diff --git a/maker/golang/main.go b/maker/golang/main.go
index a2a26bd..5eea2fc 100644
--- a/maker/golang/main.go
+++ b/maker/golang/main.go
@@ -442,7 +442,7 @@ func testBench() {
 
 	var count, errCount, tStart = 0, 0, time.Now()
 	slog.Info("Bench start", "xdbPath", dbFile, "srcPath", srcFile)
-	var iErr = xdb.IterateSegments(handle, nil, func(seg *xdb.Segment) error {
+	var iErr = xdb.IterateSegments(handle, nil, nil, func(seg *xdb.Segment) error {
 		var l = fmt.Sprintf("%d|%d|%s", seg.StartIP, seg.EndIP, seg.Region)
 		slog.Debug("try to bench", "segment", l)
 		// mip := xdb.IPMiddle(seg.StartIP, seg.EndIP)
diff --git a/maker/golang/xdb/editor.go b/maker/golang/xdb/editor.go
index d572794..3a52804 100644
--- a/maker/golang/xdb/editor.go
+++ b/maker/golang/xdb/editor.go
@@ -59,7 +59,7 @@ func (e *Editor) loadSegments() error {
 
 	var iErr = IterateSegments(e.srcHandle, func(l string) {
 		// do nothing here
-	}, func(seg *Segment) error {
+	}, nil, func(seg *Segment) error {
 		// version check
 		if len(seg.StartIP) != e.verison.Bytes {
 			return fmt.Errorf("invalid ip segment(%s expected)", e.verison.Name)
@@ -240,7 +240,7 @@ func (e *Editor) PutFile(src string) (int, int, error) {
 	var oldRows, newRows = 0, 0
 	iErr := IterateSegments(handle, func(l string) {
 		// do nothing here
-	}, func(seg *Segment) error {
+	}, nil, func(seg *Segment) error {
 		o, n, err := e.PutSegment(seg)
 		if err == nil {
 			oldRows += o
diff --git a/maker/golang/xdb/maker.go b/maker/golang/xdb/maker.go
index c4558e3..ef94f12 100644
--- a/maker/golang/xdb/maker.go
+++ b/maker/golang/xdb/maker.go
@@ -162,6 +162,9 @@ func (m *Maker) loadSegments() error {
 
 	var iErr = IterateSegments(m.srcHandle, func(l string) {
 		slog.Debug("loaded", "segment", l)
+	}, func(region string) (string, error) {
+		// apply the field filter
+		return RegionFiltering(region, m.fields)
 	}, func(seg *Segment) error {
 		// ip version check
 		if len(seg.StartIP) != m.version.Bytes {
@@ -173,14 +176,6 @@ func (m *Maker) loadSegments() error {
 			return err
 		}
 
-		// apply the field filter
-		region, err := RegionFiltering(seg.Region, m.fields)
-		if err != nil {
-			return err
-		}
-
-		// slog.Info("filtered", "region", region)
-		seg.Region = region
 		m.segments = append(m.segments, seg)
 		last = seg
 		return nil
diff --git a/maker/golang/xdb/processor.go b/maker/golang/xdb/processor.go
index eac76ba..dd703ee 100644
--- a/maker/golang/xdb/processor.go
+++ b/maker/golang/xdb/processor.go
@@ -52,20 +52,15 @@ func (p *Processor) loadSegments() error {
 
 	var iErr = IterateSegments(p.srcHandle, func(l string) {
 		slog.Debug("loaded", "segment", l)
+	}, func(region string) (string, error) {
+		return RegionFiltering(region, p.fields)
 	}, func(seg *Segment) error {
 		// check the continuity of the data segment
 		// if err := seg.AfterCheck(last); err != nil {
 		// 	return err
 		// }
 
-		// apply the field filter
-		region, err := RegionFiltering(seg.Region, p.fields)
-		if err != nil {
-			return err
-		}
-
 		// slog.Info("filtered", "source", seg.Region, "filtered", region)
-		seg.Region = region
 		p.segments = append(p.segments, seg)
 		return nil
 	})
diff --git a/maker/golang/xdb/util.go b/maker/golang/xdb/util.go
index ae21b1d..651a577 100644
--- a/maker/golang/xdb/util.go
+++ b/maker/golang/xdb/util.go
@@ -101,7 +101,7 @@ func IPMiddle(sip, eip []byte) []byte {
 	return result
 }
 
-func IterateSegments(handle *os.File, before func(l string), cb func(seg *Segment) error) error {
+func IterateSegments(handle *os.File, before func(l string), filter func(region string) (string, error), done func(seg *Segment) error) error {
 	var last *Segment = nil
 	var scanner = bufio.NewScanner(handle)
 	scanner.Split(bufio.ScanLines)
@@ -147,10 +147,19 @@ func IterateSegments(handle *os.File, before func(l string), cb func(seg *Segmen
 		// 	return fmt.Errorf("empty region info in segment line `%s`", l)
 		// }
 
