet()) {
             rows.add(Row.of(key));
         }
-        return CustomTableResultImpl.buildTableResult(new ArrayList<>(Arrays.asList(new TableSchemaField("fragmentName", DataTypes.STRING()))), rows);
+        return CustomTableResultImpl.buildTableResult(Collections.singletonList(new TableSchemaField("fragmentName", DataTypes.STRING())), rows);
     }
 
     public Iterator getSqlFragmentsIterator() {
@@ -179,10 +170,7 @@ public final class SqlManager {
     }
 
     public Table getSqlFragmentsTable(CustomTableEnvironmentImpl environment) {
-        List<String> keys = new ArrayList<>();
-        for (String key : sqlFragments.keySet()) {
-            keys.add(key);
-        }
+        List<String> keys = new ArrayList<>(sqlFragments.keySet());
         return environment.fromValues(keys);
     }
 
@@ -200,28 +188,22 @@ public final class SqlManager {
         if (Asserts.isNullString(statement)) {
             return statement;
         }
-        String[] strs = statement.split(SystemConfiguration.getInstances().getSqlSeparator());
+
+        String[] values = statement.split(SystemConfiguration.getInstances().getSqlSeparator());
         StringBuilder sb = new StringBuilder();
-        for (int i = 0; i < strs.length; i++) {
-            String str = strs[i];
-            if (str.trim().length() == 0) {
-                continue;
-            }
-            str = strs[i];
-            if (str.contains(FlinkSQLConstant.FRAGMENTS)) {
-                String[] strs2 = str.split(FlinkSQLConstant.FRAGMENTS);
-                if (strs2.length >= 2) {
-                    if (strs2[0].length() == 0) {
+        for (String assignment : values) {
+            String[] splits = assignment.split(FlinkSQLConstant.FRAGMENTS, 2);
+            if (splits.length == 2) {
+                if (splits[0].trim().isEmpty()) {
                     throw new ExpressionParserException("Illegal variable name.");
                 }
-                    String valueString = str.substring(str.indexOf(FlinkSQLConstant.FRAGMENTS) + 2);
-                    this.registerSqlFragment(strs2[0], replaceVariable(valueString));
+                this.registerSqlFragment(splits[0], replaceVariable(splits[1]));
+            } else if (splits.length == 1) {
+                // string not contains FlinkSQLConstant.FRAGMENTS
+                sb.append(replaceVariable(assignment));
             } else {
                 throw new ExpressionParserException("Illegal variable definition.");
             }
-            } else {
-                sb.append(replaceVariable(str));
-            }
         }
         return sb.toString();
     }
@@ -232,15 +214,13 @@ public final class SqlManager {
      * @param statement A sql will be replaced.
      */
     private String replaceVariable(String statement) {
-        String pattern = "\\$\\{(.+?)\\}";
-        Pattern p = Pattern.compile(pattern);
+        Pattern p = Pattern.compile("\\$\\{(.+?)}");
         Matcher m = p.matcher(statement);
         StringBuffer sb = new StringBuffer();
         while (m.find()) {
             String key = m.group(1);
             String value = this.getSqlFragment(key);
-            m.appendReplacement(sb, "");
-            sb.append(value == null ? "" : value);
+            m.appendReplacement(sb, value == null ? "" : value);
         }
         m.appendTail(sb);
         return sb.toString();