Refactor Java API (#806)

sherpa-onnx/java-api/src/com/k2fsa/sherpa/onnx/FeatureConfig.java

@@ -1,6 +1,5 @@
-/*
- * // Copyright 2022-2023 by zhaoming
- */
+// Copyright 2022-2023 by zhaoming
+// Copyright 2024 Xiaomi Corporation
 
 package com.k2fsa.sherpa.onnx;
 
@@ -8,9 +7,13 @@ public class FeatureConfig {
     private final int sampleRate;
     private final int featureDim;
 
-    public FeatureConfig(int sampleRate, int featureDim) {
-        this.sampleRate = sampleRate;
-        this.featureDim = featureDim;
+    private FeatureConfig(Builder builder) {
+        this.sampleRate = builder.sampleRate;
+        this.featureDim = builder.featureDim;
+    }
+
+    public static Builder builder() {
+        return new Builder();
     }
 
     public int getSampleRate() {
@@ -20,4 +23,23 @@ public class FeatureConfig {
     public int getFeatureDim() {
         return featureDim;
     }
+
+    public static class Builder {
+        private int sampleRate = 16000;
+        private int featureDim = 80;
+
+        public FeatureConfig build() {
+            return new FeatureConfig(this);
+        }
+
+        public Builder setSampleRate(int sampleRate) {
+            this.sampleRate = sampleRate;
+            return this;
+        }
+
+        public Builder setFeatureDim(int featureDim) {
+            this.featureDim = featureDim;
+            return this;
+        }
+    }
 }