+		// check and do the region filter
+		var region = ps[2]
+		if filter != nil {
+			region, err = filter(ps[2])
+			if err != nil {
+				return fmt.Errorf("failed to filter region `%s`: %s", ps[2], err)
+			}
+		}
+
 		var seg = &Segment{
 			StartIP: sip,
 			EndIP:   eip,
-			Region:  ps[2],
+			Region:  region,
 		}
 
 		// check and automatic merging the Consecutive Segments, which means:
@@ -166,7 +175,7 @@ func IterateSegments(handle *os.File, before func(l string), cb func(seg *Segmen
 			}
 		}
 
-		if err = cb(last); err != nil {
+		if err = done(last); err != nil {
 			return err
 		}
 
@@ -176,7 +185,7 @@ func IterateSegments(handle *os.File, before func(l string), cb func(seg *Segmen
 
 	// process the last segment
 	if last != nil {
-		return cb(last)
+		return done(last)
 	}
 
 	return nil
diff --git a/maker/golang/xdb/util_test.go b/maker/golang/xdb/util_test.go
index d3460fb..2f7bf84 100644
--- a/maker/golang/xdb/util_test.go
+++ b/maker/golang/xdb/util_test.go
@@ -163,7 +163,7 @@ func TestIterateSegments(t *testing.T) {
 
 	_ = IterateSegments(handle, func(l string) {
 		// fmt.Printf("load segment: `%s`\n", l)
-	}, func(seg *Segment) error {
+	}, nil, func(seg *Segment) error {
 		fmt.Printf("get segment: `%s`\n", seg)
 		return nil
 	})
diff --git a/maker/java/src/main/java/org/lionsoul/ip2region/xdb/Maker.java b/maker/java/src/main/java/org/lionsoul/ip2region/xdb/Maker.java
index eb793a6..b7a1938 100644
--- a/maker/java/src/main/java/org/lionsoul/ip2region/xdb/Maker.java
+++ b/maker/java/src/main/java/org/lionsoul/ip2region/xdb/Maker.java
@@ -164,6 +164,11 @@ public class Maker {
                 log.debugf("load segment: `%s`", line);
             }
 
+            @Override
+            public String filter(String region) {
+                return Util.regionFiltering(region, fields);
+            }
+
             @Override
             public void handle(Segment seg) throws Exception {
                 // ip version check
@@ -176,18 +181,14 @@ public class Maker {
                         + Util.ipToString(last.endIP)+")+1 != seg.sip("+ Util.ipToString(seg.startIP) + ", "+ seg.region +")");
                 }
 
-                // apply the field filtering
-                final String region = Util.regionFiltering(seg.region, fields);
-
                 // allow empty region
                 // if (region.length() < 1) {
                 //     throw new Exception("empty region info for segment `"+seg+"`");
                 // }
 
-                segments.add(new Segment(seg.startIP, seg.endIP, region));
+                segments.add(seg);
                 last = seg;
             }
-
         });
 
         log.infof("all segments loaded, length: %d, elapsed: %d ms", segments.size(), System.currentTimeMillis() - tStart);
diff --git a/maker/java/src/main/java/org/lionsoul/ip2region/xdb/Segment.java b/maker/java/src/main/java/org/lionsoul/ip2region/xdb/Segment.java
index c051156..1ab808c 100644
--- a/maker/java/src/main/java/org/lionsoul/ip2region/xdb/Segment.java
+++ b/maker/java/src/main/java/org/lionsoul/ip2region/xdb/Segment.java
@@ -122,6 +122,7 @@ public class Segment {
     // static class to handler the iterate callback
     public static interface IterateAction {
         public void before(final String line);
+        public String filter(final String region);
         public void handle(final Segment seg) throws Exception;
     }
 
@@ -175,7 +176,7 @@ public class Segment {
             //     throw new Exception("empty region info in segment line `"+ps[2]+"`");
             // }
 
-            final Segment seg = new Segment(sip, eip, ps[2]);
+            final Segment seg = new Segment(sip, eip, action.filter(ps[2]));
             // check and set the last segment
             if (last == null) {
                 last = seg;
diff --git a/maker/java/src/test/java/org/lionsoul/ip2region/xdb/SegmentTest.java b/maker/java/src/test/java/org/lionsoul/ip2region/xdb/SegmentTest.java
index 6383ad2..910fc60 100644
--- a/maker/java/src/test/java/org/lionsoul/ip2region/xdb/SegmentTest.java
+++ b/maker/java/src/test/java/org/lionsoul/ip2region/xdb/SegmentTest.java
@@ -54,6 +54,11 @@ public class SegmentTest {
                 // log.debugf("load segment: `%s`", line);
             }
 
+            @Override
+            public String filter(String region) {
+                return region;
+            }
+
             @Override
             public void handle(Segment seg) throws Exception {
                 log.infof("handle segment: `%s`", seg.toString());