我正在尝试做一个Android应用程序在MySQL数据库上写一些数据，但它不起作用我为此做了一个Java类，我认为问题来自于此。这是我的代码：
public class BackgroundTask extends AsyncTask<String, Void, String> {
Context ctx;
BackgroundTask(Context ctx) {this.ctx = ctx;}
@Override
protected String doInBackground(String... params) {
String reg_url = "http://localhost:8080/project/register.php";
String method = params[0];
if (method.equals("register")) {
String name = params[1];
String password = params[2];
String contact = params[3];
String country = params[4];
try {
URL url = new URL(reg_url);
HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();
httpURLConnection.setRequestMethod("POST");
httpURLConnection.setDoOutput(true);
OutputStream os = httpURLConnection.getOutputStream();
BufferedWriter bufferedWriter = new BufferedWriter(new OutputStreamWriter(os, "UTF-8"));
String data = URLEncoder.encode("name", "UTF-8") + "=" + URLEncoder.encode(name, "UTF-8") + "&" +
URLEncoder.encode("password", "UTF-8") + "=" + URLEncoder.encode(password, "UTF-8") + "&" +
URLEncoder.encode("contact", "UTF-8") + "=" + URLEncoder.encode(contact, "UTF-8") + "&" +
URLEncoder.encode("country", "UTF-8") + "=" + URLEncoder.encode(country, "UTF-8");
bufferedWriter.write(data);
bufferedWriter.flush();
bufferedWriter.close();
os.close();
InputStream IS = httpURLConnection.getInputStream();
IS.close();
return "Registration success";
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
return null;
}
@Override
protected void onPostExecute(String result) {
Toast.makeText(ctx, result, Toast.LENGTH_LONG).show();
}
@Override
protected void onPreExecute() {
super.onPreExecute();
}
@Override
protected void onProgressUpdate(Void... values) {
super.onProgressUpdate(values);
}
}
实际上我想要的是在我的数据库中保存名称，密码，联系人和国家/地区。问题是：“注册成功”永远不会返回它始终为空。但我不知道为什么。当我尝试编译它看起来没有错误，我可以看到该应用程序。 非常感谢你的帮助！
编辑：这是register.php：
<?php
require "init.php";
$u_name=$_POST["name"];
$u_password=$_POST["password"];
$u_contact=$_POST["contact"]";
$u_country=$_POST["country"];
$sql_query="insert into users values('$u_name', '$u_password', '$u_contact', '$u_country');";
//mysqli_query($connection, $sql_query));
if(mysqli_query($connection,$sql_query))
{
//echo "data inserted";
}
else{
//echo "error";
}
?>
还有init.php：
<?php
$db_name = "project";
$mysql_user = "root";
$server_name = "localhost";
$connection = mysqli_connect($server_name, $mysql_user, "", $db_name);
if(!$connection){
echo "Connection not successful";
}
else{
echo "Connection successful";
}
?>
感谢您的帮助！
答案 0 :(得分：0)
我的类PutData用于getData（），PostData，DeleteData（）。你只需要更改包名称
package fourever.amaze.mics;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.UnsupportedEncodingException;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLConnection;
import java.net.URLEncoder;
import java.util.HashMap;
import java.util.Map;
public class PutUtility {
private Map<String, String> params = new HashMap<>();
private static HttpURLConnection httpConnection;
private static BufferedReader reader;
private static String Content;
private StringBuffer sb1;
private StringBuffer response;
public void setParams(Map<String, String> params) {
this.params = params;
}
public void setParam(String key, String value) {
params.put(key, value);
}
public String getData(String Url) {
StringBuilder sb = new StringBuilder();
try {
// Defined URL where to send data
URL url = new URL(Url);
URLConnection conn = null;
conn = url.openConnection();
// Send POST data request
httpConnection = (HttpURLConnection) conn;
httpConnection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
httpConnection.setRequestMethod("GET");
BufferedReader in = new BufferedReader(
new InputStreamReader(httpConnection.getInputStream()));
String inputLine;
response = new StringBuffer();
while ((inputLine = in.readLine()) != null) {
response.append(inputLine);
}
in.close();
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
reader.close();
} catch (Exception ex) { }
}
return response.toString();
}
public String postData(String Url) {
