设置库的属性
Set attributes of libraries
我正在开发一个应用程序，我需要在其中从在线数据库中检索数据，并且我正在导入 HttpClient、HttpEntity、HttpPost 等。
现在，我遇到的问题是以下消息 "no main manifest attribute, in C:\Users(......)"
因此我打开了这些库的 manifest.mf，但我找不到任何错误，也找不到 "attribute" 字段。
HttpClient 示例
Manifest-Version: 1.0
Implementation-Title: HttpComponents Apache HttpClient Cache
Implementation-Version: 4.5.1
Built-By: oleg
Specification-Vendor: The Apache Software Foundation
Created-By: Apache Maven 3.0.5
url: http://hc.apache.org/httpcomponents-client
X-Compile-Source-JDK: 1.6
Implementation-Vendor: The Apache Software Foundation
Implementation-Vendor-Id: org.apache
Build-Jdk: 1.7.0_75
Specification-Title: HttpComponents Apache HttpClient Cache
Specification-Version: 4.5.1
Implementation-Build: tags/4.5.1-RC1/httpclient-cache@r1702448; 2015-0
9-11 14:53:18+0200
X-Compile-Target-JDK: 1.6
Archiver-Version: Plexus Archiver
我在 StackOverfFlow 和互联网上的其他地方都找不到任何帮助：如何设置属性？我还应该处理 gradle 文件吗？此外，我是否必须以相同的方式实现所有库的清单？
提前致谢
编辑：
我刚刚用 HttpURLConnection 替换了，但我遇到了问题，你知道为什么吗？
public class MainActivity extends Activity {
/** Called when the activity is first created. */
TextView resultView;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
StrictMode.enableDefaults(); //STRICT MODE ENABLED
resultView = (TextView) findViewById(R.id.result);
String line=null;
String [] stream_name;
HttpURLConnection urlConnection = null;
String value;
getData();
}
public void getData(){
String result = "";
InputStream isr = null;
try{
URL url = new URL ("xxxxxxxxxxxxxxx");
urlConnection = (HttpURLConnection) url.openConnection();
urlConnection.connect();
isr = urlConnection.getInputStream();
}
catch(Exception e){
Log.e("log_tag", "Error in http connection " + e.toString());
resultView.setText("Couldn't connect to database");
}
//convert response to string
try{
BufferedReader reader = new BufferedReader(new InputStreamReader(isr,"iso-8859-1"),8);
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
isr.close();
result=sb.toString();
}
catch(Exception e){
Log.e("log_tag", "Error converting result "+e.toString());
}
//parse json data
try {
String s = "";
JSONArray jArray = new JSONArray(result);
for(int i=0; i<jArray.length();i++){
JSONObject json = jArray.getJSONObject(i);
s = s +
"Price : "+json.getString("Price")+"\n"+
"Weight : "+json.getInt("Weight")+"\n"+
"Price/Weight : "+json.getString("P/W")+"\n\n";
}
resultView.setText(s);
} catch (Exception e) {
// TODO: handle exception
Log.e("log_tag", "Error Parsing Data "+e.toString());
}
}
}
我的Php文件是
<?php
// PHP variable to store the host address
$db_host = "xxxxx";
// PHP variable to store the username
$db_uid = "xxxxxx";
// PHP variable to store the password
$db_pass = "xxxxxxxx";
// PHP variable to store the Database name
$db_name = "xxxxxxx";
// PHP variable to store the result of
the PHP function 'mysql_connect()' which
establishes the PHP & MySQL connection
$db_con = mysql_connect($db_host,$db_uid,
$db_pass) or die('could not connect');
mysql_select_db($db_name);
$sql = "SELECT * FROM TABLE 1 WHERE ID = 'Bread AH'";
$result = mysql_query($sql);
while($row=mysql_fetch_assoc($result))
$output[]=$row;
print(json_encode($output));
mysql_close();
?>
HttpClient 已弃用，completely removed in the latest release of Android 6.0. You should be using HttpURLConnection 改为进行网络调用。如果您出于任何原因确实需要使用 HttpClient，则必须将此行包含在清单的 android 块中以使其工作：
android {
useLibrary 'org.apache.http.legacy'
}
编辑：回应以下评论...
