J2ME、诺基亚、HttpConnection

Question

该代码在索尼爱立信和摩托罗拉手机上运行良好，但在诺基亚手机上，它要么一开始就失败，根本不发出任何请求，要么返回空响应，具体取决于型号。

    HttpConnection hc = null;
    InputStream is = null;
    InputStreamReader isr = null;
    String result = "";

    try
    {
        hc = (HttpConnection) Connector.open(url);
        int rc = hc.getResponseCode();
        if (rc != HttpConnection.HTTP_OK)
        {
            throw new IOException(hc.getResponseMessage());
        }

        is = hc.openInputStream();
        isr = new InputStreamReader(is, "utf-8");
        int ch;
        while ((ch = is.read()) != -1)
        {
            result += (char) ch;
        }
    }
    finally
    {
        if (is != null)
        {
            is.close();
        }
        if (hc != null)
        {
            hc.close();
        }
    }

    return result;

尝试使用字节缓冲区、流等不同的代码，结果总是相同的。有什么问题吗？

Answer 1

尝试一下

import java.io.ByteArrayOutputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.Enumeration;
import java.util.Hashtable;
import javax.microedition.io.Connector;
import javax.microedition.io.HttpConnection;

public class Transport {

public static int BUFFER_LENGTH = 100;//1024;
public static boolean USE_FLUSH = false;

static {
    if (DeviceDetect.getDeivice() == DeviceDetect.SAMSUNG) {
        BUFFER_LENGTH = 1024;
        USE_FLUSH = true;
    }
}
public static String SESSION_COOKIE = null;


private static int rnd = 1;

private static final String request(String url, String method, Hashtable params) throws IOException {
    HttpConnection conn = null;
    DataOutputStream dos = null;
    InputStream in = null;

    try {

        String encodedParams = null;
        if (params != null && params.size() > 0) {
            encodedParams = getEncodedParams(params);
        }
        if (method == null) {
            if (encodedParams.length() < 2000) {
                method = "GET";
            } else {
                method = "POST";
            }
        }

        method = method != null && method.equalsIgnoreCase("POST") ? HttpConnection.POST : HttpConnection.GET;

        if (method.equalsIgnoreCase(HttpConnection.GET)) {
            if (encodedParams != null) {
                url += (url.indexOf("?") == -1 ? "?" : "&") + encodedParams;
                encodedParams = null;
            }
            url += (url.indexOf("?") == -1 ? "?" : "&") + "_rnd=" + rnd++;
        }

        conn = (HttpConnection) Connector.open(url, Connector.READ_WRITE, true);
        if (conn == null) {
            throw new IOException("HttpConnection is null, please check Access Point configuration");
        }

        conn.setRequestMethod(method);
        conn.setRequestProperty("User-Agent", UserAgent.getUserAgent());
        conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
        if (SESSION_COOKIE != null) {
            conn.setRequestProperty("Cookie", SESSION_COOKIE);
        }

        byte[] buff = new byte[BUFFER_LENGTH];
        if (encodedParams != null) {
            byte[] bytes = encodedParams.getBytes("UTF-8");
            String lengthStr = bytes.length + "";
            conn.setRequestProperty("Content-Length", lengthStr);

            dos = conn.openDataOutputStream();
            if (dos == null) {
                throw new IOException("OutputStream is null, please check Access Point configuration");
            }

            for (int i = 0, l = bytes.length; i < l; i += Transport.BUFFER_LENGTH) {
                if (Transport.BUFFER_LENGTH == 1) {
                    dos.writeByte(bytes[i]);
                } else {
                    int count = Math.min(Transport.BUFFER_LENGTH, l - i);
                    System.arraycopy(bytes, i, buff, 0, count);
                    dos.write(buff, 0, count);
                }
                if (Transport.USE_FLUSH) {
                    dos.flush();
                }
            }

            dos.flush();
            try {
                dos.close();
            } catch (IOException ex) {
            }
        }

        String setCookie = conn.getHeaderField("Set-Cookie");
        if (setCookie != null) {
            int ind1 = setCookie.indexOf("JSESSIONID=");
            if (ind1 > -1) {
                int ind2 = setCookie.indexOf(";", ind1);
                SESSION_COOKIE = ind2 == -1 ? setCookie.substring(ind1) : setCookie.substring(ind1, ind2 + 1);
            }
        }

        in = conn.openInputStream();
        if (in == null) {
            throw new IOException("InputStream is null, please check Access Point configuration");
        }
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        int n = in.read(buff);
        while (n > -1) {
            baos.write(buff, 0, n);
            n = in.read(buff);
        }
        baos.flush();
        baos.close();
        String response = new String(baos.toByteArray(), "UTF-8");
        try {
            in.close();
        } catch (Exception ex) {
        }
        try {
            conn.close();
        } catch (Exception ex) {
        }

        return response;
    } finally {
        try {
            dos.close();
        } catch (Exception ex) {
        }
        try {
            in.close();
        } catch (Exception ex) {
        }
        try {
            conn.close();
        } catch (Exception ex) {
        }
    }

}

public static String getEncodedParams(Hashtable params) throws IOException {
    String str = "";
    Enumeration keys = params.keys();
    while (keys.hasMoreElements()) {
        String name = (String) keys.nextElement();
        Object value = params.get(name);
        if (value == null || name == null) {
            continue;
        }            
        str += "&" + URLEncoder.encode(name.toString(), "UTF-8") + "=" + URLEncoder.encode(value.toString(), "UTF-8");
    }
    if (str.length() > 1) {
        str = str.substring(1);
    }
    return str;
}
}

Answer 2

我不确定这是否适合您，但我遇到了类似的问题，并发现指定端口号可以使其工作（在某些较旧的诺基亚型号上）。即转换：

 http://www.mysite.com/my_page.html

为：

http://mysite.com:80/my_page.html