嘿，我只是因为登录而陷入问题
这是我的servlet
/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import javax.naming.InitialContext;
import javax.naming.NamingException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.sql.DataSource;
/**
*
* @author amolbh
*/
public class AreaServlet extends HttpServlet {
private Connection connection = null;
private PreparedStatement prepStmt=null;
private String farid,password,farid1;
private ResultSet rst=null;
/**
* Processes requests for both HTTP <code>GET</code> and <code>POST</code> methods.
* @param request servlet request
* @param response servlet response
* @throws ServletException if a servlet-specific error occurs
* @throws IOException if an I/O error occurs
*/
protected void processRequest(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html;charset=UTF-8");
PrintWriter out = response.getWriter();
try {
if(request.getServletPath().equals("/login"))
loginValidation(request,response);
} finally {
out.close();
}
}
// <editor-fold defaultstate="collapsed" desc="HttpServlet methods. Click on the + sign on the left to edit the code.">
/**
* Handles the HTTP <code>GET</code> method.
* @param request servlet request
* @param response servlet response
* @throws ServletException if a servlet-specific error occurs
* @throws IOException if an I/O error occurs
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
processRequest(request, response);
}
/**
* Handles the HTTP <code>POST</code> method.
* @param request servlet request
* @param response servlet response
* @throws ServletException if a servlet-specific error occurs
* @throws IOException if an I/O error occurs
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
processRequest(request, response);
}
/**
* Returns a short description of the servlet.
* @return a String containing servlet description
*/
public String getServletInfo() {
return "Short description";
}// </editor-fold>
public void loginValidation(HttpServletRequest request, HttpServletResponse response)throws IOException
{
DataInputStream in = new DataInputStream((InputStream)request.getInputStream());
byte indata[] = new byte[request.getContentLength()];
in.readFully(indata,0,indata.length);
in = new DataInputStream(new ByteArrayInputStream(indata));
farid = in.readUTF();
password = in.readUTF();
DataOutputStream daos = new DataOutputStream((OutputStream)response.getOutputStream());
String s1,s2;
ByteArrayOutputStream baosdata = new ByteArrayOutputStream();
DataOutputStream doasdata = new DataOutputStream(baosdata);
try
{
connection=getConnection();
prepStmt=connection.prepareStatement("Select Username,Password from Login ");
rst=prepStmt.executeQuery();
int c = 0;
while(rst.next())
{
s1=rst.getString(1);
s2=rst.getString(2);
doasdata.writeUTF(s1);
doasdata.writeUTF(s2);
c++;
}
ByteArrayOutputStream baoshdata = new ByteArrayOutputStream();
DataOutputStream doashdata = new DataOutputStream(baoshdata);
if(c != 0)
{
doashdata.writeUTF("successfull");
// doashdata.writeInt(c);
doashdata.write(baosdata.toByteArray());
daos.write(baoshdata.toByteArray());
}
else{
doashdata.writeUTF("Invalid User");
daos.write(baoshdata.toByteArray());
}
}
catch(Exception e)
{
ByteArrayOutputStream baos = new ByteArrayOutputStream();
DataOutputStream daose = new DataOutputStream(baos);
daose.writeUTF(e.toString());
daos.write(baos.toByteArray());
}
}
public Connection getConnection() throws NamingException, SQLException
{
try {
/*InitialContext ic=new InitialContext();
* DataSource ds=(DataSource)ic.lookup("java:comp/env/jdbc/ImageCapture");
* connection = ds.getConnection();
* return connection;*/
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
// Step 2: Establish the connection to the database.
