Android将经Bsae64编码后的图片存储到MySQL，并解码输出查看（问题：图片失真）
Android项目下载：
链接：https://pan.baidu.com/s/1hvVupGcCf1f41fizF08SNg?pwd=9988
提取码：9988
部分源码：
package com.example.testandroidmysqlphplogin;
import androidx.appcompat.app.AppCompatActivity;
import android.annotation.SuppressLint;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.os.Message;
import android.text.TextUtils;
import android.text.method.ScrollingMovementMethod;
import android.util.Base64;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import android.os.Handler;
import android.app.Activity;
import android.content.Intent;
public class MainActivity extends AppCompatActivity {
protected static final int ERROR = 2;
protected static final int SUCCESS = 1;
private EditText et_qq;
private EditText et_psd;
Button button,button1;
private Handler handler = new Handler(){
public void handleMessage(Message msg) {
switch (msg.what) {
case SUCCESS:
Toast.makeText(MainActivity.this,(String)msg.obj, Toast.LENGTH_LONG).show();
break;
case ERROR:
Toast.makeText(MainActivity.this,"传输失败", Toast.LENGTH_LONG).show();
break;
}
};
};
private Object StreamTools;
@SuppressLint("MissingInflatedId")
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
et_qq = (EditText) findViewById(R.id.et_qq);
et_psd = (EditText) findViewById(R.id.et_pwd);
button1 = findViewById(R.id.button1);
button1.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
ImageView image1 = (ImageView) findViewById(R.id.image1);
EditText et_pwd = (EditText) findViewById(R.id.et_pwd);
et_pwd.setMovementMethod(new ScrollingMovementMethod());
et_pwd.setVerticalScrollBarEnabled(true);
et_pwd.setScrollBarStyle(View.SCROLLBARS_INSIDE_INSET);
ByteArrayOutputStream baos = new ByteArrayOutputStream();
Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.qq);
bitmap.compress(Bitmap.CompressFormat.JPEG, 0, baos);
byte[] imageBytes = baos.toByteArray();
String imageString = Base64.encodeToString(imageBytes, Base64.DEFAULT);
et_pwd.setText(imageString);
/*decode base64 string to image*/
imageBytes = Base64.decode(imageString, Base64.DEFAULT);
Bitmap decodedImage = BitmapFactory.decodeByteArray(imageBytes, 0, imageBytes.length);
image1.setImageBitmap(decodedImage);
}});
button = findViewById(R.id.button);
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
ImageView image = (ImageView) findViewById(R.id.image);
TextView et_pwd = (EditText) findViewById(R.id.et_qq);
et_qq.setMovementMethod(new ScrollingMovementMethod());
et_qq.setVerticalScrollBarEnabled(true);
et_qq.setScrollBarStyle(View.SCROLLBARS_INSIDE_INSET);
ByteArrayOutputStream baos = new ByteArrayOutputStream();
Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.ww);
bitmap.compress(Bitmap.CompressFormat.JPEG, 0, baos);
byte[] imageBytes = baos.toByteArray();
String imageString = Base64.encodeToString(imageBytes, Base64.DEFAULT);
imageBytes = Base64.decode(imageString, Base64.DEFAULT);
Bitmap decodedImage = BitmapFactory.decodeByteArray(imageBytes, 0, imageBytes.length);
image.setImageBitmap(decodedImage);
et_pwd.setText(imageString);
}});
}
public void login(View view){
final String qq = et_qq.getText().toString();
Intent i=new Intent(MainActivity.this,MainActivity.class);
startActivity(i);
if(TextUtils.isEmpty(qq)){
Toast.makeText(this, "不能为空", Toast.LENGTH_SHORT).show();
return;
}
new Thread(){
public void run(){
try {
String path = "http://192.168.228.1/PHP/MySQL/10.php";
URL url = new URL(path);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
//区别2、请求方式post
conn.setRequestMethod("POST");
conn.setRequestProperty("User-Agent", "Mozilla/5.0(compatible;MSIE 9.0;Windows NT 6.1;Trident/5.0)");
//区别3、必须指定两个请求的参数
conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");//请求的类型 表单数据
String data = "username="+qq+"&button=";
;
conn.setRequestProperty("Content-Length", data.length()+"");//数据的长度
//区别4、记得设置把数据写给服务器
conn.setDoOutput(true);//设置向服务器写数据
byte[] bytes = data.getBytes();
conn.getOutputStream().write(bytes);//把数据以流的方式写给服务器
int code = conn.getResponseCode();
System.out.println(code);
if(code == 200){
InputStream is = conn.getInputStream();