这是我编写的一些代码，用于通过网络服务访问在线数据库。它向我的服务器发出 POST 请求，发送一些 JSON 数据，并接收 JSON 作为响应，我稍后在代码中对其进行解析。
//The JSON we will get back as a response from the server
JSONArray jsonResponse = null;
//Http connections and data streams
URL url;
HttpURLConnection httpURLConnection = null;
OutputStreamWriter outputStreamWriter = null;
try {
//open connection to the server
url = new URL("your_url_to_web_service");
httpURLConnection = (HttpURLConnection) url.openConnection();
//set request properties
httpURLConnection.setDoOutput(true); //defaults request method to POST
httpURLConnection.setDoInput(true); //allow input to this HttpURLConnection
httpURLConnection.setRequestProperty("Content-Type", "application/json"); //header params
httpURLConnection.setRequestProperty("Accept", "application/json"); //header params
httpURLConnection.setFixedLengthStreamingMode(jsonToSend.toString().getBytes().length); //header param "content-length"
//open output stream and POST our JSON data to server
outputStreamWriter = new OutputStreamWriter(httpURLConnection.getOutputStream());
outputStreamWriter.write(jsonToSend.toString());
outputStreamWriter.flush(); //flush the stream when we're finished writing to make sure all bytes get to their destination
//prepare input buffer and get the http response from server
StringBuilder stringBuilder = new StringBuilder();
int responseCode = httpURLConnection.getResponseCode();
//Check to make sure we got a valid status response from the server,
//then get the server JSON response if we did.
if(responseCode == HttpURLConnection.HTTP_OK) {
//read in each line of the response to the input buffer
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(httpURLConnection.getInputStream(),"utf-8"));
String line;
while ((line = bufferedReader.readLine()) != null) {
stringBuilder.append(line).append("\n");
}
bufferedReader.close(); //close out the input stream
try {
//Copy the JSON response to a local JSONArray
jsonResponse = new JSONArray(stringBuilder.toString());
} catch (JSONException je) {
je.printStackTrace();
}
} catch (IOException ioe) {
ioe.printStackTrace();
} finally {
if(httpURLConnection != null) {
httpURLConnection.disconnect(); //close out our http connection
}
if(outputStreamWriter != null) {
try {
outputStreamWriter.close(); //close our output stream
} catch (IOException ioe) {
ioe.printStackTrace();
}
}
}
//Return the JSON response from the server.
return jsonResponse;
我正在开发一个应用程序，我需要在其中从在线数据库中检索数据，并且我正在导入 HttpClient、HttpEntity、HttpPost 等。
现在，我遇到的问题是以下消息 "no main manifest attribute, in C:\Users(......)"
因此我打开了这些库的 manifest.mf，但我找不到任何错误，也找不到 "attribute" 字段。
HttpClient 示例
Manifest-Version: 1.0
Implementation-Title: HttpComponents Apache HttpClient Cache
Implementation-Version: 4.5.1
Built-By: oleg
Specification-Vendor: The Apache Software Foundation
Created-By: Apache Maven 3.0.5
url: http://hc.apache.org/httpcomponents-client
X-Compile-Source-JDK: 1.6
Implementation-Vendor: The Apache Software Foundation
Implementation-Vendor-Id: org.apache
Build-Jdk: 1.7.0_75
Specification-Title: HttpComponents Apache HttpClient Cache
Specification-Version: 4.5.1
Implementation-Build: tags/4.5.1-RC1/httpclient-cache@r1702448; 2015-0
9-11 14:53:18+0200
X-Compile-Target-JDK: 1.6
Archiver-Version: Plexus Archiver
我在 StackOverfFlow 和互联网上的其他地方都找不到任何帮助：如何设置属性？我还应该处理 gradle 文件吗？此外，我是否必须以相同的方式实现所有库的清单？
提前致谢
编辑：
我刚刚用 HttpURLConnection 替换了，但我遇到了问题，你知道为什么吗？
public class MainActivity extends Activity {
/** Called when the activity is first created. */
TextView resultView;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
StrictMode.enableDefaults(); //STRICT MODE ENABLED
resultView = (TextView) findViewById(R.id.result);
String line=null;
String [] stream_name;
HttpURLConnection urlConnection = null;
String value;
getData();
}
public void getData(){
String result = "";
InputStream isr = null;
try{
URL url = new URL ("xxxxxxxxxxxxxxx");
urlConnection = (HttpURLConnection) url.openConnection();
urlConnection.connect();
isr = urlConnection.getInputStream();
}
catch(Exception e){
Log.e("log_tag", "Error in http connection " + e.toString());