String url = "jdbc:odbc://localhost:8080/ImageCapture";
Connection conn = DriverManager.getConnection(url);
return conn;
} catch (ClassNotFoundException ex) {
ex.printStackTrace();
return null;
}
}
}
和我正在获得响应的LoginSrv类
在字符串su = indat.readUTF（）;中获取“ javaioEOF异常”。
/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
package com.marico.model;
import com.sun.lwuit.Dialog;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import com.marico.esaff.AppConstants;
/**
*
* @author sandipp
*/
public class LoginSrv {
private ServCon srv;
public static String st1,st2,log,pas;
public static int it1;
public LoginSrv(String s1, String s2)
{
log = s1;
pas = s2;
it1=0;
try
{
Dialog.show("Successfull","i am in Loginsrv" , null,Dialog.TYPE_INFO,null,3000);
ByteArrayOutputStream baosdata = new ByteArrayOutputStream();
DataOutputStream daosdata = new DataOutputStream(baosdata);
daosdata.writeUTF(s1);
daosdata.writeUTF(s2);
srv = new ServCon(new AppConstants().str1,null,baosdata.toByteArray(),false,false,null);
ByteArrayOutputStream obj = (ByteArrayOutputStream)srv.startTransfer();
byte[] record = obj.toByteArray();
ByteArrayInputStream instr = new ByteArrayInputStream(record);
DataInputStream indat = new DataInputStream(instr);
if(srv.getRc() == 200)
{
Dialog.show("Successfull","i am in Loginsrv "+srv.getRc() , null,Dialog.TYPE_INFO,null,3000);
String su = indat.readUTF();
// if(su.equals("successfull"))
{
st1 =indat.readUTF();
st2 =indat.readUTF();
System.out.println("st1 and st2 "+ st1 + " , "+st2);
Dialog.show("Successfull",su , null,Dialog.TYPE_INFO,null,3000);
}
// else
{
// Dialog.show("Error",su , null,Dialog.TYPE_INFO,null,5000);
}
}
else
{
Dialog.show("Error",srv.getRc() + " " + srv.getRm(), null,Dialog.TYPE_INFO,null,5000);
}
}
catch(Exception e)
{
Dialog.show("Error","I am in catch "+e.toString(), null,Dialog.TYPE_INFO,null,5000);
System.out.println("Im from LoginSrv constructor: "+e);
}
}
}
这是我正在连接的ServCon.java
/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
package com.marico.model;
import com.sun.lwuit.Dialog;
import com.sun.lwuit.util.Resources;
import com.sun.lwuit.Label;
import javax.microedition.io.Connector;
import javax.microedition.io.HttpConnection;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.ByteArrayOutputStream;
import java.io.OutputStream;
/**
*
* @author sandipp
*/
public class ServCon {
private String url,sendparam,indata;
private byte sendparamb[];
private boolean instring,outstring;
private String error;
private int rc;
private String rm;
private Resources r;
//private View.DisplayProgress dp;
public static com.sun.lwuit.TextArea textobj;
public ServCon(String url,String sendparam,byte[]sendparamb,boolean instring,boolean outstring,Resources r)
{
this.url = url;
this.instring = instring;
this.outstring = outstring;
this.r = r;
//this.dp = dp;
if(this.instring)
{
this.sendparam = sendparam;
}
else
{
this.sendparamb = sendparamb;
}
}
public Object startTransfer() throws Exception
{
HttpConnection c = (HttpConnection)Connector.open(url);
c.setRequestProperty("User-Agent","Profile/MIDP-1.0, Configuration/CLDC-1.0");
c.setRequestProperty("Content-Language","en-US");
c.setRequestMethod(HttpConnection.POST);
DataOutputStream os = (DataOutputStream)c.openDataOutputStream();
if(instring)
os.writeUTF(sendparam);
else
os.write(sendparamb,0,sendparamb.length);
rc = c.getResponseCode();//getResponseCode();
rm = c.getResponseMessage();
int len = (int)c.getLength();
System.out.println( getRm() + " " + len);
DataInputStream is =(DataInputStream)c.openDataInputStream();
Object outobj = null;
if(outstring)
{
StringBuffer rdata = new StringBuffer();
int ch;
while ((ch = is.read()) != -1)
{
rdata.append((char)ch);
}
indata = rdata.toString();
outobj = indata;
}
else
{
sendparamb = new byte[len];
is.readFully(sendparamb,0,sendparamb.length);
ByteArrayOutputStream baos = new ByteArrayOutputStream();
DataOutputStream dout = new DataOutputStream((OutputStream)baos);
dout.write(sendparamb, 0, sendparamb.length);
outobj = baos;
}
is.close();
c.close();
os.flush();
os.close();
System.out.println("Reached at the end of the httpdatafetch");
return outobj;
}
/**
* @return the rc
*/
public int getRc() {
return rc;
}
/**
* @return the rm
*/
public String getRm() {
return rm;
}
}
最佳答案
在发送方中，您基本上具有writeUTF("successfull")，后跟两个write()字节数组。在接收器中，您基本上具有if readUTF() == "successfull"，如果是，则再执行两个readUTF()。但是readUTF()只能读取writeUTF()编写的内容：请参阅Javadoc。它肯定无法读取具有任意write()数组的byte[]的结果。您需要理清您的应用程序协议实际上是什么。
您也喜欢我的ByteArrayInputStream和ByteArrayOutputStream太多。这些只会增加延迟和出现上述错误的机会。如果您有东西要写，请将其直接写到输出流；如果您认为有什么要阅读的内容，请从输入流中阅读。