Question

我正在开发一个java applcation，我在一些网站托管服务器（000webhost）上存储了一个数据库，我编写了代码来从作为网站托管的PHP文件中的数据库服务器（MySQL）中获取数据。以下是相同的代码：

//http://mahaweb.ml/java.php
<?php
require "connect.php";
$db = $_POST["db"];
mysqli_select_db($con,$db);
$mysql_qry = $_POST["query"];   
$result = mysqli_query($con,$mysql_qry);    
if(mysqli_num_rows($result) > 0){
    while($row=mysqli_fetch_row($result)){                  // for each row in results
        foreach($row as $value){                           // for each column in row
                echo $value.'|';
        }   
    }
}
else
    echo 'null';
?>

从php文件中读取数据的java代码：

public static String getData(String query,String db){
        HttpURLConnection conn=null;
        String inputLine = null,result = null;
        try{
            URL url=new URL("http://mahaweb.ml/java.php");                
            conn=(HttpURLConnection)url.openConnection();
            conn.setDoInput(true);
            conn.setDoOutput(true);
            conn.setRequestMethod("POST");    
            String postData = URLEncoder.encode("db","UTF-8")+"="+URLEncoder.encode(db,"UTF-8")+"&"+URLEncoder.encode("query","UTF-8")+"="+URLEncoder.encode(query,"UTF-8");
            OutputStream out=conn.getOutputStream();    
            out.write(postData.getBytes());    
            BufferedReader in = new BufferedReader(new InputStreamReader(conn.getInputStream()));                
            while((inputLine=in.readLine())!=null){                             
                    StringBuffer tmp1 = new StringBuffer(inputLine);
                    tmp1.deleteCharAt(tmp1.length()-1);
                    result = tmp1.toString();        
            }
            in.close();
            }catch(Exception e){
                e.printStackTrace();
            }finally{
                conn.disconnect();
            }
        if(result.equals("null"))
            return null;
        return result;
}

我使用包含字节格式指纹值的blob列在数据库上存储指纹。当我使用jdbc连接器从数据库获取数据并将该数据与指纹匹配时，它成功匹配，代码在这里是相同的：

Connection con = (Connection) DriverManager.getConnection("jdbc:mysql://localhost:3306/dlap_application",user,pass);
        PreparedStatement ps = con.prepareStatement("select fingerscan from login where empID like 'MH1200001'");            
        ResultSet rs = ps.executeQuery();
        while(rs.next())          
            ISOTemplate = rs.getBytes("fingerscan");            
        ps.close();
        rs.close();
        con.close();
        int ret = mfs100.AutoCapture(data, timeout,  false, false);
        if(ret == 0){
            int score = 0;
            score = mfs100.MatchISO(data.ISOTemplate(), ISOTemplate);                
            System.out.println("Score:"+score);
            if(score > 14000){
            Alert alert = new Alert(Alert.AlertType.CONFIRMATION, "Success:"+score, ButtonType.OK);
            alert.show();
            }else if (score >= 0 && score < 14000) {
                Alert alert = new Alert(Alert.AlertType.CONFIRMATION, "Failure:"+score, ButtonType.OK);
                alert.show();
            }   
        }
        else{
        Alert alert = new Alert(Alert.AlertType.INFORMATION, "Return Code:"+ret+" "+mfs100.GetLastError(), ButtonType.OK);
        alert.show();
        }

但是当我使用PHP代码从数据库中获取数据时，它会以字符串格式获取数据。我正在将字符串数据转换为字节并尝试将其与新指纹数据匹配，但没有取得任何成功，因为数据在字符串到单播转换期间丢失。那么，如何使用PHP以字节格式从数据库获取数据而不丢失数据？

PHP MYSQL JAVA从blob错误中获取字节

0 个答案: