优化下 字符串 拼接

src/main/java/com/baomidou/mybatisplus/incrementer/DB2KeyGenerator.java

@@ -12,8 +12,9 @@ public class DB2KeyGenerator implements IKeyGenerator {
 
     @Override
     public String executeSql(String incrementerName) {
-        return "values nextval for " + incrementerName;
+        StringBuilder sql = new StringBuilder();
+        sql.append("values nextval for ");
+        sql.append(incrementerName);
+        return sql.toString();
     }
-
-
 }

src/main/java/com/baomidou/mybatisplus/incrementer/H2KeyGenerator.java

@@ -12,8 +12,10 @@ public class H2KeyGenerator implements IKeyGenerator {
 
     @Override
     public String executeSql(String incrementerName) {
-        return "select " + incrementerName + ".nextval from dual";
+        StringBuilder sql = new StringBuilder();
+        sql.append("select ");
+        sql.append(incrementerName);
+        sql.append(".nextval from dual");
+        return sql.toString();
     }
-
-
 }

src/main/java/com/baomidou/mybatisplus/incrementer/OracleKeyGenerator.java

@@ -27,7 +27,9 @@ public class OracleKeyGenerator implements IKeyGenerator {
 
     @Override
     public String executeSql(String incrementerName) {
-        return String.format("SELECT %s.NEXTVAL FROM DUAL", incrementerName);
+        StringBuilder sql = new StringBuilder();
+        sql.append("SELECT ").append(incrementerName);
+        sql.append(".NEXTVAL FROM DUAL");
+        return sql.toString();
     }
-
 }

src/main/java/com/baomidou/mybatisplus/incrementer/PostgreKeyGenerator.java

@@ -12,7 +12,10 @@ public class PostgreKeyGenerator implements IKeyGenerator {
 
     @Override
     public String executeSql(String incrementerName) {
-        return "select nextval('" + incrementerName + "')";
+        StringBuilder sql = new StringBuilder();
+        sql.append("select nextval('");
+        sql.append(incrementerName);
+        sql.append("')");
+        return sql.toString();
     }
-
 }