String result = com.example.testandroidmysqlphplogin.StreamTools.readStream(is);
Message mas= Message.obtain();
mas.what = SUCCESS;
mas.obj = result;
handler.sendMessage(mas);
}else{
Message mas = Message.obtain();
mas.what = ERROR;
handler.sendMessage(mas);
}
}catch (IOException e) {
// TODO Auto-generated catch block
Message mas = Message.obtain();
mas.what = ERROR;
handler.sendMessage(mas);
}
}
}.start();
}
public void login1(View view){
Intent i=new Intent(MainActivity.this,MainActivity.class);
startActivity(i);
final String psd = et_psd.getText().toString();
if(TextUtils.isEmpty(psd)){
Toast.makeText(this, "不能为空", Toast.LENGTH_SHORT).show();
return;
}
new Thread(){
public void run(){
try {
String path = "http://192.168.228.1/PHP/MySQL/10.php";
URL url = new URL(path);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
//区别2、请求方式post
conn.setRequestMethod("POST");
conn.setRequestProperty("User-Agent", "Mozilla/5.0(compatible;MSIE 9.0;Windows NT 6.1;Trident/5.0)");
//区别3、必须指定两个请求的参数
conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");//请求的类型 表单数据
String data = "username="+psd+"&button=";
;
conn.setRequestProperty("Content-Length", data.length()+"");//数据的长度
//区别4、记得设置把数据写给服务器
conn.setDoOutput(true);//设置向服务器写数据
byte[] bytes = data.getBytes();
conn.getOutputStream().write(bytes);//把数据以流的方式写给服务器
int code = conn.getResponseCode();
System.out.println(code);
if(code == 200){
InputStream is = conn.getInputStream();
String result = com.example.testandroidmysqlphplogin.StreamTools.readStream(is);
Message mas= Message.obtain();
mas.what = SUCCESS;
mas.obj = result;
handler.sendMessage(mas);
}else{
Message mas = Message.obtain();
mas.what = ERROR;
handler.sendMessage(mas);
}
}catch (IOException e) {
// TODO Auto-generated catch block
Message mas = Message.obtain();
mas.what = ERROR;
handler.sendMessage(mas);
}
}
}.start();
}
}转Base64编码部分：
ByteArrayOutputStream baos = new ByteArrayOutputStream()Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.ww);
bitmap.compress(Bitmap.CompressFormat.JPEG, 0, baos);
byte[] imageBytes = baos.toByteArray();
String imageString = Base64.encodeToString(imageBytes, Base64.DEFAULT);
imageBytes = Base64.decode(imageString, Base64.DEFAULT);
Bitmap decodedImage = BitmapFactory.decodeByteArray(imageBytes, 0, imageBytes.length);
image.setImageBitmap(decodedImage);
et_pwd.setText(imageString);
Android要存储的目标图片：
Android项目运行：
以上Android程序运行后会将图片的转为Base64编码进行存储，以下是图片转码后的结果。
php将MySQL中编码解码后输出验证：
下面是进行验证的php代码：
<?php
$link=mysqli_connect("localhost","your_username","your_password","your_database");
$sql = "SELECT * FROM user WHERE Id =1";
$res = mysqli_query($link,$sql);
$data = array();
$imgStr = '';
while ($row = mysqli_fetch_assoc($res)) {
$imgStr .= $row['ws_username'];
}
$binaryStr = base64_decode($imgStr);
header("Content-type:image/jpg");
echo $binaryStr;
?>但是解码后输出后的照片出现了严重失真
图片失真原因：
-
数据量增加：Base64 编码使用64个字符表示原始二进制数据，因此会对原始图片数据进行扩展。编码后的数据量通常会比原始二进制数据大约 33%。这意味着编码后的数据量更大，可能导致传输和存储方面的效率下降。
-
在写程序时对图片进行了压缩，导致很多像素点丢失，致使图片存储时就是不完整的。
经过资料查询与多次验证，找到了解决方法：
将图片转为二进制数存储到MySQL，再通过对二进制码转为图片输出可以完整的输出图片，通过php对图片的存储过可以确定，Android不失真的存储图片，可以将图片转为二进制图片进行存储。
存储图片：
转码后存到MySQL：
将二进制码转图片输出：
该理论应用于上传的Android程序中可顺利解决Android存图片输出失真问题。
php将图片转二进制码:文章来源：https://www.toymoban.com/news/detail-801597.html
<?php
// 连接到数据库
$conn = mysqli_connect("localhost", "rttt", "128", "my");
$imageData = file_get_contents("F:/编号图片/手指/001.jpg");// 读取图片文件的二进制数据
$escapedImageData = mysqli_real_escape_string($conn, $imageData);
//echo $escapedImageData;
// 执行INSERT语句将图片数据插入到数据库表中
$sql = "INSERT INTO images (`image_data`) VALUES ('$escapedImageData')";
mysqli_query($conn, $sql);
?>php将二进制码转图片验证:文章来源地址https://www.toymoban.com/news/detail-801597.html
<?php
// 连接到数据库
$conn = mysqli_connect("localhost", "rttt", "128", "my");
// 执行查询语句获取图片数据
$sql = "SELECT image_data FROM images WHERE id = '1'";
$result = mysqli_query($conn, $sql);
$row = mysqli_fetch_assoc($result);
header("Content-type: image/jpeg");// 设置HTTP标头为图像类型
echo $row['image_data'];
mysqli_close($conn);// 关闭数据库连接
?>到了这里，关于图片的编码存储与解码输出（基于Android将图片转Base64编码后再次解码会导致图片失真的解决办法）的文章就介绍完了。如果您还想了解更多内容，请在右上角搜索TOY模板网以前的文章或继续浏览下面的相关文章，希望大家以后多多支持TOY模板网！
