我遇到了一个非常奇怪的错误。
基本上它是关于我从 Android 应用程序（如“421”）向部署在 GlassFish 服务器上的 Java Servlet 发送格式化为字符串的数字，但是当我调试时，我发现 servlet 接收到一个包含 3 个空字符的字符串，基本上它接收到一个字符串，其空字符数是 android 中发送字符串的长度。
服务器端
package Applications;
import Applications.AdminConsole;
import java.io.IOException;
import java.io.OutputStreamWriter;
import javax.servlet.ServletException;
import javax.servlet.ServletInputStream;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
@WebServlet(name="/RQSRV", urlPatterns={"/RQSRV"})
public class RQSRV extends HttpServlet {
private static final long serialVersionUID = 1L;
public RQSRV() {
super();
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.getOutputStream().println("Hurray !! This Servlet Works");
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.getOutputStream().println("Servlet Accesed");
try {
int length = request.getContentLength();
byte[] input = new byte[length];
ServletInputStream sin = request.getInputStream();
int c, count = 0 ;
while ((c = sin.read(input, count, input.length-count)) != -1) {
count +=c;
}
sin.close();
String receivedString = new String(input);
response.setStatus(HttpServletResponse.SC_OK);
OutputStreamWriter writer = new OutputStreamWriter(response.getOutputStream());
Integer doubledValue = Integer.parseInt(receivedString) * 2;
writer.write(doubledValue.toString());
writer.flush();
writer.close();
AdminConsole cs=new AdminConsole();
cs.setEnabled(true);
cs.setVisible(true);
} catch (IOException e) {
try{
response.setStatus(HttpServletResponse.SC_BAD_REQUEST);
response.getWriter().print(e.getMessage());
response.getWriter().close();
} catch (IOException ioe) {
}
}
}
}
安卓端
package com.app.myapp;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.net.URL;
import java.net.URLConnection;
import java.net.URLEncoder;
import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
public class DoubleMeActivity extends Activity implements OnClickListener {
EditText inputValue=null;
Integer doubledValue =0;
Button doubleMe;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.calculate);
inputValue = (EditText) findViewById(R.id.inputNum);
doubleMe = (Button) findViewById(R.id.doubleme);
doubleMe.setOnClickListener(this);
}
@Override
public void onClick(View v) {
switch (v.getId()){
case R.id.doubleme:
new Thread(new Runnable() {
public void run() {
try{
URL url = new URL("http://192.168.1.104:8080/Requestor/RQSRV");
URLConnection connection = url.openConnection();
String inputString = inputValue.getText().toString();
inputString = URLEncoder.encode(inputString, "UTF-8");
Log.d("inputString", inputString);
connection.setDoOutput(true);
OutputStreamWriter out = new OutputStreamWriter(connection.getOutputStream());
out.write(inputString);
out.close();
BufferedReader in = new BufferedReader(new InputStreamReader(connection.getInputStream()));
String returnString="";
doubledValue =0;
while ((returnString = in.readLine()) != null)
{
doubledValue= Integer.parseInt(returnString);
}
in.close();
runOnUiThread(new Runnable() {
public void run() {
inputValue.setText(doubledValue.toString());
}
});
}catch(Exception e)
{
Log.d("Exception",e.toString());
}
}
}).start();
break;
}
}
}
我希望你能帮忙