java - 尝试使用 JSON 将 http 发布到服务器，获取 : java. io.UnsupportedEncodingException

Question

我有一台服务器，上面有一个 servlet，用作我的移动应用程序的后端。当我在 Eclipse 中测试它时，它在我的计算机上运行良好，但是当我尝试从服务器获取数据时，它出现在日志中。

Mar 15, 2012 4:38:37 AM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet [Hello] in context with path [] threw exception
java.io.UnsupportedEncodingException: The character encoding [ISO-8859-1, application/json] is not supported
at org.apache.tomcat.util.buf.B2CConverter.getCharset(B2CConverter.java:74)
at org.apache.tomcat.util.buf.B2CConverter.reset(B2CConverter.java:159)
at org.apache.tomcat.util.buf.B2CConverter.<init>(B2CConverter.java:97)
at org.apache.catalina.connector.InputBuffer.setConverter(InputBuffer.java:556)
at org.apache.catalina.connector.InputBuffer.checkConverter(InputBuffer.java:518)
at org.apache.catalina.connector.Request.getReader(Request.java:1238)
at org.apache.catalina.connector.RequestFacade.getReader(RequestFacade.java:505)
at com.myserver.server.Hello.decodeRequest(Hello.java:319)
at com.myserver.server.Hello.doPost(Hello.java:93)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:641)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:224)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:169)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:168)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:987)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:579)
at org.apache.tomcat.util.net.AprEndpoint$SocketWithOptionsProcessor.run(AprEndpoint.java:1763)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:662)

这是怎么回事？是托管公司还是我？

编辑:这是我正在使用的 jar 的列表。

asm-3.1.jar

jackson 核心-asl-1.8.3.jar

jackson -jaxrs-1.8.3.jar

jackson-mapper-asl-1.8.3.jar

jackson -xc-1.8.3.jar

jersey-client-1.10.jar

jersey-core-1.10.jar

Jersey -json-1.10.jar

jersey-server-1.10.jar

Jersey -servlet-1.10.jar

jettison-1.1.jar

jsr311-api-1.1.1.jar

sqlite-jdbc-3.7.2.jar

发布 JSON 的代码:

public class SendJSON{
JSONArray outr = new JSONArray();

GetSet gs = new GetSet();
URI u;
String out;

public JSONArray sendJ(final JSONArray json) throws JSONException{

    ATask task = new ATask(json);
    AsyncTask<URL, Integer, JSONArray> t = task.execute();
    try {
        outr = t.get();
    } catch (InterruptedException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (ExecutionException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
    return outr;
}

public JSONArray sendJ2(final JSONArray json) throws JSONException {

    try {
        u = new URI("http://mycensoredurl/Hello");
    } catch (URISyntaxException e1) {
        e1.printStackTrace();
    }

    HttpClient client = new DefaultHttpClient();

    HttpConnectionParams.setConnectionTimeout(client.getParams(), 10000); //Timeout Limit HttpResponse response;
    HttpPost post = new HttpPost(u); 

    StringEntity se = null;
    try {

        se = new StringEntity( json.toString());
    } catch (UnsupportedEncodingException e1) {
        // TODO Auto-generated catch block
        e1.printStackTrace();
    }

    se.setContentEncoding(new BasicHeader(HTTP.CONTENT_TYPE, "application/json"));

    post.setEntity(se); 

    StringBuilder builder = new StringBuilder();
    try {
        HttpResponse response = client.execute(post);
        StatusLine statusLine = response.getStatusLine();
        int statusCode = statusLine.getStatusCode();
        if (statusCode == 200) {
            Log.d("DEBUG", "status code = 200");
            HttpEntity entity = response.getEntity();
            InputStream content = entity.getContent();
            BufferedReader reader = new BufferedReader(
                    new InputStreamReader(content));
            String line;
            while ((line = reader.readLine()) != null) {
                builder.append(line);
            }
        } else {
            Log.e(SendJSON.class.toString(), "Failed to download file");
        }
    } catch (ClientProtocolException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }
    Log.d("JSON RESPONSE SHOULD", "BE NEXT..");

    Log.d("JSON RESPONSE LENGTH", ""+ builder.length());
    out = builder.toString();
    gs.setOut(out);

    Log.d("SendJSON... JSON RESPONSE String", ""+ out);
    return new JSONArray(out); 
}

private class ATask extends AsyncTask<URL, Integer, JSONArray>{
    private JSONArray jary;

    private ATask(JSONArray json) {
        this.jary = json;
    }

    @Override
    protected JSONArray doInBackground(URL... params) {
        try {
            outr = sendJ2(jary);
        } catch (JSONException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return outr;
    }

}

我认为那里的异步任务是 b.s。并且不需要在那里。作为作业的一部分，一位教授让我把它放在那里。 (顺便说一句，这不是作业帮助，那节课已经结束了)

Answer 1

看起来您的 Content-Type header 又坏了 - 它应该是这样的:

Content-Type: application/json; charset=ISO-8859-1

但看起来它可能会回来:

Content-Type: application/json; charset=ISO-8859-1, application/json

或类似的东西。查看带有 Wireshark 之类的 header

这看起来像问题:

se.setContentEncoding(new BasicHeader(HTTP.CONTENT_TYPE, "application/json"));

我怀疑 application/json 不应该是编码的一部分——它是内容类型的一部分。尝试将其更改为:

se.setContentType(new BasicHeader(HTTP.CONTENT_TYPE, "application/json"));