Question

我遇到了从网页抓取的JSON数组的奇怪字符编码问题。服务器正在发送回此标头：

Content-Type text / javascript;字符集= UTF-8

此外，我可以查看Firefox或任何浏览器中的JSON输出，并正确显示Unicode字符。响应有时会包含来自其他语言的单词，带有重音符号等。但是当我把它拉下来并把它放到Java中的字符串时，我得到那些奇怪的问号。这是我的代码：

HttpParams params = new BasicHttpParams();
HttpProtocolParams.setVersion(params, HttpVersion.HTTP_1_1);
HttpProtocolParams.setContentCharset(params, "utf-8");
params.setBooleanParameter("http.protocol.expect-continue", false);

HttpClient httpclient = new DefaultHttpClient(params);

HttpGet httpget = new HttpGet("http://www.example.com/json_array.php");
HttpResponse response;
    try {
        response = httpclient.execute(httpget);

        if(response.getStatusLine().getStatusCode() == 200){
            // Connection was established. Get the content. 

            HttpEntity entity = response.getEntity();
            // If the response does not enclose an entity, there is no need
            // to worry about connection release

            if (entity != null) {
                // A Simple JSON Response Read
                InputStream instream = entity.getContent();
                String jsonText = convertStreamToString(instream);

                Toast.makeText(getApplicationContext(), "Response: "+jsonText, Toast.LENGTH_LONG).show();

            }

        }


    } catch (MalformedURLException e) {
        Toast.makeText(getApplicationContext(), "ERROR: Malformed URL - "+e.getMessage(), Toast.LENGTH_LONG).show();
        e.printStackTrace();
    } catch (IOException e) {
        Toast.makeText(getApplicationContext(), "ERROR: IO Exception - "+e.getMessage(), Toast.LENGTH_LONG).show();
        e.printStackTrace();
    } catch (JSONException e) {
        Toast.makeText(getApplicationContext(), "ERROR: JSON - "+e.getMessage(), Toast.LENGTH_LONG).show();
        e.printStackTrace();
    }

private static String convertStreamToString(InputStream is) {
    /*
     * To convert the InputStream to String we use the BufferedReader.readLine()
     * method. We iterate until the BufferedReader return null which means
     * there's no more data to read. Each line will appended to a StringBuilder
     * and returned as String.
     */
    BufferedReader reader;
    try {
        reader = new BufferedReader(new InputStreamReader(is, "UTF-8"));
    } catch (UnsupportedEncodingException e1) {
        // TODO Auto-generated catch block
        e1.printStackTrace();
    }
    StringBuilder sb = new StringBuilder();

    String line;
    try {
        while ((line = reader.readLine()) != null) {
            sb.append(line + "\n");
        }
    } catch (IOException e) {
        e.printStackTrace();
    } finally {
        try {
            is.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    return sb.toString();
}

正如您所看到的，我在InputStreamReader上指定了UTF-8，但每次通过Toast查看返回的JSON文本时都会出现奇怪的问号。我想我需要将InputStream发送到byte []而不是？

提前感谢您的帮助。

Answer 1

试试这个：

if (entity != null) {
    // A Simple JSON Response Read
    // InputStream instream = entity.getContent();
    // String jsonText = convertStreamToString(instream);

    String jsonText = EntityUtils.toString(entity, HTTP.UTF_8);

    // ... toast code here
}

Answer 2

@ Arhimed的答案是解决方案。但是我的convertStreamToString代码看不出任何明显错误。

我的猜测是：

服务器在流的开头放置UTF字节顺序标记（BOM）。标准的Java UTF-8字符解码器不会删除BOM，因此很可能会在结果字符串中结束。（但是，EntityUtils的代码似乎也没有对BOM做任何事情。）
您的convertStreamToString一次读取一行字符串，并使用硬连线'\n'作为行尾标记重新组合。如果您要将其写入外部文件或应用程序，则应该使用特定于平台的行尾标记。

Answer 3

只是你的convertStreamToString不遵守HttpRespnose中的编码集。如果您查看EntityUtils.toString(entity, HTTP.UTF_8)内部，您将看到EntityUtils首先查明HttpResponse中是否存在编码集，然后如果存在，则EntityUtils使用该编码。如果实体中没有编码集，它将仅回退到参数中传递的编码（在本例中为HTTP.UTF_8）。

所以你可以说你的HTTP.UTF_8在参数中传递但它永远不会被使用，因为它是错误的编码。所以这里是使用EntityUtils中的helper方法更新代码。

           HttpEntity entity = response.getEntity();
           String charset = getContentCharSet(entity);
           InputStream instream = entity.getContent();
           String jsonText = convertStreamToString(instream,charset);

    private static String getContentCharSet(final HttpEntity entity) throws ParseException {
    if (entity == null) {
        throw new IllegalArgumentException("HTTP entity may not be null");
    }
    String charset = null;
    if (entity.getContentType() != null) {
        HeaderElement values[] = entity.getContentType().getElements();
        if (values.length > 0) {
            NameValuePair param = values[0].getParameterByName("charset");
            if (param != null) {
                charset = param.getValue();
            }
        }
    }
    return TextUtils.isEmpty(charset) ? HTTP.UTF_8 : charset;
}



private static String convertStreamToString(InputStream is, String encoding) {
    /*
     * To convert the InputStream to String we use the
     * BufferedReader.readLine() method. We iterate until the BufferedReader
     * return null which means there's no more data to read. Each line will
     * appended to a StringBuilder and returned as String.
     */
    BufferedReader reader;
    try {
        reader = new BufferedReader(new InputStreamReader(is, encoding));
    } catch (UnsupportedEncodingException e1) {
        // TODO Auto-generated catch block
        e1.printStackTrace();
    }
    StringBuilder sb = new StringBuilder();

    String line;
    try {
        while ((line = reader.readLine()) != null) {
            sb.append(line + "\n");
        }
    } catch (IOException e) {
        e.printStackTrace();
    } finally {
        try {
            is.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    return sb.toString();
}

Answer 4

Archimed的回答是正确的。但是，这可以通过在HTTP请求中提供额外的标头来完成：

Accept-charset: utf-8

无需删除任何内容或使用任何其他库。

例如，

GET / HTTP/1.1
Host: www.website.com
Connection: close
Accept: text/html
Upgrade-Insecure-Requests: 1
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/48.0.2564.10 Safari/537.36
DNT: 1
Accept-Encoding: gzip, deflate, sdch
Accept-Language: en-US,en;q=0.8
Accept-Charset: utf-8

您的请求很可能没有任何Accept-Charset标题。

Answer 5

从响应内容类型字段中提取字符集。您可以使用以下方法执行此操作：

private static String extractCharsetFromContentType(String contentType) {
    if (TextUtils.isEmpty(contentType)) return null;

    Pattern p = Pattern.compile(".*charset=([^\\s^;^,]+)");
    Matcher m = p.matcher(contentType);

    if (m.find()) {
        try {
            return m.group(1);
        } catch (Exception e) {
            return null;
        }
    }

    return null;
}

然后使用提取的字符集创建InputStreamReader：

String charsetName = extractCharsetFromContentType(connection.getContentType());

InputStreamReader inReader = (TextUtils.isEmpty(charsetName) ? new InputStreamReader(inputStream) :
                    new InputStreamReader(inputStream, charsetName));
            BufferedReader reader = new BufferedReader(inReader);

Android Java UTF-8 HttpClient问题

5 个答案: