在本文中，您将会了解到关于Android：尝试HttpURLConnection.getOutputStream的新资讯，同时我们还将为您解释时抛出SocketException的相关在本文中，我们将
在本文中，您将会了解到关于Android：尝试HttpURLConnection.getOutputStream的新资讯，同时我们还将为您解释时抛出SocketException的相关在本文中，我们将带你探索Android：尝试HttpURLConnection.getOutputStream的奥秘，分析时抛出SocketException的特点，并给出一些关于Android http HttpURLConnection、Android HttpURLConnection、Android HttpUrlConnection getInputStream引发NullPointerException、Android HTTPUrlConnection POST的实用技巧。
本文目录一览：- Android：尝试HttpURLConnection.getOutputStream（）时抛出SocketException（尝试检查url的错误）
- Android http HttpURLConnection
- Android HttpURLConnection
- Android HttpUrlConnection getInputStream引发NullPointerException
- Android HTTPUrlConnection POST
Android：尝试HttpURLConnection.getOutputStream（）时抛出SocketException（尝试检查url的错误）
这是我的第一个android程序，它是一个修改过的hello世界。我在MAC上的仿真器上运行它。我尝试与.NET
Web服务进行通信，但在处给出了异常connection.getOutputStream()。我可以从模拟器访问该站点。任何帮助表示赞赏:)
URL url = new URL("http://192.168.3.47/service.asmx"); HttpURLConnection connection = (HttpURLConnection)url.openConnection(); connection.setRequestMethod("POST"); connection.setRequestProperty("Content-Type", "application/soap+xml; charset=utf-8"); connection.setUseCaches(false); connection.setDoInput(true); connection.setDoOutput(true); String soapRequest = String.format(getText(R.string.ws_listemain_ds_new).toString(), city, keyword); connection.setRequestProperty("Content-Length", Integer.toString(soapRequest.getBytes("UTF-8").length)); //Send request OutputStreamWriter owr = new OutputStreamWriter(connection.getOutputStream(), "UTF-8");03-02 15:51:26.950: WARN/System.err(618): java.net.SocketException: Permission denied03-02 15:51:26.978: WARN/System.err(618): at org.apache.harmony.luni.platform.OSNetworkSystem.socket(Native Method)03-02 15:51:26.988: WARN/System.err(618): at dalvik.system.BlockGuard$WrappedNetworkSystem.socket(BlockGuard.java:335)03-02 15:51:27.009: WARN/System.err(618): at org.apache.harmony.luni.net.PlainSocketImpl.create(PlainSocketImpl.java:216)03-02 15:51:27.018: WARN/System.err(618): at java.net.Socket.checkOpenAndCreate(Socket.java:802)03-02 15:51:27.037: WARN/System.err(618): at java.net.Socket.connect(Socket.java:948)03-02 15:51:27.048: WARN/System.err(618): at org.apache.harmony.luni.internal.net.www.protocol.http.HttpConnection.(HttpConnection.java:75)03-02 15:51:27.067: WARN/System.err(618): at org.apache.harmony.luni.internal.net.www.protocol.http.HttpConnection.(HttpConnection.java:48)03-02 15:51:27.079: WARN/System.err(618): at org.apache.harmony.luni.internal.net.www.protocol.http.HttpConnection$Address.connect(HttpConnection.java:322)03-02 15:51:27.139: WARN/System.err(618): at org.apache.harmony.luni.internal.net.www.protocol.http.HttpConnectionPool.get(HttpConnectionPool.java:89)03-02 15:51:27.158: WARN/System.err(618): at org.apache.harmony.luni.internal.net.www.protocol.http.HttpURLConnectionImpl.getHttpConnection(HttpURLConnectionImpl.java:285)03-02 15:51:27.167: WARN/System.err(618): at org.apache.harmony.luni.internal.net.www.protocol.http.HttpURLConnectionImpl.makeConnection(HttpURLConnectionImpl.java:267)03-02 15:51:27.187: WARN/System.err(618): at org.apache.harmony.luni.internal.net.www.protocol.http.HttpURLConnectionImpl.connect(HttpURLConnectionImpl.java:205)03-02 15:51:27.197: WARN/System.err(618): at org.apache.harmony.luni.internal.net.www.protocol.http.HttpURLConnectionImpl.getOutputStream(HttpURLConnectionImpl.java:614)03-02 15:51:27.217: WARN/System.err(618): at gyozo.HelloWorld.HelloActivity.onClick(HelloActivity.java:55)03-02 15:51:27.269: WARN/System.err(618): at android.view.View.performClick(View.java:2485)03-02 15:51:27.311: WARN/System.err(618): at android.view.View$PerformClick.run(View.java:9080)03-02 15:51:27.327: WARN/System.err(618): at android.os.Handler.handleCallback(Handler.java:587)03-02 15:51:27.347: WARN/System.err(618): at android.os.Handler.dispatchMessage(Handler.java:92)03-02 15:51:27.367: WARN/System.err(618): at android.os.Looper.loop(Looper.java:123)03-02 15:51:27.447: WARN/System.err(618): at android.app.ActivityThread.main(ActivityThread.java:3683)03-02 15:51:27.457: WARN/System.err(618): at java.lang.reflect.Method.invokeNative(Native Method)03-02 15:51:27.519: WARN/System.err(618): at java.lang.reflect.Method.invoke(Method.java:507)03-02 15:51:27.527: WARN/System.err(618): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)03-02 15:51:27.547: WARN/System.err(618): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)03-02 15:51:27.547: WARN/System.err(618): at dalvik.system.NativeStart.main(Native Method)答案1
小编典典尝试在您的AndroidManifest.xml中添加“互联网”权限：
<uses-permission android:name="android.permission.INTERNET" />
Android http HttpURLConnection
/**
* Http get 请求
*
* @param urlPath
*
*
*/
private static String httpConnByGet(RequestUrl ru,Params params){
String token = (String) params.getMap().get("token") ;
String et = (String) params.getMap().get("et") ;
params.getMap().remove("et");
if(token != null ){
params.getMap().put("token",Md5.md5(token + et + params.getMap().get("uid") + ru.getKeywords()));
}
String urlPath = ru.getUrl() + HttpURLConstant.QMARK + HttpURLConstant.COMMON_PARAMS + et + params.toString() ; //通用参数的设置
Log.w("NETURL","geturl:"+urlPath);
URL url = null;
HttpURLConnection urlConnection = null;
try {
ByteArrayOutputStream outStream = new ByteArrayOutputStream();
byte[] data = new byte[2048]; //应该不会小吧！
int len = 0;
url = new URL(urlPath);
urlConnection = (HttpURLConnection) url.openConnection();
// Class<?> clazz=url.openConnection().getClass(); //看看返回什么鬼类型
// Class<?> clazzSuper=clazz.getSuperclass(); //父类又是什么鬼啊！
//getInputStream暗中执行了连接,不需要urlConnection.connect();
urlConnection.setReadTimeout(readTimeout); // 设置请求的超时时间
urlConnection.setConnectTimeout(connectTimeout);
if (urlConnection.getResponseCode() == HttpURLConnection.HTTP_OK) {
InputStream inStream = urlConnection.getInputStream(); //获取输入流，此时才真正建立链接
while ((len = inStream.read(data)) != -1) {
outStream.write(data, 0, len);
}
inStream.close();
if(isDebug){Log.e(TAG,"get 返回数据"+new String(outStream.toByteArray()));}
return new String(outStream.toByteArray());
}else{ //返回的是HTTP的错误码，不是我们自己定义的错误码！
//处理一下http的错误返回码
Log.e(TAG,"get 网络连接失败"+urlConnection.getResponseCode());
return "HTTP_ERROR-"+urlConnection.getResponseCode();
}
} catch (MalformedURLException e) {
e.printStackTrace();
Log.e(TAG,"MalformedURLException e");
} catch (IOException e) {
e.printStackTrace();
Log.e(TAG,"IOException e");
} finally{
if(urlConnection!=null){
urlConnection.disconnect(); //总是需要关闭的吧！
}
}
return null;
}
/**
* Http Post 请求
*
* @param urlpath
* @param paramsDatas
*/
private static String httpConnByPost(RequestUrl ru,Params params) {
String token = (String) params.getMap().get("token") ;
String et = (String) params.getMap().get("et") ;
params.getMap().remove("et");
if(token != null ){
params.getMap().put("token", Md5.md5(token + et + params.getMap().get("uid") + ru.getKeywords()));
}
URL url = null; // 根据地址创建URL对象
HttpURLConnection urlConnection = null; // 根据URL对象打开链接
try {
url = new URL(ru.getUrl()); // 根据地址创建URL对象
urlConnection = (HttpURLConnection) url.openConnection(); // 根据URL对象打开链接
urlConnection.setRequestMethod("POST"); // 设置请求的方式
urlConnection.setReadTimeout(readTimeout); // 设置请求的超时时间
urlConnection.setConnectTimeout(connectTimeout);
String paramsData = HttpURLConstant.COMMON_PARAMS + et + params.toString(); //通用参数的使用要注意
Log.w("NETURL",url+"?"+paramsData);
urlConnection.setRequestProperty("Connection", "keep-alive"); // 设置维持长连接
urlConnection.setRequestProperty("Content-Type","application/x-www-form-urlencoded"); // 设置文件的类型
urlConnection.setRequestProperty("Content-Length",String.valueOf(paramsData.getBytes().length)); // 设置数据的长度
urlConnection.setRequestProperty("User-Agent","Devond_Watch,Android-device."); // ???
urlConnection.setDoOutput(true); // 发送POST请求必须设置允许输出
urlConnection.setDoInput(true); // 发送POST请求必须设置允许输入，setDoInput的默认值就是true
urlConnection.setUseCaches(false); // 为安全，不允许使用缓存
urlConnection.connect(); //urlConnection.getInputStream()的时候会自动的打开连接的
OutputStream os = urlConnection.getOutputStream(); //获取输出流developer
os.write(paramsData.getBytes());
os.flush();
if (urlConnection.getResponseCode() == HttpURLConnection.HTTP_OK) {
InputStream is = urlConnection.getInputStream(); // 获取响应的输入流对象
ByteArrayOutputStream baos = new ByteArrayOutputStream(); // 创建字节输出流对象
int len = 0; // 定义读取的长度
byte buffer[] = new byte[2048]; // 定义缓冲区
while ((len = is.read(buffer)) != -1) { // 按照缓冲区的大小，循环读取
baos.write(buffer, 0, len); // 根据读取的长度写入到os对象中
}
is.close();// 释放资源
baos.close();
final String result = new String(baos.toByteArray());
if(isDebug){
Log.e(TAG,"Post返回的数据:"+result);
}
return new String(baos.toByteArray());
}else{ //返回的是HTTP的错误码，不是我们自己定义的错误码！
//处理一下http的错误返回码
Log.e(TAG,urlConnection.getResponseCode()+"#Post 网络连接失败#"+urlConnection.getErrorStream());
return "HTTP_ERROR-"+urlConnection.getResponseCode();
}
} catch (MalformedURLException e) {
e.printStackTrace();
Log.e(TAG,"MalformedURLException e");
}catch (Exception e) {
e.printStackTrace();
}finally{
if(urlConnection!=null){
urlConnection.disconnect();
}
}
Log.e(TAG,"Post 请求返回为空");
return null;
}
Android HttpURLConnection
谷歌推荐用HttpUrlConnection
HttpURLConnection默认使用GET方式 :
URL url = new URL("www.baidu.com");
//使用HttpURLConnection打开连接
HttpURLConnection urlConn = (HttpURLConnection) url.openConnection();
//得到读取的内容(流)
InputStreamReader in = new InputStreamReader(urlConn.getInputStream());
// 为输出创建BufferedReader
BufferedReader buffer = new BufferedReader(in);
String inputLine = null;
//使用循环来读取获得的数据
while (((inputLine = buffer.readLine()) != null)){
//我们在每一行后面加上一个"\n"来换行
resultData += inputLine + "\n";
}
//关闭InputStreamReader
in.close();
//关闭http连接
urlConn.disconnect();使用POST方式，则需要setRequestMethod设置 :
String httpUrl = "http://192.168.1.110:8080/httpget.jsp";
//获得的数据
String resultData = "";
URL url = null;
try {
//构造一个URL对象
url = new URL(httpUrl);
}
catch (MalformedURLException e){
Log.e(DEBUG_TAG, "MalformedURLException");
}
if (url != null){
try{
// 使用HttpURLConnection打开连接
HttpURLConnection urlConn = (HttpURLConnection) url.openConnection();
//因为这个是post请求,设立需要设置为true
urlConn.setDoOutput(true);
urlConn.setDoInput(true);
// 设置以POST方式
urlConn.setRequestMethod("POST");
// Post 请求不能使用缓存
urlConn.setUseCaches(false);
urlConn.setInstanceFollowRedirects(true);
// 配置本次连接的Content-type，配置为application/x-www-form-urlencoded的
urlConn.setRequestProperty("Content-Type","application/x-www-form-urlencoded");
// 连接，从postUrl.openConnection()至此的配置必须要在connect之前完成，
// 要注意的是connection.getOutputStream会隐含的进行connect。
urlConn.connect();
//DataOutputStream流
DataOutputStream out = new DataOutputStream(urlConn.getOutputStream());
//要上传的参数
String content = "par=" + URLEncoder.encode("ABCDEFG", "gb2312");
//将要上传的内容写入流中
out.writeBytes(content);
//刷新、关闭
out.flush();
out.close();
//返回响应结果
BufferedReader br = new BufferedReader(new InputStreamReader(urlConn.getinputstream()))
string line = br.readline();
while(line != null){
system.out.printli(line);
line = br.readline();
}
Android HttpUrlConnection getInputStream引发NullPointerException
我正在尝试从以下网址下载图像：
https://hme_player_pictures.s3.amazonaws.com/test-512813ed3b83286c72f376c7-thumb100.jpg
这是堆栈跟踪：
03-21 12:58:04.040: W/System.err(7084): java.lang.NullPointerException
03-21 12:58:04.040: W/System.err(7084): at libcore.net.http.httpconnection$Address.hashCode(httpconnection.java:343)
03-21 12:58:04.045: W/System.err(7084): at java.util.HashMap.get(HashMap.java:298)
03-21 12:58:04.050: W/System.err(7084): at libcore.net.http.httpconnectionPool.get(httpconnectionPool.java:67)
03-21 12:58:04.050: W/System.err(7084): at libcore.net.http.httpconnection.connect(httpconnection.java:128)
03-21 12:58:04.050: W/System.err(7084): at libcore.net.http.HttpEngine.openSocketConnection(HttpEngine.java:308)
03-21 12:58:04.055: W/System.err(7084): at libcore.net.http.HttpsURLConnectionImpl$HttpsEngine.makeSslConnection(HttpsURLConnectionImpl.java:460)
03-21 12:58:04.055: W/System.err(7084): at libcore.net.http.HttpsURLConnectionImpl$HttpsEngine.connect(HttpsURLConnectionImpl.java:432)
03-21 12:58:04.055: W/System.err(7084): at libcore.net.http.HttpEngine.sendSocketRequest(HttpEngine.java:282)
03-21 12:58:04.060: W/System.err(7084): at libcore.net.http.HttpEngine.sendRequest(HttpEngine.java:232)
03-21 12:58:04.065: W/System.err(7084): at libcore.net.http.HttpURLConnectionImpl.getResponse(HttpURLConnectionImpl.java:273)
03-21 12:58:04.065: W/System.err(7084): at libcore.net.http.HttpURLConnectionImpl.getInputStream(HttpURLConnectionImpl.java:168)
03-21 12:58:04.070: W/System.err(7084): at libcore.net.http.HttpsURLConnectionImpl.getInputStream(HttpsURLConnectionImpl.java:270)
03-21 12:58:04.070: W/System.err(7084): ...