StringBuilder sb = new StringBuilder();
for (String key : params.keySet()) {
String value = null;
value = params.get(key);
if (sb.length() > 0) {
sb.append("&");
}
sb.append(key + "=" + value);
}
try {
// Defined URL where to send data
URL url = new URL(Url);
URLConnection conn = null;
conn = url.openConnection();
// Send POST data request
httpConnection = (HttpURLConnection) conn;
httpConnection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
httpConnection.setRequestMethod("POST");
httpConnection.setDoInput(true);
httpConnection.setDoOutput(true);
OutputStreamWriter wr = null;
wr = new OutputStreamWriter(conn.getOutputStream());
wr.write(sb.toString());
wr.flush();
BufferedReader in = new BufferedReader(
new InputStreamReader(httpConnection.getInputStream()));
String inputLine;
response = new StringBuffer();
while ((inputLine = in.readLine()) != null) {
response.append(inputLine);
}
in.close();
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
reader.close();
} catch (Exception ex) {
}
}
return response.toString();
}
public String putData(String Url) {
StringBuilder sb = new StringBuilder();
for (String key : params.keySet()) {
String value = null;
try {
value = URLEncoder.encode(params.get(key), "UTF-8");
if (value.contains("+"))
value = value.replace("+", "%20");
//return sb.toString();
// Get the server response
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
if (sb.length() > 0) {
sb.append("&");
}
sb.append(key + "=" + value);
}
try {
// Defined URL where to send data
URL url = new URL(Url);
URLConnection conn = null;
conn = url.openConnection();
// Send PUT data request
httpConnection = (HttpURLConnection) conn;
httpConnection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
httpConnection.setRequestMethod("PUT");
httpConnection.setDoInput(true);
httpConnection.setDoOutput(false);
OutputStreamWriter wr = null;
wr = new OutputStreamWriter(conn.getOutputStream());
wr.write(sb.toString());
wr.flush();
reader = new BufferedReader(new InputStreamReader(conn.getInputStream()));
;
String line = null;
// Read Server Response
while ((line = reader.readLine()) != null) {
// Append server response in string
sb1.append(line + " ");
}
// Append Server Response To Content String
Content = sb.toString();
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
reader.close();
} catch (Exception ex) {
}
}
// Send PUT data request
return Url;
}
public String deleteData(String Url) {
StringBuilder sb = new StringBuilder();
for (String key : params.keySet()) {
try {
// Defined URL where to send data
URL url = new URL(Url);
URLConnection conn = null;
conn = url.openConnection();
// Send POST data request
httpConnection = (HttpURLConnection) conn;
httpConnection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
httpConnection.setRequestMethod("DELETE");
httpConnection.connect();
reader = new BufferedReader(new InputStreamReader(conn.getInputStream()));
String line = null;
// Read Server Response
while ((line = reader.readLine()) != null) {
// Append server response in string
sb1.append(line + " ");
}
// Append Server Response To Content String
Content = sb.toString();
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
reader.close();
} catch (Exception ex) {
}
}
}
return Url;
}
}
并像这样使用这个类
@Override
protected String doInBackground(String... params) {
res = null;
PutUtility put = new PutUtility();
put.setParam("ueid", params[0]);
put.setParam("firm_no", params[1]);
put.setParam("date_incorporation", params[2]);
put.setParam("business_name", params[3]);
put.setParam("block_no", params[4]);
try {
res = put.postData(
"Api URL here");
Log.v("res", res);
} catch (Exception objEx) {
objEx.printStackTrace();
}
return res;
}
@Override
protected void onPostExecute(String res) {
try {
} catch (Exception objEx) {
mProgressDialog.dismiss();
objEx.printStackTrace();
}
}
请使用此。希望它也能帮助你。 如果这是问题，请检查
$u_contact=$_POST["contact"]"
这是我认为兄弟的问题。替换为
$u_contact=$_POST["contact"];