Add VAD demo for Java API (#928)

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

@@ -0,0 +1,81 @@
+// Copyright 2024 Xiaomi Corporation
+
+package com.k2fsa.sherpa.onnx;
+
+public class SileroVadModelConfig {
+    private final String model;
+    private final float threshold;
+    private final float minSilenceDuration;
+    private final float minSpeechDuration;
+    private final int windowSize;
+
+    private SileroVadModelConfig(Builder builder) {
+        this.model = builder.model;
+        this.threshold = builder.threshold;
+        this.minSilenceDuration = builder.minSilenceDuration;
+        this.minSpeechDuration = builder.minSpeechDuration;
+        this.windowSize = builder.windowSize;
+    }
+
+    public static Builder builder() {
+        return new Builder();
+    }
+
+    public String getModel() {
+        return model;
+    }
+
+    public float getThreshold() {
+        return threshold;
+    }
+
+    public float getMinSilenceDuration() {
+        return minSilenceDuration;
+    }
+
+    public float getMinSpeechDuration() {
+        return minSpeechDuration;
+    }
+
+    public int getWindowSize() {
+        return windowSize;
+    }
+
+    public static class Builder {
+        private String model = "";
+        private float threshold = 0.5f;
+        private float minSilenceDuration = 0.25f;
+        private float minSpeechDuration = 0.5f;
+        private int windowSize = 512;
+
+        public SileroVadModelConfig build() {
+            return new SileroVadModelConfig(this);
+        }
+
+
+        public Builder setModel(String model) {
+            this.model = model;
+            return this;
+        }
+
+        public Builder setThreshold(float threshold) {
+            this.threshold = threshold;
+            return this;
+        }
+
+        public Builder setMinSilenceDuration(float minSilenceDuration) {
+            this.minSilenceDuration = minSilenceDuration;
+            return this;
+        }
+
+        public Builder setMinSpeechDuration(float minSpeechDuration) {
+            this.minSpeechDuration = minSpeechDuration;
+            return this;
+        }
+
+        public Builder setWindowSize(int windowSize) {
+            this.windowSize = windowSize;
+            return this;
+        }
+    }
+}