请求很简单，代码如下：

public class VoiceSynthesis {

private static final String serverURL = "http://tsn.baidu.com/text2audio";

private static String token = "";

private static final String apiKey = "g1wSfeYnnLxt7NbErHtrSD75";

private static final String secretKey = "8b5ad2c63a8d75d5012348b836c4b55e";

private static final String cuid = "B8-88-E3-E7-FB-7B";

private static final String lan = "zh";

private static final String testContext = "人道主义";

public static void main(String[] args) throws Exception {

getToken();

method1();

}

private static void getToken() throws Exception {

String getTokenURL = "https://openapi.baidu.com/oauth/2.0/token?grant_type=client_credentials"

+ "&client_id=" + apiKey + "&client_secret=" + secretKey;

HttpURLConnection conn = (HttpURLConnection) new URL(getTokenURL)

.openConnection();

token = new JSONObject(printResponse(conn)).getString("access_token");

}

private static void method1() throws Exception {

HttpURLConnection conn = (HttpURLConnection) new URL(serverURL)

.openConnection();

// construct params

JSONObject params = new JSONObject();

params.put("tex", testContext);

params.put("lan", lan);

params.put("tok", token);

params.put("ctp", 1);

params.put("cuid", cuid);

// add request header

conn.setRequestMethod("POST");

conn.setRequestProperty("Content-Type",

"application/json; charset=utf-8");

conn.setDoInput(true);

conn.setDoOutput(true);

// send request

DataOutputStream wr = new DataOutputStream(conn.getOutputStream());

wr.writeBytes(params.toString());

wr.flush();

wr.close();

printResponse(conn);

}

private static String printResponse(HttpURLConnection conn)

throws Exception {

if (conn.getResponseCode() != 200) {

// request error

return "";

}

InputStream is = conn.getInputStream();

BufferedReader rd = new BufferedReader(new InputStreamReader(is));

String line;

StringBuffer response = new StringBuffer();

while ((line = rd.readLine()) != null) {

response.append(line);

response.append('\r');

}

rd.close();

System.out.println(new JSONObject(response.toString()).toString(4));

return response.toString();

}

运行后控制台打印如下：

{

    "scope": "public audio_voice_assistant_get audio_tts_post wise_adapt lebo_resource_base lightservice_public hetu_basic lightcms_map_poi kaidian_kaidian",

    "session_secret": "4db44e79ad8c8f99f3246ec50ae7aebd",

    "expires_in": 2592000,

    "refresh_token": "25.b1d448fc31da25207da8105cafcdbb2e.315360000.1780049836.282335-8202548",

    "session_key": "9mzdWEjl9j9XcU+5OXFMp7W9IazpUIEna2kTY76zU7nHDr07u28d5kUoxuJg9XZA11JiEaG8IEsJIo2EtL7fNuuRRnb+",

    "access_token": "24.c8e56c992c8d6c5e1ecc231e4e5a4bd6.2592000.1467281836.282335-8202548"

}

{

    "err_msg": "parameter error.",

    "err_no": 501

}

提示参数错误，到底错在哪里