码：
URL imageUrl = new URL(url);
HttpURLConnection c = (HttpURLConnection)imageUrl.openConnection();
InputStream in = c.getInputStream(); // Nullpointer exception on this line, c is definitely not null, I debugged
无法弄清楚为什么会引发NullPointerException.上面的网址确实可以在浏览器中使用.
解决方法:
对于它的价值,我在Android HTTP库中看到很多错误.从条码扫描器中,我可以看到大约3500万人员的堆栈跟踪,因此,我想我已经看到了其中的一切.这是我们在下面的应用程序中发现并吞下的所有怪异内容.我建议您将其作为平台错误来解决,并优雅地失败.
https://code.google.com/p/zxing/source/browse/trunk/android/src/com/google/zxing/client/android/HttpHelper.java
private static int safelyConnect(String uri, HttpURLConnection connection) throws IOException {
try {
connection.connect();
} catch (NullPointerException npe) {
// this is an Android bug: http://code.google.com/p/android/issues/detail?id=16895
Log.w(TAG, "Bad URI? " + uri);
throw new IOException(npe.toString());
} catch (IllegalArgumentException iae) {
// Also seen this in the wild, not sure what to make of it. Probably a bad URL
Log.w(TAG, "Bad URI? " + uri);
throw new IOException(iae.toString());
} catch (SecurityException se) {
// due to bad VPN settings?
Log.w(TAG, "Restricted URI? " + uri);
throw new IOException(se.toString());
} catch (indexoutofboundsexception ioobe) {
// Another Android problem? https://groups.google.com/forum/?fromgroups#!topic/google-admob-ads-sdk/U-WfmYa9or0
Log.w(TAG, "Bad URI? " + uri);
throw new IOException(ioobe.toString());
}
try {
return connection.getResponseCode();
} catch (NullPointerException npe) {
// this is maybe this Android bug: http://code.google.com/p/android/issues/detail?id=15554
Log.w(TAG, "Bad URI? " + uri);
throw new IOException(npe.toString());
} catch (NumberFormatException nfe) {
// Again seen this in the wild for bad header fields in the server response!
Log.w(TAG, "Bad server status? " + uri);
throw new IOException(nfe.toString());
}
}
Android HTTPUrlConnection POST
我正在使用HttpURLConnection通过POST将数据发送到服务器.我设置头,然后获取输出流并写入5个字节的数据(“ M = 005”),然后关闭输出流.
在服务器上,我收到了所有标头,正确的内容长度,但是随后得到的长度为零,并且服务器挂在readLine上.
似乎发生的事情是客户端关闭实际上从未发生,因此不会写入整个数据,因此服务器永远不会获得它.
我已经阅读了许多示例,并尝试了各种更改,以查看我是否可以以任何方式实现此目标,而效果均不理想.例如,关闭保持活动状态,然后在数据末尾强制执行CRLF(这会迫使我的数据在服务器端发出,但连接仍无法关闭.(仅用于测试),尝试使用打印写程序.
由于很多示例都在执行我的操作,因此我认为这很简单,但是我看不到它.任何帮助,将不胜感激.
StringBuilder postDataBuilder.append("M=").append(URLEncoder.encode("005", UTF8));
byte[] postData = null;
postData = postDataBuilder.toString().getBytes();
url = new URL("http://" + serverAddress + ":" + String.valueOf(serverPort));
conn = (HttpURLConnection) url.openConnection();
conn.setDoOutput(true);
conn.setRequestMethod("POST");
conn.setRequestProperty("Content-Length", Integer.toString(postData.length));
conn.setUseCaches(false);
OutputStream out = conn.getoutputStream();
out.write(postData);
out.close();
int responseCode = conn.getResponseCode();
// After executing the above line the server starts to successfully readLines
// until it gets to the post data when the server hangs. If I restart the
// client side then the data finally gets through but the connection on the
// server side never ends.
解决方法:
哎呀我们服务器端的错误是执行readLine而不是字符读取.由于没有CRLF,它将挂起.
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