Java SDK

合成语音

以下示例获取 Token、初始化客户端，使用 siyue 合成 16 kHz WAV 音频，并保存到临时文件。程序记录首包延迟，并检查合成失败、等待超时和文件写入异常。

import com.alibaba.nls.client.AccessToken;
import com.alibaba.nls.client.protocol.NlsClient;
import com.alibaba.nls.client.protocol.OutputFormatEnum;
import com.alibaba.nls.client.protocol.SampleRateEnum;
import com.alibaba.nls.client.protocol.tts.SpeechSynthesizer;
import com.alibaba.nls.client.protocol.tts.SpeechSynthesizerListener;
import com.alibaba.nls.client.protocol.tts.SpeechSynthesizerResponse;
import java.io.IOException;
import java.io.OutputStream;
import java.nio.ByteBuffer;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.concurrent.TimeoutException;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicReference;

public class SpeechSynthesizerDemo {
    private static String requireEnv(String name) {
        String value = System.getenv(name);
        if (value == null || value.trim().isEmpty()) {
            throw new IllegalArgumentException("Missing environment variable: " + name);
        }
        return value;
    }

    public static void main(String[] args) throws Exception {
        String appKey = requireEnv("NLS_APP_KEY");
        String accessKeyId = requireEnv("ALIYUN_AK_ID");
        String accessKeySecret = requireEnv("ALIYUN_AK_SECRET");
        AccessToken accessToken = new AccessToken(accessKeyId, accessKeySecret);
        accessToken.apply();
        if (accessToken.getToken() == null || accessToken.getToken().isEmpty()) {
            throw new IllegalStateException("Failed to obtain an NLS token");
        }

        NlsClient client = new NlsClient("wss://nls-gateway-cn-shanghai.aliyuncs.com/ws/v1", accessToken.getToken());
        try {
            Path output = Files.createTempFile("tts-", ".wav");
            try (OutputStream audio = Files.newOutputStream(output)) {
                AtomicBoolean completed = new AtomicBoolean(false);
                AtomicBoolean firstPacket = new AtomicBoolean(true);
                AtomicReference<Exception> failure = new AtomicReference<>();
                final long[] startedAt = new long[1];
                SpeechSynthesizerListener listener = new SpeechSynthesizerListener() {
                    @Override
                    public void onMessage(ByteBuffer message) {
                        if (firstPacket.compareAndSet(true, false)) {
                            long elapsedMs = (System.nanoTime() - startedAt[0]) / 1_000_000;
                            System.out.println("First packet latency (ms): " + elapsedMs);
                        }
                        byte[] bytes = new byte[message.remaining()];
                        message.get(bytes);
                        try {
                            audio.write(bytes);
                        } catch (IOException e) {
                            failure.compareAndSet(null, e);
                        }
                    }

                    @Override
                    public void onComplete(SpeechSynthesizerResponse response) {
                        if (response.getStatus() == 20000000) {
                            completed.set(true);
                            System.out.println("Synthesis completed, task_id: " + response.getTaskId());
                        } else {
                            onFail(response);
                        }
                    }

                    @Override
                    public void onFail(SpeechSynthesizerResponse response) {
                        failure.compareAndSet(null, new IOException(
                            "task_id=" + response.getTaskId() + ", status=" + response.getStatus()
                            + ", status_text=" + response.getStatusText()));
                    }

                    @Override
                    public void onMetaInfo(SpeechSynthesizerResponse response) {
                        System.out.println("Subtitles: " + response.getObject("subtitles"));
                    }
                };

                SpeechSynthesizer synthesizer = new SpeechSynthesizer(client, listener);
                try {
                    synthesizer.setAppKey(appKey);
                    synthesizer.setVoice("siyue");
                    synthesizer.setFormat(OutputFormatEnum.WAV);
                    synthesizer.setSampleRate(SampleRateEnum.SAMPLE_RATE_16K);
                    synthesizer.setVolume(50);
                    synthesizer.setSpeechRate(0);
                    synthesizer.setPitchRate(0);
                    synthesizer.setText("欢迎使用智能语音交互语音合成服务。");
                    synthesizer.addCustomedParam("enable_subtitle", false);

                    startedAt[0] = System.nanoTime();
                    synthesizer.start();
                    synthesizer.waitForComplete(30_000L);
                    if (failure.get() != null) {
                        throw failure.get();
                    }
                    if (!completed.get()) {
                        throw new TimeoutException("Synthesis did not complete within 30 seconds");
                    }
                } finally {
                    synthesizer.close();
                }
            }
            System.out.println("Audio file: " + output.toAbsolutePath());
        } finally {
            client.shutdown();
        }
    }
}

调用成功后，程序输出 Synthesis completed 和音频文件路径。打开生成的 WAV 文件检查音频内容。发生异常时，生成的临时文件可能不完整，不应作为合成结果使用。

示例等待上限为 30 秒，这是应用设置，不是服务耗时承诺。需要低延迟播放时，可在 onMessage 中边接收边播放；流式播放不改变输入文本的长度限制。

如果应用部署在上海地域的 ECS 上并需要内网访问，请从语音合成服务地址中选择适用的内网地址，不要将公网地址作为内网地址使用。

关键接口

调用流程为获取 Token、创建客户端及合成对象、设置参数、启动任务、处理回调并释放资源。

常见问题

<dependency>
    <groupId>org.json</groupId>
    <artifactId>json</artifactId>
    <version>20170516</version>
</dependency>
<dependency>
    <groupId>com.google.code.gson</groupId>
    <artifactId>gson</artifactId>
    <version>2.8.2</version>
</dependency>