resultView.setText("Couldn't connect to database");
}
//convert response to string
try{
BufferedReader reader = new BufferedReader(new InputStreamReader(isr,"iso-8859-1"),8);
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
isr.close();
result=sb.toString();
}
catch(Exception e){
Log.e("log_tag", "Error converting result "+e.toString());
}
//parse json data
try {
String s = "";
JSONArray jArray = new JSONArray(result);
for(int i=0; i<jArray.length();i++){
JSONObject json = jArray.getJSONObject(i);
s = s +
"Price : "+json.getString("Price")+"\n"+
"Weight : "+json.getInt("Weight")+"\n"+
"Price/Weight : "+json.getString("P/W")+"\n\n";
}
resultView.setText(s);
} catch (Exception e) {
// TODO: handle exception
Log.e("log_tag", "Error Parsing Data "+e.toString());
}
}
}
我的Php文件是
<?php
// PHP variable to store the host address
$db_host = "xxxxx";
// PHP variable to store the username
$db_uid = "xxxxxx";
// PHP variable to store the password
$db_pass = "xxxxxxxx";
// PHP variable to store the Database name
$db_name = "xxxxxxx";
// PHP variable to store the result of
the PHP function 'mysql_connect()' which
establishes the PHP & MySQL connection
$db_con = mysql_connect($db_host,$db_uid,
$db_pass) or die('could not connect');
mysql_select_db($db_name);
$sql = "SELECT * FROM TABLE 1 WHERE ID = 'Bread AH'";
$result = mysql_query($sql);
while($row=mysql_fetch_assoc($result))
$output[]=$row;
print(json_encode($output));
mysql_close();
?>
HttpClient 已弃用，completely removed in the latest release of Android 6.0. You should be using HttpURLConnection 改为进行网络调用。如果您出于任何原因确实需要使用 HttpClient，则必须将此行包含在清单的 android 块中以使其工作：
android {
useLibrary 'org.apache.http.legacy'
}
编辑：回应以下评论...
这是我编写的一些代码，用于通过网络服务访问在线数据库。它向我的服务器发出 POST 请求，发送一些 JSON 数据，并接收 JSON 作为响应，我稍后在代码中对其进行解析。
//The JSON we will get back as a response from the server
JSONArray jsonResponse = null;
//Http connections and data streams
URL url;
HttpURLConnection httpURLConnection = null;
OutputStreamWriter outputStreamWriter = null;
try {
//open connection to the server
url = new URL("your_url_to_web_service");
httpURLConnection = (HttpURLConnection) url.openConnection();
//set request properties
httpURLConnection.setDoOutput(true); //defaults request method to POST
httpURLConnection.setDoInput(true); //allow input to this HttpURLConnection
httpURLConnection.setRequestProperty("Content-Type", "application/json"); //header params
httpURLConnection.setRequestProperty("Accept", "application/json"); //header params
httpURLConnection.setFixedLengthStreamingMode(jsonToSend.toString().getBytes().length); //header param "content-length"
//open output stream and POST our JSON data to server
outputStreamWriter = new OutputStreamWriter(httpURLConnection.getOutputStream());
outputStreamWriter.write(jsonToSend.toString());
outputStreamWriter.flush(); //flush the stream when we're finished writing to make sure all bytes get to their destination
//prepare input buffer and get the http response from server
StringBuilder stringBuilder = new StringBuilder();
int responseCode = httpURLConnection.getResponseCode();
//Check to make sure we got a valid status response from the server,
//then get the server JSON response if we did.
if(responseCode == HttpURLConnection.HTTP_OK) {
//read in each line of the response to the input buffer
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(httpURLConnection.getInputStream(),"utf-8"));
String line;
while ((line = bufferedReader.readLine()) != null) {
stringBuilder.append(line).append("\n");
}
bufferedReader.close(); //close out the input stream
try {
//Copy the JSON response to a local JSONArray
jsonResponse = new JSONArray(stringBuilder.toString());
} catch (JSONException je) {
je.printStackTrace();
}
} catch (IOException ioe) {
ioe.printStackTrace();
} finally {
if(httpURLConnection != null) {
httpURLConnection.disconnect(); //close out our http connection
}
if(outputStreamWriter != null) {
try {
outputStreamWriter.close(); //close our output stream
} catch (IOException ioe) {
ioe.printStackTrace();
}
}
}
//Return the JSON response from the server.
return jsonResponse;